U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY

MISCELLANEOUS HELD STUDIESMAP MF-1835-F

PAMPHLET

MAP SHOWING DISTRIBUTION OF ALKAUNE IGNEOUS ROCKS ANDASSOCIATED CARBONATITES AND PERIDOTITES IN THE

NORTHERN MIDCONTINENT, U.S.A.

Compiled by

F. Allan Hills*, Richard W. Scott, Jr.i, Theodore J. Armbrustmacher1 , and Pieter Berendsen2

INTRODUCTION

This l:l,000,000-scale map of the northern Midcontinent area shows the locations of alkaline igneous rocks and associated carbonatites and mica peridotites, and of structural domes and diatremes known or thought to be associated with similar igneous rocks. In addition, it shows the location of other structural features and geophysical anomalies of uncertain origin that may be related to buried igneous rocks. These include cryptoexplosion features, some of which have been interpreted as astroblemes, and gravity and magnetic anomalies that have been interpreted to result from buried mafic plutons. Precambrian igneous rocks having a wide range of compositions are exposed or buried at shallow depth in South Dakota, Minnesota, and Wisconsin, and they are found beneath the Paleozoic strata throughout the study area. Only those Precambrian rocks that are clearly alkaline, carbonatitic, or kimberlitic are included in this compilation. Table 1 shows a summary of available information on the petrology, structural setting, and age of each occurrence or group of occurrences and lists the principal references for each. Because the authors have not studied most of the occurrences in this compilation, they made no attempt to change the rock terminology to make it consistent or up to date. Generally, the name used for each occurrence is the one in the most recent, cited publication on the occurrence. Figures 1 and 2 are larger scale maps that show the locations of igneous rocks and diatremes where they are clustered too closely to be shown clearly on the main map.

This map is part of a folio of maps and cross sections of the northern Midcontinent area (bounded by lats 36*-46* N. and longs 88'-100* W.) prepared under the Midcontinent Strategic and Critical Minerals Project. This project is a cooperative activity between the U.S. Geological Survey and the

^.S. Geological Survey, Denver, CO 80225. 2Kansas Geological Survey, Lawrence, KS

66044.

geological surveys of the included States. Other maps in this folio to date include U.S. Geological Survey Miscellaneous Field Studies Maps MF-1835-A through E (Mugel, 1986; Jorgensen and others, 1986; Marvin, 1988; Pratt, 1987; Andercon, 1988) and U.S. Geological Survey Miscellaneous Investigations Service Map I-1853-A (Sirrr 1990).

REFERENCES CITED

Amos, D.H., 1967, Geologic map of part of the Smithland quadrangle, LJvingston County, Kentucky: U.S. Geological Survey Geologic Quadrangle Maps of the United States, Map GQ-657, scale 1:24,000.

Anderson, R.R., compiler, 1988, Phanercroic structural features in the northern Midcontinent, U.S.A.: U.S. Geological Survey Miscellaneous Field Studies Map MF-1835-E, scale 1:1,000,000.

Baxter, J.W., Desborough, G.A., and Shew, C.W., 1967, Areal geology of the Illinois fluorspar district, Pt. 3-Herod and Shetlervir? quadrangles: Illinois State Geological Survey Circular 413, 41 p.

Berendsen, P., Cullers, R.L., Mansker, W.L., and Cole, G.P., 1985, Late Cretaceous kimberlite and lamproite occurrences in eastern Kansas, U.S.A.: Geological Society of America Abstracts with Programs, v. 17, no. 3, p. 151.

Bickerman, M., Udiak, E.G., and Lewis, Richard, 1982, K-Ar ages of phlogopite from mica peridotite, Omaha oil field intrusion, Gallatin County, southern Illinois: Geological Society of America Abstracts with Programs v. 14, no. 5, p. 255.

Bickford, M.E., Mose, D.H., Wetherill, G.W., and Franks, P.C., 1971, Metamorphisrr of Precambrian granitic xenoliths in a mica peridotite at Rose dome, Woodson County, Kansas-Part 1, Rb-Sr isotope stud : ?.s: Geological Society of America Bulletin, v. 82, p. 2863-2868.

Brock, M.R., and Heyl, A.V., Jr., 1961, Post- Cambrian igneous rocks of the central craton, western Appalachian Mountains, and Gulf Coastal Plain of the United States, in Short papers in the geologic and hydrologic sciences: U.S. Geological Survey Professional Paper 424-D, p. D33-D35.

Brookins, D.G., 1970a, Kimberlite at Winkler crater, Kansas: Geological Society of America Bulletin, v. 81, p. 241-246.

____1970b, The kimberlites of Riley County, Kansas: Kansas State Geological Survey, Bulletin 200, 32 p.

Brookins, D.G., Delia Valle, R.S., and Bolivar, S.L., 1976, Uranium geochemistry of some United States kimberlltes [abs.]: American Geophysical Union Transactions (EOS), v. 57, p. 762.

