Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
INTRODUCTION, PURPOSE AND SCOPE OF THE STUDY
As part of the Counterminous United States Mineral Assess-
ment Program (CUSMAP), the United States Geological Survey found
anomalous copper in stream sediments from washes draining Black
Mountain and the Batamote Mountains, two miles south and ten miles
northeast of Ajo, Arizona, respectively. The anomalous area defined
by the values to the northeast of Ajo encompasses the northwestern
two -thirds of the Batamote range. However, the source of the values
was not determined by the U.S.G.S.
The purpose of the present study is to define, characterize
and explain this anomaly. Five mechanisms are considered to be
possible explanations of the anomaly:
1. Airborne contamination from a smelter located in Ajo;
2. Abnormally high background copper concentrations in the
volcanics composing the Batamote Mountains;
3. Primary hydrothermal mineralization within the study area;
4. Dispersion through the volcanic pile along normal
faults; and
S. Contamination of the volcanics immediately before or
during their eruption.
Each of these working hypotheses should have a unique dispersion
pattern and a characteristic partitioning of copper among mineral
phases.
1
2
The smelter is located just south of Ajo. Smelters are
known to produce anomalies in soil samples, and the wind in the area
was observed to blow southwest to northeast at times; consequently,
airborne dispersion from the smelter could produce, the observed
anomalies. Dispersion from this source would tend to have a plumose
form and decrease in intensity downwind. Any copper would be held
in glass as part of the smelter dust.
The second possible mechanism, abnormally high background
values, would be characterized by a highly uniform distribution of
high values within the stream sediments. Additionally, the source
rock unit would have to have high copper concentrations; the copper
would probably be held as a trace component within silicate minerals.
Primary hydrothermal mineralization would be characterized by
a dispersion pattern localized around the mineralization. As such,
anomalies would tend not to be very widespread. Given the aridity and
nature of weathering in the Batamote Mountains, primary copper minerals
could be preserved in sediments in addition to secondary minerals and
oxides.
Dispersion of copper along normal faults would yield broad
dispersion patterns at the surface, related spatially to the faulting.
Copper would probably be held in oxide coatings, organics or as
chrysocolla.
The final mechanism considered, contamination of the volcanics
before or during their eruption, would produce uniformly high values
in streams draining the volcanics or a zonation about the volcanic
center. If the contaminants were not assimilated, the bulk of the
3
volcanics would not contain unusual values of copper --only xeno-
lithic fragments would contain anomalous copper. However, if the
hypothesized contaminants were totally assimilated, the dispersion
would be similiar to that observed for an andesite with high back-
ground copper; therefore, this mechanism could be indistinguishable
from an andesite with high background.
Given the expected responses for the five different mechan-
isms, the purpose of this study is to define the surficial dispersion
of copper, both mineralogically and areally, within the Batamote
Mountains. This information, in combination with lithogeochemical
and geological data can then be used to infer the genesis of the
copper anomaly discovered by Barton and others (1982).
The study was conducted in three stages: 1. Resampling of
the sites found to be anomalous by Barton and others (1982); 2. High
density collection of stream sediment and heavy mineral concentrate
samples; and 3. Reconnaissance geologic mapping, rock chip sampling
and resampling the anomalies found in the second step. Field and
analytical work was performed between December, 1982 and February,
1984.
LOCATION, PHYSIOGRAPHY AND CLIMATE
The study was conducted in the Batamote Mountains which are
within the Basin and Range Province of southwestern Arizona- -five to
ten airmiles (8 to 16 km) northeast of Ajo in Pima County. Ajo is
the site of Phelps Dodge's New Cornelia porphyry copper deposit and
the previously mentioned smelter. Figure 1 shows the location of
the thesis area in relation to Ajo, Phoenix, and Tucson. The study
area lies almost entirely within the Ajo and Sikort Chuapo 15-
minute U.S.G.S. quadrangles.
The mountains trend west -northwesterly and have a length
of twelve miles (19 km) and a width of up to five miles (8 km).
Maximum elevation is 3202 feet (972 m) with relief of up to 1700
feet (520 m). Physiographically, the mountains occur as relatively
low plateaus surrounding a high central peak that has the appear-
ance of a dissected stratovolcano (see Figure 2). However, the
preserved surface of the peak is not depositional (Gilluly, 1946).
The mountains have relatively youthful drainages which are charac-
terized by narrow canyons with moderate to steep gradients (Gilluly,
1937) .
The area around Ajo receives an average of nine inches of
precipitation annually, with the rainiest months being July and
August (NOAA, 1981). Temperatures range from 30 °F to 120 °F (0 °C
to 50 °C) with temperatures in excess of 100 °F (38 °C) common from
4
S
May to September. Consequently, drainages in the area consist of dry
washes. Field observations indicate that the wind often blows from
the southwest to the northeast, creating a potential for airborne
smelter contamination in the study area.
GILA BEND
AJO
LUKEVILLE r TUCSON
Figure 1 -- Location of study area
6
10 MILES
N
100 MILES
/
Figure 2 -- Photograph, looking east, of the high point, Batamote
Mountains
PREVIOUS WORK
Previous work on the geology, surficial geochemistry and
geophysics of the Batamote Mountains is contained within reports
encompassing larger or nearby areas. Early work in the area began
with Joralemon's report in 1914. The most recent report was pre-
pared in 1984 by Harris. Existing literature pertaining to the
geology, geochemistry and geophysics of the area is reviewed in
this section.
Geology
Joralemon (1914) discussed the history and economic geology
of the Ajo district. DeKalb (1918) and Ingham and Barr (1932) dis-
cussed the same topics, but they also concentrated on the mining
methods employed at the New Cornelia Mine. These three papers refer
only briefly to the geology outside the immediate Ajo district.
Bryan (1928) described the physiography and geology of the
Batamote Mountains in general terms. Additionally, he described
the log of a well located one mile west of the mountains. Through
1936 this is the only paper that described the geology of the area
of interest.
In 1935, Gilluly published the first of four papers that
are probably the best work on the geology of the Ajo area. In
this paper Gilluly described the history and geology of the Ajo
mining district. However, in papers published in 1937. 1942 and
8
9
1946, Gilluly discussed the geology and physiography of the Ajo 15-
minute quadrangle in addition to the district geology. These papers
contain excellent descriptions of the geology, lithology and physi-
ography of the western half of the Batamote Mountains.
Following the last Gilluly paper, there was a long hiatus
on publications relating to the Ajo area. Dixon (1966) and Wadsworth
(1968) described the geology of the New Cornelia Mine and Cornelia
pluton, respectively. Jones (1974) discussed the geology of the
Ajo Range, south of the study area.
The most recent publication covering the Batamote Mountain
area is a compilation of the geology of the Ajo 1 °by 2°quadrangle
by Kahle and others (1978). As this is part of CUSMAP, more litera-
ture should be forthcoming from this group.
The geology of the Hat Mountain and Sikort Chuapo 15- minute
quadrangles has been mapped and reports are in preparation as part
of a cooperative study between the U.S. Geological Survey and the
Bureau of Indian Affairs on the geology and mineral resources of
the Papago Indian Reservation (Haxel and others, 1980).
Surf icial Geochemistry
Also as part of CUSMAP, the U.S. Geological Survey conducted
a reconnaissance exploration geochemistry study over the Ajo 1° by 2°
quadrangle (Barton and others, 1982). Anomalies discovered as part
of this project served as the impetus for the present study. Most
recently, Theobald and Barton (1983) discussed the statistical
10
relationships within the U.S.G.S. data. More literature should come
out of this group in the future.
Geophysics
Finally, Klein (1983) published a residual aeromagnetic map
of the Ajo and Lukeville 1° by 2° quadrangles. Raines and Theobald
(1981) are conducting remote sensing studies in the Ajo 1° by 2° quad-
rangle. Again, future papers should be forthcoming about the geo-
physics of the area.
REGIONAL GEOLOGY
The regional geology of the Ajo area is described in excel-
lent detail by Gilluly (1946). This section is largely based on
that work. For further discussion, the reader is referred to this
and other papers by Gilluly (1937 and 1942).
The Ajo and Sikort Chuapo 15- minute quadrangles consist
mainly of Tertiary volcanics and Quaternary alluvium. Pre -Cenozoic
rocks crop out dominantly in the Little Ajo Mountains and the Chico
Shunie Hills, west of the town of Ajo. Figure 3, based on Gilluly
(1946), gives the stratigraphy of the Ajo 15- minute quadrangle and
can be inferred to represent the general stratigraphy of the entire
area. Figure 4 is a regional geologic map of these two quadrangles
based on Wilson and others (1969).
Stratigraphy
The oldest unit in the area is the Precambrian Cardigan Gneiss.
The unit has a wide variety of rock types within it, ranging from
gneisses through schists with minor pegmatites. This unit has been
intruded throughout by small bodies of Precambrian hornblendite
that show chilled contacts against the gneiss. The Cardigan Gneiss
crops out principally in the Gibson Arroyo, west of Ajo.
According to Gilluly (1946), the only Paleozoic rock present
in the region is hornfelsic sandstone, shale and volcanics occuring
as xenoliths in the Chico Shunie Quartz Monzonite, which crops out
11
4i ú IF tu _
IQV' 1111119lb _
El tom I11141 RlpiEZ - s1a I4 tll1(I/Um;, ilílÌllUte..w.í-üw
ivI ,11 mI11 i111!lilmu ululi wlwillilIII Lilllillunn nlunluwuuiIll. 1 IIAIU111 IIIII'I IIIII I f/ IId l'/'1Il ° .q1111lI/11'::RII191IIIIIIIIIIIIIIItil11I
'e'd";U fit Iua11nu1 uwoL.I;u1+I
VeInrivautno.uor,nIImvmu.Nia HIM on (I6\/1I111111 {
vlMIR III 11111111'il li_ mid niiinnnit us1 ,' .- ^7 :.:iì- :b..
Cs' °~:` `' =`\\ - `>ii.,` , o2̀ .., ~
01.7 9 K '
6Y ,,te5°' ,.e.`.
'1./.1a0'0....á.;
Unit
16 Alluvium
Unconformity
1Older Alluvium
Unconformity
15 Batamote Andesíte--intrusive facies
14 Batamote Andesite--extrusive
13 Batamote Andesite--vent facies
Unconformity
12 2Childs Latite11 Daniels Conglomerate
Unconformity
10 2Sneed Andesite
Unconformíty
9 2Aj o Volcanics8 Locomotive Fanglomerate
Unconformity
1Felsic to intermediateplugs, sills and dikes
7 Cornelia Quartz Monzo-nite (main facies)
6 Cornelia Quartz Monzo-nite (dioritic facies)
5 Concentrator Volcanics
Unconformity
4 Chico Shunie QuartzMonzonite
3 Hornfels
Unconformity
2 Hornblendite1 Cardigan Gneiss
ZUnit from Wilson and others, 1969The Childs Latite, Sneed Andesite and AjoVolcanics were combined in Wilson and others,.1969
12
Age Symbol
Quaternary Qa
Plio -Pleis- QTatocene
Miocene
Miocene Tba
Miocene
MioceneMiocene
Miocene
MioceneMiocene
Tertiary/CretaceousTertiary/CretaceousTertiary/CretaceousCretaceous
TvTps
Tv
TvTms
TKi
TKg
Mesozoic Mzgr
Paleozoic
PrecambrianpCgnPrecambrian
Figure 3-- Stratigraphy of the Ajo area (after Billuly, 1946)
TE
A
B R
TA
MO
TE
MOUNTRItJS
CO
FFE
EPO
TM
OU
NT
AIN
Tho
Qa
P69"
5 M
Is.E
SS
cALt
: o:2
5q00
0
Figure 4-- Simplified geologic map of the Ajo and Sikort Chuapo 15- minute quadrangles, Arizona (after
Wilson and others, 1969).
See Figure 3 and text for description of units.
14
extensively in the southwestern part of the region. This unit has a
highly variable texture and composition, but the predominant variety
is a coarsely porphyritic quartz monzonite.
Unconformably overlying the basement, the Cretaceous Concen-
trator Volcanics crop out one to two miles south of Ajo. This forma-
tion consists of andesitic tuffs, flows and breccias that have been
extensively altered.
No pre- Tertiary rocks crop out in the Sikort Chuapo quad-
rangle (Wilson and others, 1969).
The Laramide Cornelia pluton intrudes the Concentrator Vol -
canics, Cardigan Gneiss and Chico Shunie Quartz Monzonite over much
of the Little Ajo Mountains, several miles west of the town of Ajo.
The pluton is composed of a wide range of distinct facies, many of
which show gradational contacts. Two units have been separated out
by Gilluly (1946), a border quartz diorite facies, located in the
western part of the intrusive, and a quartz monzonite facies. These
two units show a sharp contact. As the description of these rocks
is not the thrust of this discussion, the reader is referred to
papers by Dixon (1966) and Wadsworth (1968) in addition to the papers
by Gilluly and a thesis by Harris (1984) for a more detailed descrip-
tion of these units.
The New Cornelia orebody, which was originally the cupola of
the Cornelia pluton (Wadsworth, 1968) has been downfaulted several
thousand feet by the Gibson fault; it lies south of the town of Ajo
and southeast of the main pluton. Through 1962 two million tons of
copper had been recovered from 255 million tons of ore and 270 million
15
tons of waste (Dixon, 1966). Recently, after a short shutdown caused
by the depressed price of copper, Phelps Dodge reopened the New
Cornelia Mine. The smelter was built in 1950 and is currently not
operating.
Unconformably overlying the Cardigan Gneiss, the Concentrator
Volcanics and the Cornelia Quartz Monzonite in pediments and slopes
to the southeast of the Little Ajo Mountains, the Middle Tertiary
Locomotive Fanglomerate consists of clasts of widely varying compo-
sition and grain size. Boulders up to two feet in diameter are
common, although the average size of the fragments is less than one
inch. The quality of bedding and degree of sorting increase to the
southeast.
The Middle Tertiary Ajo Volcanics, located west and southwest
of the Ajo Peaks, conformably overlie the Locomotive Fanglomerate and
consist of andesitic breccias, flows and tuffs. The Middle Tertiary
Sneed Hornblende Andesite conformably overlies the Ajo Volcanics in
the southern part of the Childs Mountain, four miles northwest of
Ajo, and in Copper Canyon in the western part of the Little Ajo
Mountains. Unconformably overlying the Sneed andesite, the Middle
Tertiary Daniels Conglomerate crops out along the southern flanks of
both Childs Mountain and the Chico Shunie Hills. The unit consists of
alternating pebbly and sandy layers, with boulders up to four feet
in diameter.
As the two youngest bedrock units in the area are the only
bedrock in the study area, they will be described in much detail
in the following chapter. Their regional distribution in the Ajo
16
and Sikort Chuapo 15- minute quadrangles will be discussed in this
section. The only information available to the author on the Sikort
Chuapo quadrangle comes from a geologic map of the State of Arizona
(Wilson and others, 1969). Owing to the scale of the map, many
Tertiary volcanic units were not distinguished according to their
relative ages and compositions.
The Miocene Childs Latite crops out extensively throughout
southwestern Arizona. In the Ajo 15- minute quadrangle, the unit
crops out on the western side of Childs Mountain and as a small
patch in the north -central Batamote Mountains. Within the Sikort
Chuapo quadrangle, intermediate "Pliocene" volcanics (probably the
Childs Latite or its equivalent) compose the eastern part of the
Batamote Mountains, the Pozo Redondo Mountains, south of the Bata-
mote Mountains, and the western part of the Sikort Chuapo Mountains,
east of the Batamote Mountains (Wilson and others, 1969).
The Miocene Batamote Andesite, which was split into three
facies -- extrusive, intrusive and vent --by Gilluly (1946) crops out
extensively in the Batamote Mountains and on Childs Mountain. It
also crops out in the south -central part of the Ajo 15- minute quad-
rangle and in Black Mountain, four miles south -southeast of Ajo.
The extrusive facies is by far the most abundant. Outcrops of
vent breccias and the intrusive occur in the northeast part of
Childs Mountain and the central part of the Batamote Mountains; they
probably represent vents from which the Batamote andesite was ex-
truded. In the Sikort Chuapo quadrangle, "Plio -Pleistocene" basaltic
volcanics (probably the Batamote Andesite) crop out in the eastern
17
part of the Sikort Chuapo Mountains and around Coffeepot Mountain in
the northeastern section of the quadrangle (Wilson and others, 1969).
Two units of alluvium are present within the area. Plio -
Pleistocene alluvium crops out in several places in the Sikort
Chuapo quadrangle (Wilson and others, 1969). Quaternary alluvium
fills valleys and occurs as active stream deposits.
Structure
The oldest unit in the area, the Cardigan Gneiss, has undergone
several phases of deformation, the first of which probably occured in
the Precambrian. The Chico Shunie Quartz Monzonite intruded during
the Mesozoic; both the Cardigan Gneiss and the Chico Shunie Quartz
Monzonite show cataclastic deformation inferred by Gilluly (1946)
to be Mesozoic in age.
The pre- Tertiary rocks were intruded by the New Cornelia
stock in early Tertiary time (Dixon, 1966). Other Tertiary structure
in the Ajo area is characterized by normal faulting, some of which
is probably related to basin and range tectonism. The Little Ajo
Mountains are bounded on the northeast and east by the Little Ajo
Mountain and Black Mountain faults, respectively. The Childs
Mountain fault partially bounds Childs Mountain and the Little Ajo
Mountains on the west. The Gibson fault has dropped the New Cor-
nelia orebody relative to the quartz monzonite stock. Other faults
within the Little Ajo Mountains include the Chico Shunie and Ajo
Peak faults ( Gilluly, 1946).
18
The Batamote Mountains have been broken by a northerly to
northeasterly trending set of normal faults in the northwest part
of the range. These will be discussed in the next chapter in more
detail. Tertiary faulting in the Sikort Chuapo quadrangle includes
northerly to northwesterly trending normal faults in the Pozo Redondo
and Sikort Chuapo Mountains (Wilson and others, 1969).
The only folding present in the area is gentle warping in the
northern part of the Batamote Mountains (Gilluly, 1946).
In summary, the most important structural features present in
the region, relative to the problem being addressed, are Tertiary
normal faults. Motion began before the Miocene with early movement
on the Gibson fault and continued into the Holocene.
LOCAL GEOLOGY
The study area was mapped at a reconnaissance scale using
aerial photos. The results were then compared with earlier maps by
Gilluly (1937 and 1946) and Wilson and others (1969). Additionally,
contacts and faults were field checked as much as possible. Two
distinct bedrock units were recognized, the Childs Latite and the
Batamote Andesite, as named by Gilluly (1946). The Batamote Andesite
has been subdivided into three subunits -- extrusive, intrusive and
vent facies. Two units of alluvium were observed: an older unit that
forms low, sinuous hills in the north and dissected pediments in
the south, and a younger unit that fills the valleys as active
alluvium. The stratigraphy and structure of the immediate thesis
area are described in this chapter.
Stratigraphy
The oldest unit in the thesis area is the Miocene Childs
Latite with an age between 17 and 20 million years (May and others,
1980). Disconformably overlying the Childs Latite, the Batamote
Andesite also has a Miocene age of 15.52 ±0.54 million years (Shafi-
qullah and others, 1980). The two units of alluvium post -date the
Batamote Andesite. The distribution, physiography and petrography
of these units are described below.
19
20
Childs Latite
Distribution and Physiography. Within the study area, the
majority of the Childs Latite occurs toward the eastern edge. Small
patches occur in the north -central part and the northwestern part of
the area. The morthwestern patch is the southeasternmost extension
of the Crater Range.
The Childs Latite tends to form rounded to pointed hills in
the study area; however, on the western flanks of the Sikort Chuapo
Mountains, the unit tends to form prominent cliffs. In general, this
unit weathers to colors ranging from white to maroon.
Petrology and Mineralogy. In hand specimen, the Childs Latite
is typically holocrystalline and porphyritic -aphanitic, with white,
glassy, subhedral, medium to coarse grained feldspar phenocrysts in a
pink to maroon, aphanitic groundmass. However, the grain size and de-
velopment of crystal faces of the phenocrysts varies widely from out-
crop to outcrop; in some instances, the feldspar phenocrysts are anhedral
and fine grained. The unit, in general, shows excellent flow banding.
In addition to the extrusive porphyry, the Childs Latite
contains small outcrops of dikes and breccia. The dikes have the
same general texture as the extrusive unit, but they are character-
ized by discordant attitudes relative to the subhorizontal dip of
the unit. The breccia, which weathers from brown to yellowish
white, consists of coarse to very coarse (0.5 to 50 cm) blocks in a
slightly vesicular, aphanitic matrix. The blocks are composed of
flow banded, porphyritic -aphanitic Childs Latite. The breccia crops
out in the northeast in a geographical embayment of latite into the
21
Figure 5 -- Photomicrograph of Childs Latite (under crossed polars).
Note zoned plagioclase and augite phenocrysts (135 X).
22
Batamote Andesite. In the same area, stratigraphically below the
breccia, the latite has been extensively argillized.
In thin section, the latite shows the same textural vari-
ability seen in the hand specimens. The typical texture is holo-
crystalline, porphyritic -cryptocrystalline to microcrystalline, with
very fine to coarse grained anhedral to subhedral phenocrysts in a
felted cryptocrystalline to microcrystalline groundmass. The
phenocrysts, which comprise 40 to 60 volume percent of the rock, are
dominated by andesine and /or labradorite (An to An ) with lesser40 60
orthoclase, magnetite and augite. The plagioclase phenocrysts show
marked zoning, with calcic cores that have been locally argillized
to montmorillonite. Some sections contain partially resorbed,
zoned sanidine and minor biotite. The groundmass, when its com-
position is distinguishable, consists of plagioclase, augite and
magnetite. Figúre 5 shows the typical microscopic textures and
mineral compositions of the Childs Latite.
Batamote Andesíte-- Extrusive Facies
Distribution and Physiography. The Batamote Basaltic Andesite
is the most widespread unit in the study area, and it crops out over
most of the Batamote Mountains. The extrusive facies makes up the bulk
of the outcrop and forms mesas that have been extensively dissected
by deep canyons. This facies, in general, dips away from a central
plug located near the high point of the range. This is interpreted
as the volcanic vent.
23
Petrology and Mineralogy. The extrusive facies of the Batamote
Andesite occurs dominantly in flows which range in thickness up to 20
meters. The flows show a strong textural zonation, grading from a
basal gray, fissile rock of aphanitic texture, through an inter-
mediate black, massive, aphanitic section, and finally into a black,
or yellow, while the intermediate and upper units weather maroon or
scoriaceous cap. The basal unit of a flow typically weathers maroon or
black. Some sections show flow banding. Secondary minerals include
zeolites filling amygdules and chalcedony along joints and fractures.
This unit also includes minor volcanic breccia and volcano -
clastics. The volcanic breccia, which is probably a result of flow
brecciation, consists of blocks up to 50 cm in a medium to coarse
grained matrix. The volcanoclastics consist of a medium to coarse
grained, poorly sorted, poorly consolidated wacke. The minor
lithologies are not described microscopically.
The three textural zones characteristic of the flows are dis-
tinctive under the petrographic microscope. The basal zone is typically
flow banded, holocrystalline and porphyritic -microcrystalline, with fine
grained subhedral to euhedral plagioclase and olivine phenocrysts in a
felted, pilotaxitic microcrystalline groundmass consisting of plagio-
clase laths. Some sections had glass in the groundmass.
The intermediate zone is characteristically hypocrystalline,
porphyritic -microcrystalline or vitric, with fine grained, subhedral
mafic phenocrysts in a pilotaxitic, microcrystalline plagioclase
groundmass or a black hyaloophitic groundmass of microcrystalline
plagioclase laths and glass.
24
Finally, the upper zone is scoriaceous, hypocrystalline,
porphyritic - vitric with one or two sizes of phenocrysts in a vitric
groundmass. The larger phenocrysts consist of fine grained subhedral
to euhedral olivine crystals, whereas the smaller phenocrysts are
typically plagioclase microlites. Figures 6 and 7 show typical
textures and mineralogies of the basal and upper zones of the flows.
Although the texture varies widely within the flows, the
mineralogy remains relatively constant. The coarsest phenocrysts in
all thin sections are olivine grains that have been partially to
completely replaced by iddingsite. Plagioclase occurs both as
phenocrysts and microlites within the groundmasses. It has composi-
tions ranging from sodic andesine (An ) to calcic labradorite36
(An ); more typical anorthite contents range from 45 to 60 %.
Magnetite is a common accessory mineral, while hypersthene and augite
occur infrequently.
Batamote Andesite- -Vent Facies
Distribution and Physiography. The vent facies of the Bata -
mote Andesite occurs in the central part of the study area just
southwest of the high point of the Batamote Mountains. This facies
crops out on the periphery of, or stratigraphically above, the intru-
sive facies. The unit forms outcrops that stand out relative to the
surrounding rocks.
Petrology. The vent facies is a red to maroon oxidized
volcanic breccia that consists of blocks ranging in size from 10 cm
to 1 m in an aphanitic to coarse grained matrix. The easternmost
25
Figure 6 -- Photomicrograph of the basal section of a typical flow,Batamote Andesite (under crossed polars). Note plagioclase and
olivine phenocrysts in felted, pilotaxitic microcrystallinegroundmass (135 X).
26
Figure 7-- Photomicrograph of the upper unit of a typical flow,Batamote Andesite (under crossed polars). Note two sizes of pheno-
crysts in hyaloophitic groundmass (135 X)..
27
outcrop has a sub -horizontal, sedimentary -like bedding up to 2 m
thick. This facies was not described microscopically.
Batamote Andesite -- Intrusive Facies
Distribution and Physiography. The intrusive facies of the
Batamote Andesite crops out in a one square mile area in the central
part of the study area southwest of the high point of the range.
The facies has no distinctive topographic expression.
Petrology and Mineralogy. The Batamote intrusive can be
subdivided into two distinct units, a fine grained, equigranular
diorite (or gabbro ?) in the south and a dense, massive porphyritic-
aphanitic basaltic andesite in the north. The nature of the con-
tact between the two phases was not determined.
In hand specimen, the diorite is holocrystalline, hypidiomor-
phic- granular, fine grained with a salt and pepper texture. In out-
crop, the unit, which weathers gray to reddish -yellow, is massive
towards the center and grades outwards into an outer zone that is
highly jointed.
In thin section, the diorite has a grain size ranging from
0.3 to 1 mm. It is dominated by andesine (An to An ) with40 50
accessory olivine (that has been altered extensively to iddingsíte),
magnetite and minor intergranular augite and hypersthene. The
olivine /iddingstie crystals have a slightly larger grain size than
the other crystals. Figure 8 shows the textures and mineralogy of
this unit.
28
The porphyritic -aphanitic unit, which composes the bulk of
the intrusive, weathers yellow on outcrop. Towards the center of the
intrusive, the phase develops two roughly perpendicular sets of
vertical joints. Towards the edges, this jointing is less well
developed. At the edges, the unit interfingers extensively, or
grades into, the vent facies described earlier.
This unit is holocrystalline, porphyritic- cryptocrystalline
to microcrystalline, with subhedral to euhedral fine grained
(0.3 to 1 mm) phenocrysts in a cryptocrystalline to microcrystalline
groundmass. The phenocrysts are composed of olivine that has been
altered slightly to iddingsite; the groundmass, when distinguishable,
consists of andesine to labradorite (An to An ) with lesser hypers-45 60
thene, magnetite and augite. In this unit, the hypersthene predomin-
ates over the augite, whereas in the dioritic unit, augite predomin-
ates over hypersthene. Figure 9 shows the textures and mineralogy
of this phase of the intrusive.
In summary, the intrusive facies of the Batamote Andesite has
two distinct units: a diorite and a basaltic andesite. The rela-
tionship between the two units was not determined.
Older Alluvium
This alluvium, which is younger than the Batamote Andesite,
consists of pebbles and cobbles in an unconsolidated fine sand to
silt matrix. In the northwest, the unit forms low (3 m), sinuous
hills on the outwash plain north of the Batamote Mountains; the
pebbles and cobbles are composed of Batamote Andesite. On the other
29
Figure 8 -- Photomicrograph of the dioritic unit of the intrusivefacies of the Batamote Andesite (under crossed polars). Note therelative coarse granularity of the unit (135 X).
30
Figure 9-- Photomicrograph of the porphyritic unit of the intrusivefacies of the Batamote Andesite (under crossed polars) (135 X),
31
hand, in the southeast, the unit forms a dissected pediment and the
pebbles and cobbles consist of Childs Latite.
Quaternary Alluvium
The valleys and active stream channels are filled with an
unconsolidated gravel with cobbles and pebbles in a sandy to silty
matrix. In places, the alluvium has been cemented by extensive
caliche.
Structure
Deformation within the study area is limited to normal
faults in the Batamote Andesite and minor warping of both the Childs
Latite and the Batamote Andesite. Since there are no marker beds
in the study area, the structure in the area is largely conjectural,
and is based on topography and aerial photographs.
Faulting
The only faults present are located in the northwest.
Although inferred from aerial photographs, they agree well with
those reported by Gilluly (1946). Additionally, fault gouge was
observed along one fault trace. However, due to the lack of marker
beds, the displacement of the faults could not be determined. The
fault as shown by Wilson and others (1969) to pass through the center
of the range, was not observed in the field.
Folding
Gilluly (1946) reports relatively minor warps within the
Batamote Andesite; however, the majority of the attitudes in this
32
unit are depositional. During reconnaissance mapping, an anticline
was observed in the Childs Latite in the northeastern embayment
into the Batamote Andesite.
Alteration
In view of the geochemical anomalies derived from it, the
Batamote Andesite is notable for its lack of significant alteration.
The only secondary minerals present in the unit are amygduloidal
zeolites, and joint and fracture filling chalcedony. However, a
"limonite" multispectral imaging anomaly occurs around the Batamote
plug (Gary Raines, U.S. Geological Survey, personal communication,
1984) .
On the other hand, an extensive zone of alteration was ob-
served in the Childs Latite in the northeastern embayment of this
unit into the Batamote Andesite. In this area, the unit has been
strongly argillized.
LITHOGEOCHEMISTRY
A total of 58 rock chip samples were collected within the
study area, pulverized and analyzed for 31 elements using semi -
quantitative emission spectro -scopy (Grimes and Marranzino, 1968). The
results of these analyses are given in Appendix Ia, while their
locations are given in Plate 2. Of these samples, 41 came from the
extrusive facies of the Batamote Andesite, three came from the intru-
sive facies of the Batamote Andesite, five came from the Childs
Latite, and six samples came from other rock types, including chalce-
dony, caliche and volcanoclastics. In addition, Gilluly (1946) and
Jones (1974) presented major element oxide analyses for Childs Latite
and Batamote Andesite within the region.
In this chapter, the analyses of the major and minor oxides
from other studies are reviewed, and the distribution of trace elements
in the Batamote Andesite and Childs Latite, especially copper, lead
and zinc, are discussed.
Major and Minor Elements
Gilluly (1946) reported analyses of rocks for 18 oxides and
sulfur, and Jones (1974) reported analyses for nine oxides. The
results of these two studies are summarized in Table 1. The analyses
indicate that the Childs Latite and the Batamote Andesite have
essentially the same concentrations of silica, alumina, ferric oxide,
soda and titanium oxide. On the other hand, the Batamote Andesite
33
34
has significantly higher concentrations of ferrous oxide, magnesia
and lime, while the Childs Latite has higher concentrations of
potash. The most marked difference is in magnesia, where the con-
centration in the Batamote Andesite is more than twice that of the
Childs Latite.
The mineralogy of these two rock types reflects the differ-
ence in their composition. The presence of olivine as the predomin-
ant mafic mineral in the Batamote Andesite reflects the high magnesia
content, while the presence of orthoclase and sanidine in the Childs
Latite reflects its higher potash content. Based on the relatively
high silica concent, Gilluly (1946) classified the Batamote Andesite
as an andesite, although he said true basalt flows may occur within
the Batamote Mountains.
Table 1-- Summary of major element oxide analyses of the Childs Latite
Oxide
and the Batamote Andesite (after Gilluly, 1946 and Jones, 1974)
Childs Latitel Batamote Andesite2Mean Range Mean Range
Si02 55.52 53.00-57.65 55.93 49.06-59.88
A1203 16.08 14.56-18.14 16.33 15.69-17.33
Fe203 4.70 2.29-5.61 4.09 3.10-5.38
Fe0 2.58 1.65-4.07 3.78 1.41-6.37
Mg0 1.73 0.52-3.22 4.14 2.74-6.17
Ca0 5.37 4.42-6.38 7.03 5.31-8.95
Na20 3.98 3.40-4.39 3.41 3.11-3.62
K20 3.80 2.36-4.27 2.22 1.52-3.25
TiO2 1.20 0.79-1.55 1.05 0.79-1.40
All values in weight percent.
1Four samples from Gilluly (1946) and four samples from Jones (1974)
2Five samples from Gilluly (1946)
35
The results of the semi -quantitative analyses for elements
that had greater than 75% unqualified values are summarized in Table
2. For statistical analysis, qualified values were assigned values
one and one -half of a spectrographic step below the detection limit
for "N" (not detected), and "L" (detected at levels below the detec-
tion limit), respectively. Because of the small population for the
Childs Latite, the standard deviations are not given. The semi -
quantitative nature of the data in Table 2 should be remembered.
The major and minor elements, as determined by semi- quanti-
tative emission spectroscopy, show the same relative abundances by
rock type as the oxide analyses. The Batamote Andesite has higher
concentrations of iron, magnesium, calcium, titanium and manganese.
For the Batamote Andesite, all major and minor elements have relatively
low standard deviations relative to their means. Only calcium has
a relatively high standard deviation.
Trace Elements
Trace elements are defined as elements that have abundances
of less than 0.1 percent (Levinson, 1980). Fourteen elements in
Table 2 have this characteristic. Of these, two (B and Be) have
significantly higher concentrations in the Childs Latite, which
probably reflects the more felsic nature of this unit. On the other
hand, seven elements (Co, Cr, Cu, Ni, Sc, Sr and V) have higher
concentrations in the Batamote Andesite, which reflects its more mafic
nature. Four elements (La, Pb, Y and Zr) have approximately the
same concentration in these two rock types. Barium proved to be
36
Table 2 -- Summary of emission spectroscopic analysis on the Childs
Element
Latite and Batamote Andesite
Childs Latite Batamote AndesiteStandard
Range Mean Range Mean Deviation
Fe (%) 0.3-2 1.1 2 -7 4.5 1.2
Mg (%) 0.2-1 0.48 1 -2 1.3 0.4
Ca (%) 0.2-1.5 0.82 1.5 -10 1.9 1.3
Ti (%) 0.03-0.3 0.12 0.2 -0.7 0.44 0.11
Mn 700-1000 760 1000 -2000 1200 330
B 20-70 42 10-50 19 7
Ba 50-500 190 300-1000 630 180
Be 1-7 4.7 L(1)-2 1.4 0.3
Co N(5)-10 3.8 10-30 20 7
Cr N(10) 5 10-150 34 29
Cu L(5)-10 6 15 -50 28 10
La 50-100 72 50 -100 82 21
Ni N(5)-20 5.6 10 -70 28 18
Pb 10-30 20 10 -30 19 5
Sr N(100)-500 190 500 500 0
V N(10)-50 23 50 -100 86 17
Y 20-30 22 10 -50 34 12
Zr 50-200 110 50 -300 199 58
Replacement values for qualified values
Element Qualified Value Element Qualified Value
N L N L
Be 0.5 0.7 Ni 2 3
Co 2 3 Sc 2 3
Cr 5 7 Sr 50 70
Cu 2 3 V 5 7
Values in parts per million unless otherwise indicated.
37
unusual in that it has higher concentrations in the andesite; yet,
in general, it is concentrated in more potassium -rich rocks (Levin-
son, 1980). Therefore with the exception of barium, major, minor and
trace elements conform to the expected relative abundances of the two
rock types.
As this study is concerned with the concentration of copper,
the distribution of base metals in the Batamote Andesite is important
to later interpretations. Figures 10 through 12 are histograms
showing the distributions of values of copper, lead and zinc, respec-
tively, in the extrusive facies of the Batamote Andesite.
Copper values have a restricted range of values characterized
by one mode at 30 ppm, indicating that the Batamote Andesite has a
relatively even distribution of copper. Moreover, because the average
abundance of copper in andesite is 55 ppm (Wedepohl, 1969) the Batamote
Andesite is somewhat depleted in copper relative to other rocks of
similar composition.
Lead has a similar restricted range of values around 20 ppm,
which is enriched relative to the 5.8 ppm average abundance in andes-
ite (Wedepohl, 1969). Zinc has an irregular distribution with values
up to 1000 ppm, but clustering around L(200). This distribution
indicates that zinc has a higher than average abundance relative to
andesite at 70 ppm (Wedepohl, 1969).
R -Mode Factor Analysis
R -mode factor analysis was performed on 41 samples from the
extrusive facies of the Batamote Andesíte, as this is the most
38
important rock in the study area. All elements, except strontium,
that had greater than 75% unqualified values using semi- quantitative
emission spectroscopy (18 total) were used in this analysis. Quali-
fied values were assigned numerical values as in earlier statistical
treatments of the data. Strontium was not used because it had no
variance over the sample population. The exact method used was
principal factoring with iterations and varimax rotation (c.f. Nie
and others, 1974). The results of the factor analysis are given in
Table 3, and a graphical depiction of the factor loadings (which
represent both correlation coefficients and regression weights be-
tween the elements and the factors) is given in Figure 13.
Four initial factors with eigenvalues greater than one (i.e.
the factor explains a greater amount of the total variance than is
explained by a single element), explained 70.5% of the total variance
within the data. The other 14 initial factors explained 29.5% of
the variance.
When terminal factors were determined by iteration, the first
two factors accounted for 81.0% of the total variance. The other two
terminal factors explained less than 20% of the variance; they have
much less importance than the first two factors. Low communalities
(less than 0.5) for titanium and boron imply that the four terminal
factors do not explain the variance of these elements well; other
factors played a greater role in determining their concentrations.
Factor 1 probably represents the mafic component of the
Batamote Andesite; it corresponds very well with the ferride assem-
blage of Theobald and Barton (1983). High positive factor loadings
VALUE
(PPM)
N(5)
L(5)
5
7
10
15
20
30
50
FREQUENCY
5 10 15 20
39
figure 10 -- Histogram showing the distribution of copper in the Batamote
Andesite
VALUE
(PPM)
N(10)
L(1O)
10
15
20
30
O
FREQUENCY
5 10 15 20 25 30
Figure 11 -- Histogram showing the distribution of lead in the BatamoteAndesíte
40
VALUE FREQUENCY
(PPM) 0 5 10 15 20 25 30
N(200)L(200)2003005007001000
Figure 12 -- Histogram showing the distribution of zinc in the BatamoteAndesite
41
Table 3-- Results of R -mode principal factor analysis with iterations
after varimax rotation for the extrusive facies of the Bata -
mote Andesite, Batamote Mountains, Arizona
Element Communality Factor Loadings
Factor 1 Factor 2 Factor 3 Factor 4
Fe 0.66560 0.78658 0.18030 0.02773 0.11667
Mg 0.61128 0.67672 -0.32253 0.21855 -0.03932
Ca 0.75973 0.04594 -0.07245 -0.03935 0.86650
Ti 0.38460 0.33886 0.51152 0.00967 0.08959
Mn 0.55794 0.17178 0.18675 0.70138 0.04017
B 0.19663 0.24489 0.28708 -0.22155 0.07184
Ba 0.39957 -0.10538 0.52316 0.30878 0.13938
Be 0.61659 -0.19760 0.70325 0.24807 -0.14645
Co 0.72540 0.78461 -0.10914 0.30995 0.04253
Cr 0.70063 0.62398 -0.55629 0.04274 -0.00172
Cu 0.51839 0.42356 0.13340 0.56102 -0.08020
La 0.82499 0.04252 0.86665 -0.13663 -0.23114
Ni 0.92211 0.82012 -0.47226 0.15327 -0.05122
Pb 0.66127 -0.02951 0.71231 0.39013 -0.03104
Sc 0.73552 0.76293 0.17019 0.12324 0.33062
V 0.68194 0.80772 0.11867 -0.10038 -0.07330
Y 0.69455 0.36794 0.59870 0.22903 0.38508
Zr 0.64201 -0.13381 0.78843 0.02032 0.04560
Factor Eigenvalue Percent of Variance Cummulative Percent
1 4.93591 43.7 43.7
2 4.22015 37.4 81.0
3 1.12328 9.9 91.0
4 1.01915 9.0 100.0
FA
CT
OR
11.
0T
0.0
Ni -V
Fe
Co
Sc
Cr
Mg
-Cu
YT
iB
gM
n Fe
Mn
Sc
Cu
FA
CT
OR
2
Cu
LaP
bB
aZ
r
-1.0
Bç
FA
CT
OR
3 Mn
Cu
Pb -C
oB
aBe
NiM
9C
rSc
ZrF
e Ti
Ca
vLa -- B
FA
CT
OR
4 Sc
Fe
Ba Ti
BZ
rC
oMn
MP
b
gNi
VC
u
geLa
Figure 13 -- Factor loadings for 18 elements from R -mode factor analysis of the Batamote Andesite
43
clearly group elements with a mafic association (Ni, V, Fe, Co,
Sc, Mg and Cr). Additionally, elements with a felsic association
(e.g. Be, Zr, Pb and La) tend to have either a low or negative
factor loading.
Conversely, factor 2 probably has a felsic or intermediate
association. In this case three groupings of elements can be seen:
a group with high positive loadings (La, Zr, Pb, Be, Y, Ba and Ti), a
group with low absolute factor loadings (B, Mn, Fe, Sc, Cu, V,
Ca and Co), and a group with high negative loadings (Mg, Ni and
Cr). With the exception of titanium, the elements in the first
group --the group that defines the factor --all have a felsic or
intermediate association; the elements in the third group --which
has a negative correlation with the factor --have a more mafic
association. This factor, therefore, seems to be positively correl-
ated with the intermediate to felsic component of the rock.
The nature of the other two factors is much less straight-
forward. Factor 3 separates manganese and copper, with relatively
high factor loadings, from the rest of the elements. Possibly this
factor could be associated with the copper anomalies discussed later
in this report. Factor 4 separates calcium and possibly yttrium
and scandium from the other elements. It could represent calcite -
filled amygdules or the effect of caliche on the samples. Both
these factors account for relatively little variance (less than
10% each).
STREAM SEDIMENT GEOCHEMISTRY
A total of 101 stream sediment samples were collected from
89 sites. The samples were collected in three phases: 1. A pre-
liminary phase to check the anomalies observed by Barton and others
(1982); 2. The main phase to define the distribution of copper; and
3. Follow -up work to determine the changes in the concentration of
copper upstream along anomalous drainages. Sample locations, along
with the drainage patterns and areas of influence of the samples,
respectively, are given in Plates 3 and 4. The samples were analyzed
using semi- quantitative emission spectroscopy (Grimes and Marranzino,
1969; E.F. Cooley, U.S. Geological Survey, personal communication,
1983), a hot nitric acid leach (modified after Ward and others, 1969)
and two sequential extraction techniques. The results of the semi -
quantitative emission spectroscopic analysis are presented in Appendix
Ib; the analytical methods are described in Appendix II; and the
results of the chemical analyses are given in Appendices IIIa through
IIIb.
Preliminary Phase
To confirm the results of the survey by Barton and others
(1982) and to check the possibility of contamination from the Ajo
smelter, seven stream sediment samples were collected in December
1982. Of these, two (AJ001S and AJ002S) came from washes that
drained the Valley of the Ajo, which lies between the smelter and
44
45
the area of interest, while the others drained the Batamote Mountains.
Using nylon and aluminum screens, five size fractions were
sieved and then pulverized to -200 mesh. The size fractions are:
-30 mesh ( <600 pm), 30 mesh to 80 mesh (600 pm to 180 pm), 80 mesh
to 150 mesh (180 pm to 100 pm), 150 mesh to 200 mesh (100 pm to
75 pm), and -200 mesh ( <75 pm). Each size fraction was analyzed
for copper with atomic absorption spectrophotometry using a hot
nitric acid leach (see Appendix II). The results of this analysis
are given in Table 4.
The results of this preliminary phase indicate that the
anomalies described by Barton and others (1982) are real, that air-
borne smelter contamination is not significant, and that -30 mesh
stream sediment is perfectly adequate for more detailed work.
The values of 100 to 190 ppm copper in the -30 mesh fraction
correspond nicely with the anomalous values ranging from 100 to 200
ppm copper reported by Barton and others (1982). Consequently,
further work was justified.
Smelter contamination was considered unlikely at the end of
this phase of the study for two reasons. First, high values persist
on the eastern (downwind) side of the Batamote range. Samples
AJ003S, AJ005S and AJ007S came from this area; their values remain
anomalous, especially in light of the background values of copper
in the Batamote Andesite. Additionally the intensity of the anomaly
does not increase significantly on the west side of the range as
might be expected with airborne contamination.
46
Table 4-- Concentrations of copper in selected stream sediment samples
Sample
relative to particle size
Size Classes (U.S. Standard Mesh)-30 -301+80 -80/ +150 -150/ +200 -200
AJ001S 170 190 190 160 230
AJ002S 90 60 30 140 170
AJ003S 140 120 120 160 290
AJ005S 120 120 120 120 160
AJ007S 110 120 130 140 190
AJ008S 190 170 200 210 260
AJOlOS 130 110 130 170 220
Second, high copper values are present in the coarsest
fractions of the samples. For a typical smelter, 50% of the smelter
dust passes through a 400 mesh screen, and 80% of the dust passes
through a 150 mesh screen. (E. Partelpoeg, Phelps Dodge, personal
communication, 1984). Therefore, barring sorption, airborne contam-
ination would be important only in the finest fractions. Although
the concentrations of copper increase with decreasing grain size
(which is expected anyway), the presence of anomalous values in the
-30/ +80 mesh fraction argues against airborne smelter contamination.
Additionally, the results of later work also argue against this
mechanism.
Finally, the -30 mesh size fraction proved to give adequate
values and reasonable contrast. Therefore to minimize effort in
sample preparation and to decrease problems with eolian transport
and contamination, the -30 mesh size fraction was chosen for further
work.
47
Main Phase
The second phase of stream sediment collection involved
sampling 78 sites at a sampling density of 0.89 samples /tang to
determine the distribution of copper in the Batamote Mountains.
Each of the preliminary sample sites in the mountains was resampled;
replicate samples were collected at seven additional sites. Repli-
cate stream sediment sample pairs are listed in Table 5:
Table 5-- Replicate stream sediment sample pairs
AJ003S- AJ036S AJ010S- AJO3OS AJ096S- AJ097S
AJ005S- AJO11S AJ083S- AJ084S AJ098S- AJ099S
AJOO7S- AJ021S AJ087S- AJO88S AJ1O3S- AJ104S
AJOO8S- AJO29S AJ091S- AJ092S AJ105S- AJ106S
Field Methods
At each sample site, stream sediment and heavy mineral con-
centrate samples were collected. Sediment, composited along a 100
foot reach of channel, was screened through a 5 mm sieve in the field.
Between 400 and 1600 g (usually 500 to 1000 g) of -5 mm sediment was
collected as a stream sediment; between 1500 and 3500 g (usually
2000 to 3000 g) were collected as a heavy mineral concentrate.
Sample Preparation
In the laboratory the stream sediment samples were sieved
to -30 mesh and split. Between 30 and 80 g were pulverized to -200
mesh. The rest was saved for later investigations. The +30 mesh
material was discarded.
48
Results of the Hot Nitric Acid Extraction
All samples were analyzed for copper using atomic absorp-
tion spectrophotometry with a hot nitric acid extraction (see
Appendix II for technique). The extraction solubilizes all adsorbed
ions and most common sulfides and oxides. However, it is not total
because silicates are not attacked to a significant degree (Ward
and others, 1969).
The results (see Appendix IIIa) of this analysis suggested a
bimodal frequency distribution, with one mode at 75 ppm and the other
mode at 150 ppm (see Figure 14). Two anomalous areas (defined using
a threshold of 100 ppm) separated by a trough of lower values occur
in the northwest and north -central parts of the study area (see
Plate 5). The values trail off to the east and southeast to values
around 50 ppm.
The northwestern anomaly (which has values up to 280 ppm) has
a strong spatial association with the northerly trending normal
faults described earlier in this paper. However, the easternmost
fault in this group lies within the trough of low copper values.
The north -central anomaly (which has values up to 150 ppm)
has no obvious structural or lithological control. Conceivably,
it could be a continuation of the northweatern anomaly. In fact,
later analyses tend to support this hypothesis.
Results of Semi -Quantitative Emission Spectroscopic Analysis
Each sample was analyzed for 31 elements using semi- quanti-
tative emission spectroscopy (Grimes and Marranzino, 1969) modified
49
RANGE(PPM)
1- 2526- 5051- 7576-100
101 -125
126 -150
151 -175176 -200201 -225226 -250251 -275276 -300
FREQUENCY0 5 10 15 20
3
3
Figure 14 -- Histogram showing the distribution of copper (extractedusing hot nitric acid) in -30 mesh stream sediments
50
to lower the detection limits of certain elements (Ag, As, Au,
Be, Bi, Cd, Cu, Pb, Sb, Sn, W and Zn; E.F. Cooley, personal communi-
cation, 1983). The results (see Appendix Ib) indicated anomalous
areas in the northwest and north -central part of the study area
characterized by highs of copper, silver and bismuth.
Copper. The results of semi -quantitative emission spectro-
scopic analysis of copper, an analysis for total copper, are similar
to the results for the hot nitric acid extraction. Both procedures
show a bimodal frequency distribution and similar areal distributions.
In fact, the two procedures have a correlation coefficient of 0.8185
based on 92 samples. Therefore, owing to the high variance inherent
in semi -quantitative emission spectroscopy, only the results for the
nitric acid extraction are presented graphically in this paper.
Silver and Bismuth. Both silver and bismuth mimic the anomaly
pattern observed in copper. Figures 15 and 16 and Plates 6 and 7
show the frequency and areal distributions of silver and bismuth,
respectively. High silver values (greater than or equal to L(0.1))
have a wider distribution than the high copper values, yet they occur
in the same general areas. Bismuth shows a distribution that has
a better visual correlation with copper than silver. A trough of
low values, corresponding with the one for copper, also appears in
the bismuth map; the trough is not apparent on the silver map. As
the values reported are right at the detection limit (especially for
bismuth), the true backgrounds for these two elements could not be
determined.
VALUE
(PPM)
N(0.1)
L(O.1)
0.1
0.15
0.20,3
0.50.7
1
FREQUENCY
0 5 10 15 20 25 30 35
51
Figure 15 -- Histogram showing the distribution of silver (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh stream
sediment
VALUE
(PPM)
N(2)
L(2)
2
FREQUENCY
0 5 10 25 30 40 45
Figure 15 -- Histogram showing the distribution of bismuth (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment
52
Silver is a chalcophile element that is typically associated
with copper in "red bed" sandstone deposits and some porphyry copper
deposits. Crustal abundance averages 0.07 ppm and ranges from 0.04
ppm in felsic rocks to 0.1 ppm in mafic rocks (Levinson, 1980).
For intermediate igneous rocks, average abundance is 0.07 ppm (Wede-
pohl, 1969). It has a high mobility in the primary environment,
but is only slightly mobile in oxidizing, acid and gley secondary
environments (Levinson, 1980). Consequently, the association of sil-
ver with copper is not unusual; however, the lower values of silver
are near the background for andesites.
A chalcophile element, bismuth has a crustal abundance of
0.17 ppm, which implies that the observed anomaly of 2 ppm is signif-
icant. The abundance of bismuth varies from 0.1 ppm in felsic rocks
to 0.15 ppm in mafic rocks. Bismuth can occur with copper in poly -
metallic deposits. Although its mobility in the primary environment
is high, it has a very low mobility at the surface, commonly precip-
itating with iron oxides (Levinsion, 1980). However, relatively
little is known about the detailed geochemical behavior of this
element.
Within the Ajo 1° by 2° quadrangle, bismuth has an association
with the Precambrian. It best characterizes a "half- moon" shaped
Bi -Pb -Mo anomaly, centered over a magnetic bullseye (possibly indi-
cating a shallow intrusive) in the presumed Precambrian of the
Mohawk Range, northeast of the study area (P.K. Theobald, U.S. Geo-
logical Survey, personal communication, 1984). Elsewhere in
southern Arizona bismuth has been observed in pegmatites and is
53
associated with pyrometasomatic deposits in the Pima District
(Cooper, 1962).
Other Base Metals. Plate 8 shows the distribution of anomal-
ous values of molybdenum, lead, tin and zinc in -30 mesh stream sed-
iment. Figures 17 through 20 show the frequency distributions for
the same elements. Of these, only anomalous values of tin (ranging
from L(5) to 10 ppm) seem to be associated with the copper- silver-
bismuth anomaly. The anomalous values of molybdenum, lead and zinc
occur in no recognizable systematic way throughout the study area.
This, in combination with the relatively low values of the anomalies,
suggests that they are not significant.
R -Mode Factor Analysis. R -mode factor analysis was performed
on the stream sediment data using the same criteria and methodology
described earlier in the chapter on lithogeochemistry (replacements
of qualified data were different as different lower detection limits
were used). In this case, strontium was used in the analysis be-
cause it had siggíficant variance. The results of the analysis are
given in Table 6 and graphically depicted in Figure 21.
Five initial factors with eigenvalues greater than one
accounted for 67.5% of the total variance. Fourteen other initial
factors accounted for 32.5% of the total variation.
After transformation to terminal factors, the first factor
explained 59.8% of the variance - -by far the dominant factor. The
other factors each explained 15.6% or less of the variance. So in
this case there is one dominant factor and four lesser factors.
VALUE
(PPM)
N(5)
L( 5)
5
7
10
FREQUENCY
0 5 10 70 75
3
54
Figure 17 -- Histogram showing the distribution of molybdenum (analyzedusing semi- quantitative emission spectroscopy) in -30 mesh
stream sediment
VALUE
(PPM)
N(2)
L(2)
2
3
5
7
10
15
20
30
50
70
100
150
200
300
FREQUENCY
0 5 10 15 20 45 50
J7
Figure 18 -- Histogram showing the distribution of lead (analyzed using
semi -quantitative emission spectroscopy) in -30 mesh stream
sediment
VALUE
(PPM)
N(5)
L(5)57
10
FREQUENCY
0 5 10 70 75
55
Figure 19 -- Histogram showing the distribution of tin (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment
VALUE
(PPM)
N(50)
L(5O)
5070
FREQUENCY
0 5 10 6 0
Jl
Figure 20-- Histogram showing the distribution of zinc (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment
56
Table 6 -- Results of R -mode principal factor analysis with iterationsafter varimax rotation for -30 mesh stream sediments, Batamote
Element
Mountains, Arizona
CommunalityFactor 1
Factor LoadingsFactor 2 Factor 3 Factor 4 Factor 5
Fe 0.74229 0.69705 0.33028 0.31758 0.18934 0.10304Mg 0.74964 0.84115 0.12003 0.05638 -0.07092 0.13959Ca 0.26428 0.18574 -0.07881 0.39103 0.14340 0.22382Ti 0.91213 0.35775 0.83552 0.25571 0.09664 0.01646Mn 0.46846 0.60964 0.15351 0.01800 0.21378 0.16494
B 0.41485 -0.51733 -0.05579 -0.21456 -0.20552 -0.23630Ba 0.68883 0.39648 0.48920 0.08998 0.53036 -0.05418Be 0.28242 -0.37576 0.00893 0.15277 -0.29445 0.17634Co 0.76290 0.80419 0.32809 0.07367 -0.03520 0.04324Cr 0.73356 0.72339 0.12224 -0.29935 -0.23905 0.22038
Cu 0.54530 -0.22608 -0.05215 -0.26265 -0.07471 -0.64568La 0.32292 -0.16380 0.14914 0.37634 0.33595 0.13910Ni 0.54275 0.63838 0.22980 -0.20687 -0.04416 0.20535Pb 0.31048 -0.07723 0.04165 -0.04738 0.54749 0.02800Sc 0.90160 0.85625 0.07096 0.36210 -0.14707 -0.10332
Sr 0.59892 0.44652 0.30450 0.33982 0.38647 0.20490V 0.46831 0.45452 0.46389 -0.17469 0.12519 0.01850Y 0.47772 -0.01590 0.11381 0.65063 -0.20183 0.02171Zr 0.36704 -0.05413 -0.03312 0.00217 0.01597 -0.60229
Factor Eigenvalue Percent of Variance Cummulative Percent
1 6.31778 59.8 59.82 1.64818 15.6 75.43 1.15515 10.9 86.44 0.84477 8.0 94.45 0.59299 5.6 100.0
FA
CT
OR
11.
0
Mg
Sc
Co
Cr
Ni
Fe
-Mn
FA
CT
OR
2
Ti
VB
a
Ba
Fe
Co
-Ti
Sc
.