Brown, J.S., Emery, J.A., and Meyers, P.A., Jr., 1954, Explosion pipe in test well on Hicks Dome, Hardin County, Illinois: Economic Geology, v. 49, p. 891-902.

Clegg, K.E., 1955, Metamorphism of coal byperidotite dikes in southern Illinois: Illinois Geological Survey Report of Investigations, no. 178, p. 5-18.

Clegg, K.E., and Bradbury, J,C, 1956, Igneous intrusive rocks in Illinois and their economic significance: Illinois Geological Survey Report of Investigations, no. 197, 19 p.

Cordua, W.S., 1985, Rock Elm structure, Pierce County, Wisconsin-A possible cryptoexplosion structure: Geology, v. 13, p. 372-374.

Cullers, R.L., Mullenax, J., Di Marco, M.J., and Nordeng, S., 1982, The trace element content and petrogenesis of kimberlites in Riley County, Kansas, U.S.A.: American Mineralogist, v. 67, p. 223-233.

Cullers, R.L., Ramakrishnan, S., Berendsen, P., and Griffin, T., 1985, Geochemistry and petrogenesis of lamproites, Late Cretaceous age, Woodson County, Kansas, U.S.A.: Geochimica et Cosmochimica Acta, v. 49, no. 6, p. 1383-1402.

Englehardt, R.L., 1973, The petrology of some igneous dikes of western Kentucky: Richmond, Ky., University of Eastern Kentucky M.S. thesis, 59 p.

English, R.M., and Grogan, R.M., 1948, Omaha pool and mica-peridotite intrusives, Gallatin County, Illinois: Illinois Geological Survey Report of Investigations, no. 130, p. 189-212.

Franks, P.C., 1959, Pectolite in mica peridotite, Woodson County, Kansas: American Mineralogist, v. 44, p. 1082-1086.

Greenberg, J.K., and Brown, B.A., 1985,Deformational and metamorphic features associated with 1,500-Ma anorogenic magmatism in Wisconsin, in Tithis, August, ed., The crust-The significance of

granites/gneisses in the lithosphere: Theophrastus Publications, p. 79-93.

Grohskopf, J.G., 1955, Subsurface geology of the Mississippi embayment of southeast Missouri: Missouri Division of Geological Survey and Water Resources [Report], 2nd ser., v. 37, 133 p.

Harlem, C.L., 1982, The Elk Creek Carbonatites, in Schultz, C. B., ed.: Nebraska Academy of Sciences and Affiliated Societies Proceedings, v. 92, p. 48-49.

Hendriks, H.E., 1965, The Crooked Creek structure in Snyder, F.G., and others, Cryptoexplosion structures in Missouri-Geological Society of Amercia Guidebook, 1965 Annual Meeting: State of Missouri Report of Investigations no. 30, p. 68-72.

Heyl, A.V., Jr., and McKeown, F.A., 1978,Preliminary seismotectonic map of the central Mississippi Valley and environs: U.S. Geological Survey Miscellaneous Field Studies Map MF-1011, scale 1:500,000.

Hildenbrand, T.G., Kane, M.F., and Stauder, S.J., 1977, Magnetic and gravity anomalies in the northern Mississippi embayment and their special relation to seismicity: U.S. Geological Survey Miscellaneous Field Studies Map MF- 914, scale 1:1,000,000.

Jorgensen, D.G., Helgesen, J.O., Leonard, R.B., and Signer, D.C., 1986, Equivalent freshwater head and dissolved-solids concentration of water in rocks of Cambrian, Ordovician, and Mississippian age in the northern Midcontinent, U.S.A.: U.S. Geological Survey Miscellaneous Field Studies Map MF-1835-B, scale 1:1,000,000.

Kidwell, A.L., 1947, Post-Devonian igneous activity in southeastern Missouri: State of Missouri Department of Business and Administration, Division of Geological Survey and Water Resources, Report of Investigations no. 4, 83P-

Kisvarsanyi, E.B., and Howe, W.B., 1983a, The southeast Missouri minerals district and its relationship to post-Precambrian igneous activity: Missouri Geological Survey map no. OFM-83-170a-GI, scale 1:250,000.

____1983b, Bee Fork center contoured on the top of the volcaniclastic facies: Missouri Geological Survey map no. OFM-83-170b-GI, scale 1:24,000.

____1983c, Cross section A-A', Bee Fork:Missouri Geological Survey map no. OFM-83- 170C-GI.

____1983d, Isopach map of volcaniclastic facies in the lower Bonneterre Formation along the Viburnum trend (Bee Fork area): Missouri Geological Survey map no. OFM-83-170d-GI, scale 1:24,000.

.1983e, The Bee Fork volcanic center and itsrelationship to the southeast Missouri lead-

zinc district: Geological Society of America Abstracts with Programs, v. 15, no. 6, p. 614.