Mnn
Ca
LaM
_ gCr
0.0
Zr
YP
bS
c
-1.0
Pb
Cu
LaC
a-C
uB
e
B
FA
CT
OR
3
a
Y
Sc
La-S
rF
eTi
Be oB
a
Mñ
gP
bS
r
Ni
V
-B
Cu
Cr
FA
CT
OR
4
Pb
Ba
Ca
Sr
Cr
Ni
LaS
rB
eM
nM
gLa
Mg
Fe
Co
Y Ba
FA
CT
OR
5
Mn
Ca
ZrT
i Co
CuM
gS
c B Be
Figure 21-- Factor loadings for 19 elements from R -mode factor analysis of stream sediments
58
As with the bulk rock analysis, the dominant factor is rela-
tively easy to explain, but the four lesser factors are problematic.
Factor 1 in stream sediments has relatively high loadings for
scandium, magnesium, cobalt, chromium, iron, nickel and manganese,
with possible associations of vanadium, strontium and barium. As
with factor 1 in the bulk rock analysis, most of the elements with
high loadings are associated with mafic rocks. Additionally, boron
and beryllium, elements associated with felsic rocks, have high
negative loadings, indicating a negative correlation with the factor.
Therefore, factor 1 probably reflects the mafic component of the
Batamote Andesite, which crops out in the majority of the sampled
area. It also corresponds to the ferride factor of Theobald and
Barton (1983).
Factor 2 is characterized by high factor loadings for titanium,
barium and vanadium; factor 3 has high loadings for yttrium, and
possibly calcium, lanthanum, scandium, strontium, iron and titanium;
factor 4 has high loadings for lead, barium, strontium and lanthanum;
and factor 5 has high negative loadings for copper and zirconium.
Of these, only factor 5 has meaning in context of this study.
In it, copper and zirconium are the controlling elements, with some
possible contribution from boron. These three elements are distinctly
separated from the other elements. Both boron and zirconium are
weakly correlated with copper (correlation coefficients are 0.4466
and 0.4153, respectively). Also high values of boron and zirconium
do occur in the anomalous areas as defined by copper. Therefore,
59
this factor might reflect the mechanism that produced the anomalous
values observed.
The factors with obscure explanations could represent contri-
butions to the sediment from a single mineral or suite of minerals.
Factor 2 could represent rutile and other titanium oxides and hydrox-
ides; factor 3 could represent the presence of xenotime or monazite
(thorium was found in the non - magnetic fraction of heavy mineral
concentrates); and factor 4 could relate to the presence of potassic
feldspar as lead, barium and strontium are common trace elements
in this mineral.
In the final factor solution, the five factors explained
less than 50% of the variance for calcium, manganese, boron, beryllium,
lanthanum, lead, vanadium, yttrium and zirconium. Additionally,
several other elements have low communalities. Therefore many other
factors are required to explain the variance beyond the five terminal
factors generated.
Results of the First Sequential Extraction
To determine the mineralogic distribution of copper within
the stream sediment samples, two sequential extractions were performed.
The first, which was performed on one sample from each site, involved
three steps. First, hot oxalic acid was used to remove the "oxide"
fraction (T.T. Chao, U.S. Geological Survey, personal communication,
1983). Then a combination of potassium perchlorate and cold hydro-
chloric acid was used to remove the "reduced" (i.e. sulfide and
organic) fraction (Glade and Fletcher, 1974). Finally an aqua
60
RANGE FREQUENCY
or 102) 0 5 10 15 20 25
0.01-0.250.26-0.500.51-0.750.76- 1.001.01- 1.25
1.26-1.501.51- 1.75
1
1.76-2.002.01-2.252.26-2.502.51-2.752.76-3.003.01-3.253.26-a5O3.51-3.753.76-4.004.01-425
Figure 22-- Histogram showing the distribution of copper normalized toiron (extracted using hot oxalic acid) in -30 mesh stream
sediment
RANGE(PPM)
1- 1011- 2021- 3031- 4041- 5051- 6061- 7071-8081 -9091 -100
101 -110
O
FREQUENCY
5 10 15 20 25
Figure 23 -- Histogram showing the distribution of copper (extractedsequentially using potassium perchlorate and hydrochloric acid
after oxalic acid) in -30 mesh stream sediment
61
regia /hydrofluoric acid leach was used to determine the residual
fraction for 20 samples (Filipek and Owen, 1978). The analytical
methods are presented in Appendix II, while the results are pre-
sented in Appendix llla. The results of each step are summarized
in the following discussion.
Oxalic Acid Leach. To minimize the effects of large vari-
ations in the concentrations of iron, copper values were normalized
to iron. Figure 22 and Plate 9 give the frequency and areal distri-
butions for this extraction. In this extraction, a unimodal
frequency distribution was produced with an upper shoulder. Assuming
the shoulder to contain the anomalous values, the threshold was set at
0.0100.
With this threshold, anomalous values occur in the areas
defined by the nitric acid extraction. Although the area covered
by the northwestern anomaly does not change, the north -central
anomaly is significantly reduced in area as anomalous values do not
extend as far to the north.
This leach accounted for between 30 and 61% of the total
copper in the stream sediments (calculated using the sum of the
different fractions as the total; for samples in which the residual
fraction was not determined, a value of 15 ppm was assumed). Within
the anomalous population, the percentage of copper extracted using
oxalic acid ranged from 40 to 61% of the total (x = 48.44 %, s = 4.51 %,
n = 21); on the other hand, in the non -anomalous population, the
percentage of total copper ranged from 30 to 57% (x = 43.20 %,
s = 6.40 %, n = 53). At the 95% confidence level, these two
62
populations are statistically different, indicating that in the
anomalous samples, the oxide fraction constitutes a greater propor-
tion of total copper than in the non -anomalous samples. This is
probably due to the increasing relative importance of copper in the
residual fraction of the non -anomalous population. While the copper
concentration in the oxide fraction decreases in the non -anomalous
samples, the residual concentration remains constant and has a
higher relative contribution.
In general, the oxalic acid extractable fraction contains
more copper than the potassium perchlorate -hydrochloric acid extract-
able fraction. Only in sample AJ001S, which came from a wash
draining the area containing the New Cornelia tailings ponds, does
the reduced fraction predominate over the oxide fraction. In all
but the lowest background samples, the oxide fraction predominates
over the residual fraction. In summary, the oxide fraction is
quantitatively the most important fraction of this sequential
extraction.
Potassium Perchlorate -Hydrochloric Acid Leach. This extract -
tion, originally designed for the analysis of base metal sulfides
(Olade and Fletcher, 1974), attacks the sulfide and organic portion of
the sample. Both the frequency and areal distributions for the copper in
this step are slightly different from those of the oxalic acid and
nitric acid extractions. Figure 23 and Plate 10 show the frequency
and areal distributions for this extraction.
The frequency distribution for this step has the appearance
of a log - normal distribution, as opposed to the bimodal distribution
63
observed in the nitric acid extraction. Due to the form of the dis-
tribution, the threshold is not obvious. However, the values in
the northwestern anomalous area increase upwards from 40 ppm,
suggesting that this is the probable threshold.
With this threshold, the north -central anomaly does show up,
but with significantly less contrast than in the other methods.
Moreover, this anomalous area is more spread out, with no distinct
highs. The northwestern anomaly does not change significantly in
either areal extent or character. As with the other techniques,
the values decrease to southeast to values around 10 to 20 ppm.
Therefore this extraction shows the same areal distribution
as the other methods; however, the frequency distribution is signif-
icantly different, suggesting additional or different processes
controlled the dispersion of copper into the sulfide and organic
fraction of stream sediments.
Aqua Regia /Hydrofluoric Acid Leach. This extraction is
designed to decompose silicate minerals, releasing copper and other
trace elements from silicate structures (Filipek and Owen, 1974).
Owing to the time required and the difficulty of the procedure,
only 20 samples were analyzed. Samples were chosen to include both
anomalous and background samples as indicated by previous analyses.
The results indicate that this fraction has a relatively uniform,
low distribution throughout the study area. Values ranged from 8 to
19 ppm with an average of 14.05 ppm (s = 3.03 ppm). By inspection,
high values from this extraction show no correlation with high
64
values from other extractions. Therefore, copper extracted using
this method probably represents the lithogeochemical background.
Summary. The first sequential extraction indicated that the
copper that constitutes the anomalous values probably resides in
both the oxide, and organic and sulfide portions of the stream sediment.
The technique does not give any indication of exactly how the copper
is held in these two chemical fractions. Copper held in the silicate
framework of the stream sediment does not contribute to the anomalous
values.
Results of the Second Sequential Extraction
To determine the mineralogic fractions that holds the copper,
a second, more selective sequential extraction (modified after Filipek
and Owen, 1978; modified after Chao and Zhou, 1983) involving five
separate steps was used. The concentrations of manganese and iron
were also determined in each step. The steps were intended to
remove the carbonate and exchangeable fraction, followed by the
easily reducible, moderately reducible, sulfide and organic, and
crystalline (silicate) fractions. Although the steps attack princi-
pally the mineralogic fractions described, they are not perfectly
selective, so the values determined cannot be taken as a strict
description of the behavior of these elements according to the
mineralogic fraction.
To further define the phases that hold the copper, samples
were separated into three parts using bromoform: the portion that
sinks (the "heavies "), the portion that remains suspended (the
65
"slimes "), and the portion that floats (the "lights "). The informal
terms "heavies ", "slimes ", and "lights" will be used in this paper
for clarity and efficiency. The heavies contain minerals that have
a specific gravity of greater than 2.90 (the specific gravity of
bromoform) -- typically amphiboles, pyroxenes, olivine, sulfides and
other heavy minerals. The slimes contain minerals that have spe-
cific gravities of about 2.90 and flocculant minerals such as clays.
The lights contain minerals that have specific gravities less than
2.90 such as feldspars, calcite and quartz. All three fractions
were pulverized to -200 mesh and analyzed using the five -step extract-
ion. Additionally a bulk sample was also analyzed, making a total
of four separates per stream sediment sample.
Owing to the length of the procedure, only ten stream sedi-
ment samples were analyzed in this manner. Four were selected from
the anomalous group of samples, three from a group considered
borderline anamalous, and three from samples representing the
background. For comparison, a sample running 300 ppm copper held as
chrysocolla was prepared and analyzed. Table 7 lists the samples
selected. All four samples from the anomalous group came from the
northwest anomaly, while samples AJ012S and AJ015S of the borderline
Table 7 -- Samples analyzed using five -step sequential analysis
Anomalous Group: AJ019S, AJ038S, AJ039S and AJ040S.
Borderline Group: AJ012S, AJ015S and AJ049S.
Background Group: AJ069S, AJ094S and AJ103S.
66
anomalous group came from the north -central anomaly. The results of
this sequential extraction are given in Appendix IIIb, and they are
graphically displayed in Figure 24.
In general, the heavies have the highest concentrations of all
elements of interest in all mineralogic fractions, while the lights
have the lowest concentrations. Because the lights comprise the
bulk of the samples (always greater than 87% by weight), the bulk
analyses reflect those of the lights.
The Distribution of Iron and Manganese. More specifically,
both iron and manganese concentrate in the silicate fraction of the
heavies, slimes and lights. In fact, the heavies contain up to 29%
iron in this fraction. The other mineralogic fractions contain
less iron and manganese by several orders of magnitude. Of the
other fractions, the moderately reducible, and the sulfide and organic
fractions contain most of the rest of the iron, whereas the manganese
content does not vary significantly. In both the moderately reducible,
and the sulfide and organic fractions, the heavies and slimes contain
the most iron. The concentrations of manganese and iron vary inde-
pendently of the concentration of copper, although the sulfide and
organic fraction of the anomalous samples does contain more iron
than that of the borderline and background samples.
The greatest variation between samples, density separates
and mineralogic fractions occurs in the concentration of copper.
The anomalous samples contain significantly more copper in all
mineralogic fractions for heavies, slimes and lights. The heavies
and slimes contain more copper than the lights.
PPM1000 --
700
0CHYSOCOLLA
500
300
BH S L
AJ019S
B H S L O H S L
AJ03BS AJ039SANOMALOUS SAMPLES
200
100
O
200
100
0
ñB H S L
AJ012SB H S L B H S L
AJO15S AJ049S
BORDERLINE SAMPLES
ii:i%
v, j.=°' ..:_ T.! 7:77.
BH S L
AJ069SB H S L B H S l
AJ094S AJ103S
BACKGROUND SAMPLES
SYMBOL
®Iilil
8 H S L
AJ04OS
FRACTION
CRYSTALLINE
SULFIDE AND ORGANIC
MODERATELY REDUCIBLE
EASILY REDUCIBLE
CARBONATE ANDEXCHANGEABLE
B BULK
H HEAVIES
S SLIMES
L LIGHTS
67
Figure 24 -- Distribution of copper among mineralogic and densityfractions of selected stream sediments, Batamote Mountains,
Arizona
68
The Distribution of Copper in the Crystalline Fraction. Of
the five fractions analyzed, the least variation occurs in the crys-
talline fraction. Although the heavies and slimes do contain more
copper in this fraction, the difference is small compared to the
variations seen in other fractions. Additionally, the concentrations
of iron and manganese in this fraction do not vary significantly
relative to total copper content. This indicates that the crystalline
fraction represents a background value; copper in other fractions
determine whether a sample is anomalous or not.
The Distribution of Copper in the Carbonate and Exchangeable
Fraction. The carbonate and exchangeable fraction shows large
variation between anomalous and background, and between heavies,
slimes and lights. Anomalous samples have a 10 to 20 times enrich-
ment over the background in this fraction. Moreover, the heavies
show a two to four times enrichment over the lights and a lesser
enrichment over the slimes. However, the percentage of total copper
accounted for by this fraction increases significantly from background
to anomalous samples; the percentage does not increase as markedly
for the slimes and heavies. This implies that the lights are
affected the most by this mineralogic fraction.
The Distribution of Copper in the Easily Reducible Fraction.
On the other hand, although the anomalous samples have higher concen-
trations in the easily reducible fraction, the concentrations do not
vary significantly between heavies, slimes and lights. The nature of
the extraction and the low variation between the density separates
suggest that this fraction occurs ubiquitously through the sample,
69
probably as coatings on grains. The relatively low contribution of
this fraction to total copper and its ubiquitous nature indicate
that it is a quaternary affect of tertiary dispersion in the stream
sediment- -i.e., it is a product of higher order dispersion of the
copper introduced into stream sediment by secondary processes.
The Distribution of Copper in the Moderately Reducible, and
Sulfide and Organic Fractions. The moderately reducible, and sulfide
and organic fractions show the greatest variability between heavies,
slimes and lights, and between anomalous and background. Both
fractions have higher copper concentrations in the anomalous samples
and in the heavies and slimes. The sulfide and organic fraction,
by far, has the largest contribution of copper in the heavies and
slimes, implying that it controls the distribution of copper within
these two density separates. The distribution of the moderately
reducible fraction in the heavies and lights mimics this pattern.
However, in the lights the easily reducible and moderately reducible
fractions control the distribution of non -silicate copper. In com-
parison, the sulfide and organic fraction contributes relatively
little copper to the lights. This distribution is prevalent in the
anomalous and borderline samples; in background samples, the moder-
ately reducible, and sulfide and organic fractions contribute little
copper in comparison to the crystalline fraction.
Summary. To summarize, the crystalline fraction represents
a regional background concentration of copper. The anomalous values
stem from concentrations of copper in the carbonate and exchangeable,
easily reducible, moderately reducible, and sulfide and organic
69
probably as coatings on grains. The relatively low contribution of
this fraction to total copper and its ubiquitous nature indicate
that it is a quaternary affect of tertiary dispersion in the stream
sediment- -i.e., it is a product of higher order dispersion of the
copper introduced into stream sediment by secondary processes.
The Distribution of Copper in the Moderately Reducible, and
Sulfide and Organic Fractions. The moderately reducible, and sulfide
and organic fractions show the greatest variability between heavies,
slimes and lights, and between anomalous and background. Both
fractions have higher copper concentrations in the anomalous samples
and in the heavies and slimes. The sulfide and organic fraction,
by far, has the largest contribution of copper in the heavies and
slimes, implying that it controls the distribution of copper within
these two density separates. The distribution of the moderately
reducible fraction in the heavies and lights mimics this pattern.
However, in the lights the easily reducible and moderately reducible
fractions control the distribution of non -silicate copper. In com-
parison, the sulfide and organic fraction contributes relatively
little copper to the lights. This distribution is prevalent in the
anomalous and borderline samples; in background samples, the moder-
ately reducible, and sulfide and organic fractions contribute little
copper in comparison to the crystalline fraction.
Summary. To summarize, the crystalline fraction represents
a regional background concentration of copper. The anomalous values
stem from concentrations of copper in the carbonate and exchangeable,
easily reducible, moderately reducible, and sulfide and organic
71
Follow -Up Phase
To check the distribution of copper in anomalous drainages,
samples were collected upstream of samples AJ003S and AJ039S.
Stream sediment samples with numbers greater than 140 are part of
this group. The samples were analyzed using semi- quantitative
emission spectroscopy (with higher detection limits, however), the
nitric acid leach, the oxalic acid leach, and the potassium perchlor-
ate- hydrochloric acid leach. These results are given in Appendices
Ia and IIIa. All analyses illustrate the same observation:
anomalous concentrations of copper do not change significantly up
drainage. Figures 25 and 26 depict this point using the results of
the oxalic acid leach.
The lack of significant variation upstream from anomalous
samples implies that the input of anomalous copper occurs through-
out the drainage area of anomalous sample sites. This argues against
input from a single structure, or localized mineralization. Instead,
the copper came from a source that does not change in intensity over
a wide area.
Summary of the Information Derived From Stream Sediments
Analysis of stream sediments yielded two anomalous areas
characterized by high concentrations of copper, bismuth and silver.
The presence of anomalous values on both sides of the Batamote
Mountains and the presence of significant copper in coarse sediment
indicate that airborne smelter contamination is unlikely.
Tba
142(1.28)
143(1.47)'Tba..3$(2.27) ` f
.
P>././
\ K137(1.40 --/ Qa
2000 FEETSCALE: 1:24,000
/
N
72
Figure 25-- Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstream ofsample AJ003S (concentrations in parentheses)
¡- iL-N
4:,10(t71) )1.l
4391
\\(2.56)11
148(j.38) 1499 Iba/.(1.85)
154(2.39);50(2.50) ,rTba ( 15301
i
.1
Iba \ --`" .QaN 42(1.65)
2000 FEETSCALE: 1:24,000
N
73
Figure 26-- Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstream ofsample AJ039S (concentrations in parentheses)
74
Most of the anomalous copper is held in a reducible form
(probably iron or manganese oxides), although significant copper
does occur in a oxidizable form in the heavies and slimes (probably
organics, but possibly sulfides). The source of the anomalous
copper occurs ubiquitously throughout the anomalous areas because
copper does not change concentration upstream. Although the north-
western anomaly does have a spatial association with northerly
trending normal faults, the source of the copper cannot be traced
solely to these structures because of the ubiquitous nature of the
anomaly.
INTERPRETATIONS FROM HEAVY MINERAL CONCENTRATES
During the main phase of sample collection, heavy mineral
concentrates were collected at each sample site for a total of 78
samples. Replicate samples were collected at four sites to confirm
anomalies shown in the main phase of sample collection. After
preparation, the non -magnetic heavy mineral fraction was analyzed
using semi -quantitative emission spectroscopy, and its mineralogy
was examined visually. Sulfide grains were extracted from the sam-
ples and analyzed for copper with a microprobe. Finally, the C -1
and C -2 (magnetic) fractions were analyzed for copper using the
nitric acid extraction. The methods used, results, and interpreta-
tions of this part of the study are discussed in this chapter.
Field Methods
As with stream sediments, samples were composited along a
100 foot reach of the drainage and passed through a 5 mm sieve in
the field. Between 1500 and 3500 g (usually 2000 to 3000 g) of
sample were collected. As no water was present in the field area,
samples were taken elsewhere and panned to remove the bulk of the
light minerals (e.g. feldspar and caliche). For efficient panning,
fines were removed from the sample by kneading and washing. Samples
were panned down so their dry weight was between 50 and 200 g. The
samples were then taken to the laboratory for further preparation.
75
76
Sample Preparation
The panned samples were sieved through a 30 mesh screen;
the +30 mesh material was discarded. Heavy minerals were then
separated using bromoform (s.g. = 2.90). The lights were discarded.
The heavies were split into three magnetic fractions with a hand
magnet and a Frantz Isodynamic Magnetic Separator (front slope =
5 °; side slope = 10 °). Table 8 gives the setting and typical
mineralogy of each fraction. The minerals listed in the "C -3"
fraction include all the minerals observed during the study.
Table 8 -- Magnetic fractions and representative mineralogy
Fraction Range (amps)
C-1 <0.2
C-2 0.2 - 0.6
C -3 <0.6
Mineralogy
Magnetite and ilmenite
Pyroxenes, amphiboles, olivineand iron oxides
Sphene, zircon, apatite, pyrite,chalcopyrite, covellite, arsen-opyrite, galena, barite, cerus-site, wulfenite ( ?), cassiter-
ite, copper carbonates, lead shot,caliche fragments, rock frag-ments and pyroxene
The presence of caliche fragments and pyroxenes in the C -3
(non- magnetic) fraction indicates that the process is not 100%
efficient. The presence of lead shot points out one other signifi-
cant problem with this kind of a study: contamination due to cultural
activities.
Of the three fractions the C -1 and C -2 fractions had the
greatest mass. Masses of the C -1 fraction ranged from 0.61 to 31.88
g, while those of the C -2 fraction ranged from 0.53 to 12.40 g.
77
The C -3 fraction has the least mass; it ranged from 0.04 to 1.29 g.
Both the C -2 and C -3 fractions were split. One split from
each fraction was pulverized; the C -3 fraction was hand pulverized.
The C -1 fraction of ten samples was also pulverized.
Analysis of the C -1 and C -2 Fractions
The pulverized splits of the C -2 fraction, and the pulver-
ized C -1 fraction of ten samples were analyzed using hot nitric
acid. The results of the analysis are given in Appendix IIIc.
Figure 27 and Plate 11 depict the frequency and areal distributions,
respectively, for copper in the C -2 fraction.
As with the stream sediments, this sample medium shows a
bimodal distribution, implying possible background and anomalous
populations. The modes occur at 15 ppm and 50 ppm.
However, the areal distribution is slightly different. If
40 ppm or more is considered anomalous, the northwestern and north-cen-
tral anomalies merge into one continuous anomaly with rather erratic
highs. Moreover, anomalous values do not extend as far to the
east, and an anomaly in the south -central area appears. As with
other sample media, the values fade off to the southeast.
Of possible greater significance, the values reported for
this analysis range from 30 to 260 ppm in the C -1 fraction and 15
to 100 ppm in the C -2 fraction. As shown in the previous chapter,
the concentrations of copper using the same nitric acid extraction
in the heavies and the slimes separated directly out of stream
sediments (i.e. without washing away the fines) ran upwards to
VALUE
(PPM)
1- 10
11- 20
21- 30
31- 40
41- 50
51- 60
61- 70
71- 80
81- 90
91 -100
0
FREQUENCY10 15 20 25
78
Figure 27 -- Histogram showing the distribution of copper (extracted usinghot nitric acid) in the C -2 fraction of heavy mineral concen-trates
79
1000 ppm copper. Obviously, the values observed in the C -1 and C -2
fractions cannot explain the high values of the stream sediment
heavies. Therefore, the copper must occur in some other form--
in either the C -3 fraction or in the fines washed away during the
panning process. The lost fines are the better candidate for two
reasons. First, due to its relatively small mass contribution, the
C -3 fraction cannot produce the required copper (in fact, analyses
of this fraction indicate maximum concentrations of copper to be
300 ppm). Second, the slimes --which would have been washed away
during panning --also have high concentrations of copper. Therefore
the lost fines probably contain high concentrations of copper to
account for the copper in the heavy fraction of stream sediments.
Spectroscopic Analysis of the C -3 Fraction
The C -3 fractions of all 78 initial samples and four repli-
cate samples were analyzed for 31 elements using semi- quantitative
emission spectroscopy. Because different weights of sample were
used in the analysis, the detection limits are different. The
results of this analysis and the detection limits are presented in
Appendix Ic.
The four replicate samples were collected in order to confirm
anomalies found in the original 78 samples. Replicate sample pairs
are listed in Table 9. In all cases, the anomalies were confirmed;
however, the replicate values did fluctuate significantly from the
original values. One of the most severe problems with the type of
sample is the high variation of values in samples collected at the
80
Table 9-- Replicate heavy mineral concentrate sample pairs
AJ011C - AJ132C
AJ013C - AJ128C
AJ090C - AJ127C
AJ105C - AJ117C
same site. This is due both to the small size of the analytical
sample (5 mg) and to the small amount of sample actually realized
when preparation is finished. These problems should be considered
when reading this or other studies using the non -magnetic fraction
of heavy mineral concentrates as a sample medium. The distribution
of copper and other economic and economically -related elements are
discussed in the following section.
Copper
Both the frequency and areal distributions of copper in the
C -3 fraction of heavy mineral concentrates (see Figure 28 and Plate
12, respectively) differ from those in the whole stream sediment.
The correlation coefficient between these two sample media is only
0.4395 for copper. The frequency distribution for this medium is
unimodal, with the mode occurring at 70 ppm. Assuming the top 10%
of the values to be anomalous, the threshold is 200 ppm.
With this threshold, the anomalous values of copper occur
without any systematic order. However, if a cutoff of 150 ppm
were used (this includes 63% of the samples), the northwestern two -
thirds of the study area would be anomalous. This area would be
consistent with --but much larger than --the anomalous areas observed
with stream sediments.
This sample medium does not enhance the values observed in
stream sediments. The high values reported in both media are about
81
VALUE
(PPM) O
N(2)
L (2)
2
3
5
7
10
15
20
30
50
70
100
150
200
300
FREQUENCY5 10 15 35 40
JFigure 28 -- Histogram showing the distribution of copper in the non-
magnetic fraction (C -3) of heavy mineral concentrates
82
300 ppm. Therefore, the minerals in the C -3 fraction cannot be the
major cause of the anomalies observed in stream sediments. The
distribution observed is consistent with known anomalies, but it
does not enhance them in any way.
Other Elements
A totally unexpected result of this study is the discovery
of significant anomalous values for other interesting elements besides
copper in the non - magnetic fraction of heavy mineral concentrates.
Plate 13 shows the distribution of anomalous values (upper 10 to
15% of reported values) of silver, arsenic, barium, copper, molybden-
um, lead, antimony, tin and zinc. Figures 29 through 36 show the
frequency distributions of these elements (except copper).
The distribution of anomalous values is rather widespread
within the study area. To pick out possibly significant anomalies,
the clustering of anomalous values of elements with similar geochemi-
cal associations was used as the primary criterion. Based on this,
three anomalies were considered most significant.
The first anomaly, located in the northwest portion of the
study area, consists of a tight grouping of three samples with
anomalous values of molybdenum and tin. Of the three anomalies,
this one has the easiest explanation. The samples come from washes
that drain the Childs Latite in the area that alteration was ob-
served. The Childs Latite has also produced anomalous tin in other
parts of the Ajo 1° by 2° quadrangle (P.K. Theobald, personal commu-
nication, 1983).
VALUE FREQUENCY(PPM) 0 5 10 70
N(O.2)
L(O.2)
0.20.30. 50.7
1
1.52
3
57
10
15
2030
3
J
Figure 29 -- Histogram showing the distribution of silver in the non-magnetic fraction (C -3) of heavy mineral concentrates
t l
VALUE FREQUENCY
(PPM) 0 5 10 70 75
N(1OO)
L(1OO)
100150
200300500700
83
Figure 30-- Histogram showing the distribution of arsenic in the non-magnetic fraction (C -3) of heavy mineral concentrates
VALUE FREQUENCY(PPM) 0 5 10 15
N(50)
L(50)
50
70
100
150
200
300
500
700
1000
1500
2000
3000
5000
7000
10,000
.J
jFigure 31 -- Histogram showing the distribution of barium in the non-
magnetic fraction (C -3) of heavy mineral concentrates
VALUE FREQUENCY(PPM) 0 5 10 65 70
N(10)
L(10)
10
15
20
30
50
70
100
150
200
J
3
3
84
Figure 32 -- Histogram showing the distribution of molybdenum in the non-magnetic fraction (C -3) of heavy mineral concentrates
85
VALUE FREQUENCY(PPM) 0 5 10 15 20 25 30N(5)L ( 5)
5
7
10
15
2030
5070
100
150
200300500700
100015002000
3
I
I
Figure 33 -- Histogram showing the distribution of lead in the non -magiñetic fraction (C -3) of heavy mineral concentrates
VALUE FREQUENCY(PPM) 0 5 10 70 75
N(20) l=1L(20) J20305070
100 3
Figure 34 -- Histogram showing the distribution of antimony in the non-magnetic fraction (C -3) of heavy mineral concentrates
86
VALUE
(PPM)
N(10)
LOO)
10
15
20305070
100150
200300500700
1000
FREQUENCY0 5 10 15 20 25 30 35
J
J
J
JFigure 35 -- Histogram showing the distribution of tin in the non-
magnetic fraction (C -3) of heavy mineral concentrates
VALUE
(PPM)
N(100)
L(100)
100150
200300500
FREQUENCY
0 5 10 75 80
J
Figure 36-- Histogram showing the distribution of zinc in the non -magnetic fraction (C -3) of heavy mineral concentrates
87
The second anomaly, defined by a clustering of four sample
sites showing high values of the volatile elements arsenic and anti-
mony with lesser copper, molybdenum and tin, occurs in the north -
central part of the study area. Of the four sites, two were re-
sampled, confirming the anomaly. A contiguous sample also contained
grains of chalcopyrite and covellite (see next section) although only
70 ppm was reported in the analysis. No geologic expression of the
cause of the anomaly was observed by traversing the drainage. But
owing to colluvium on the walls of the canyons, any alteration pre-
sent could easily be missed. The anomaly deserves follow -up work
in the future.