Kisvarsanyi, E.B., Pratt, W.P., and Heyl, A.V., Jr., 1981, Fluorine-thorium and rare-earth-bearing kimberlitic carbonatite complexes, in Pratt, W.P., ed., Metallic mineral resource potential of the Rolla 1" x 2* quadrangle, Missouri, as appraised in September, 1980: U.S. Geological Survey Open-File Report 81-518, p. 35-40.

Knight, G.L., and Landes, K.K., 1932, Kansaslaccoliths: Journal of Geology, v. 40, p. 1-15.

Koenig, J.B., 1956, The petrography of certain igneous dikes of Kentucky: Kentucky Geological Survey Series 9, Bulletin 21, 57 p.

LaBerge, G.L., and Meyers, P.E., 1983, Precambrian geology of Marathon County, Wisconsin: Wisconsin Geological and Natural History Survey, Information Circular 45, 88 p.

Lewis, Richard, 1982, Petrology and mineralogy of the monticellite alnoite associated with the Omaha oil field, Gallatin County, Illinois: Geological Society of America Abstracts with Programs, v. 14, no. 5, p. 265.

Lockwood, R.P., 1967, Petrologic study of syenites near Wausau, Wisconsin: University of Wisconsin at Madison M.S. thesis, 72 p.

____1970, Petrology of syenites, Wausau,Wisconsin: The Compass of Sigma Gamma Epsilon, v. 48, no. 1, p. 32-44.

Mansker, W.L., Richards, B.D., and Cole, G.P., 1985, A review and comparison of Kansas kimberlites: Geological Society of America Abstracts with Programs, v. 17, no. 3, p. 166.

Marvin, R.F., compiler, 1988, Radiometric ages ofbasement rocks in the northern Midcontinent, U.S.A.: U.S. Geological Survey Miscellaneous Field Studies Map MF-1835-C, scale 1:1,000,000.

McDowell, R.C., Grabowski, G.J., Jr., and Moore, S.L., 1981, Geologic map of Kentucky: U.S. Geological Survey in cooperation with 10th and llth Kentucky Geological Surveys, scale 1:250,000.

Meyer, H.O.A., and Brookins, D.G., 1976,Sapphirine, sillimanite, and garnet in granulite xenoliths from Stockdate kimberlite, Kansas: American Mineralogist, v. 61, p. 1194-1202.

Mugel, D.N., compiler, 1986, Map showing availability of data for selected deep drill holes in the northern Midcontinent, U.S.A: U.S. Geological Survey Miscellaneous Field Studies Map MF-1835-A, scale 1:1,000,000.

Offield, T.W., and Pohn, H.A., 1979, Geology of the Decaturville impact structure, Missouri: U.S. Geological Survey Professional Paper 1042, 48 p.

Pratt, W.P., compiler, 1987, lospach and lithofacies map of the Sauk sequence (excluding basal elastics) in the northern Midcontinent, U.S.A.:

U.S. Geological Survey Miscellaneous Field Studies Map MF-1835-D, scale 1:1,000,000.

Sayeed, U.A., Smith, R., and Carlson, M,P., 1972, Geophysical anomaly around Stella, Richardson Co., Nebraska: Geolcqical Society of America Abstracts with Programs, v. 4, no. 6, p. 407.

Sims, P.K., compiler, 1990, Precambrian basement map of the northern Midcontinent, U.S.A.: U.S. Geological Survey Miscellaneous Investigations Series Map I-1853-A, scale 1:1,000,000.

Snyder, F.G., and Gerdemann, P.E., 1965, Explosive igneous activity along an Illinois-Missouri- Kansas axis: American Journal of Science, v. 263, p. 465^493.

Snyder, F.G., Williams, J.H., and others, 1965, Cryptoexplosive structures in Missouri- Geological Society of America GuHebook, 1965 Annual Meeting: State of Missouri Report of Investigations no. 30, 73 p.

Trace, R.D., 1966, Geologic map of the Marionquadrangle, Crittenden and Caldw^ll Counties, Kentucky: U.S. Geological Surveu Geologic Quadrangle Maps of the U.S., Map GQ-547, scale 1:24,000.

Trace, R.D., and Amos, D.H., 1984, Stratigraphyand structure of the western Kentucky fluorite district: U.S. Geological Survey Professional Paperll51-D,41p.

Treves, S.B., Burchett, R.R., and Low, E.J., 1982, Precambrian investigations in eastern Nebraska: Geological Society of America Abstracts with Programs, v. 14, ro. 3, p. 138.

Wagner, H.C., 1954, Geology of the Fredoniaquadrangle, Kansas: U.S. Geolog'cal Survey Geologic Quadrangle Map GQ-49, scale 1:62,500.

Wagner, R.E. and Kisvarsanyi, E.B., 1969, Lapilli tuffs and associated pyroclastic sediments in Upper Cambrian strata along Dent Branch, Washington County, Missouri: Missouri Geological Survey and Water Resources Report of Investigations no. 43, 80 p.