The final anomaly, located towards the southeast, consists
of a group of six samples showing high values of silver, molybdenum
and arsenic. This anomaly is the most obscure because its cause
was not seen on the ground or during visual examination of the
samples (with the exception of one sample which contained arseno-
pyrite).
Apart from the three anomalies just described, other samples
could be considered anomalous. However, they are not discussed
because they do not meet the previously described criteria.
Mineralogy of the C -3 Fraction
To determine the sources of metals in the non -magnetic frac-
tion, the non -pulverized split of each sample was examined under
the binocular microscope to determine the minerals present. Ore
88
and related minerals are commonly preserved in stream sediments under
conditions of rapid erosion.
This fraction contains sphene, zircon and apatite as the
dominant minerals. Pyrite, chalcopyrite, covellite, arsenopyrite,
galena, barite, cerussite, wulfenite ( ?), cassiterite and malachite
occurred in one or more samples. Other significant materials ob-
served in the samples include lead shot, caliche fragments, rock
fragments and pyroxene. Plates 14 and 15 show the distribution of
economically significant and related minerals.
From these data, two generalizations can be made. First,
pyrite occurs throughout the study area. Its widespread occurrence
implies pyrite is probably a minor accessory mineral in the Batamote
Andesite.
Second, high values of lead, bismuth, antimony and tin should
not be trusted. In three samples, lead shot was observed, raising
the possibility of contamination in other samples. Bismuth, anti-
mony and tin are common alloys in shot. Solitary high lead values
should be regarded with suspicion.
Other minerals reflect the analytical values to greater and
lesser degrees. Arsenic occurs as arsenopyrite; lead occurs as
galena, lead shot, cerussite or wulfenite; copper occurs as chalco-
pyrite, malachite and covellite; and tin occurs as cassiterite.
The second anomaly, as described above, is caused by the
presence of arsenopyrite, chalcopyrite, malachite and covellite. In
the third anomaly, only one sample contained arsenopyrite. Other
scattered mineral occurrences were observed through the study area.
89
The Concentration of Copper in Pyrite Grains
Pyrite grains represent a possible source of copper within
the heavies and therefore the stream sediments. To test this hypoth-
esis, pyrite grains were extracted from seven samples and analyzed
for copper using a microprobe. During this analysis, other minerals
besides pyrite were found. Although the majority of the grains did
turn out to be pyrite, grains of rutile, chalcopyrite, arsenopyrite
and covellite were also analyzed. The results of this analysis are
given in Table 10. The galena grain was analyzed to determine its
identity.
Of the samples analyzed, two are considered anomalous (based
on copper values in stream sediments), two samples are considered
borderline anomalous and three samples are at background. Although
some pyrite grains in the anomalous samples did contain significant
copper (up to 3400 ppm), the average grain from the anomalous
samples did not contain significantly more copper than grains from
the background samples. Therefore, the copper held in pyrite cannot
explain the anomalous copper present in stream sediments.
Summary
The distribution of copper in the C -3 fraction of heavy
mineral concentrates reflects that in the stream sediments in a very
general way. The northwestern anomaly shows up when the threshold
is 150 ppm; however, at this threshold 63% of the samples would be
considered anomalous. More importantly, the anomaly is not enhanced
90
Table 10-- Concentrations of copper in pyrite grains from selected heavy
Sample
mineral concentrate samples
Grain Concentration (percent)Cu Fe S As Pb Total Mineral
AJ029C 1 0.000 47.833 53.973 -- 101.806 PY2 0.010 47.358 53.912 -- 101.279 PY3 0.023 47.921 53.967 101.911 py
4 0.071 48.136 54.030 102.236 PY5 0.000 47.934 53.854 101.789 PY6 0.014 47,753 54.256 102.024 PY7 0.113 48.093 54.214 -- 102.240 PY
0.049. 47.917 54.181 -r- -- 102.146
0.091 47.433 53.962 -- 101.486
8 0.040 47.591 54.197 -- 101.827 PY9 0.029 47.715 54.012 - 101.757 PY
AJ037C 1 0.000 47.499 51.940 99.389 1Y2 0.002 47.568 52.596. -- 10-0.166 PY3 0.141 46.634 51.643 -- 98.419 PY
0.341 46.588 53.688 100.617
0.072 46.322 52.654 99.058
4 0.002 47.619 53.949 101.571 py
AJ056C 1 -- - ru
2 30.689 30.774 34.837 96.300 cp
3 64.709 0.038 27.654 92.401 cv
4 ' 0.00.0 47.814 53.65.1 101.465 py
AJ069C 1 0.003 46.558 53.003 . 99.563 py
2 0.035 47.327 53.188 100.549 py
3 0.023 47.191 53.7.11 -- 100.9.26 py
4 0.007 48.057 53.927 -- 101.991 py
AJ076C 1 0.006 47.980 54.020 -- 102.005 py
2 0.000 35.592 22.82.1 40.938 99.351 as
3 0.013 35.744 23.001 40.971 99.778 as
4 0.000 35.240 20.775 40.934 -- 96.949 as
5 0.006 35.367 22.533 40.909. 98.815 as
AJ077C 1 0.011 46.751 53.557 100.319 py
2 0.001 47.412 53.562 100.975 py
3 0.000 47.077 54.078 10.1.155 py
4 0.026 47.210 53.879 10.1.166 py
AJ091C 1 -- -11.177 -- 83.870 95.047 gn
2 0.000 46.289 54.018 100.307 py
3 0.000 47.892 53.832 -- 10.1.724 py
91
relative to stream sediments in this fraction, implying that this
fraction is not the primary source of copper in the anomalous areas.
The low values of copper in the C -1 and C -2 fractions preclude
them from being a significant source of anomalous copper. This
suggests that the bulk of the copper present in the heavy fraction
of stream sediments could occur in fines that were washed away during
the panning process. The high copper values in the slime fraction
of the stream sediments supports this assertion.
Copper is not held to a significant degree in pyrite, which
implies the copper held in a reduced form probably occurs as organics.
Since the slimes would be expected to contain organics in preference
to sulfide, the high concentrations of oxidizable copper (along with
relatively low concentrations of reduced iron) in the slimes support
this hypothesis.
The most intriguing results of this part of the study are the
presence of high concentrations of volatile and base metals in
certain parts of the study area. Of the three anomalies defined by
heavy mineral concentrates, only one has a ready explanation.
OTHER RESULTS
As a test of the hypothesis that the anomaly could be caused
by dispersion from material within or related to the normal faults,
samples containing oxide coatings along fractures or broken zones
within the Batamote Andesite were collected in both anomalous and
background areas. Three samples (AJ136R, AJ152R and AJ155R)
were collected in areas considered to be anomalous, and six samples
(AJ162R through AJ167R) were collected in areas considered to be
background (see Plate 2 for locations). The oxide coatings were
removed using a hot oxalic acid leach and analyzed using semi -
quantitative emission spectroscopy. The results are tabulated in
Appendix Id.
Because the anomaly of interest is comprised of high values
of copper, silver and bismuth, this discussion will concentrate on
these three elements. Of these, copper and bismuth showed a signifi-
cant enrichment in the samples collected the anomalous area. Copper
is enriched by factors ranging between 6 and 20, and bismuth is en-
riched by factors between 20 and 50. This indicates that these
coatings are possible sources of bismuth and copper in anomalous
stream sediments.
However, silver is concentrated in the samples from non -
anomalous areas by factors up to 15. But the highest concentrations
of silver also come from a drainage area that has high silver in
92
93
heavy mineral concentrates --part of the third anomaly discussed in
the previous chapter.
Other elements that show some enrichment in the samples from
anamalous areas include arsenic, beryllium, antimony and tin.
Therefore the enrichment of these elements -- espically copper
and bismuth --lends credence to the hypothesis that the anomalous
copper values were derived from dispersion from normal faults and
fractures within the northwestern part of the study area.
On sample AJ136R, oxides as "limonite" extend into the rock
for up to one cm. The silicate minerals within this zone were not
altered to a greater extent than in the rest of the rock. However,
calcite was observed in the zone in addition to the oxides. The
lack of alteration of silicates in this zone indicates that the
,waters that deposited the copper and bismuth in this crack were
relatively cool.
SUMMARY OF DATA PRESENTED,EVALUATION OF WORKING HYPOTHESES, AND CONCLUSIONS
The distribution of trace elements (principally copper,
silver and bismuth) in stream sediments and rocks of the Batamote
Mountains was examined in this study to determine the cause of
anomalous values of copper reported in earlier studies.
The Batamote Andesite has a copper concentration of around
30 ppm, which is relatively low for rocks of similar compositions.
The values of copper have a very tight distribution, implying that
copper has a homogeneous distribution throughout the unit. The
Batamote Andesite is the predominant bedrock in the study area,
so its copper concentration must control background copper concen-
trations in stream sediments from washes draining the mountains.
Analysis of stream sediments defined two anomalous areas
within the Batamote Mountains, which are characterized by the suite of
copper, bismuth and silver. The most significant anomaly, located in
the northwestern part of the study area, has a distinct spatial asso-
ciation with a series of northerly trending normal faults. The
second anomaly, located in the north -central part of the study area,
has no obvious lithologic or structural control. In several of the
chemical extractions, a definite trough separated the two anomalous
areas; however, in other extractions and sample media, the two
anomalous areas merged together, suggesting that they might be
part of one larger anomaly. Since copper values do not vary
94
95
significantly upstream of anomalous sample sites, the input of
anomalous material comes from throughout the drainage basin; there-
fore, anomalies cannot be traced to a localized source.
Detailed sequential extractions imply that the copper in
anomalous samples is held dominantly in a reducible state although sig-
nificant copper is held in an organic or sulfide state in the heavies
and slimes of stream sediments. Values of copper in all fractions of
heavy mineral concentrates cannot account for the values observed
in the heavies and slimes of stream sediments. Since fines are lost
during the panning process, this material could contain the missing
copper. In fact, the high values for slimes support this hypothesis,
as they would tend to be washed away during panning.
Analysis of pyrite grains extracted from the non -magnetic
fraction of heavy mineral concentrates demonstrates that coarser
grained sulfide cannot account for the copper anomalies observed
in any sample medium.
Analysis for other elements in the non - magnetic fraction
of heavy mineral concentrates produced three other anomalies not
related to the stream sediment anomalies. One anomaly, character-
ized by tin (cassiterite) and molybdenum, occurs in an area where
extensive alteration was observed in the Childs Latite. The other
two anomalies, characterized by arsenic and antimony, and silver,
molybdenum and arsenic, respectively, remained unexplained. No
alteration, other than the presence of chalcedony and zeolites, was
observed in these two areas.
Finally, analysis of oxide coatings from fractures in both
96
anomalous and non -anomalous areas (as determined from stream sedi-
ments) show that oxide coatings in anomalous areas contain signif i-
cantly more bismuth and copper than those in non -anomalous areas.
Evaluation of Working Hypotheses
In the introduction to this paper, five working hypotheses
were presented as possible explanations for the anomalies observed
by Barton and others (1982). In this section, each hypothesis is
reviewed in the light of the data generated by this study in order
to determine its relative merit.
Airborne Contamination from a Smelter in Ajo
This hypothesis calls upon wind blown smelter dust from Ajo
as the source of copper. This mechanism is unlikely because the
anomaly does not decay significantly downwind from the smelter
(anomalous values occur on both sides of the Batamote Mountains),
and the coarser fractions contain anomalous values of copper
(smelter dust is very fine grained). Therefore, this mechanism
probably did not cause the observed anomalies, although it cannot
be ruled out due to the immense amount of copper that went up the
stack of the Ajo smelter.
Abnormally High Background in the Batamote Andesíte
Another possible source of copper is the rock unit that the
washes drain. However, analysis of samples of the Batamote Andesíte
give a background value of around 30 ppm for copper. Since anomalous
values in stream sediments range upwards to 280 ppm, this mechanism
is impossible.
97
Primary Mineralization
Primary hydrothermal mineralization alone could not account for
the broad copper anomalies observed in the stream sediments. Yet, it
best explains the three anomalies observed in heavy mineral concen-
trates. The minerals that cause the anomalies include primary minerals.
But in two of the anomalies, evidence for primary mineralization
was not observed on the ground.
Dispersion Along Normal Faults
Most evidence presented in this paper suggests that the best
explanation for the anomalies observed in stream sediments is that
they were produced as the result of dispersion of metals from oxide
coatings in faults and joints in the northwestern part of the study area.
Two principal pieces of evidence point to this mechanism. First, the
anomalous values have a definite spatial association with the normal
faults. Second, analysis of oxide coatings from fractures in the anoma-
lous areas indicate that they have concentrated both copper and bismuth
relative to oxide coatings in fractures from non -anomalous areas.
On the other hand, the fact that entire drainages contribute
significantly to the anomalies implies that the actual faults were
not the only contributors to the anoalies. Mineralized fractures
and joints within the northwestern faulted block also probably
contributed significant metals.
The evidence presented to this point ties the source of
metals in stream sediments to oxide coatings in faults, joints and
fractures in the northwestern section of the study area. However,
98
a more basic and interesting problem remains to be solved: the
original source of metals in these structures. Clearly, the metal
in the faults, joints and fractures is the result of secondary or
even tertiary disperson from some other source.
Possible sources of the metals in the faults, joints and
fractures include: 1. Unusual weathering processes that somehow
concentrated metals from background andesite into weathering rinds
along openings in the rock; 2. A higher water table that allowed
groundwater to deposit the metals; 3. Solutions migrating from the
New Cornelia Deposit; and 4. An upper -level hydrothermal system in
the Batamote Andesite that deposited metals that were subsequently
concentrated into the oxide coatings. This should not be consid-
ered an exhaustive list, as many other mechanisms could be called
upon to deposit the metals; however it does include the most reasonable
(in the author's view) possibilities for a source of metal.
Weathering can and does produce oxide coatings that signifi-
cantly concentrate metals relative to their host rock. However,
oxide coatings from, the anomalous area contain significantly more
copper and bismuth than those from the background. Presumably,
weathering of the Batamote Andesite could not account for the great
differences in metal concentrations observed, and it could not
produce the observed distributions.
If a higher water table existed in the recent geologic past,
solutions enriched in metals leached from rock below could provide
the metals observed in the oxides. The original source of the metals
would have had to be relatively close, possibly directly below, the
99
observed anomaly. This would be a reasonable mechanism to produce
the metals in the faults, joints and fractures.
The third possibility, lateral migration of supergene
solutions from the New Cornelia orebody, is unlikely because of the
long distances involved (up to 10 miles), and because the observed
metal assemblage in the stream sediments (Cu- Bi -Ag) differs from
that observed around the orebody (Cu- Mo -Pb) (P.K. Theobald, personal
communication, 1984). Therefore, this mechanism is considered
unlikely.
The fourth alternative in which the primary metals were
deposited by the distal portion of a hydrothermal system and then
weathered and deposited into oxide coatings in faults and joints, is
considered the best possibility for several reasons. First, although no
extensive hydrothermal alteration is present in the Batamote Andesite,
evidence for hydrothermal circulation does exist. Chalcedony fills
joints and fractures throughout the unit, and a "limonite" multi -
spectral imaging anomaly exists around the intrusive plug. It is
not unreasonable that a hydrothermal cell developed during or shortly
after the volcanism that produced the Batamote Andesite.
Second, the anomalies observed in the heavy mineral concen-
trates are best explained as the results of hydrothermal activity.
The arsenic- antimony anomaly observed in the north -central
section of the study area would be best explained as the result
of primary low temperature hydrothermal circulation. The scattered
base metal anomalies could also be produced by hydrothermal activ-
ity. Therefore, a distal hydrothermal system could provide the
100
necessary metal as sulfide, which in turn could be weathered and
redeposited into faults, fractures and joints as oxides.
It should be remembered that the above discussion is only
speculation about the source of the metals in the faults --none of
the hypotheses presented could be confirmed by this type of a
study. They should be regarded as working hypotheses for future
investigations. Based on the data presented, the only conclusion
that can be made is that the observed anomalies are best explained
as dispersion into stream sediments from metals tied up with
faults, fractures and joints in the northwestern section of the
study area.
Contamination of the Batamote Andesite During its Eruption
The mechanism involving contamination of the Batamote An-
desite before or during its eruption is also unlikely. The back-
ground values for the Batamote Andesíte are too low to allow total
assimilation of the contaminant to be a cause. Additionally, the
copper values show no zonation relative to the central vent from
which the unit was extruded as might be expected from contamination
without assimilation. Therefore this mechanism is considered
unlikely.
Conclusions
At least two processes were involved in the production of the
observed anomalies: primary mineralization and dispersion along
normal faults. The anomalies observed in the non -magnetic fraction
of heavy mineral concentrates are best explained as a result of
101
primary mineralization. The minerals observed in this fraction
include primary sulfides of copper, lead and arsenic. These minerals
usually occur in hydrothermal environments.
The copper- bismuth -silver anomalies observed in stream
sediments are best explained as the result of higher order dispersion
from metal held as oxide coatings along fractures and joints.
The original source of the metals that were deposited in the oxide coat-
ings still remains unresolved. Viable possibilities include ground-
water solution and deposition and distal hydrothermal activity in
the Batamote Andesíte. Assuredly, these are not the only possibil-
ities, but they can serve as models for further exploration in the
area. Given the location of the study area within the porphyry
copper belt of southwestern North America and the requisite size of
the original copper source to produce such a widespread anomaly, the
potential for a porphyry copper deposit buried in the subsurface
below the Batamote Andesite as the original source of metals exists.
This potential is enhanced by the presence of a magnetic dipole coin-
cident with the copper- bismuth -silver anomaly presented in this paper
(Klein, )982). Additionally, the anomaly lies along the Jemez lineament,
upon which the New Cornelia and Casa Grande West porphyry copper depo-
sits lie. Therefore a potential for porphyry copper mineralization
exists below the Batamote Mountains.
APPENDIX Ia
ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSION SPECTROSCOPY)
FOR ROCK CHIP SAMPLES, BATAMOTE MOUNTAINS, ARIZONA
102
., zzzzz zzzzzc.
ti)zzzzz zzzzz
o00000000inO00 inN N H
M r u1 111O0 O co O O
N N N N u1
N u1 in MH H d
1.r) in tf'1 tfl .-t
.,
a)
ca.
x x x xVO CTO O O N N0000066666
00000000000 0 in 0 U1
U1 111 tn M M
00000
cf1 +-- Cf1 N
H
U'1 u1 u1 U1
zzzzz
Z 4Z ZZ
000000 0 0 0 0u1 u1 cnH .-1 H H
u'1 M Cf1 M NO 0 0 O
OO
U1 U1 u1 N N-+ - H 0
.--i H 111 N U1
O
U1 N in M 121O
v rocu a) a) a) a) u w a)+ 4-1 .0 ,.y .0 ü .0 u., 4-1ri U rl r1 ri rl ri ra O riU) U Ce U) U) U) U) CA ü U)a) a) a) v y a) a) a) a)d -1:1 b ub0 .0 0
cOd
0m ro
U r.1
CO
ro 4-1 a-+ r-1 r--1 .N rI ] 4.Jr-4 U ri r-I O ^.3 r-i r-1
Cro) O U) CA U) rei r± Ui -1 CID
cd p cd ct1 cr) to ro U) cdPa pa txl a) p Pa
rlr1
CD
t7
x x x x xO r1co 0.d . u1 u10 0 0 06 6 6 6 6
xcaxxN r+ -+ M ,DD r. N. CO0000066666
zzzzz
zzzzz
000000 0 0 0tf1 0 ^ O NH
u1 N N u1 MOO O 0 0
N Lt1
N ti u'1 NO -+ O
r, N N u1 r`O
103
zzzzz
zzzzz
0 0 0 0 00 0 0 0 0r` U'1 tf'1 O
C1 u1 C1 tt1 inO d
O - 0 0O O
N N r-+ tl'1 inO *- ,-1
M N N 11 NG O
U1 0, U1 u1 11
C.
° Gü r{ro.4.4 .r1 O .r{ .1-'1 r{ ,a U r1 .r1U) +-1 1.1 U) 4.4 1.+ U) U U) U)Cl.) ct! U) a) cd ro a) a) a) a)
G4.-4 4-4 GG c 7:).
ro u ro cd u u a1 it ror-Í U) r! r! U.
i-i +-1 U 4)-1 4-1 ).4 ri U UCO ri U rl ri r-! CK 1.1 ri rirti }-I rd 1J í4 i.d rI ri 14 4-J
U .0 U) CO ,.0 .-O U ro ro ror1 a. Cd Cl) ß. G. ri r-1 Cl) U;
CO i-, r-i Cd }-+ 3-i U) CG Cda) O u z o o a) "a Pa Aa> Pa
GPa Pa > Ñ
Cd rlU r-ir-{ r-iO ri> bC
e
x x 6 x xin co orO'r0Or 0 0 0 *-iO -4 H66666
xxxxxH N M
.--{H H H6666
104
.. CD 4 4 4 z 4 4 4,4 4 4 4 4 0 4 4 4 4 4 0 0 4 0 4 4N N N N NCL
z 4 z z z z Z Z z z z z z z z Z Z Z Q Z z z Z Z zo E .-.
. o o 0 0 0 O O O C O 0 0 0 0 0 O o 0 0 o C O o 0 0C1 E u, C O O N r- it1 n ul r- O u1 n r- O O n r, c O n un N r- n
ß. .-o .-i -o --rP.
.. Oo00ir1 O O O O O O u, -oinO OcunO 4 0 400M un ul M N N M u1 N ul ,o N N ct1 M M N
U CLCL
0 0 ul 0 2i 0 0 0 0 0 O O O Zun O Z O O Z z o z O ocf1 01 N M 01 ul O^a N N N N N u1 un un N
U O. ,-4 .-i
i-. O O O C Z C O O O O O O O Z C 0 4 4 0 Z Z O Z O Oo E N r1 N cV N N N M N-+ fV -- M N M CA CVC..) a
CL
ZzzZZ ZzzzZ ZzZZZ zzzzz zzZZzb EC.) a.,a
oa
..
CL.
ER.a._,
,.E
CL
.
Eß+a
zzzzz
oo un un u1 Zoo --i oo
O O o O OO O O O OO O O
,-a
0 0 0 0 0N N Noo un
zzzzz
un -+ un ,--r N
o 0 0 o OO O O O Oul r- en M u1
O O O O ON N N N N
zzzzz
N ul u1 n ul.
0 0 0 0 0O O O cn Or- u-) n n
O O O c 0N N ul N
zzzzz zzzzz
..,
. zzzzz ZzzzZ zzzzz zzzzz zzzzz-4 p.a
w xxxxx o4xo4 wrx x<4oaxx o4x<4Foz o4xxrxxr i 7 O\ ,so qD r, Co O 7 '-+ r1 vO in Co On 01 O .-o N M 7 unG. O O O N N 7 7 7 ul ul qD r, n r, oo O O O'--1 r-+ -+ .-+ --rE 0 0 0 0 0 O O O_ O O O O O O O O-+ -+
< 6 4 < 4 < < 4 <4 6 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4 <4
Appendix Ta -- continued
Sample
Ni
(PPm)
Pb
(PPm)
Sb
(PPm)
Sc
(PPm)
Sn
(PPm)
Sr
(PPm)
V
(PPm)
W
(PPm)
Y
(PPm)
Zn
(PPm)
Zr
(PPm)
Th
(PPm)
AJOO4R
50
20
N10
N500
100
N10
L70
N
AJOO6R
50
30
N20
N500
100
N50
L300
N
AJOO9R
20
30
N15
N500
70
N50
L200
N
AJ025R
15
20
N15
N500
70
N50
L200
N
AJ026R
NL
NN
N200
LN
NN
30
N
AJ046R
30
15
N20
N500
100
N50
L200
N
AJ047R
20
15
N20
N500
70
N50
L200
N
AJ048R
30
20
N20
N500
100
N50
500
200
N
AJO5OR
70
10
N20
N500
100
N20
L100
N
AJ054R
10
20
N10
N500
70
N30
L200
N
AJ062R
20
30
N20
N500
100
N50
200
300
N
AJ071A
10
20
N10
N500
50
N20
L150
N
AJ071B
30
20
N20
N500
100
N30
L200
N
AJ073R
N30
NN
NN
NN
20
N50
N
AJ086R
20
30
N20
N500
100
N50
L200
N
AJ095R
50
20
N20
N500
100
N50
1000
200
N
AJ108R
N20
N5
N300
50
N20
L200
N
AJ109A
15
30
N5
N2000
50
N20
N100
N
AJ109B
50
20
N20
N500
100
N50
L200
N
AJ11OR
N20
NN
NL
NN
30
N100
N
AJ111R
N20
NN
NN
NN
30
N70
N
AJ112R
70
10
N20
N500
100
N30
L50
N
AJ113R
N10
NN
NN
NN
30
N50
N
AJ114R
50
10
N15
N500
100
N30
L200
N
AJ115R
30
10
N15
N500
100
N30
L150
Nó ui
Appendix Ia-- continued
Sample
Description
Fe
(%)
Mg
Ca
Ti
Mn
(PPm)
Ag
iPPm)
As
OPm)
AJ116R
Latite
21
1.5
0.3
700
NN
AJ118R
Basaltic andesite
31
1.5
0.3
1000
NN
AJ119R
Intrusive andesite
31.5
1.5
0.3
1000
NN
AJ12OR
Basaltic andesite
31.5
1.5
0.5
1000
NN
AJ121R
Intrusive andesite
52
20.5
1500
NN
AJ122R
Intrusive andesite
32
20.2
1000
NN
AJ123R
Vesicular andesite
52
20.3
1000
NN
AJ124R
Basaltic andesite
51
1.5
0.5
1000
NN
AJ125R
Basaltic andesite
31
1.5
0.5
1000
NN
AJ126R
Vesicular andesite
31
20.5
1000
NN
AJ129R
Hydrothermally breccíated andesite
21
1.5
0.3
1000
NN
AJ13OR
Chalcedony
0.2
0.02
0.1
0.03
300
NN
AJ131R
Basaltic andesite
51
1.5
0.3
1000
NN
AJ133R
Vesicular andesite
51
1.5
0.5
1000
NN
AJ134R
Basaltic andesite
51,5
1.5
0.5
1000
NN
AJ135R
Basaltic andesite
51
1.5
0.5
1000
NN
AJ137A
Caliche
0.5
120
0.05
200
NN
AJ137B
Basaltic andesite
31
1.5
0.5
1000
NN
AJ137C
Caliche
0.3
120
0.05
100
NN
AJ137D
Caliche
0.3
120
0.05
100
NN
AJ138R
Basaltic andesite
21
1.5
0.3
1000
1N
AJ139R
Vesicular andesite
71.5
20.5
1000
NN
AJ14OR
Vesicular andesite
51
20.5
2000
NN
AJ144R
Basaltic andesite
51
1.5
0.5
1000
NN
AJ146R
Vesicular andesite
31.5
1.5
0.3
1000
5N
1-, o rn
107
r- zaaaz zaaaa .4Z1-4 aa azazZ .4a.4Ñaz áa
z Z z z z z Z z z z z z z ZZ z Z-+ z z z z z z z ZO á
C4..,
0 0 0 0 o O o o O O O o 0 0 0 o O O O O 0 0 0 0 0R1 E u1 u1unO1.01 u1u10rrO r,N O O O ONONN 0, 000r-a a rl 1-1
r`0000 00000 un,.aoo0 COOr,O 00 000N 01 M t, 01 cYi CYf N M N c+l 01 N N C'1 M c'') N NU
.. zoo 00 000oo OZO00 0001-4Z OOOOLnE N N N O O O *-4 4--1CV ,4 CJ CJ N Cr) NNr !a CV
...