Weller, J.M., Grogan, R.M., and Tippie, F.E., 1952, Geology of the fluorspar deposits of Illinois: Illinois State Geological Survey Bu"etin 76, 147 p.

Weller, Stuart, and Sutton, A.H., 1951, Geology of the western Kentucky fluorspar district: U.S. Geological Survey Mineral Investigations Field Studies Map MF-2, scale 1:24,000.

Willman, H.B., and others, compilers, 1967, Geologic map of Illinois: Illinois State Geological Survey, scale 1:500,000.

Zartman, R.E., Brock, M.R., Heyl, A.V., Jr., andThomas, H.H., 1967, K-Ar and RV Sr ages of some alkalic intrusive rocks from central and eastern United States: American .Journal of Science, v. 265, p. 848-870.

Tab

le 1

. Sum

mar

y of

pet

rolo

gy,

stru

ctur

al i

nfor

mat

ion,

and

pri

mar

y re

fere

nces

on

alka

line

igne

ous

rock

s, c

arbo

natit

es,

and

peri

doti

tes

in t

he n

orth

ern

Mid

cont

inen

t ar

ea

[Lea

ders

(-)

, in

form

atio

n no

t av

aila

ble]

Loca

lity

Roc

k ty

pe

No.

Feat

ure

or

stru

ctur

eD

escr

iptio

nR

efer

ence

s

AR

KA

NSA

SG

reen

e C

ount

y:

GR

1M

agne

tic a

nd

grav

ity a

nom

aly.

Maf

ic o

r ul

tram

afic

int

rusi

on i

terp

rete

d fr

om m

agne

tic a

nd

grav

ity a

nom

alie

s.H

ilden

bran

d an

d ot

hers

(1

977)

.

ILLI

NO

ISFr

ankl

in C

ount

v:

FR

1M

afic

alk

alin

e ig

neou

s ro

ck.

Gal

latin

Cou

ntv.

Om

aha

dom

e:

GA

1

Mic

a pe

ridot

ite

Dik

e

Dik

es a

nd s

ills

Gal

latin

Cou

ntv.

Sha

wne

etow

n di

kes:

GA

2

Igne

ous

rock

D

ike

GA

3

Igne

ous

rock

-

GA

4

Igne

ous

rock

-

GA

5

Igne

ous

rock

-

GA

6

Igne

ous

rock

-

Har

din

Cou

nty,

Hic

ks D

ome

and

near

by a

reas

:

HA

1

- D

iatre

me

or p

lug

Igne

ous

rock

s pe

netr

ated

by

drill

hol

es in

Om

aha

oil f

ield

. Sm

all d

ikes

and

sill

s ne

ar s

urfa

ce d

escr

ibed

as

serp

entin

ized

mic

a pe

ridot

ite.

Two

thic

k sil

ls of

m

ontic

ellit

e al

noite

at

unsp

ecifi

ed d

epth

acc

ount

for

st

ruct

ural

rel

ief

of t

he O

mah

a do

me.

Pe

rovs

kite

, m

elan

ite,

and

Cr-

mag

netit

e re

port

ed in

aln

oite

.

Drill

hol

e pe

netr

atin

g un

desc

ribed

ign

eous

roc

k

Drill

hol

e pe

netr

atin

g un

desc

ribed

ign

eous

roc

k

Drill

hol

e pe

netr

atin

g un

desc

ribed

ign

eous

roc

k

Dril

l hol

e pe

netr

atin

g un

desc

ribed

ign

eous

roc

k

Hey

l an

d M

cKeo

wn

(197

8).

Bic

kerm

an a

nd o

ther

s,

(198

2);

Cle

gg a

nd

Bra

dbur

y (1

956)

; En

glis

h an

d G

roga

n (1

948)

; Le

wis

(198

2).

Will

man

and

oth

ers

(196

7).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Will

man

and

oth

ers

(196

7).

HA

2

Igne

ous

rock

Dik

es a

nd u

ncla

ssifi

ed

mas

ses.

Two

dike

s an

d tw

o ig

neou

s m

asse

s of

unc

erta

in f

orm

Cle

gg a

nd B

radb

ury

(195

6).

HA

S Ig

neou

s ro

ck

HA

4

Bre

ccia

con

tain

ing

igne

ous

rock

fr

agm

ents

.

HA

S

HA

6

HA

7

Bre

ccia

con

tain

ing

igne

ous

rock

fr

agm

ents

and

ig

neou

s m

iner

als.

Mic

a pe

ridot

ite,

lam

prop

hyre

.

Bre

ccia

Alte

red

mic

a pe

ridot

ite o

r la

mpr

ophy

re.

Har

din

Cou

nty.

Ros

icla

re d

ikes

:

HA

8

Bre

ccia

Alte

red

mic

a pe

ridot

ite.

Phila

delp

hia

Scho

ol

dike

.

Plug

or

diat

rem

e of

Sp

arks

Hill

.