00000 000u10 O Zirlul0 o Zu1Z z ul0 0u1u1O e ,- .-i N N un N c+1 N N N N --i ,4 cV CV -- r-!U aa...
"ti EZZZZZ ZZZZZ ZZZZZ ZZZZZ zzZZz
U
aa a..,
vw
cQ EPa a
-.E
Z z Z Z Z
u, u1 a.
0 0 0 0 000000CY1 u1 u1 u1 c1
00000CV 0,1 N
Z Z Z z Z
ra u1 i.n irl-; -
0 0 0 0 000000N 01 u1 u-1 t.
o0ooun.. N.-+ 4--+
z z Z Z Z
r+ Z u> irl u1
0 0 0 0 000000ul -+ u1 u1 r
00000C"1 cV -+ N N
Z z Z Z Z
u, Z u1 Z Z
0 0 0 0 0O u100 0u1 -+ u1 N r+
0,..ao.4oN N '--i
Z Z z Z Z
r+ u1 u1 u, r+- -
0 0 0 0 0CD CD 000r` O r t\ O
--+
00000N N N C1 N
Z Z Z Z Z Z Z Z z Z Z Z Z Z Z Z Z Z z Z Z Z Z Z Zá
N C4 P~ A4 P4 M Pa P4 P4 P; ß: P: P.', 04 P' P; P4 <C PI C U Q P; P4 P4 ß+ P4r-1 q D CO CT O r-+ N C1 t u1 q O CT O--+ ce) ,T ul r, r` r` 0, 00 on O-43 OCL - .-+ 4-4 N N N N N N N N M 01 on 01 01 01 C*1 CY} CM on c¡l -d- ,fE .. .. .. .-. .-a .. ,. .-4 .. .-r ...I --.1 .. .4.4 .. F.-1 F-i 1--1 1-1 ,-1
1-.1 1-1 c 6¢
Appendix Ia -- continued
Sample
Ni
(PPm)
Pb
(PPm)
Sb
(PPm)
Sc
(PPm)
Sn
(PPm)
Sr
(PPm)
V
(PPm)
W
(PPm)
Y
(PPm)
Zn
(PPm)
Zr
(PPm)
Th
(PPm)
AJ116R
20
10
N5
N500
50
N10
L150
N
AJ118R
20
10
N10
N500
70
N20
200
150
N
AJ119R
20
10
N15
N500
70
N30
200
150
N
AJ12OR
20
20
N15
N500
70
N50
200
200
N
AJ121R
100
10
N20
N500
100
N20
L50
N
AJ122R
70
10
N20
N500
100
N20
L50
N
AJ123R
70
10
N20
N500
100
N20
L70
N
AJ124R
20
20
N10
N500
70
N30
L200
N
AJ125R
15
20
N10
N500
70
N30
200
200
N
AJ126R
15
20
N15
N500
70
N30
200
200
N
AJ129R
10
20
N7
N500
50
N20
L150
N
AJ13OR
NL
NN
N100
20
NN
N10
N
AJ131R
15
20
N15
N500
70
N30
L200
N
AJ133R
10
20
N15
N500
100
N30
L200
N
AJ134R
15
20
N15
N500
100
N30
200
200
N
AJ135R
20
20
N15
N500
70
N20
200
300
N
AJ137A
510
NN
N500
LN
30
L20
N
AJ137B
20
15
N10
N500
70
N30
200
300
N
AJ137C
L10
NN
N500
NN
LN
20
N
AJ137D
LL
NN
N200
LN
LN
20
N
AJ138R
15
10
N10
N500
50
N20
L200
N
AJ139R
20
20
N20
N500
100
N50
N300
N
AJ14OR
20
20
N15
N500
100
N30
L200
N
AJ144R
20
20
N15
N500
100
N30
L200
N
AJ146R
15
20
N10
N500
70
N20
L200
Nf,- o oo
Appendix Ia-- continued
Sample
Description
Fe
(%)
Mg
Ca
(%)
Ti
CZ)
Mn
íPPm)
Ag
(PPm)
As
(PPm)
AJ147R
Vesicular andesite
31
1.5
0.3
1000
LN
AJ151R
Vesicular andesite
51
20.5
1000
NN
AJ156R
Basaltic andesite
51
1.5
0.5
1000
NN
AJ157R
Vesicular andesite
31
1.5
0.5
1000
NN
AJ159R
Basaltic andesite
31
1.5
0.3
1000
1N
AJ160A
Basaltic andesite
51
1.5
0.5
1000
NN
AJ160B
Caliche
0.5
0.7
20
0.05
200
NN
AJ161R
Vesicular andesite
51.5
20.3
2000
1.5
N
Appendix Ia -- continued
Sample
Au
BBa
Be
Bi
Cd
Co
Cr
Cu
La
Mo
Nb
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
iPPm)
(PPm)
Wm)
iPPm)
(PPm)
(PPm)
AJ147R
N20
700
1N
N15
20
20
70
NL
AJ151R
N20
700
1.5
NN
20
50
30
100
NL
AJ156R
N10
700
1.5
NN
20
70
15
100
NL
AJ157R
N20
700
1.5
N20
30
20
100
NL
AJ159R
N10
700
1.5
NN
20
30
30
70
NL
AJ160A
N20
700
1.5
NN
30
50
30
100
NL
AJ160B
N10
300
NN
NN
10
15
20
NN
AJ161R
N20
700
1.5
NN
30
70
30
50
NL
Appendix Ia -- continued
Sample
Ni
Pb
Sb
Sc
Sn
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPn)
AJ147R
15
10
N10
N500
70
N20
L200
NAJ151R
20
20
N15
N500
100
N30
L200
NAJ156R
20
20
N15
N500
100
N30
L200
NAJ157R
20
20
N15
N500
70
N30
L200
NAJ159R
20
20
N15
N500
70
N30
L200
N
AJ160A
50
20
N15
N500
100
N50
L300
NAJ160B
510
NN
N300
LN
LN
30
NAJ161R
50
20
N20
N500
100
N50
N200
N
L = Detected at levels below the detection limit
N = Not detected at lower detection limit
Lower detection limits:
Element
Lower
Detection
Limit
Fe
MgCa
Ti
Mn
Ag
AsAu
B Ba
0.05 %
0.02 %
0.05 %
0.002 %
10 ppm
0.1 ppm
200 ppm
10 ppm
10 ppm
20 ppm
Element
Lower
Detection
Limit
Be
Bi
Cd
Co
Cr
Cu
La
Mo
Nb
Ni
1 ppm
10 ppm
20 ppm
5 ppm
10 ppm
5 ppm
20 ppm
5 ppm
20 ppm
5 ppm
Element
Lower
Detection
Limit
Pb
10 ppm
Sb
100 ppm
Sc
5 ppm
Sn
10 ppm
Sr
100 ppm
V10 ppm
W50 ppm
Y10 ppm
Zn
200 ppm
Zr
10 ppm
Element
Lower
Detection
Limit
Th
100 ppm
APPENDIX Ib
ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSION SPECTROSCOPY)
FOR STREAM SEDIMENTS, BATAMOTE MOUNTAINS, ARIZONA
112
Appendix Ib -- Analytical Results (Using Semi -Quantitative Emission Spectroscopy) for Stream Sediments,
Sample
Batamote Mountains, Arizona
Fe
Mg
Ca
Ti
(%)
(%)
(%)
(%)
Mn
(PPm)
Ag
(PPm)
As
(PPm)
Au
(PPm)
B
(PPm)
Ba
(PPm)
Be
(PPm)
Bi
(PPm)
AJ001S
31
1.5
0.5
500
LN
N50
700
1.5
N
AJ002S
51.5
21
1000
LN
N50
700
1.5
N
AJ003S
31.5
20.5
700
LN
N100
700
1.5
L
AJ005S
31
1.5
0.5
700
LN
N70
700
1.5
L
AJ007S
51.5
20.5
500
0.2
NN
70
700
1N
AJ008S
31
1.5
0.5
500
LN
N70
700
1.5
2
AJOlOS
31
20.5
500
LN
N70
700
1.5
2
AJ011S
21
20.5
500
LN
N70
700
1L
AJ012S
31
20.5
500
LN
N70
700
1L
AJ013S
31
20.5
500
LN
N100
700
1.5
L
AJ014S
31
20.5
700
LN
N100
700
1.5
L
AJ015S
21.5
20.5
700
LN
N70
700
1L
AJ016S
21
20.5
700
LN
N70
700
1L
AJ017S
21
20.5
500
LN
N50
700
1L
AJ018S
31
20.5
500
LN
N70
700
1L
AJ019S
51.5
20.5
500
0.1
NN
70
700
1L
AJO2OS
31
20.5
700
LN
N50
700
1L
AJ021S
31
20.5
500
0.7
NN
70
700
12
AJ022S
31
20.5
500
0.5
NN
70
700
1L
AJ023S
31.5
20.5
500
0.2
NN
70
700
12
AJ024S
31.5
20.5
500
0.1
NN
70
700
1L
AJ027S
31.5
20.5
500
0.1
NN
50
700
1L
AJ028S
31.5
20.5
500
0.1
NN
50
700
1L
AJ029S
51
20.5
1000
0.1
NN
50
1000
1L
AJO30S
51.5
20.5
1000
0.1
NN
50
1000
1L
114
OOOZZ zzzzz ZZZZZ zzOLrlLri ZZZZZLn N -+ N
0 Lr1 0 0 Lll 00000 O Lrl O O O Ln Ln 0 0 111 Ln Ln Lf 0 Ln,--i -I .-1 rd 1-1 4-1 1-1 .-I 14-1
Z Z Z Z Z Z Z Z Z Z z z z z z z z z z z Z Z Z Z Z
00000 0 0 0 0 0 00000 O O O O O 00000Lr'1 Lrl Ill Ln h Ln h Ln h Ln Ln Ln h Ln h h h h Lrl h h h h h h
O Ln Ln Lr11--1 .-i 11 '-1 Ln Lr1 Ln O O Lrl Ill 0 Ln O Ln 00000 0 0 0 0 0
.-a '-d .-+ -1 -I N--I N N N N N N N N N N
aaaaa aaaaa aaaa aaaaa aaaaa
zzzzLn ZZZZZ zzzzz Lnzzzz zzzzz
O O O O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0tf'1 Lrl Ln Ln h Ln O h h h h h i11 h h h h h h h h h h 1 / l
00000Ln O Lrl Li-1 0
00000M h Ln h h
OLrIOOL.n.-i 1--1 reel
00000Ln vl 0 LnN v-1 .-1
00000 O O O O O 000000001/10 00000 000a-)0N N C''1 N Cn
00000 0 0 0 0 0 00000 O O O O Oh h Ln Ln h h h u'1 Ln h h h h h h h h h h h
in 0 0 0 O O Ln Ln Ln Lr1 Lr1 Lr'1 Ln Ln Lnrl -I e--1 rM 1-4 .-i 1 If) Ln «l O Ln'-1 1-1 1--1 N r-1
Z Z Z Z Z Z Z Z Z Z z z z z z Z Z Z Z Z z z z z z
C/D C/D C/l Cll Vl C/D C/l CO cil VI Cr) CO Cn Cr: CIl C/l CO CO cl] CO CO C/D C1]N M Lrl h 00 O - N Lrl kO h 7O O 0-1 N M .t h CO 0\ OO 00 po 0r-4'--1 r-1 r-1 .-1 .--1 .-1 r-1 ..-1 .-1 N N N N N N N N M00000 0 0 0 0 0 00000 O O 0 O O 000006 1-) 1.7 1-.1
Appendix Ib -- continued
Sample
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ001S
500
100
N20
L100
N
AJ002S
500
150
N30
L200
N
AJ003S
500
100
N30
I.
300
N
AJ005S
500
100
N30
L200
N
AJ007S
500
100
N30
L300
N
AJ008S
500
100
N30
L300
N
AJOlOS
500
100
N30
L200
N
AJ011S
500
100
N50
L200
N
AJ012S
500
100
N30
L200
N
AJ013S
500
100
N30
L300
N
AJ014S
500
100
N30
L300
N
AJ015S
500
100
N30
I.
200
N
AJ016S
500
100
N30
L200
N
AJ017S
500
100
N30
L200
N
AJ018S
500
100
N30
L200
N
AJ019S
500
100
N30
L200
N
AJO2OS
500
100
N30
L500
N
AJ021S
500
100
N30
L500
N
AJ022S
500
100
N30
L200
N
AJ023S
500
100
N50
L500
N
AJ024S
500
100
N50
L500
N
AJ027S
500
100
N30
L500
N
AJ028S
500
100
N30
I.
500
N
AJ029S
700
100
N30
I_,
300
N
AJO3OS
700
100
N30
L300
N
116116
u1 u1 un u'1 u"1 r, u'1 un un u1 u1 u1 u'1 C'7 u'1 u1 u'1 u'1 u1 M un u'1 ui u1 unW
d) U) U) U1 C/] U] U) C7 U1 U) U1 U] U] C!] U) UJ V) co U) Cn U] U] CID U] U]Ni C1 N. 00 0T O '-+ Ni Cl 1.0) N 01 Ln ,O r` CO CT O
01 M M M C1 C'l M on C1 .1- ,T ,t ,7 7 u1 ul in u1 u1 ul i.n u1 D .O O O O O O O O O O O O O O O 0 0 0 0 0 O O O O O6
1-4 a CV N N N N N N a 1--1 a r Z,rl GFA a.
.-A .- -- .-1 . .-+ .- . r. .i ..- r-, .- ,-1 tnW E
c 0 0 0 0 00000 O O c O o 0 0 0 0 0 0 0 0 0 00000o coocO o0000 00000 00000aa a 0000O c000O OOOrO oOOOO O r. 0,Oa -r ..
..+ o O o O O O Ó 0 0 0 O 0 O o O o O o O O o O O O OPO E Ln Ln Ln Ln in Ln un h r` r` un un un u1 un u1 un Ln un un ^ un u1 r, uî
a.._,
-. Z ZZ Z Z z ZZ z Z ZZ z z z z z Z Z Z Z Z Z Z Z
E¢ a.
zzZZZ zzzzz ZzzzZ ZzZZZ zzzZZ
.. ,4 CA aar- aa N ,4 -4 aaaaa azzzz6 á. óó ó ó
O O o O O O O O o o C O 0 0 0 c O O o O 0 0 0 0 0E O O O O O O O O O O 0 0 0^ O O O O O O O O O O OZ 00 0 ulnr,r.r. r,r- OhO r,0 r, r- r.r,r,r.r..
u1 u1 un u'1 u"1 r, u'1 un un u1 u1 u1 u'1 C'7 u'1 u1 u'1 u'1 u1 M un u'1 ui u1 unW
d) U) U) U1 C/] U] U) C7 U1 U) U1 U] U] C!] U) UJ V) co U) Cn U] U] CID U] U]Ni C1 N. 00 0T O '-+ Ni Cl 1.0) N 01 Ln ,O r` CO CT O
01 M M M C1 C'l M on C1 .1- ,T ,t ,7 7 u1 ul in u1 u1 ul i.n u1 D .O O O O O O O O O O O O O O O 0 0 0 0 0 O O O O O6
. .Z\ li .1 . r 1-4 ti .-r r-r . i ,- ;-i 1.-1 + .- 11 ,+ ,-
117
.. z z z z z z z z z z z z z z z z z z z z z z z z zO Een a
a
un un u1 un u1 un u1 un u1 0 u1 0 o u1 ul u1 ul ul u1 o u1 u1 u1 u1 unu E ,-, .-1 .--i .-i -1 .-t .-i .-1 -1 --i -1 -1 --1 -1 .-4 .-+ ,-.1 .-i ..-i -1 .--1 -1m aa"
. - - , Z Z Z Z Z z z z z z Z Z Z Z Z Z Z Z Z Z z z z z z-0Emaa
....
-. O O O O O 0 0 0 0 0 O O O O O O O O O O O O O O O,I1 N. O r\ ul r, N. r. r r` r` N. N. O M u'1 M r r- r.- O r. r` r` r, f\Fo. a ^4 M Na
..,
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0rl E M M M N M M N M M M M N CV un n r, r, r, un un r, N N N Nz aP.
g.a44444 44444 44444 4 a,-404 4 ra a4 4a
...
z z z z z z z z z z z z z z z z z z z z Z Z Z Z ZO F.
...
00000 00000 00000 00000 00000cu E u1 r. r. o o O o o r, o 0 0 o u1 r. N. r, r, r, r, r, r, o u, Lt)4 a . - -, -1 - -, -a .
CL
O O O O O O O O O O O O O O O O O O O O 0 0 0 0 0e 0 0 0 r, 0 r 0 0 0 0 O (il r, r, O r- 0 o u1 r, O O r` O r,C) a N ,-i .-, N M N 1-1 .--i
CL
O O O O O O O O O O O O O O O O O O O O O O O O Orrrunr, un r- r, r, r.ulr-ul0 OOO Cr- un u1r,r\r.U N u1 on N .u1 OOOO
COO
C)
O ul 1/1 ul u1 u1 u1 ul ul O O O O ul ul O ul u1 O ONi N N N ,-1 r- N N
z z z z z z z z z z z z z z z Z Z Z Z Z Z Z Z Z Z
(11 Cn vo vo vo vo Cn Cn vo co Cn C/) Cf1 Cn C/1 Cn CID vo Cn Cil pl C!1 Cn CI1 Cn DOr I N M.t ul qD r. C O 01 O N M.t ul CT N M u1 .D r` co Cr) OCL MMCIMM MMMM T ,t,1 ,f ,tulu1u1u1 ulinulul.OO O O O O 0 0 0 0 0 0 0 0 0 0 O 0 0 0 0 O O O O Oc<4
Appendix Ib -- continued
Sample
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPn)
(PPm)
(PPm)
(PPm)
AJ031S
700
100
N30
L300
NAJ032S
700
100
N50
L200
NAJ033S
700
100
N50
L500
NAJ034S
1000
100
N30
L200
NAJ035S
700
100
N30
L300
N
AJ036S
1000
150
N30
L200
NAJ037S
700
100
N30
50
200
NAJ038S
700
100
N50
L200
NAJ039S
700
150
N50
L200
NAJO4OS
700
100
N50
L200
N
AJ041S
700
100
N50
L200
NAJ042S
700
100
N30
L300
NAJ043S
700
150
N30
70
200
NAJ044S
700
100
N30
L200
NAJ045S
700
150
N30
L200
N
AJ049S
700
150
N30
L200
NAJ051S
700
150
N30
L300
NAJ052S
700
100
N50
L300
NAJ053S
700
100
N30
L300
NAJ055S
1000
100
N20
L200
N
AJ056S
1000
100
N30
L200
NAJ057S
700
100
N50
L200
NAJ058S
700
100
N50
L200
NAJ059S
1000
100
N50
L300
NAJO6OS
700
100
N50
L300
N
119
.1 z a z z z aaazz ZZ z z z z z z z z zzazzGa
Lr) tn tn .-r N N Ill N itl -4 N. r`yE . .Pc) 1--1 0 0 0 O
...
00000 O c 0 0 0 00000 0 0 c 0 0 00000ro E 00000 0 0 0 0 0 00000 O c 0 0 0 00000a? a OOCrO r,r`r\ r`r`r` rrc0 000N.0a -, - r.1...
,. 0 0000 0 0000 0 0000 OOOOO O0000pC1 Lrl Ln in Lr1 r` r\ tr1 Le-1 tn tn tn tn ul Lr'1 Lr1 CV (V Lt-1 un N. tn
ázzzzz zzzzz zzzzz zzzzz zzzzz
áz z zz z z z z z z z z z z z z z z z z z z z z z
z z z z z z z z z z z z z i-1 -i z< á ó ó ó
...
0 0 0 c c O o 0 0 0 0 0 0 0 0 O c O O o o c o o OE c c O o c 0 0 0 0 0 0 0 0 0 o c c o o c o o c c oa -
r` ti-) Li.) rv i.n r r. O Lc) tn-4 '--
r r` r` in r` v1 In r` N. r` r` nt r, r` N. r` N. r\71 ,. . . .H O0000 O0000 000 O 000 0 0 000
M N M M C*) M M CV M N In c'') tn M N c*1 M N N N N N N N N
N N N N N N N N N In N N N -I N to c"'1 CN tr1
\ .-r - .-i
t+'1 tr1 tn tn tr1 tn tn to in in N tn N r` N to If) is) to O r` r` ul to ur1QJ i.
N C!1 C/] L!) Cn C/) C/) rn C!1 C/] Cn G] C/] C/] C/) C/: C/] C/1 C/1 C/7 Cn C/] C/) Cnr I - M to .O N. DO Ch c N Lc) .O r` CO O1 O. N c*1 r CO O1a .o O O .O .D O n r- 00 00 CO 00 Co CO C)o CO CO00000 0 0 0 0 0 00000 O O O c 0 00000
f-- h P: h h r ?c! 6 6 < 6
r7¢ < 6 d 6 <4 < 6 6
120
Z Z Z Z Z Z Z Z Z Z ZZ z z z Z Z z Z Z Z Z Z Z Zgen .
CL.
.. u Ln Ln uÌ in O Ln Ln O L1-1 Ln L:1 ul L:1 Ln Ln Ln 0 0 0 u1 ul u,U E M M N ,-a --i --
C!)C-`
Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z.=C/0
0 0 0 0 0 0 0 0 0 0 O O C C Ln O O O O C O o o O O.fl E r` r` r` Q r` r` r` r` L!1 Ln Ln r` Mr- in ul M r` Ln N M O r` r`P-i a
O O O O O O C C O O O O Ln O u-) O o Ln O O 0 0 0 0 0ri E N N M N Ln N Ln Ln o M s-1 Ln -- Ln fn Ln .'-+ M r` r` r, C`'1 u, NZ -+
.-ID aZ a
Á
.,có Ea aa
e-sE
C..J a
}+ EU
a a a a a
z z z z z
p o 0 o OO r` r, C r,r -4
O C O 0 0r,Or,rr-
O O C O OOr`u,r`
a a a a a
z z z o z
p o O o Or, r, Ln r. r,
O O O O OOr`LnCDr,1--1
0 0 0 0 0r,LnOOO
a a a a a
Z Z z z z
O O O C OO r- r r- r,
0 0 0 0 LnLnoul Ln-+
O O C O OLnOr- ON
a a a a a
z z z z z
o O C o 0r- o r. O Ln,,- ,--
O 0 0 0 0Lnr1c*1Lnr`
0 0 0 0 0r,r`LnLnO
Ln
a a a a a
Z Z Z Z Z
0 0 0 0 0Ln r- r, r,
0 0 0 O Or`Cr`OO
C O 0 0 0OOr`r`OCr) Cr)
r O C O O O u1 O O O u, O O Li-) O a O C Ln 0 0 0 0 0 «1 OO E N N N N N .1 N N N -+ r 0 . 1 - I 0 . 1 N N Ln Ln Ln N CV
a
Z Z Z Z Z Z Z Z Z z z z z z z Z Z Z Z Z Z Z Z Z ZU
a
Cl) C/) Cr) Cr) Cr) U) CI) Cl) C!] CJ) C!) CID C/) CID C/) Cf) Cf) :n en Cr) Cr) Cn CID C!) Cr) Cl)ri ,--4 M d' u l S D r` 00 C A O N , t Ln V D r, 00 CT O'-+ N M ,t Ln r` 00 CNPL. Vo L.0 V0 V0 V0 .o Lo .o r r r., r- r- r, r, r, oo co 00 00 00 00 00 00 00E O O O O O o O O o O O O o p O o O O O c O O o 0 0
Appendix Ib -- continued
Sample
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ061S
1000
150
N50
I.
200
NAJ063S
700
100
N50
L200
NAJ064S
700
150
N50
L200
NAJ065S
700
100
N50
Lr
200
NAJ066S
700
150
N50
50
200
N
AJ067S
700
100
N50
L300
NAJ068S
700
100
N50
L300
NAJ069S
500
70
N30
L200
NAJO7OS
500
100
N30
L150
NAJ072S
500
70
N50
L150
N
AJ074S
500
70
N50
50
200
NAJ075S
700
100
N50
L200
NAJ076S
500
100
N50
50
200
NAJ077S
1000
100
N50
L200
NAJ078S
500
100
N50
L150
N
AJ079S
1000
100
N50
L200
NAJO8OS
700
100
N50
L200
NAJ081S
500
100
N50
L200
NAJ082S
1000
150
N50
50
300
NAJ083S
1000
150
N30
50
100
N
AJ084S
1000
150
N30
L100
NAJ085S
700
200
N50
L300
NAJ087S
700
100
N50
L300
NAJ088S
700
100
N30
L300
NAJ089S
700
100
N50
L300
N
122
zzzzz zzzzz zzZZZ zz..E O O O COCO OW e-IP .. .. .. ., , .. .. .. ..zzz zzzz z
ti ,r --iC
Pgl
P.
Ln Ln Ln Ln Lfl Ln u1 u1
.--i ..4 1-1 1-1 e--i
O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0c*J E 00000 00000 O O O O C O O O O O O O O O OGU CL OLnO O O Or\O O O 0000o O OLnulLfl u-) un un un u1
CL
O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 OE Lfi Ln Ln Lfi Ln Ln Ln u-) Ln Ln Ln Ln Ln Ln Ln ui u1 Ln Lf1 Ln ui Ln Ln Ln LnCLCL
6 aa
E
o) ei6 a
../
Z z z z z z z z ZZ z z z z z
zzzzz zzzzz zzzzz
zzzzz zzaaz zzzzz
.. o 0 0 0 0 0 0 0 0 0 O o 0 0 0E 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
N. U1 I, f` f\ C\ Ln r, ti t\ O 0w r, Co Lna, +
O 0 0 o O 0 0 0.. ... .. .. . .. ...zzz zzzzz
z z .. ,. .. ,. .. .. .. ..O 00 00000O O o O O O O ON N N N N N N
.,.zzz zzzzzLn Ln
tf1 ui Lfi Ln ,
ò 0 ó0o
z z z
0 0 0 0 00 0 0 0 0un u1 f, r, r,
0 0 0 0 0o c o 0 0t\ f` n t\ Ln
t\ .-+ f, r\ n n n t\ r` t\ n t\ N Lf) N N N N N M{ .-I .. . . . . . . . .H\ O 0 0 0 O O O O O O O O O O O O O O
O
O 01 M cn N N N N N N Ln N N N M N N N N N Ln N Ln Ln u1cd -U ,-I .-i ,-4 .-+
.--i N N ul N N,--i N N N N N N N Ln N N n n r\ Ln Ln un Ln N-O-'
O 0 0 oc 00 C
Ln O Lf1 Ln ul ul un u1 Ln ul Ut I- U1 Ln Ln Ln Ln M N N .-i M N N M
H
N En C/] a] u] ul V] U C/o C!7 En vo CI] vo C/] Cn C/o vo U] C/5 uIJ Cu] Cfi Cll Cn fnr-I O r+ N M7 ,O r` CO C r O N Mt ul ) . 0 n r-+ N M co O, O 01 ,i-CL a, C0 gr) c h 01 CN CN Cr, T o 0 0 0 0 0 O 0 - - -1 - u-) Ln u1E O O O C O O C_ O O, ,--I ,-+ r, .-a .-.i ,-i ,-- .-+ , .--. '-, .-
CO ; 6 6 2 r C , '1,262 : 2 ' -< , . 2 : 2 ', 2 ' <4.6
.. Z Z Z Z Z Z Z Z Z Z Z Z Z Z ZO E
cn a
123
Z Z .. ,-, ,. ,-, ,. .-N000 O O O O O... .. ../ .. `/ `/ .,.zzz zzzzz
U1 O U1 U1 U1 U1 U1 U1 in in U1 U1 U1 Ul U1 Ul v1 O O O O C O O Ori ri
cn
P4
rlZ
..
a
..a
,E
Z Z Z Z Z
00000r. r.
o000oN U1
z z z Z Z
O O O O Oh U) Ln r` N.
OoOOOr N V'1 r` N
Z Z z z z
00000N. r` r` r` U1
o0000Cr) M U1 U1 M
/\ ,1 r\000000.-e ... ..zzz
0 0 0 0 0u'1 ul U1 M M
00 LnoinM
/1 /-. .-.O O O C O00000.. . .. ... ...zzzzz00000N c'1 M M M
0000Ln
/ a a I-- F+ I--; ra I--1 ha aZ á
zzzzz zzzzz zzzzz zzzzz ZZZZZE
..,
.-Nro Ea a
..O EU p,a..,
$.+ EUQ.a
00000r` 0 0 r r.