Plug

s or

dia

trem

es

of H

icks

dom

e.

Dik

es o

f H

icks

dom

e

Plug

or

diat

rem

e (G

rant

s pl

ug o

f C

legg

and

B

radb

ury,

195

6).

Cry

stal

dik

e

Plug

or

diat

rem

e (S

owar

d pl

ug).

Arg

o di

kes

Ang

ular

to

suba

ngul

ar f

ragm

ents

of

rock

(ch

iefly

sed

imen

­ ta

ry b

ut s

ome

frag

men

ts o

f ig

neou

s an

d m

etam

orph

ic

rock

s fr

om b

asem

ent a

nd p

ossi

bly

from

man

tle)

in h

ighl

y al

tere

d m

atrix

con

tain

ing

angu

lar

frag

men

ts o

f qu

artz

, m

usco

vite

, pl

agio

clas

e, a

nd m

icro

clin

e.

(N1/

2NE

1/4

sec.

13,

T.

US

., R

. 8 E

.)

Frag

men

ts o

f ch

ert

and

silic

ified

roc

ks in

fin

e-gr

aine

d qu

artz

cem

ent,

and

frag

men

ts o

f se

dim

enta

ry r

ocks

in

mat

rix o

f fin

ely

grou

nd r

ock

and

quar

tz.

Con

tain

s ap

atite

gra

ins

and

rock

fra

gmen

ts t

houg

ht t

o be

ig

neou

s.

(Sec

. 30

. T.

11

S.,

R. 8

E.)

Frag

men

ts o

f m

etam

orph

osed

sed

imen

tary

roc

k an

d la

rge

piec

es o

f ho

rnbl

ende

and

bio

tite

(as

long

as

2.5

cm)

and

augi

te in

mat

rix o

f ca

lcite

with

ang

ular

qua

rtz a

nd

feld

spar

. (N

W1/

4NW

1/4

sec.

6, T

. 12

S.,

R. 8

E.)

K-A

r ag

es:

horn

blen

de 2

8111

4 M

a, b

iotit

e 25

8±13

Ma.

Fine

-gra

ined

cal

cite

with

sca

ttere

d ap

atite

. D

ike

15 c

m

wid

e in

roo

f of

flu

orsp

ar m

ine.

(S

haft

No.

4,

Cry

stal

M

ine,

SE

1/4N

E1/

4 se

c. 3

4, T

. 11

S.,

R. 9

E.)

Ang

ular

to

suba

ngul

ar f

ragm

ents

of

igne

ous

and

sedi

men

­ ta

ry r

ock

in h

ighl

y al

tere

d m

atrix

. A

ltere

d fr

agm

ents

of

mic

a, q

uartz

, pla

gioc

lase

, and

mic

rocl

ine.

(N

E1/

4SW

1/4

sec.

31,

T.

12 S

., R.

8 E

.)

Dik

es,

3-60

cm

wid

e, i

n flu

orsp

ar m

ine

on A

rgo

vein

. Fi

ne­

grai

ned,

dirt

y ca

lcite

with

abu

ndan

t ap

atite

and

sca

ttere

d,

tart

ly c

hbri

tizad

bio

tite.

(N

E1 '4

SW

1/4

sec.

3%

T.

12

S.,

R. 8

E.)

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6);

A.V

. H

eyl,

Jr.

(ora

l co

mm

un.,

1987

).

Bro

wn

and

othe

rs (

1954

); C

legg

and

Bra

dbur

y (1

956)

.

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6);

Zartm

an a

nd o

ther

s (1

967)

.

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Tab

le 1

. Sum

mar

y o

f pe

trol

ogy,

str

uctu

ral

info

rmat

ion,

and

pri

mar

y re

fere

nces

on

alka

line

igne

ous

rock

s, c

arbo

natit

es,

and

peri

doti

tes

in t

he n

orth

ern

Mid

cont

inen

t ar

ea

Co

nti

nu

ed

Loca

lity

No.

Roc

k ty

peFe

atur

e or

st

ruct

ure

Des

crip

tion

Ref

eren

ces

ILL

INO

IS C

ontin

ued

Har

din

Coun

ty;.

Ros

icla

re d

ikes

Con

tinue

d:

Goo

d H

ope

dike

Alte

red

mic

a pe

ridot

ite.

Alte

red

mic

a pe

ridot

ite.

Alte

red

mic

a pe

ridot

ite.

Alte

red

mic

a pe

ridot

ite.

Dik

e of

Orr

's La

ndin

g.

Unn

amed

dik

es

Dow

ney'

s Bl

uff

sill

Pope

Cou

nty,

Hic

ks d

ome

area

:

PO

1 B

recc

ia

Dia

trem

e or

plu

g

PO 2

B

recc

ia

PO

3 Ig

neou

s ro

ck

Pope

Cou

nty,

. D

ike$

:

PO 4

M

ica

perid

otite

Dia

trem

e or

plu

g

Unc

lass

ified

ign

eous

m

ass.

Mix

dik

e

Dik

e as

thic

k as

30

cm o

n G

ood

Hop

e ve

in in

flu

orsp

ar

min

e.

Chl

orite

and

qua

rtz w

ith a

bund

ant a

patit

e.

(NE

1/4N

W1/

4 se

c. 5

, T.

13 S

., R.

8 E

.)

Larg

e cr

ysta

ls o

f ca

lcite

and

les

s co

mm

only

of

serp

entin

e in

fin

e-gr

aine

d ca

rbon

ate

grou

ndm

ass.

A

bund

ant a

patit

e.

(SW

1/4N

E1/

4 se

c. 3

3, T

. 12

S.,

R. 8

E.)

Dik

es in

dia

mon

d dr

ill h

ole

at d

epth

s of

290

-375

m.

Mic

a an

d fe

w la

rge

augi

te g

rain

s in

gro

undm

ass

of

carb

onat

e an

d m

inor

ser

pent

ine.

A

bund

ant a

patit

e.

(NW

1/4S

W1/

4 se

c. 3

2, T

. 12

S.,

R. 8

E.)

Thin

ana

stom

osin

g sil

l in

lim

esto

ne o

utcr

op.

Aug

ite a

nd

mic

a cr

ysta

ls in

car

bona

te g

roun

dmas

s.

Abu

ndan

t ap

atite

. B

iotit

e K

-Ar a

ge 2

69±1

3 M

a.

Inco

mpl

etel

y de

scrib

ed.

Show

n as

dik

e by

Will

man

and

ot

hers

(19

67).

Tes

t pi

t un

cove

red

boul

ders

of

gran

itic

rock

.

Partl

y se

rpen

tiniz

ed o

livin

e, m

ica,

aug

ite,

and

apat

ite

pres

ent i

n bo

ulde

rs.

(NE

1/4N

E1/

4, s

ec.

18, T

. 13

S.,

R. 7

E.)

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6);

Zartm

an a

nd o

ther

s (1

967)

.

Bax

ter

and

othe

rs (

1967

); W

illm

an a

nd o

ther

s.

Bax

ter

and

othe

rs (

1967

); W

illm

an a

nd o

ther

s (1

967)

.

Cle

gg a

nd B

radb

ury

(195

6);

Wel

ler

and

othe

rs (

1952

); W

illm

an a

nd o

ther

s (1

967)

.

Cle

gg a

nd B

radb

ury

(195

6).

PO 5

M

ica

perid

otite

Gol

cond

a di

keC

legg

and

Bra

dbur

y (1

956)

.

Salin

e C

ount

y r E

ldor

ado

dike

s:

SA 1

Ig

neou

s ro

ck

Dik

es(?

)

SA 2

M

ica

perid

otite

SA 3

Ig

neou

s ro

ck

SA 4

M

ica

perid

otite

SA 5

Ig

neou

s ro

ck

Will

iam

son

Cou

nty:

WM

1

Mic

a pe

ridot

ite

Der

ing

dike

s

Dik

es(?

)

Dik

es

Dik

es

Abs

her

dike

s

Serp

entin

e an

d m

ica

with

min

or p

yrox

ene

and

apat

ite.

Kno

wn

from

bou

lder

s fr

om o

ld p

rosp

ect p

it.

(SW

1/4N

E1/

4 se

c. 2

5, T

. 13

S.,

R. 6

E.)

Seve

ral u

ndes

crib

ed d

ikes

or

sills(

?).

One

is 1

50 m

long

, ab

out

10 m

wid

e, a

nd c

uts

Penn

sylv

ania

n ro

cks;

ano

ther

is

mor

e th

an 1

,200

m lo

ng.

K-A

r age

261

±9 M

a.

Dik

es in

coa

l min

e.

As

thic

k as

5 m

. La

rge

grai

ns o

f se

rpen

tine

and

partl

y ch

lorit

ized

mic

a in

gro

undm

ass

of

serp

entin

e an

d ch

lorit

e.

Min

or a

patit

e.

(SE

1/4N

E1/

4 se

c. 2

4, T

. 8

S.,

R. 6

E.)

Und

escr

ibed

, nu

mer

ous

dike

s an

d sil

ls(?)

Seve

ral d

ikes

in c

oal m

ine.

La

rge

grai

ns o

f se

rpen

tine

in

grou

ndm

ass

of c

hlor

ite a

nd s

erpe

ntin

e.

Scat

tere

d cl

inop

yrox

ene

and

mic

a.

Abu

ndan

t apa

tite.

(S

E1/

4NE

1/4

sec.

17,

T.9

S.,

R. 6

E.)

Mai

nly

unde

scrib

ed d

ikes

. Jo

hn N

elso

n (w

ritte

n co

mm

un.,

1987

) re

port

ed m

ica

perid

otite

dik

e, 5

-6 m

wid

e, in

coa

l m

ine.