COCCOO O U1 N . r`.- ,--i .-a
00000r` O O n r`r-a r-i
0 0 0 0 0N. r` N. r. N.
0 0 0 0 0r` r, r` O r`I-I
O O O O Or r\ O Or--.N N
00000N. N. N. N.
0 0 0 0 0in r- U1 O r1--I -4
00000N. N- r` O r`r-i
0 0 0 0 0N. N. N- i.n
0 0 0 0 0N-0 O r` r,1--1 r-i
0 0 o c Or\ r` U1 M U1
00000Ln Ln Ln
Q0000r` O O r, Or-1 -I r-1
00000M tf1 N U1 r`
..
. 0 0 0 0 0 O Ln O O t.l1 u'1 0 0 0 0 0 0 Oinin v1 O U1 Ln OO E N M M N N cr1 N-+ ,--I N N N N N NU
Z Z Z Z Z Z Z Z Z Z z Z z,7. zEb ó o o ó ó ó ó.. zzz zzzzz
N Cln Ul Cn CID Cn Cn Cn G] CID C/) Cn Cn V] Cn Cn Cn Cf) C!] Cf) Cf) cn up Cn CI: Cn.-I O--, N M1' .O r. OJ 0 O --I N re) .1' u-1 O n.-; N M OC) O, O M-.7CL Ol O1 O) O a, Cr, O\ O", CT O O O O O O O O 7 7 T -..1' .....t u1 in tnE 00000 O O O O r1 ,-a r-+ ,-.1 r-r .--i r-a r1 r-+ r-{ .-i r-, r-r ,--i 1--1.-1
cñ < 6 < < d < < < < < 6 < 6 < < < d < ¢ < < <
Appendix Ib -- continued
Sample
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJO9OS
700
100
N30
L200
NAJ091S
1000
100
N50
L300
NAJ092S
700
150
N30
50
300
NAJ093S
700
100
N30
L200
NAJ094S
700
150
N30
L300
N
AJ096S
1000
150
N30
L300
NAJ097S
500
100
N30
L300
NAJ098S
500
150
N30
L200
NAJ099S
700
150
N30
L300
NAJ100S
700
150
N30
L300
N
AJ101S
700
150
N30
L300
NAJ102S
700
150
N30
L200
NAJ103S
1000
100
N30
L300
NAJ104S
1000
150
N30
L200
NAJ105S
700
150
N30
L200
N
AJ106S
700
150
N50
L300
NAJ107S
700
150
N30
L300
NAJ141S
300
70
N(50)
15
L(200)
150
NAJ142S
300
70
N(50)
15
N(200)
150
NAJ143S
300
50
N(50)
15
L(200)
150
N
AJ148S
300
70
N(50)
15
N(200)
150
NAJ149S
300
70
N(50)
30
L(200)
200
NAJ150S
300
50
N(50)
20
L(200)
100
NAJ153S
300
50
N(50)
20
L(200)
150
NAJ154S
300
70
N(50)
20
N(200)
300
N
Appendix Ib -- continued
Sample
Fe
Mg
Ca
Ti
Mn
Ag
As
Au
BBa
Be
Bi
(%)
(%)
(%)
(%)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ158S
20.7
10.2
500
N(0.5)
N(200)
N(10)
50
500
1N(10)
Appendix Ib -- continued
Sample
Cd
Co
Cr
Cu
La
Mo
Nb
Ni
Pb
Sb
Sc
Sn
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ158S
N(20)
10
20
70
50
NL
10
20
N(100)
7N(10)
Appendix Ib -- continued
Sample
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPm)
(pptn)
(PPm)
(PPm)
AJ158S
300
50
N(50)
20
N(200)
150
N
L = Detected at levels below the detection limit
N = Not detected at lower detection limit
Lower detection limits
Element
Lower
Detection
Limit
(unless otherwise indicated):
Element
Lower
Element
Detection
Limit
Lower
Detection
Li
Element
Lower
Detection
Limit
Fe
0.05 %
Be
0.5 ppm
Pb
Th
100 ppm
Mg
0.02 Z
Bi
2 ppm
Sb
Ca
0.05 Z
Cd
5 ppm
Sc
5 ppm
Ti
0.002 Z
Co
5 ppm
Sn
5 ppm
Mn
10 ppm
Cr
10 ppm
Sr
100 ppm
Ag
0.1 ppm
Cu
1 ppm
V10 ppm
As
50 ppm
1.a
20 ppm
W100 ppm
Au
2 ppm
Mo
5 ppm
Y10 ppm
B10 ppm
Nb
20 ppm
Zn
50 ppm
Ba
20 ppm
Ni
5 ppm
Zr
10 ppm
APPENDIX Ic
ANALYTICAL RESUTLS (USING SEMI -QUANTITATIVE EMISSION SPECTROGRAPHY)
FOR THE C -3 FRACTION OF HEAVY MINERAL CONCENTRATES,
BATAMOTE MOUNTAINS, ARIZONA
128
129
Go.C)
Cd
wM
1
UN,C4J
)-1
Ow
,CL0uCl)
EPg G.
...
a) Eca
ÇS,v
i.Cd ECU aa
oa Ea.a.
zzzZZ
Z z Z1-4 z
00000O O O O Or, CV u1 ul Cn
O O O O OO O r. u1 O-a 4-1 -,
zzzZZ
Z Z Z Z Z
O O O O OO O O O Or` r 0 0 0-, N r,
O O O O Oul O O O r.-, -1 -4
zzzZZ
Z Z Z Z Z
00000O O O O OO r Lr1 r ul'--i .-r
O O O O OO u1 O r` r.r, r,
Zzzzz
Z Z Z Z Z
O 0 0 0 0O O O O Or- C1 M O ul.-1 ,,
O O O O Otl r- cln u,
zzz2z
z z z z z
00000O O O O ON O M N. O-, .-+
O O O O Ou1 O r` r--,
0+4-1 cd
U G Z Z Z z Z Z Z Z Z Z z z z z z z z Z z z z z z zÓ. Ñ 6 Ó.
GL
Go.,cc en 00004 Z Z Z OZ ZZZZZ Z ZZ Z Z Z Z ZZ Z
G á 0000 OE ro cL
Lr) Ln 01 01
w+G
N GOz
rd a)r-+ 4-1
r- O
á roMG cd
C" aa
rE ua) vcf) 4-1
GCD $.4
G+-)r-I Gcl)
) u
OmJJrl r-IG cd
Cn laa) a)
CG Gr-I
r!Cd
4-) ro
a)x
GO
.ood ß.
P.-..
G Eaa.
r1E-a \
(d i.U \
ZZZZZ
COCCOO O O O Or, r u l i.n tr1
i. ,-,N N N N NvC7 C7 C) C7 ü
O O O O N.I--I ri '-. r-I
N N N --i N
M M M M M
ZZZZZ
OOOOOO O O O OLr1 Cn rr1 r.
i.N N N N NuC.) C7 0 C7 C7
O O O O O.-i r-1 .-i .-- --
N N N N N
N M 01 M M
ZZZZZ
COCCOO O O O OCr1 r r, Cr1 r-
,-. r. r. ,-.N N N CV CV
C7 C7 C7 C_) C7
O O O O Or-I --i -- r-I .--
N N N N N
N 01 M M M
ZZZZZ
COCCOO O O O Oir1 un N. Lr1 M
,-, r-. i. r. ,-,N N N N N
).C7 C7 C7 C7 C7
O O O O O.-1 -1 r-1 ,-- --i
N N N N N
M M M M 01
ZZZZZ
OOOOOO O O O Ou r1 N. u i
i. i. .. .-. i.N N N CV N
C7 C7 CL CD C7
O O O O Or-1 ri r-1 .-i rI
N N N N
M M M N N[-
CJ `H
ri M M M M M M M M M M M M M M M M M M M M M M M M M^Cy a) CJ CJ CJ C.) U ü CJ 0 0 0J C7 CJ CJ U C) J CJ U C) U CJ CJ C) U C.7G N M.7 url ,O h- CO Oh O --r N 01 ,t r, CX) ON CO N 01 ,T r,a) p. N N N N N N N N M M M M M c+1 M MPL E O O O O O O O O O O O O O O O O O O O O O O O O OCL
6 1.-eZ
Appendix Ic-- continued
Sample
Cd
(ppm)
Co
(ppm)
Cr
(ppm)
Cu
(PPm)
La
(PPm)
Mo
(131m)
Nb
(PPm)
Ni
(PPm)
Pb
(PPm)
Sb
(PPm)
Sc
(PPm)
Sn
(PPm)
AJ011C3
NL
200
200
500
N100
L70
100
70
100
AJ012C3
NL
200
150
500
N100
L100
L50
150
AJ013C3
NL
200
150
500
N100
L70
L50
50
AJ014C3
NL
200
150
500
N100
L70
N30
50
AJ015C3
NL
100
100
500
N100
50
20
N20
30
AJ016C3
NL
200
150
500
N100
30
70
N30
50
AJ017C3
NL
150
150
500
N100
L50
N30
50
AJ018C3
NL
100
150
500
N100
L50
N30
50
AJ019C3
NL
150
150
500
N100
L200
N30
50
AJ020C3
NL
150
200
500
N100
L300
N30
70
AJ021C3
NL
200
150
500
N100
L100
N30
70
AJ022C3
NL
200
150
500
N100
L70
N30
70
AJ023C3
NL
150
200
500
N100
50
70
N30
70
AJ024C3
NL
100
150
500
N100
20
50
N30
50
AJ027C3
NL
200
150
500
N100
L50
N50
70
AJ028C3
NL
150
150
500
N100
L70
N30
50
AJ029C3
NL
150
150
500
N100
50
2000
N20
70
AJ030C3
NL
200
150
500
N100
L70
N30
100
AJ031C3
NL
150
200
500
N100
50
50
N20
50
AJ032C3
NL
150
150
500
N100
20
70
N20
50
AJ033C3
NL
200
150
500
N100
L50
N30
50
AJ034C3
NL
200
200
500
N100
L70
N30
70
AJ035C3
NL
200
150
500
N100
20
50
N30
70
AJ036C3
NL
200
150
500
N100
20
30
N30
30
AJ037C3
NL
200
200
500
N100
20
70
N30
50
w o
Appendix Ic -- continued
Sample
Sr
(PPm)
V
(PPm)
W
(PPm)
Y
(PPm)
Zn
Zr
(PPm)
(PPm)
Th
(PPm)
AJ011C3
300
200
N700
N G(2000)
NAJ012C3
300
200
N700
N G(2000)
L
AJ013C3
300
200
N500
N G(2000)
N
AJ014C3
300
200
N500
N.G(2000)
L
AJ015C3
300
200
N300
N G(2000)
N
AJ016C3
300
200
N500
N G(2000)
NAJ017C3
300
200
N500
N G(2000)
L
AJ018C3
700
200
N300
N G(2000)
N
AJOI9C3
700
200
N500
N G(2000)
N
AJ020C3
300
200
N500
N 0(2000)
L
AJ021C3
300
200
N500
N G(2000)
L
AJ022C3
500
200
N500
N G(2000)
L
AJ023C3
500
300
N500
N G(2000)
L
AJ024C3
500
200
N500
N G(2000)
N
AJ027C3
300
200
N500
N G(2000)
L
AJ028C3
300
200
N500
N 0(2000)
L
AJ029C3
300
200
N500
N 0(2000)
N
AJ030C3
300
200
N500
N 0(2000)
L
AJ031C3
300
200
N500
N G(2000)
N
AJ032C3
1000
200
N500
N G(2000)
N
AJ033C3
700
200
N500
N 0(2000)
N
AJ034C3
700
200
N500
N G(2000)
N
AJ035C3
700
200
N500
N 0(2000)
N
AJ036C3
500
200
N500
N 0(2000)
NAJ037C3
500
200
N500
N G(2000)
Nw
t!
-
132
r4a1
vaa
cuPa
PD
EC.a,
EwCL
EGLCL
a.GL
zzzzz
0 0 0 O 0oCOO oO O O u1 ON N r-e
O o 0 O CO h. O(, n-a ,
zzzzz
z z z z z
0 0 0 0 oOOOOOO(', I, 1/1 u1
O
O O O O Ou1 C n u1 ul
zzzzz
z z z z z
O O O 0 0CoCOOr, r` r. M u1
O O O 0 0111 t, u'f ul
zzzzz
z z z z z
0 0 0 0 0OOCCOO n O ul O
u1 .-a u1
O C C O OO O N h, ir1
zzzzz
z z z z z
o C O a oooOCc,r` u1 u1
--
0 0 C o 0N u"1 01 h, n
Z Z Z Z Z Z z z z z z z z z z Z Z Z Z Z z Z z z z< P1.
Z Z Z Z Z z z z z z z z z z z Z Z Z Z Z Z z z z Zz17
6 a....
zzzzz zzzzz zzzzz zzzzz zzzzzWE<4 a
...
O O o 0 0 0 O o O C O O O O C C O O o CE O O O O O o o O o o O O C o 0 C O C o 0
x a. 1, ,-, u1 u1 h, u1 u1 01 r, c1 M M u1 u1 u1 u1 111 u1 u1 u1
o 0 0 0 00 0 0 0 0u1 u1 u1 u1 Cl
.-. .. .-. .. ,-, .-. .. .-, ., .. .. .-. . .. ,-. ,-. ., .. ., .. .. ,. .. .-. ,-. ..H\ N N N N N N N N cV N N N N N N N N N N N N N N N N...i\..,u v \-,
C7 C7 C7 U U CD C" C.7 C7 CD C7 U C7 CJ C7 U U C7 C7 U CD U C.7 C.: C7
O O O O O O O O O O O O O O O O O O O C C u1 O O OcÒ r-t
C.) \
M Ci N N C1 N r*1 u1 C1 u1 N N u1 na N N N N N C1 N N N N u1On ..
C1 M M N Cl N N N 01 N M c*1 N N 01 01 M N C1 M 01 M N N N(1)
w \
c'1 cl M M M M M M M 01 r1 M M 01 M 01 M 01 c*1 M 01 01 C1 C1 01(I) U U U U U U U U U C.) C) U U U U U U U U U U U U U U
,--i o0 01 0--+ N 01 -4' ul 01 ,--1 N 01 u1 qa r, 00 01 O,--+ c+1 .t ul ,0 h, 00CL M 01 .t .t .t .T .t .t .t u1 In u1 In In u1 ul u1 AO AO AO AD AD AD AD AUa o o C 0 0 C C O O O O O 0 0 0 0 0 0 0 0 C O O 0 0c ¢
Appendix Ic -- continued
Sample
Cd
(PPm)
Co
(PPm)
Cr
(PPm)
Cu
(PPm)
La
(PPm)
Mo
(PPm)
Nb
(PPm)
Ni
(PPm)
Pb
(PPm)
Sb
(PPm)
Sc
(PPm)
Sn
(PPm)
AJ038C3
NL
200
300
500
N100
50
50
N50
50
AJ039C3
NL
200
150
500
L100
30
100
N30
50
AJ040C3
NL
200
50
500
N100
L70
N30
50
AJ041C3
NL
200
100
500
N100
L50
N30
30
AJ042C3
NL
200
100
500
N100
20
100
N50
30
AJ043C3
NL
200
100
500
N100
50
50
N20
30
AJ044C3
NL
500
70
500
N100
20
50
N30
20
AJ045C3
NL
100
150
500
N100
20
50
N20
30
AJ049C3
NI.
200
150
500
N100
20
50
N30
30
AJ051C3
NL
100
150
500
N100
20
50
N20
30
AJ052C3
NL
100
150
500
N100
10
100
N30
30
AJ053C3
NL
150
150
500
N100
50
30
N50
30
AJ055C3
NL
150
100
500
L100
50
50
N30
30
AJ056C3
NL
150
50
500
N100
50
50
N20
30
AJ057C3
NL
150
150
500
70
100
10
300
N50
50
AJ058C3
NL
200
150
500
N100
50
50
N50
150
AJ059C3
NL
150
150
500
N100
20
30
N30
70
AJ060C3
NL
150
150
500
N100
10
30
N30
20
AJ061C3
NL
200
150
500
N100
10
50
N30
30
AJ063C3
NL
200
200
500
N100
10
1000
N30
20
AJ064C3
NL
200
150
500
N100
10
100
N30
30
AJ065C3
NL
200
150
700
N100
20
50
N50
50
AJ066C3
NL
200
100
500
N100
L30
N30
50
AJ067C3
NL
200
150
500
N100
L200
N30
70
AJ068C3
NL
150
150
500
N150
L100
N30
50
134
. z azzz azzzz zzzzz zzzzz z zOa aEF 0,
,. .. .. .-. , . . .. . . .. ,, .. .-. ,1 .-. . -. .. .1. . ..1 .. .-. .-. .. ..ooOOC ooOCO 00000 COCCO 00000N a o O C o 0 o O o 0 o O O o C 0 coco 0 0 0 0 0 0C3 O C 0 0 0 co 0 0 0 0 0 0 0 0 0 0 0 0 0 00000..i N N N N N N N N N N N N N N Cl N N N N N N N N N Nv.. .. ..i .v`. .,,.
C7 V C7 C7 C7 C7 C7 C7 Cä C7 C C7 C J C,7 C7 C.7 C.:' C C7 C7 C-7 C7 O C7
EZ Z Z Z Z z z z z z Z z z z z Z Z Z Z Z z Z Z Z Z
N fS...
G.yOU
I
I
UH
r177GUp..
6
i.CL
E
CL
Ep.
..
+ EC/) P.
ß.
vr-i
O.E
co
O C O O OO O O O Ou1 u1 u1 u1 411
Z Z Z Z Z
c c c c cN Cl N N N
00000O O C O Cul O r, O
M M M M MU U CJ U U00 0h O,--1 NM M -Zr -Zr 7O o C C C
O O O O CO O O O Ou1 M M M M
z z z z z
c c c c cN N N N N
0 0 0 0 0C C O O OO Or, f\ n
M M M M MU U C.) CD UM -Zr u1 ON ,--i-Zr -Zr -Zr -Zr u1C O O O O6 6
O O O O CO C C O OM u1 01 M u1
Z z z z z
c c c c cN N N N N
00000O O O C OOr, n n u1
M M M M MCD U U U UN M ul `C nu1 u1 un u1 u1O O C O O6 6 d 6
O C O O OO O O O C
. M u1 ul u1 u1
Z Z Z Z Z
c c c c cN N N N N
O O O C OO C C O O1`, r- Cr, r,
M M M M MU U CJ U Uco Cr) O,--f Mu1 u1 JD JD gDO C O O O6 6 d
O O O O CO O O O Cu1 u1 u1 u1 ul
z z z z z
c CC c c cN N N N N
0 0000O C O O Ot\ un un (, N
M M M M MU U U U U-Zr Li-) ,D r, COJD D s.D gD ,DO C O O O6 6
Appendix Ic -- continued
Sample
Fe
Mg
Ca
Ti
Mn
Ag
As
Au
BBa
Be
Bi
(%)
(%)
(%)
(%)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ069C3
31
15
G(2)
1000
NN
N20
150
NN
AJ070C3
21
10
2200
NN
N50
500
NN
AJ072C3
31
10
C(2)
1000
NN
N70
150
NN
AJ074C3
33
10
G(2)
500
NN
N20
50
LN
AJ075C3
51.5
15
G(2)
300
N(0.5)
N(200)
N(10)
150
150
1N(10)
AJ076C3
21
10
G(2)
500
N700
N50
200
LN
AJ077C3
20.7
10
G(2)
300
NN
N30
100
LN
AJ078C3
20.7
10
G(2)
500
30
NN
50
1000
LN
AJ079C3
21
10
G(2)
300
2N
N50
200
LN
AJ080C3
20.7
10
G(2)
300
NN
N50
1000
LN
AJ081C3
31
10
G(2)
700
NN
N20
1000
LN
AJ082C3
10.7
15
1500
NN
N20
150
LN
AJ083C3
10
710
11000
NN
N20
700
LN
AJ085C3
52
10
2500
NN
N20
700
LN
AJ087C3
30.7
10
G(2)
300
NN
N20
700
LN
AJ089C3
30.7
10
G(2)
500
NN
N30
5000
LN
AJ090C3
20.7
10
G(2)
500
NN
N70
1500
LN
AJ091C3
21.5
10
G(2)
700
NN
N50
500
LN
AJ093C3
21.5
10
G(2)
700
NN
N50
700
LN
AJ094C3
32
10
G(2)
500
NN
N70
300
LN
AJ096C3
32
10
G(2)
500
NN
N50
300
LN
AJ098C3
31.5
7G(2)
500
NN
N50
500
LN
AJ100C3
32
10
G(2)
500
0.5
NN
100
1500
NN
AJ101C3
32
10
G(2)
500
NN
N50
500
LN
AJ102C3
35
10
G(2)
500
NN
N100
200
LN
Appendix Ic-- continued
Sample
Cd
(PPm)
Co
(PPm)
Cr
(PPm)
Cu
(PPm)
La
(PPm)
Mo
(PPm)
Nb
(PPm)
Ni
(PPm)
Pb
(PPm)
Sb
(PPm)
Sc
(PPm)
Sn
(PPm)
AJ069C3
NL
70
70
700
L100
10
70
N30
100
AJ070C3
NL
70
150
200
N200
L30
N20
NAJ072C3
NL
100
100
500
10
100
L70
N30
1000
AJ074C3
NL
200
30
506
N100
L50
N50
500
AJ075C3 N(100)
N(20)
200
150
700
N(20)
200
10
20
N(50)
50
70
AJ076C3
NL
50
50
500
N100
L150
N20
50
AJ077C3
NL
150
50
500
N150
L50
N20
30
AJ078C3
NL
150
30
700
L100
L50
N20
50
AJ079C3
NL
150
100
700
N100
L50
N20
50
AJ080C3
NL
100
100
700
N100
L50
N20
50
AJ081C3
NL
200
100
1000
N100
L50
N20
100
AJ082C3
NL
20
100
1000
N100
L20
NN
20
AJ083C3
NL
500
100
200
N100
100
10
N50
NAJ085C3
NL
150
150
500
N100
L30
N30
20
AJ087C3
NL
50
70
500
N100
L30
N20
50
AJ089C3
NL
100
150
500
N100
L300
N30
50
AJ090C3
NL
100
150
500
N100
L200
N20
30
AJ091C3
NL
200
300
500
100
100
L2000
N20
50
AJ093C3
NL
300
100
500
N100
L100
N20
50
AJ094C3
NL
200
70
500
N100
L30
N30
50
AJ096C3
NL
300
70
700
L100
L200
N20
50
AJ098C3
NL
150
100
500
N100
L30
N20
30
AJ100C3
NL
300
100
500
N100
L50
N30
50
AJ101C3
NL
300
150
500
L200
L30
N20
50
AJ102C3
NL
500
30
500
L150
L50
N30
50
w ch
137
zzzOr. zzzaz zzzzz zzzzo oazza. o 0 o 0E-I a, ' N O N ina ,n
z¡-s i. i. i. i. .. i. r. ..$.4 C o o O O O C O 0 0 C O C O O C O O C C o 0 0 0 0N O. O O O O O O O O O O 0 o C C 0 0 0 0 0 0 O C O O O
G. O C O o 0 O O C O 0 C o 0 0 0 O C O 0 0 0 0 0 0 0N N N N N N N N N N N N N N N N N N N N N N N N NC7 U C.7 C7 G 0 0 0.7 C7 U C7 C7 C7 C7 C7 C.7 U :7 C.7 U C: C7 C7 U C.7
z z ZZ Z Z z z z z z z z z z ZZ Z Z Z Z ZE ON C, CN
z0 0 0 0 0 O 0 o C o O o C o 0 0 0 0 0 o O O o 0 0E oOOCO OoOOO ooOOO 000OO OooOO
CL O M O M to 01 M M u1 to u1 ul . M u1 u1 in un u'1 u1 u") M ur1 u'1 u1C. -+
i. zzzzr, Z Z Z Z z Z Z Z Z Z Z Z Z Z Z Z Z Z Z ZE OCL Ca u1... .zr. o C o o C O C C O O o C o C o C o o O C C C C O OD> E CCOCC ululCO C OoOu10 OOOOC o000ON-- N N Cn N N N N-+ N N N N N N cg N N N N
C.`.
O O O O O O C O O C 0 0 0 0 0 O O O O O C C O 0 0>+ E O o O O c o 0 o O O o C O 0 0 O 0 o O o O C O O OCO p., M r, M N r` M N i11 M u'1 ul N u1 ur1 in r, u1 r, r, Grl un N ul u un
CL
M M M M M M M M M M M M M M M M M M M M M M M M Ma) U C.J U C) CJ C) U U CJ CJ C7 CJ U C) CJ C) CJ U C) U CJ C) U U C)
O1 O cg . t ul u ) r - c l ) C N M u1 n Q1 C M,.7 O CO CD .-i Nt3 O r\ r, r, r- r, n t\ r, co co 00 co 00 co co Oh Oh ch ch CT Ch O O C00000 00000 00000 00000 00.-+-+cif r, ro
<4 <4 <4 -4 <4 <4 -4 <4 <4 <4 <4
Appendix Ic -- continued
Sample
Fe
Mg
Ca
Ti
Mn
Ag
As
Au
BBa
Be
Bi
(X)
(X)
(%)
(X)
(PPm)
(PPn)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ103C3
33
10
G(2)
700
NN
N70
200
LN
AJ105C3
35
15
G(2)
700
NN
N50
700
LN
AJ107C3
35
15
G(2)
700
NN
N50
5000
LN
AJ117C3
52
30
G(2)
5000
N(1)
700
N(20)
200
700
520
AJ127C3
10
220
G(2)
5000
N(1)
700
N(20)
200
2000
5L(20)
AJ128C3
21
15
G(2)
2000
N(1)
L(500)
N(20)
200
2000
5N(20)
AJ132C3
31
15
G(2)
2000
N(1)
1000
N(20)
200
2000
5N(20)
Appendix Ic -- continued
Sam
ple
Cd
Co
Cr
Cu
La
Mo
Nb
Ni
PbSb
ScSn
(PPm
)(P
Pm)
(PPm
)(P
Pm)
(PPn
)(P
Pm)
(PPm
)(P
Pm)
(PPm
)(P
Pm)
(PPm
)(P
Pm)
AJ103C3
NL
500
50500
N150
L30
N30
50
AJ105C3
NL
500
200
500
200
100
20
700
N30
50AJ107C3
NI.
500
5050
0L
150
20
70
N30
100
AJ117C3
N(5
0)N
30
500
500
N10
0L
200
300
N50
AJ127C3
N(5
0)N
150
500
500
N10
0L
200
200
N50
AJ128C3
N(5
0)N
50300
500
N10
0L
150
200
N50
AJ132C3
N(5
0)N
70
200
500
N10
0L
150
200
N200
Appendix Ic -- continued
Sample
Sr
VW
YZn
Zr
Th
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
(PPm)
AJ103C3
300
200
N500
N G(2000)
L
AJ105C3
700
200
N500
500 G(2000)
N
AJ107C3
700
200
N500
N G(2000)
L
AJ117C3
1500
200
N(100)
500
N(500) G(2000)
N
AJ127C3
2000
200
N(100)
500
N(500) G(2000)
N
AJ128C3
2000
200
N(100)
700
N(500) G(2000)
N
AJ132C3
2000
100
N(100)
500
N(500) G(2000)
N
L = Detected at levels below the detection limit
N = Not detected at lower detection limit
G = Greater than value shown
Lower detection limits (unless otherwise indicated):
Element
Lower
Detection
Limit
Element
Lower
Detection
Limit
Element
Lower
Detection
Limit
Element
Lower
Detection
Limit
Fe
0.1 %
Be
1 ppm
Pb
5 ppm
Th
200 ppm
Mg
0.05 %
Bi
5 ppm
Sb
20 ppm
Ca
0.1 %
Cd
10 ppm
Sc
10 ppm
Ti
0.005 %
Co
10 ppm
Sn
10 ppm
Mn
20 ppm
Cr
10 ppm
Sr
200 ppm
Ag
0.2 ppm
Cu
2 ppm
V20 ppm
As
100 ppm
La
50 ppm
W200 ppm
Au
5 ppm
Mo
10 ppm
Y20 ppm
B Ba
20 ppm
50 ppm
Nb
Ni
50 ppm
10 ppm
ZnZr
100 ppm
20 ppm
}-, ó
APPENDIX Id
ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSION SPECTROGRAPHY)
FOR OXIDE COATINGS ALONG JOINTS AND FRACTURES, BATAMOTE MOUNTAINS, ARIZONA
141
Appendix Id-- Analytical Results (Using Semi -Ouantitative Emission Spectroscopy) for Oxide Coatings
Along Joints and Fractures, Batamote Mountains, Arizona
Sample
Fe
(1)
Mg
(%)
Ca
U.)
Ti
Mn
(70)
(PPm)
Ag
(pPm)
As
(PPm)
Au
(PPm)
B
(PPm)
Ba
(PPm)
Be
(PPm)
Bi
(PPm)
AJ136R
50
15
0.2 G(10,000)
2500
N(20)
500
5000
20
100
AJ152R
50
110
0.2 G(10,000)
1700
N(20)
100
1000
15
150
AJ155R
50
75
0.7 G(10,000)
1L(500)
N(20)
500
2000
15
100
AJ162R
75
20.1
5000
7N(200)
N(10)
100
700
25
AJ163R
10
23
0.2
G(5000)
7N(200)
N(10)
100
700
72
AJ164R
15
23
0.15
G(5000)
1N(200)
N(10)
100
2000
72
AJ165R
20
1.5
30.15
G(5000)
30
N(200)
N(10)
100
1500
77
AJ166R
15
1.5
20.2
G(5000)
2N(200)
N(10)
100
2000
75
AJ167R
51
0.5
0.02
1500
5N(200)
N(10)
100
150
23
Appendix Id-- continued
Sample
Cd
(PPm)
Co
(PPm)
Cr
(PPm)
Cu
(PPm)
La
(PPm)
Mo
(PPm)
Nb
(PPm)
Ni
(PPm)
Pb
(PPm)
Sb
(PPm)
Sc
(PPm)
Sn
(PPm)
AJ136R
N(50)
700
200
2000
200
50
L(50)
150
1500
1000
20
500
AJ152R
N(50)
500
50
2000
500
100
L(50)
100
1500
300
50
20
AJ155R
N(50)
500
150
3000
100
50
100
300
1000
200
20
100
AJ162R
10
200
150
500
50
70
20
500
700
20
5N(10)
AJ163R
10
70
100
200
100
50
20
70
700
20
10
N(10)
AJ164R
20
200
100
200
100
50
20
100
200
N(10)
20
N(10)
AJ165R
20
500
50
500
200
70
20
100
1000
30
20
N(10)
AJ166R
20
500
50
100
200
70
20
100
200
10
30
N(10)
AJ167R
N(10)
50
100
100
50
N(5)
L(20)
50
150
N(l0)
L(5)
N(10)
Appendix Id -- continued
Sample
Sr
(PPm)
V
(PPm)
W
(PPm)
Y
(PPm)
Zn
(PPm)
Zr
(PPm)
Th
(PPm)
AJ136R
200
300
N(100)
200
1500
500
N(200)
AJ152R
200
200
N(100)
700
500
500
N(200)
AJ155R
200
500
N(100)
50
2000
700
N(200)
AJ162R
200
500
N(50)
10
500
100
N(100)
AJ163R
200
200
N(50)
50
500
300
N(100)
AJ164R
200
200
N(50)
150
500
300
N(100)
AJ165R
200
200
N(50)
150
500
200
N(100)
AJ166R
200
150
N(50)
200
500
300
N(100)
AJ167R
N(100)
30
N(50)
10
L(200)
50
N(100)
L = Detected at levels below the detection limit
N = Not detected at lower detection limit
G = Greater than value shown
APPENDIX II
ANALYTICAL TECHNIQUES
145
146
Appendix II-- Analytical Techniques
Nitric Acid Extraction (Modified after Ward and others, 1969)
1. Weigh 0.50 grams of sample into 20 ml disposable test tube contain-ing boiling chip.
2. Add 2.5 ml of concentrated nitric acid.
3. Heat for 30 minutes to drive off nitrous oxides.
4. Dilute to 10 ml with distilled water and bring to a boil.
5. Cool and centrifuge.
6. Analyze extract using atomic absorption spectrophotometry (expansion20).
First Sequential Extraction (T. T. Chao, 1983, personal communication;modified after Olade and Fletcher, 1974; modified after Filipek andOwen, 1978)
Oxide Fraction
1. Weigh 0.50 grams of sample into 50 ml centrifuge tube.
2. Add 25 ml of.3% oxalic acid, cap and shake.
3. Heat in preheated block at 100 °C for 15 minutes.
4. Centrifuge and decant liquid into 50 ml beaker.
5. Wash and dry remnant sample in test tube.
6. Evaporate liquid in beaker to dryness.
7. Place beaker in furnace at 500 °C for 4 hours to burn off oxalic acid.
8. Dissolve residue in 25 ml of 4 N nitric acid (2.4 N hydrochloricacid is also adequate) and stir.
9. Analyze extract using atomic absorption spectrophotometry (expansion= 50).
Sulfide and Organic Fraction
10. Add 0.50 grams of potassium perchlorate to remaining sample.
11. Add 5 ml of concentrated hydrochloric acid.
147
Appendix Il -- continued
12. Let stand for 30 minutes.
13. Dilute to 25 ml with distilled water and shake.
14. Centrifuge.
15. Analyze extract using atomic absorption spectrophotometry (expan-sion = 50).
16. Decant off extract and wash remaining sample.
Crystalline Fraction
17. Wash sample into 50 ml teflon beaker and evaporate to dryness.
18. Add 10 ml of concentrated hydrofluoric acid and digest at 120 °C todryness.
19. Add 6 ml of aqua regia (3 parts nitric acid to 1 part hydrochloricacid), cover and heat to dryness.
20. Repeat steps 18 and 19.
21. Extract with 25 ml of 2.4 N hydrochloric acid and stir.
22. Analyze extract using atomic absorption spectrophotometry (expan-sion =_50).
Second Sequential Extraction (Modified aftermodified after Chao and Zhou, 1983)
Carbonate and Exchangeable Fraction
1. Weigh 1.00 grams of sample into 50 ml centrifuge tube.
2. Add 20 ml of 1.0 M acetic acid and agitate for 2 hours in a mechani-cal shaker.
3. Centrifuge.
4. Analyze extract using atomic absorption spectrophotometry (expansion= 20).
5. Decant off extract and wash remaining sample.
Easily Reducible Fraction
6. Add 40 ml of 0.1 N nitric acid to sample and agitate for 30 minutes
148
Appendix Il -- continued
7. Centrifuge.
8. Analyze extract using atomic absorption spectrophotometry (expansion= 40).
9. Decant off extract and wash remaining sample.
Moderately Reducible Fraction
10. Add 40 ml of 0.25 M hydroxylamine hydrochloride in 0.25 M aceticacid and agitate for 30 minutes in a 50 °C water bath.
11. Centrifuge.
12. Analyze extract using atomic absorption spectrophotometry (expan-sion = 40).
13. Decant off extract and wash remaining sample.
Organic and Sulfide Fraction
14. Add 15 ml of 30% hydrogen peroxide acidified to a pH of 2.
15. Heat at 80 °C.
16. After 1 hour, add an additional 5 ml of acidified 30% hydrogen per-oxide.
17. Continue heating until dry.
18. Extract with 40 ml of 1 M ammonium acetate in 6% nitric acid for30 minutes.
19. Analyze extract using atomic absorption spectrophotometry (expan-sion = 40).
20. Decant off extract and wash remaining sample.
Crystalline Fraction
21. Wash sample into 50 ml teflon beaker and evaporate to dryness.
22. Add 10 ml of concentrated hydrofluoric acid and digest at 120 °C todryness.
23. Add 6 ml of aqua regia (3 parts nitric acid to 1 part hydrochloricacid), cover and heat to dryness.
24. Repeat steps 22 and 23.
149
Appendix II-- continued
25. Extract with 25 ml of 2.5 N hydrochloric acid and stir.
26. Analyze extract using atomic absorption spectrophotometry (expan-sion = 25).
APPENDIX IIIa
ANALYTICAL RESULTS OF THE NITRIC ACID EXTRACTION AND
THE FIRST SEQUENTIAL EXTRACTION ON STREAM SEDIMENTS,
BATAMOTE MOUNTAINS, ARIZONA
150
151
Appendix IIIa -- Analytical Results of the Nitric Acid Extraction and theFirst Sequential Extraction on Stream Sediments, BatamoteMountains, Arizona
Sample Extraction Technique
HNO3 Oxalic Acid HCl -KC103 . HF /Aqua Regia
Cu Cu Fe Cu /Fe (x102) Cu Cu
AJ001S 170 47 3800 1.24 106
AJ002S 90 46 3600 1.28 21
AJ003S 140(150) 52 3300 1.58 51
AJ005S 120(120) 51 5300 0.96 33
AJ007S 110(130) 52 3200 1.63 43
AJ008S 190(180) 76 4300 1.77 61 13
AJOlOS 130(140) 67 5100 1.31 36
AJO11S 60(70)AJ012S 90 32 3300 0.97 33 16
AJ013S 140 44 3800 1.14 38
AJ014S 110 46 3900 1.18 36
AJ015S 100 35 3400 1.03 35 18
AJ016R 140 63 4800 1.31 41
AJ017S 130 53 4700 1.13 43AJ018S 160 64 3600 1.78 58 10
AJ019S 280 109 2600 4.19 104 16
AJO2OS 160 66 3500 1.89 50 10
AJ021S 170(180) --
AJ022S 130 53 4800 1.10 39
AJ023S 200 105 6100 1.72 67
AJ024S 150 55 3600 1.53 48
AJ027S 150 54 4100 1.32 51
AJ028S 140 55 4500 1.22 43AJ029S 170(180)
AJO3OS 130(130)
AJ031S 150 64 5400 1.19 45
AJ032S 90 42 8700 0.48 24
AJ033S 80 29 6000 0.48 30 15
AJ034S 80 37 10,300 0.36 20AJ035S 130 50 6400 0.78 39
AJ036S 110(110)
AJ037S 160 56 4000 1.40 61 15
AJ038S 200 75 3300 2.27 80 15
AJ039S 230 105 4100 2.56 85 13
AJO4OS 170 70 4100 1.71 62 12
Appendix IIIa- continued
Sample
152
Extraction Technique
HNO3 Oxalic Acid HC1 -1(C103
HF /Aqua Regia
Cu Cu Fe Cu /Fe (x102) Cu Cu
AJ041S 160 76 4700 1.62 60 14
AJ042S 140 79 4800 1.65 36
AJ043S 75 33 6200 0.53 22
AJ044S 95 38 7600 0.50 32
A.J045S 80 28 7700 0.36 21
AJ049S 95 33 4700 0.70 25 19
AJ051S 110 40 6200 0.65 26
AJ052S 130 50 6900 0.72 42
AJ053S 120 44 6200 0.71 44
AJ055S 60 24 4700 0.51 16 8
AJ056S 120 55 8000 0.69 27
AJ057S 150 58 4100 1.41 63 12
AJ058S 100 44 10,700 0.41 22
AJ059S 95 37 7500 0.49 25
AJO6OS 90 38 8500 0.45 20
AJ061S 70 26 4200 0.62 21
AJ063S 80 27 3500 0.77 31
AJ064S 70 23 4300 0.53 18
AJ065S 110 44 6000 0.71 33
AJ066S 70 26 6100 0.43 24
AJ067S 120 46 5800 0.79 42
AJ068S 70 27 6200 0.44 25
AJ069S 50 20 4300 0.47 15 18
AJO7OS 60 22 6800 0.32 30
AJ072S 55 22 4300 0.51 16
AJ074S 50 26 5200 0.50 11
AJ075S 65 28 6200 0.45 16
AJ076S 55 21 4800 0.44 14 17
AJ077S 40 17 12,200 0.14 1]
AJ078S 50 18 4500 0.40 13
AJ079S 40 13 5700 0.23 10
AJO8OS 45 13 4600 0.28 12
AJ081S 55 21 7000 0.30 9
AJ082S 45 17 9400 0.18 9
AJ083S 30(25) 10 4100 0.24 3
Appendix IIIa-- continued
Sample
153
Extraction Technique
HNO3 Oxalic Acid HC1 -KC103 HF /Aqua Regia
Cu Cu Fe Cu /Fe (x102) Cu Cu
AJ084S 30(25)AJ085S 80 40 7800 0.51 16
AJ087S 80(70) 35 5300 0.66 30
AJ088S 80(70)AJ089S 75 33 5400 0.61 28
AJO9OS 70 33 7100 0.46 23
AJ091S 95(100) 30 4400 0.68 26 16
AJ092S 90(90)AJ093S 55 23 7100 0.32 16
AJ094S 40 13 4700 0.28 11 10
AJ096S 60(55) 23 9100 0.25 19
AJ097S 70(50)
AJ098S 60(60) 24 10,100 0.24 17
AJ099S 70(50) --AJ100S 60 21 9700 0.22 15
AJ101S 70 30 8600 0.35 20AJ102S 70 23 8800 0.26 19
AJ103S 35(35) 13 7100 0.18 17 14
AJ104S 45(45)AJ105S 50(40) 19 6300 0.30 13
AJ106S 60(60)AJ107S 65 28 5300 0.53 24
AJ141S 95 45 4000 1.13 49AJ142S 75 46 3600 1.28 42
AJ143S 75 50 3400 1.47 42
AJ148S 80 55 4000 1.38 54
AJ149S 100 63 3400 1.85 52
AJ150S 130 70 2800 2.50 60AJ153S 130 80 2600 3.08 71
AJ154S 140 67 2800 2.39 64
All values in parts per million unless otherwise indicated.Parantheses indicate duplicate analyses.
APPENDIX IIIb
ANALYTICAL RESULTS OF THE SECOND SEQUENTIAL EXTRACTION
ON STREAM SEDIMENTS, BATAMOTE MOUNTAINS, ARIZONA
154
Appendix IIIb-- Analytical Results of the Second Sequential Extraction on Stream Sediments, Batamote
Sample
Mountains, Arizona
Density
Separate
Carbonate /Exchangeable
Cu
Fe
Mn
Mineralogie Fraction
Easily Reducible
Cu
Fe
Mn
Moderately Reducible
Cu
Fe
Mn
AJ012S
Bulk
613
40
15
61
40
17
400
50
Heavies
23
52
70
23
260
50
64
1900
50
Slimes
912
65
28
66
50
27
600
65
Lights
620
40
13
61
35
14
400
40
AJ015S
Bulk
411
40
14
62
40
17
400
45
Heavies
12
30
60
19
200
65
51
1600
100
Slimes
612
50
19
65
40
22
600
75
Lights
415
35
13
61
35
12
200
35
AJ019S
Bulk
24
13
55
49
113
35
38
400
25
Heavies
57
56
75
46
270
25
120
1400
60
Slimes
36
16
90
52
121
30
49
700
40
Lights
25
14
60
45
129
30
35
400
15
AJ038S
Bulk
18
11
40
31
142
45
29
400
20
Heavies
65
52
65
46
300
30
180
2800
80
Slimes
33
19
50
50
160
125
65
1400
55
Lights
18
18
45
31
139
40
27
500
20
AJ039S
Bulk
26
13
50
41
114
40
39
500
20
Heavies
56
59
60
46
305
30
125
3000
80
Slimes
46
22
70
67
200
30
75
1100
45
Lights
25
20
50
40
118
35
30
300
15
Appendix IIIh- continued
Sample
Density
Separate
Mineralogic Fraction
Sulfide /Organic
Crystalline
Cu
Fe
Mn
Cu
Fe
Mn
AJ012S
Bulk
9320
15
34
18,000
140
Heavies
240
750
25
59
270,000
2650
Slimes
39
740
30
66
41,000
340
Lights
1230
10
22
13,000
65
AJ015S
Bulk
10
220
10
46
26,000
220
Heavies
180
500
25
105
290,000
2450
Slimes
15
280
20
58
40,000
440
Lights
4170
10
26
18,000
100
AJ019S
Bulk
52
430
10
54
15,000
70
Heavies
460
1350
25
115
105,000
1950
Slimes
200
1100
25
82
31,000
280
Lights
32
580
10
32
12,000
45
AJ038S
Bulk
33
420
15
44
17,000
95
Heavies
520
1500
20
105
65,000
1200
Slimes
240
1100
30
77
51,000
580
Lights
9290
10
36
10,000
40
AJ039S
Bulk
38
450
10
46
18,000
90
Heavies
480
1450
20
95
95,000
1950
Slimes
360
1100
25
115
45,000
580
Lights
14
310
10
40
13,000
60
Appendix Illb -- continued
Sample
Density
Separate
Carbonate /Exchangeable
Cu
Fe
Mn
Mineralogic Fraction
Easily Reducible
Cu
Fe
Mn
Moderately Reducible
Cu
Fe
Mn
AJO4OS
Bulk
15
14
40
27
62
25
31
400
40
Heavies
41
54
65
31
290
35
110
2000
,95
Slimes
27
16
75
53
89
50
70
1000
70
Lights
14
22
40
23
60
30
25
400
30
AJ049S
Bulk
513
45
12
74
50
17
800
55
Heavies
9120
150
15
350
90
42
3800
115
Slimes
512
50
19
62
40
35
900
135
Lights
517
40
11
49
40
14
400
50
AJ069S
Bulk
215
45
898
45
10
600
30
Heavies
5160
170
8335
60
24
3800
90
Slimes
213
65
976
40
22
800
135
Lights
220
45
768
35
8200
20
AJ094S
Bulk
215
45
491
45
7700
40
Heavies
6130
130
7340
55
27
3000
140
Slimes
211
55
973
40
14
1100
19
Lights
221
45
482
40
6500
30
AJ103S
Bulk
223
45
5110
60
81500
85
Heavies
7240
180
9485
60
21
5800
90
Slimes
210
60
12
68
50
17
2000
135
Lights
236
50
593
50
61300
75
Chrysocolla
Standard
230
14
523
17
L(5)
20
N(100)
N(5)
Appendix IIIb -- continued
Sample
Density
Separate
Mineralogie Fraction
Sulfide /Organic
Crystalline
Cu
Fe
Mn
Cu
Fe
Mn
AJO4OS
Bulk
21
340
15
44
17,000
85
Heavies
460
1250
20
90
65,000
1250
Slimes
250
980
30
125
50,000
560
Lights
5250
10
36
13,000
85
AJ049S
Bulk
8420
15
43
26,000
200
Heavies
80
730
30
100
85,000
1500
Slimes
63
1050
35
64
44,000
150
Lights
4390
15
30
21,000
130
AJ069S
Bulk
6360
15
28
23,000
120
Heavies
40
450
15
60
115,000
2400
Slimes
41
420
25
75
55,000
760
Lights
4230
10
22
15,000
70
AJ094S
Bulk
7410
20
26
19,000
90
Heavies
35
420
20
52
75,000
960
Slimes
19
720
40
48
60,000
680
Lights
2370
15
22
17,000
70
AJ103R
Bulk
3450
20
29
28,000
170
Heavies
36
610
30
70
330,000
3050
Slimes
18
890
40
52
43,000
270
Lights
3400
20
17
17,000
60
Chrysocolla
Standard
780
N(5)
5L(1000)
L(5)
All values in
parts per million.
APPENDIX IIIc
ANALYTICAL RESULTS (USING NITRIC ACID EXTRACTION) FOR COPPER
IN THE C -1 AND C -2 FRACTIONS OF HEAVY MINERAL CONCENTRATES,
BATAMOTE MOUNTAINS, ARIZONA
159
160
Appendix IIIc-- Analytical Results (Using Nitric Acid Extraction) for
Copper in the C -1 and C -2 Fractions of Heavy Mineral
Concentrates, Batamote Mountains, Arizona
Sample C -1 C -2 Sample C -1 C -2 Sample C -1 C -2
AJ011C 45 AJ043C 55 AJO81C 20
AJ012C 85 35 AJ044C 20 AJ082C 20
AJOI3C 50 AJ045S 50 AJ083C 15
AJ014C 35 AJ049C 60 20 AJ085C 20
AJ015C 90 20 AJ051C 15 AJ087C 60
AJ016C 45 AJ052C -- 20 AJ089C 50
AJ017C 60 AJ053C 25 AJ090C 55
AJ018C 55 AJ055C 30 AJ091C 35
AJO19C 70 60 AJ056C 30 AJ093C 15
AJ020C 55 AJ057C 100 AJ094C 40 25
AJ021C 65 AJ058C 55 AJ096C 20
AJ022C 50 AJ059C 65 AJ098C 15
AJ023C 70 AJ060C 60 AJ100C 25
AJ024C 55 AJ061C 55 AJIOIC 25
AJ027C 65 AJ063C 45 AJ102C \20
AJ028C 70 AJ064C 25 AJ103C 30 15
AJ029C 45 AJ065C 40 AJ105C 30 15
AJ030C 50 AJ066C 20 AJ107C 20
AJ031C 60 AJ067C 50
AJ032C 50 AJ068C 15
AJ033C 45 AJ069C 45 15
AJ034C 70 AJ070C 10
AJO35Ç 55 AJ072C 15
AJ036C 50 AJ074C 10
AJ037C 65 AJ075C 10
AJ038C 260 120 AJ076C 25
AJ039C 90 85 AJ077C 10
AJ040C 75 45 AJ078C 25
AJ041C 50 AJ079C 10
AJ042C 55 AJ080C 20
All values in parts per million.
REFERENCES
Barton, H. N., Theobald, P. K., Turner, R. L., Eppinger, R. G.,and Frisken, J. G., 1982. Geochemical data for the Ajo two degreequadrangle, Arizona. U.S. Geological Survey Open File Report82 -419. 119 p.
Bryan, K., 1925. The Papago country, Arizona. U.S. GeologicalSurvey Water -Supply Paper 499. 436 p.
Chao, T. T., and Zhou, L., 1983. Extraction techniques for selectivedissolution of amorphous iron oxides from soils and sediments.Soil Science Society of America Journal, 47, p. 225 -232.
Cooper, J. R. Bismuth in the United States. U.S. GeologicalSurvey Mineral Inventory Resource Map MR -22. 19 p., 1 sheet.
DeKalb, C., 1918. Ajo copper mine. Mining and Science Press, 116,p. 115 -116 and 153 -156.
Dixon, D. W., 1966. Geology of the New Cornelia mine, Ajo, Arizona.In: Titley, S. R., and Hicks, C. L., eds. Geology of thePorphyry Copper Deposits -- Southwestern North America, p. 123 -132.
Filipek, L. H., and Owen, R. M., 1978. Analysis of heavy metaldistributions among different mineralogical states in sediments.Canadian Journal of Spectroscopy, 23, p. 31 -34.
Gilluly, J., 1935. Ajo district (Arizona). In: Copper Resourcesof the World, 16th International Geological Congress, 1,p. 228 -233.
, 1937. Geology and ore deposits of the Ajo quadrangle, Ari-zona. Arizona Bureau of Mines Geological Series, No. 9,Bull. 141. 83 p.
, 1942. The mineralization of the Ajo copper district, Ari-zona. Economic Geology, 37, p. 247 -309.
, 1946. The Ajo mining district, Arizona. U.S. GeologicalSurvey Professional Paper 209. 112 p.
Grimes, D. J., and Marranzino, A. P., 1968. Direct- current andalternating- current spark emission spectrographic field for thesemi -quantitative analysis of geological materials. U.S.Geological Survey Circular 591. 6 p.
161
162
Harris, J. 0., 1984. Emplacement and crystallization of the Cor-nelia zoned pluton, Ajo, Arizona: An analysis based on compo-sitional zoning of plagioclase and field relations. UnpublishedM.S. Thesis, The University of Arizona. 78 p.
Haxel, G., Wright, J. E., May, J. E., and Tosdal, R. M., 1980.Reconnaissance geology of the Mesozoic and Lower Cenozoic rockof the Southern Papago Indian Reservation: A preliminary report.Arizona Geological Society Digest, 12, p. 17 -29.
Ingham, G. R., and Barr, A. T., 1932. Mining methods and costs atthe New Cornelia Branch, Phelps Dodge Corporation, Ajo, Arizona.U.S. Bureau of Mines Information Circular 6666. 18 p.
Jones, W. C., 1974. General geology of the northern portion of theAjo Range, Pima County, Arizona. Unpublished M.S. Thesis,
The University of Arizona. 77 p.
Joralemon, I. B., 1914. The Ajo copper mining district. AmericanInstitute of Mining, Metallurgical and Petroleum EngineersTransactions, 49, p. 593 -610.
Kahle, K., Conway, D., and Haxel, G., 1978. Preliminary geologicmap of the Ajo 1° by 2° quadrangle, Arizona. U.S. Geological
Survey Open File Report 78 -1096. 2 sheets.
Klein, D. P., 1982. Residual aeromagnetic map of the Ajo andLukeville 1° by 2° quadrangles, southwestern Arizona. U.S.
Geological Survey Open File Report 82 -599. 1 sheet.
Levinson, A. A., 1980. Introduction to Exploration Geochemistry.Second edition, 924 p.
May, D. J., Peterson, D. W., Tosdal, R. M., LeVeque, R. A., andMiller, R. J., 1981. Miocene volcanic rocks of the Ajo Range,
south -central Arizona. In: Tectonic Framework of the Mojaveand Sonoran Deserts, California and Arizona, p. 65 -66.
National Oceanic and Atmospheric Administration, 1981. Annual
Summary of Climatalogical Data for Arizona, No. 13. 19 p.
Nie, N. H., Hull, C. H., Jenkins, J. G., Steinbrenner, K., andBent, D. H., 1975. Statistical Package for the Social Sciences.
675 p.
Olade, M., and Fletcher, K., 1974. Potassium chlorate -hydrochloric
acid: A sulfide selective leach for bedrock geochemistry.Journal of Geochemical Research, 3, p. 337 -344.
163
Raines, G. L., and Theobald, P. K., 1981. Remote sensing in theAjo 1° by 2° quadrangle, Arizona. In: Geological Survey Re-search, 1981. U.S. Geological Survey Professional Paper 1275,p. 21 -22.
Shafiqullah, M., Damon, P. E., Lynch, D. J., Reynolds, S. J.,Rehrig, W. A., and Raymond, R. H., 1980. K -Ar geochronologyand geologic history of southwestern Arizona and adjacentareas. Arizona Geological Society Digest, 12, p. 201 -260.
Theobald, P. K., and Barton, H. N., 1983. Statistical parametersfor resource evaluation of geochemical data from the Ajo 1° by2° quadrangle, Arizona. U.S. Geological Survey Open File Report83 -734. 44 p.
Wadsworth, W. B., 1968. The Cornelia pluton, Ajo, Arizona.Economic Geology, 63, p. 101 -115.
Ward, F. N., Nakagawa, H. M., Harms, T. F., and VanSickle, G. H.,1969. Atomic- absorption methods useful in geochemical explora-tion. U.S. Geological Survey Bulletin 1289. 45 p.
Wedepohl, K. H., ed., 1969. Handbook of Geochemistry. 6 vols.
Wilson, E. D., Moore, R. T., and Cooper, J. R., 1969. GeologicMap of Arizona. 1 sheet.
32°30
112°50' 4 112° 40'
iN
Tba
Qa
EXPLANATION:
112'50
3025
CONTACT, DASHED WHERE APPROXIMATEOR UNCERTAIN, DOTTED WHERECOVERED.
FAULT, DASHED WHERE APPROXIMATE ORUNCERTAIN, DOTTED WHERE COVERED.
,a.ATTITUDE
O
O
45"2 3 4 MILES
2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE I- SKETCH GEOLOGIC MAP,BATAMOTE MOUNTAINS, ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
g.ha i4itËeve cP,adFnsr 'RoomDEPART : GEOSCIcNCESUNIVERSITY FSZJNA
DESCRIPTIONr4Z
O W1-
OF UNITS
Qa QUATERNARY ALLUVIUM. POORLY SORTEDBY EXTENSIVE
NSIVE ANDVALLEY FILL. CEMENTED IN PLACES BY EXTENSIVE CALICHEDEVELOPMENT.
32° 30'
QTa UNCONSOLIDATED ALLUVIUM PREDATING Oa. FORMS SINUOUS LOWMOUNDS IN THE NORTH AND DISSECTED PEDIMENTS IN THESOUTH.
Tbi BATAMOTE ANDESITE, INTRUSIVE UNIT. APHANI TIC TO FINEGRAINED HYPERSTHENE OLIVINE ANDESITE. OCCURS IN TWODISTINCT PHASES A FINE GRAINED SALT AND PEPPERHYPERSTHENE OLIVINE ANDESITE AND A WEAKLY PORPHYRITIC-APHANITIC OLIVINE ANDESITE. WEATHERS GRAY TO YELLOWON OUTCROP.
Tba BATAMOTE ANDESITE, EXTRUSIVE UNIT. APHANITIC OLIVINEBASALTIC ANDESITE WITH HIGHLY VARIABLE TEXTURES.OCCURS IN FLOWS UP TO 50 FEET THICK, AS A TUFF ANDA VOLCANIC BRECCIA. THE FLOWS TYPICALLY GRADEUPWARDS FROM A GRAY APHANITIC COARSELY FISSILESECTION, THROUGH A MASSIVE INTERMEDIATE ZONE, AND INTOA HIGHLY VESICULAR UPPER SECTION. ALSO INCLUDES
H
rclTb,I
MINOR VOLCANOCLASTIC SEDIMENTS. WEATHERS GRAY, YELLOW,MAROON AND BLACK ON OUTCROP.