Se

vera

l sm

all d

ikes

par

alle

l lar

ger

dike

, whi

ch s

trike

s ab

out N

. 35*

W.

A 3

0-cm

-wid

e di

ke o

f ca

rbon

ate

rock

st

rikes

nor

thea

st.

Mag

netic

sur

vey

sugg

ests

con

tinua

tion

of d

ike

for a

bout

3.2

km

. (S

E1/

4 se

c. 1

1, T

. 20

S.,

R. 5

E.)

Two

para

llel d

ikes

, 0.3

-5.2

m w

ide,

in a

band

oned

stri

p m

ine.

C

legg

and

Bra

dbur

y (1

956)

; Ph

enoc

ryst

s of

mic

a an

d pa

rtly

serp

entin

ized

oliv

ine

and

Cle

gg (

1955

). hy

pers

then

e in

gro

undm

ass

of b

iotit

e, c

hlor

ite,

and

apat

ite.

Cle

gg a

nd B

radb

ury

(195

6);

John

Nel

son

(writ

ten

com

mun

., 19

87).

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6),

Cle

gg a

nd B

radb

ury

(195

6).

Cle

gg a

nd B

radb

ury

(195

6);

Will

man

and

oth

ers

(196

7)

Tab

le 1

. S

um

mar

y o

f pe

trol

ogy,

str

uctu

ral

info

rmat

ion,

and

pri

mar

y re

fere

nces

on

alka

line

igne

ous

rock

s, c

arbo

natit

es,

and

peri

doti

tes

in t

he n

orth

ern

Mid

cont

inen

t ar

ea

Co

nti

nu

ed

Loca

lity

No.

Roc

k ty

peFe

atur

e or

st

ruct

ure

Des

crip

tion

Ref

eren

ces

KA

NSA

SRi

lev

Cou

ntu:

RI 1

Mic

aceo

us k

imbe

rlite

D

iatre

me

or p

ipe

R12

Lam

prop

hyric

ki

mbe

rlite

.D

iatre

me

or p

ipe

00

RI3

Lam

prop

hyric

ki

mbe

rlite

.D

iatre

me

or p

ipe

Circ

ular

stru

ctur

e 30

0 m

in

diam

eter

with

rel

ief

of a

bout

B

rook

ins

(197

0a,

b);

15 m

. O

rigin

ally

cal

led

Win

kler

cra

ter

and

thou

ght t

o be

B

eren

dsen

and

oth

ers

an a

stro

blem

e.

Dril

ling

and

trenc

hing

rev

eale

d ki

mbe

rlite

(1

985)

. m

ixed

with

fra

gmen

ts o

f co

untr

y ro

ck.

Pyro

clas

tic

mat

eria

l in

dica

tes

that

kim

berli

te r

each

ed t

he C

reta

ceou

s su

rfac

e.

Min

eral

s in

kim

berii

te-b

earin

g zo

nes

are:

ch

lorit

ized

phl

ogop

ite,

fors

terit

ic o

livin

e, k

elyp

hitiz

ed

pyro

pe,

dino

pyro

xene

, or

thop

yrox

ene,

ilm

enite

, pe

rovs

kite

, m

agne

tite-

bear

ing

serp

entin

e, a

nd a

patit

e.

Ran

dolp

h N

o. 1

kim

berli

te f

orm

s a

3-m

-hig

h kn

oll a

bout

60

Cul

lers

and

oth

ers

(198

2).

m in

dia

met

er.

Lim

esto

ne c

ount

ry r

ocks

are

upw

arpe

d at

co

ntac

t but

sho

w n

o co

ntac

t m

etam

orph

ism

. K

imbe

rlite

sh

ows

min

imum

bre

ccia

tion,

is

porp

hyrit

ic,

and

cont

ains

as

muc

h as

25

perc

ent

phen

ocry

sts.

Ph

enoc

ryst

s ar

e se

rpen

­ tin

e, c

alci

te, h

emat

ite, a

nd b

lack

oxi

des

that

form

ed f

rom

ol

ivin

e an

d py

roxe

ne.

Gro

undm

ass

is f

ine-

grai

ned

lizar

dite

, ca

lcite

, an

d iro

n ox

yhyd

roxi

des.

C

onta

ins

few

xen

olith

s.

Ran

dolp

h N

o. 2

kim

berli

te fo

rms

a to

pogr

aphi

c hi

gh 1

5 m

in

dia

met

er.

Con

tact

s w

ith c

ount

ry r

ock

wer

e ex

pose

d by

tren

chin

g an

d dr

illin

g.

Pipe

app

ears

to h

ave

a m

ushr

oom

-like

cap

ind

icat

ing

that

kim

berli

te m

ay h

ave

have

intru

ded

to th

e su

rfac

e.

Com

posi

tion

sim

ilar

to

kim

berli

te o

f the

Ran

dolp

h N

o. 1

. Fe

w x

enol

iths

and

few

meg

asco

pic

pseu

dom

orph

s of

ser

pent

ine

afte

r ol

ivin

e.