BATAMOTE ANDESITE, VENT FACIES. RED TO MAROON VOLCANICBECCIA. TEN CENTIMETER TO ONE METER BLOCKS IN A RED,OXIDIZED, VESICULAR, APHANITIC TO MEDIUM GRAINED
GROUNDMASS.
II
ANDESITIC
w Tai CHILDS LATITE. FLOW BANDED PORPHYRI TIC AUGITE LATITE.l1111 TYPICALLY PORPHYRITIC -APHANITIC WITH SUB- TO ANHEDRAL,
'GRAINEDMEDIUM TO COARSE POTASSIC FELDSPAR PHENOCRYSTSIN A PINK APHANITIC GROUNDMASS. FORMS FLOWS UP TO 80FEET_ THICK. LAHARIC BRECCIA ALSO PRESENT. WEATHERSrFROM WHITE TO MAROON ON OUTCROP. FORMS ROUNDED,POINTED HILLS. .
32° 25'
112° 40'
I32° 30'
112° 50' 45' 112° 40'
112° 50'
EXPLANATION: 32°25'N
0e--/ LINE OF EQUAL CONCENTRATION/ ON PPM)
BOUNDARY OF SAMPLED AREA
1 0 1
45'3 4 MILES
2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 10-COPPER, LEACHED USING POTASSIUM PERCHLORATE ANDHYDROCHLORIC ACID, SEQUENTIALLY AFTER AN OXALIC ACID LEACH,
FROM -30 MESH STREAM SEDIMENT, BATAMOTE MOUNTAINS, ARIZONAN, AEevt /Ceadinff DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCES
DEPARTMENT 0F GEOSCIENCES
UNIVERSITY OF ARIZONAUNIVERSITY OF ARIZONA, 1964
32° 30'
32° 25'
112 °40'
32° 30'
112° 50' 45 112° 40'
i EXPLANATION:
112°50'
32° 25
/1 LINE F EQUAL CONCENTRATION
BOUNDARY OF SAMPLED AREA
1 0 4 MILES
1 0 1 2 3 4 5 KILOMETERS
SCALE : 1:62500
PLATE 1 I- COPPER, LEACHED USING NITRIC ACID,IN THE C -2 FRACTION OF HEAVY MINERAL CONCENTRATES,
BATAMOTE MOUNTAINS, ARIZONA`:7h. 04"ntevs %Ceading( WooersOEPARTI'ÍLNT OF GEOSCIENCESUNIVERSITY OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
112° 40'
32° 30
112°50'
N
45' 112° 40'
112° 50'
EXPLANATION: 32 °251
°o' LINE OF EQUAL CONCENTRATION/ (IN PPM)
./ BOUNDARY OF SAMPLED AREA
45'1 0 1 2 3 4 MILES
1 O 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 12- COPPER IN THE C -3 FRACTION OF HEAVYMINERAL CONCENTRATES, BATAMOTE MOUNTAINS, ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
CAlevs 9eaC>!inff /'Coon.DEPARTP? i'il ' G[OSCIENCES
UNIVERSI-fiY or ;,RiZOt`iA
32° 30
32° 25'
112° 40'
32° 30'
112° 50' 45, 112° 40'
112° 50'
iEXPLANATION 32 °25'
N ELEMENT CONCENTRATION RANGES(PPM)
1 2Ag L(0.2) -10 15 -30As L(100)-500 700Ba 2000 -5000 7000 -10,000Cu 200 300Mo L(10)-50 70-100Pb 200 -500 700 -2000Sb L(20) 20 -100Sn 100-300 500-1000Zn L(100) -500
OANOMALOUS DRAINAGE BASIN
"°. BOUNDARY OF SAMPLED AREA
1 0 1
2
45,3
2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 13- ANOMALOUS SILVER, ARSENIC, BARIUM, COPPER, MOLYBDENUM,LEAD, ANTIMONY, TIN AND ZINC IN THE C -3 FRACTION OF HEAVY
MINERAL CONCENTRATES, BATAMOTE MOUNTAINS, ARIZONAg %a Ctnfç-vF lrCeading' WoQmDEPARTNE:N GEOSCIENCES
UNIVERSITY OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
32° 30'
112 °50' 45' 112° 40'
\\ J
t
i-
EXPLANATION:
N o SAMPLE SITE
WASH
MINERALS PRESENT
PYRITE
.0 CHALCOPYRITEA MALACHITE
V COVELLITEOARSENOPYRITE
112 °50'
32° 25'
---- --> > \..,-- .r.
_ ,
..--1./ .; i \f / : . (-/*- -)
..Jr- . ?r-e....: - - --(.i- _ _;---l -- `. \.-, /
.. . S._ . ) .). i\ . ..` : \ / o ^..¡.:-. .-...-- .J 1 i _\.\ ../ /.. 1 .1\ --
. ),.:<- .,-i :\.\.."N..------ ' ' ._ -- . . . _ \..
1\ L_..
/ti
. ---.45'
O 1 2 31
. \ /1 Y ..l I
1 / /4 MILES
1 0 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 14- PYRITE, CHALCOPYRITE, MALACHITE, COVELLITE ANDARSENOPYITE IN THE C -3 FRACTION OF HEAVY MINERAL CONCENTRATES,
BATAMOTE MOUNTAINS, ARIZONA;14ntdVr /Q.4lidlMff ROCYH
pEF'AR`i`WhlÌ' (.', G"._OSCIENCES
UIdIVERSIT! OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
32° 30'
32 °25'
112 °40
32° 3Ó
112° 50' 45,
'r~`.
112° 40'
EXPLANATION:
o SAMPLE SITE
r r WASH
MINERALS PRESENT
BARITE
AVO
O
CERRUSITE
GALENA
LEAD SHOT
WULFENITE
CASSITERITE
r `o»
. I:
%
..)4
. , !- ' -- (
r-11 Os...
f -./112°50'
32° 25'
r\O
45'2 3 4 MILES
0 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 15- BARITE, CERUSSITE, GALENA, LEAD SHOT, WULFENITE ANDCASSITERITE IN THE C-3 FRACTION OF HEAVY MINERAL CONCENTRATES,
BATAMOTE MOUNTAINS, ARIZONA43.4 ,gevs leadingDEPARTfa9 i ï ; GEOSCIENCESUNIVERSITY OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
32°3d
112 °50' 45 112° 40'
N
147157
15'4E152 +1s5 161
561 159 6160A, B
138 135137A-D 136
112° 50'
32 °25'
134
254126
9 140139
£144
146
i133
412944131130
54±A,48
47 46
50
12211162
121g 123120119,118
86A.
124125
62 164 126
71A,B
73
.113111
112 110
EXPLANATION:95
25 ROCK CHIP136. OXIDE COATING
1 O
109A,B
£108
165
/1166
115 116
114167
1 2
45"3 4 MILES
1 0 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 2 -ROCK CHIP AND OXIDE COATING SAMPLE SITESBATAMOTE MOUNTAINS, ARIZONA
'JAe C4intevs 92eading ieoarwDEPARTMENT ,.;= GEOSCIENCES
- UNIVERSITY OF ARIZONA
DAt/ID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF AR ZONA, 1984
32° 30'
3 2° 25'
112 °40'
32 °30
112 °50' 45, 112° 4d
40 \t\ jA\ 2 5P).\\.
g- \ 0 / 53 52 511.49
544, S `--
5,11,132 )
kL.2 ).' 13,128
< 7,21 ' .41 ;"-
J . 22~ )sy
\1 /"56
.-. 1, ( 7
l\ '.'.
I
69
- \S \ 1 15 \ ) , / \\ 34
N
EXPLANATION:
. WASHES7 SAMPLE SITE
ghe nEevs eadin8 /oamDEPART:T (=7 GEOSCIENCES
UNIVERSITY OF 'r,rILONA
112°50'
32 °25
427`3,36 . ;35 '
Ì
11,, \2
\ ' % '8 .n r 3k '. i75
--...
(.
10.30 )( 85' ts3,84 ( )
c ._ ..,t
(
64c \ 1 ' 1 l J J38..i ` ^ 11 l37 \ l \.. ,s7,8á 89.--- \.r7 ) L. .63. fr
1' 67 .. 98,9g
58 59 "0,127 /60 /r % '101
1
93t921 102
\..',
78
9 100 \ 1 r 1
79
` /103,104 . 182(2 . ..-.c . .1 -..
/...
! - - eo
\ Í ` )i i
\ \,.`..TEN/s4/\ ._fE _.SH"'"\'
' 94 96,9% :. 1. --..
/ ('-1SIK .'..LÇHUgAo
1 0 1
107 : n05, / /Y- . -_ i'.
106117 --, . '.2
45'3 4 MILES
1 O 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 3- DRAINAGE MAP SHOWING STREAM SEDIMENTAND HEAVY MINERAL CONCENTRATE SAMPLE SITES,
BATAMOTE MOUNTAINS, ARIZONADAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCES
UNIVERSITY OF ARIZONA, 1984
32° 30'
32° 25
112 °401
32° 30
112° 50' 45' 112° 40'
40.39
+
' % `- -7, 2141¡ 11J23`_1 r i42 \ \ I 24
/,_,720
N
EXPLANATION:
\
55 +5153 52 4544 6856
/
)\_,49/\l
,11,1328 7
13 128
rc\\ \ 7 691 1
1 I
(
27 --\36
34131 14f 15 l )
28\ J (----, y-I'l
721
16
\I ' ,8,2 -I
"941.-\, t_,. f I
\ \,/ ) /6 '\ l ( -- ).8,54.84/10, 30 I
1 1 ,./., - r64 > `>v
38<i37 \- f--,, / /1
\ C 78 88¡g/I /'67
\ \ / 7775\ `~ /
57¡___ 1 63? \-\61
580' -40_,/'
7 SAMPLE SITE
DRAINAGE BASIN BOUNDARY
o
59 t_ f 90, 12760 l.
93 t91,92 \/ -- 81
!103, 104 r"-82
\394 96,97
1 2
45,3 4 MILES
1 0 1 2 3 4 5 KILOMETERS
PLATE 4- STREAMSAMPLE
431'¢ .a4ritevg CPeading 92oa,yDEPAR M; CEúSCIENCES11fVIVFRSITY OF ARI7nNa
SCALE: 1 :62500
SEDIMENT AND HEAVY MINERAL CONCENTRATESITES, SHOWING AREAS OF INFLUENCE,BATAMOTE MOUNTAINS, ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
32° 30'
32° 25'
112 °40'
32° 30
112°50' 45, 112°40'
N
112° 50
EXPLANATION: 32° 25
LINE OF EQUAL CONCENTRATION(IN PPM)
BOUNDARY OF SAMPLED AREA
1 0 1 2 3 4 MILES
0 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 5- COPPER, LEACHED USING NITRIC ACID,FROM -30 MESH STREAM SEDIMENT,
BATAMOTE MOUNTAINS, ARIZONA4Eí4'4a riti CF
ding 9eoóm DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY
OF ARIZONAUNIVERSITY OF ARIZONA, 1984
32 °30
112 °50' 45 112° 40'
iN
EXPLANATION:
112° 50'
32° 25'
BOO/ LINE OF EQUAL CONCENTRATION/ (IN PPM)/ BOUNDARY OF SAMPLED AREA
1 0 1
1 0 1
2
45,3 4 MILES
2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 6 SILVER IN -30 MESH STREAM SEDIMENT,BATAMOTE MOUNTAINS, ARIZONA
`1e cAtevs,-
jDEPlR7ivi{i7 eading
,COOn,
CGEOSCIcNCESUNIVERSITY
OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
32 °30'
32° 25'
112 °40'
32 °30/
112 °50 45, 112 °40
N
112 °50'
EXPLANATION: 32 °25
° LINE OF EQUAL CONCENTRATION/ (IN PPM)y BOUNDARY OF SAMPLED AREA
1 O 1 2 4 MILES
1 0 1 2 3 4 5 KILOMETERS
SCALE: 1 :62500
PLATE 7- BISMUTH IN -30 MESH STREAM SEDIMENT,BATAMOTE MOUNTAINS, ARIZONA
é cri cvs Vading WoonDEPARTM_NT CF. GEOSCIENCESUNIVERSITY OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIECESUNIVERSITY OF ARIZONA, 1984
112°40'
32° 30'
112°50' 45, 112° 45'
EXPLANATION 32 °25
N ELEMENT CONCENTRATION(PPM)
1
RANGES
2Mo L(5)-5 7 -10Pb 100-150 200 -300Sn L(5) -5 7 -10Zn 50 70
4
OANOMALOUS DRAINAGE BASINS
BOUNDARY OF SAMPLED AREA
1 0
1 0 1 2 3 4 5 KILOMETERS
SCALE: 1:62500
PLATE 8- ANOMALOUS MOLYBDENUM, LEAD, TIN AND ZINCIN -30 MESH STREAM SEDIMENT, BATAMOTE MOUNTAINS, ARIZONA
isadevs Weadi»DEPARTrviIPT ;;,-
t7 CooUNIVERSITY OF ARIZONA
DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA, 1984
32° 30
112° 50' 45, 112° 40'
N
112° 50'
EXPLANATION: 32° 2
°° LINE OF EQUAL CONCENTRATIONRATIOS (Cu /Fe x 10 -2)BOUNDARY OF SAMPLED AREA
1 O 1 2
32° 30'
32°25'
45' 112°40'3 4 MILES
1 0 1 2 3 5 KILOMETERS
SCALE: 1:62500
PLATE 9- COPPER (NORMALIZED TO IRON), LEACHED USING OXALIC ACID,FROM -30 MESH STREAM SEDIMENT,
ghe :4nfevs `12eading %ooI BATAMOTE MOUNTAINS, ARIZONADEPARTMENT OF GEOSCIENCES DAVID LOWELL HUSTON, DEPARTMENT OF GEOSCIENCESUNIVERSITY OF ARIZONA UNIVERSITY OF ARIZONA, 1984
THE SIGNIFICANCE OF A WIDESPREAD STREAM SEDIMENT COPPER ANOMALY
IN THE BATAMOTE MOUNTAINS, PIMA COUNTY, ARIZONA
by
David Lowell Huston
A Thesis Submitted to the Faculty of the
DEPARTMENT OF GEOSCIENCES
In Partial Fulfillment of the RequirementsFor the Degree of
MASTER OF SCIENCES
In the Graduate College
THE UNIVERSITY OF ARIZONA
1 9 8 4
STATEMENT BY AUTHOR
This thesis has been submitted in partial fulfillment of re-quirements for an advanced degree at The University of Arizona and isdeposited in the University Library to be made available to borrowersunder the rules of the Library.
Brief quotations from this thesis are allowable without specialpermission, provided that accurate acknowledgement of source is made.Requests for permission for extended quotation from or reproduction ofthis manuscript in whole or in part may be granted by the head of themajor department of the Dean or the Graduate College when in his or herjudgement the proposed use of the material is in the interests ofscholarship. In all other instance however, permission must beobtained from the author. l n
This thes
SIGNED:
APPROVAL BY THESIS DIRECTOR
Ms been approved f the date shown below:
S. R. TITLEYProfessor of Geosciences
ACKNOWLEDGEMENTS
This research was undertaken with the assistance of many indivi-
duals associated with the U. S. Geological Survey and The University of
Arizona. First of all, I would like to thank Spencer Titley and Chris
Eastoe of The University of Arizona, William Payne of Getty Mining, and
Henry Alminas of the U. S. Geological Survey for their criticisms and
assistance during the fieldwork and the preparation of this paper. I
would especially like to thank Paul Theobald of the U. S. Geological
Survey for suggesting the topic, for his invaluable assistance and advice
in conducting the research, and for providing funding.
Additionally, I acknowledge the help of T. T. Chao and Lori
Filipek of the U. S. Geological Survey, Burt Lamoureux, and all the
other individuals who helped me in analyzing my samples. A special thanks
must be given to E. F. Cooley of the U. S. Geological Survey for reading
my spectroscopic films.
Finally, I thank my father Richard Huston, my step- brother Larry
Green, and my friends Roy Jemison and Greg Zeihen their assistance in
collecting samples. Without the help of all these people, the completion
of this project would have taken much longer, and the research would not
have been as complete.
iii
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS viii
LIST OF TABLES xi
LIST OF PLATES xii
ABSTRACT xív
INTRODUCTION, PURPOSE AND SCOPE OF THE STUDY 1
LOCATION, PHYSIOGRAPHY AND CLIMATE 4
PREVIOUS WORK 8
Geology 8
Surficial Geochemistry 9
Geophysics 10
REGIONAL GEOLOGY 11
Stratígraphy 11
Structure 17
LOCAL GEOLOGY 19
Stratígraphy 19
Childs Latíte 19
Distribution and Physiography 19
Petrology and Mineralogy 20Batamote Andesite -- Extrusive Facies 22
Distribution and Physiography 22
Petrology and Mineralogy 22
Batamote Andesite- -Vent Facies 24Distribution and Physiography 24Petrology 24
Batamote Andesite -- Intrusive Facies 27Distribution and Physiography 27Petrology and Mineralogy 27
iv
TABLE OF CONTENTS -- Continued
V
Page
Older Alluvium 28
Quaternary Alluvium 31
Structure 31
Faulting 31
Folding 31
Alteration 32
LITHOGEOCHEMISTRY 33
Major and Minor Elements 33
Trace Elements 35
R -Mode Factor Analysis 37
STREAM SEDIMENT GEOCHEMISTRY 44
Preliminary Phase 44
Main Phase 47
Field Methods 47
Sample Preparation 47
Results of the Hot Nitric Acid Extraction 48
Results of Semi -Quantitative Emission. SpectroscopicAnalysis 48
Copper 50Silver and Bismuth 50Other Base Metals 53
R -Mode Factor Analysis 53
Results of the First Sequential Extraction 59Oxalic Acid Leach 61
Potassium Perchlorate -Hydrochloric Acid Leach . . . 62
Aqua Regia /Hydrofluoric Acid Leach 63
Summary 64Results of the Second Sequential Extraction 64
The Distribution of Iron and Manganese 66
The Distribution of Copper in the CrystallineFraction 68
The Distribution of Copper in the Carbonate andExchangeable Fraction 68
The Distribution of Copper in the Easily ReducibleFraction 68
The Distribution of Copper in the ModeratelyReducible, and Sulfide and Organic Fractions 69
vi
TABLE OF CONTENTS -- Continued
Page
Summary 69
Summary 70
Follow -Up Phase 71
Summary of the Information Derived From Stream Sediments . . 71
INTERPRETATIONS FROM HEAVY MINERAL CONCENTRATES 75
Field Methods 75
Sample Preparation 76
Analysis of the C -1 and C -2 Fractions 77
Spectroscopic Analysis of the C- tion 79
Copper 80
Other Elements 82
Mineralogy of the C -3 Fraction . 87
The Concentration of Copper in Pyr ains 89
Summary 89
OTHER RESULTS 92
SUMMARY OF DATA PRESENTED, EVALUATION OF WOR !YPOTHESES, ANDCONCLUSIONS 94
Evaluation of Working Hypotheses . . 96
Airborne Contamination from a Sm, in Ajo 96
Abnormally High Background in th mote Andesíte 96
Primary Mineralization . . . . 97
Dispersion Along Normal Faults 97
Contamination of the Batamote to During itsEruption 100
Conclusions l00
APPENDIX Ia: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR ROCK CHIP SAMPLES, BATAMOTE MOUNTAINS,ARIZONA 102
TABLE OF CONTENTS -- Continued
APPENDIX Ib: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR STREAM SEDIMENTS, BATAMOTE MOUNTAINS,ARIZONA
V11
Page
112
APPENDIX Ic: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR THE C -3 FRACTION OF HEAVY MINERALCONCENTRATES, BATAMOTE MOUNTAINS, ARIZONA 128
APPENDIX Id: ANALYTICAL RESULTS (USING SEMI -QUANTITATIVE EMISSIONSPECTROSCOPY) FOR OXIDE COATINGS ALONG JOINTS AND FRACTURES,BATAMOTE MOUNTAINS, ARIZONA 141
APPENDIX II: ANALYTICAL TECHNIQUES 145
APPENDIX IIIa: ANALYTICAL RESULTS OF THE NITRIC ACID EXTRACTIONAND THE FIRST SEQUENTIAL EXTRACTION ON STREAM SEDIMENTS,BATAMOTE MOUNTAINS, ARIZONA 150
APPENDIX IIIb: ANALYTICAL RESULTS OF THE SECOND SEQUENTIALEXTRACTION ON STREAM SEDIMENTS, BATAMOTE MOUNTAINS, ARIZONA . 154
APPENDIX IIIc: ANALYTICAL RESULTS (USING NITRIC ACID EXTRACTION)FOR COPPER IN THE C -1 AND C -2 FRACTIONS OF HEAVY MINERALCONCENTRATES, BATAMOTE MOUNTAINS, ARIZONA 159
REFERENCES 161
LIST OF ILLUSTRATIONS
Figure
Page
1. Location of study area 6
2. Photograph, looking east, of the high point, BatamoteMountains 7
3. Stratigraphy of the Ajo area 12
4. Simplified geologic map of the Ajo and Sikort Chuapo 15- minutequadrangles, Arizona 13
5. Photomicrograph of Childs Latite 21
6. Photomicrograph of the basal section of a typical flow,Batamote Andesite 25
7. Photomicrograph of the upper unit of a typical flow, BatamoteAndesíte 26
8. Photomicrograph of the dioritic unit of the intrusive facies
of the Batamote Andesite 29
9. Photomicrograph of the porphyritíc unit of the intrusivefacies of the Batamote Andesite 30
10. Histogram showing the distribution of copper in theBatamote Andesíte 39
11. Histogram showing the distribution of lead in the BatamoteAndesíte 39
12. Histogram showing the distribution of zinc in the BatamoteAndesíte 40
13. Factor loadings for 18 elements from R -Mode factor analysisof the Batamote Andesite 42
14. Histogram showing the distribution of copper (extractedusing hot nitric acid) in -30 mesh stream sediments 49
viii
LIST OF ILLUSTRATIONS -- Continued
Figure
ix
Page
15. Histogram showing the distribution of silver (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 51
16. Histogram showing the distribution of bismuth (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 51
17. Histogram showing the distribution of molybdenum (analyzedusing semi -quantitative emission spectroscopy) in -30 meshstream sediment 54
18. Histogram showing the distribution of lead (analyzed usingsemi- quantitative emission spectroscopy) is -30 mesh streamsediment 54
19. Histogram showing the distribution of tin (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 55
20. Histogram showing the distribution of zinc (analyzed usingsemi -quantitative emission spectroscopy) in -30 mesh streamsediment 55
21. Factor loadings for 19 elements from R -Mode factor analysisof stream sediments 57
22. Histogram showing the distribution of copper normalized toiron (extracted using hot oxalic acid) in -30 mesh streamsediments 60
23. Histogram showing the distribution of copper (extractedsequentially using potassium perchlorate and hydrochloricacid after oxalic acid) in -30 mesh stream sediments 60
24. Distribution of copper among mineralogic and density fractionsof selected stream sediment samples, Batamote Mountains,Arizona 67
25. Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstreamof sample AJ003S 72
LIST OF ILLUSTRATIONS -- Continued
Figure
X
Page
26. Distribution of copper normalized to iron (extracted usingoxalic acid) in -30 mesh stream sediment samples upstreamof sample AJ039S 73
27. Histogram showing the distribution of copper (extractedusing hot oxalic acid) in the C -2 fraction of heavy mineralconcentrates 78
28. Histogram showing the distribution of copper in thenon - magnetic fraction (C -3) of heavy mineral concentrates . 81
29. Histogram showing the distribution of silver in thenon - magnetic fraction (C -3) of heavy mineral concentrates . 83
30. Histogram showing the distribution of arsenic in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 83
31. Histogram showing the distribution of barium in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 84
32. Histogram showing the distribution of molybdenum in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 84
33. Histogram showing the distribution of lead in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 85
34. Histogram showing the distribution of antimony in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 85
35. Histogram showing the distribution of tin in thenon -magnetic fraction (C -3) of heavy mineral concentrates . 86
36. Histogram showing the distribution of zinc in thenon - magnetic fraction (C -3) of heavy mineral concentrates . 86
LIST OF TABLES
Table
Page
1. Summary of major element oxide analyses of the Childs Latiteand the Batamote Andesite 34
2. Summary of emission spectroscopic analyses on the ChildsLatite and Batamote Andesite 36
3. Results of R -Mode principal factor analysis with iterationsafter varimax rotation for the extrusive facies of theBatamote Andesíte, Batamote Mountains, Arizona 41
4. Concentrations of copper in selected stream sediment samplesrelative to particle size 46
5. Replicate stream sediment sample pairs 47
6. Results of R -Mode principal factor analysis with iterationsafter varimax rotation for -30 mesh stream sediments,Batamote Mountains, Arizona 56
7. Samples analyzed using five -step sequential analysis 66
8. Magnetic fractions and representative mineralogy 76
9. Replicate heavy mineral concentrate sample pairs 80
10. Concentrations of copper in pyrite grains from selectedheavy mineral concentrate samples 90
xi
LIST OF PLATES
Plate
1. Sketch Geologic Map, Batamote Mountains, Arizona
2. Rock Chip and Oxide Coating Sample Sites, Batamote Mountains, Arizona
3. Drainage Map Showing Stream Sediment and Heavy Mineral ConcentrateSample Sites, Batamote Mountains, Arizona
4. Stream Sediment and Heavy Mineral Concentrate Sample Sites, ShowingAreas of Influence, Batamote Mountains, Arizona
S. Copper, Leached Using Nitric Acid, from -30 Mesh Stream Sediment,Batamote Mountains, Arizona
6. Silver in -30 Mesh Stream Sediment, Batamote Mountains, Arizona
7. Bismuth in -30 Mesh Stream Sediment, Batamote Mountains, Arizona
8. Anomalous Molybdenum, Lead, Tin and Zinc in -30 Mesh Stream Sediment,Batamote Mountains, Arizona
9. Copper (Normalized to Iron), Leached Using Oxalic Acid, from -30Mesh Stream Sediment, Batamote Mountains, Arizona
10. Copper, Leached Using Potassium Perchlorate and Hydrochloric Acid,Sequentially After an Oxalic Acid Leach, from -30 Mesh StreamSediment, Batamote Mountains, Arizona
11. Copper, Leached Using Nitric Acid, in the C -2 Fraction of HeavyMineral Concentrates, Batamote Mountains, Arizona
12. Copper in the C -3 Fraction of Heavy Mineral Concentrates, BatamoteMountains, Arizona
13. Anomalous Silver, Arsenic, Barium, Copper, Molybdenum, Lead,Antimony, Tin and Zinc in the C -3 Fraction of Heavy MineralConcentrates, Batamote Mountains, Arizona
14. Pyrite, Chalcopyrite, Malachite, Covellité and Arsenopyrite in theC -3 Fraction of Heavy Mineral Concentrates, Batamote Mountains,Arizona
xii
LIST OF PLATES -- Continued
Plate
15. Barite, Cerussite, Galena, Lead Shot, Wulfenite and Cassiteritein the C -3 Fraction of Heavy Mineral Concentrates, BatamoteMountains, Arizona
ABSTRACT
To determine the cause and distribution of a widespread copper
anomaly in the Batamote Mountains discovered by the U. S. G. S. (Barton
and others, 1982), detailed stream sediment and heavy mineral concentrate
sampling and reconnaissance geologic mapping were undertaken in the area.
The stream sediments yielded two anomalous areas characterized
by copper, silver and bismuth, separated by a narrow trough of low values.
The anomalous values are spatially associated with a series of northerly
trending normal faults.
The anomalous copper is held predominantly in iron and manganese
oxides, but a significant portion is held in a reduced form (probably
organics). Analysis of pyrite grains from heavy mineral concentrates for
copper indicates that pyrite cannot contribute enough copper to cause the
observed anomalies.
Analysis of the non -magnetic fraction of heavy mineral concen-
trates produced a similar anomaly pattern for copper, but no enhancement
was realized relative to stream sediments. This analysis also yielded
three other anomalous areas characterized by a volatile element assem-
blage, a tin -molybdenum assemblage and a silver- arsenic -molybdenum assem-
blage, respectively. The cause of these anomalies remains problematic.
The primary anomaly is best explained as the result of disper-
sion along normal faults. The original source of the metals in the normal
faults could not be absolutely determined in the present study.
xiv