Pyro

pe a

nd p

hlog

opite

abs

ent.

Cul

lers

and

oth

ers

(198

2);

Bro

okin

s (1

970b

).

RI 4

M

icac

eous

kim

berli

te

Dia

trem

c or

pip

e

RI 5

M

icac

eous

kim

berli

te

Dia

trem

e or

pip

e

RI 6

La

mpr

ophy

ric

kim

berli

te.

Dia

trem

e or

pip

e

RI 7

RI 8

Kim

berli

te

Kim

berli

te

Dia

trem

e or

pip

e

Dia

trem

e or

pip

e

RI 9

RI 1

0

Kim

berli

te

Kim

berli

te

Dia

trem

e or

pip

e

Dia

trem

e or

pip

e

Kim

berli

te n

ear

Leon

ardv

ille

is po

orly

exp

osed

in t

wo

smal

l m

ound

s. Tr

ench

es e

xpos

e a

stee

ply

dipp

ing

cont

act

with

co

untry

roc

k.

Kim

berli

te is

por

phyr

itic

and

cont

ains

as

muc

h as

30

perc

ent p

heno

crys

ts (

as la

rge

as 5

mm

) of

ol

ivin

e an

d py

roxe

ne, a

ltere

d to

cal

cite

, ser

pent

ine,

or

mag

netit

e, w

ith a

few

phe

nocr

ysts

of

pyro

pe,

phlo

gopi

te,

and

mag

netit

e.

Fine

-gra

ined

gro

undm

ass

of s

erpe

ntin

e w

ith le

sser

phl

ogop

ite, o

paqu

e ox

ides

, ca

lcite

, and

gar

net.

As

muc

h as

10

perc

ent x

enol

iths

of s

hale

con

tain

ing

finel

y di

ssem

inat

ed c

alci

te.

Kim

berli

te n

ear

Stoc

kdal

e cr

ops

out i

n a

stre

am b

ed a

nd

is th

orou

ghly

bre

ccia

ted

and

porp

hyrit

ic,

with

as

muc

h as

20

per

cent

phe

nocr

ysts

(as

larg

e as

2 m

m)

of s

erpe

ntin

e (p

seud

omor

phou

s af

ter

oliv

ine

and

pyro

xene

) an

d ph

logo

pite

, in

a fin

e-gr

aine

d m

atrix

of

lizar

dite

with

min

or

calc

ite a

nd b

lack

oxi

des.

Con

tain

s ab

out

20 p

erce

nt

alte

red

xeno

liths

of d

unite

, ecl

ogite

, gab

bro,

am

phib

olite

, gr

anul

ite, I

herz

olite

, phy

llite

, and

sha

les.

Kim

berli

te a

t Bal

a fo

rms

a kn

oll 4

-5 m

hig

h an

d ab

out 6

0 m

in

dia

met

er.

It is

porp

hyrit

ic w

ith a

s m

uch

as 3

0 pe

rcen

t ph

enoc

ryst

s (a

s la

rge

as 2

mm

) of

oliv

ine

and

pyro

xene

(m

ostly

alte

red

to s

erpe

ntin

e, c

alci

te,

and

mag

netit

e) a

nd

a fe

w p

heno

crys

ts o

f py

rope

. G

roun

dmas

s is

serp

entin

e,

calc

ite, o

paqu

e ox

ides

, and

hem

atite

. C

onta

ins

few

xe

nolit

hs a

nd is

min

imal

ly b

recc

iate

d.

Kim

berli

te m

ass,

calle

d Lo

ne T

ree

A, i

s no

t exp

osed

at

surf

ace.

Sh

arpl

y di

ppin

g co

ntac

t with

cou

ntry

roc

k w

as e

xpos

ed b

y tre

nchi

ng.

Loca

ted

appr

oxim

atel

y 60

0 m

nor

thw

est o

f ki

mbe

rlite

nea

r St

ockd

ale.

Kim

berli

te m

ass,

calle

d Lo

ne T

ree

B, w

as e

xpos

ed b

y tre

nchi

ng.

Tren

ches

rev

eal a

ste

eply

dip

ping

con

tact

w

ith c

ount

ry r

ock.

Th

is m

ass

is sm

alle

r th

an L

one

Tree

A

mas

s, an

d is

loca

ted

abou

t 25

0 m

nor

thw

est o

f Lo

ne

Tree

A m

ass.

Kim

berli

te a

t Sw

ede

Cre

ek is

a s

mal

l mas

s an

d is

not

expo

sed

at s

urfa

ce.

Tren

ches

exp

osed

wea

ther

ed

kim

berli

tic m

ater

ial

and

a co

ntac

t with

cou

ntry

rock

.

Kim

berli

te a

t Fa

ncy

Cre

ek is

exp

osed

at s

urfa

ce,

but i

s m

ostly

cov

ered

by

a fa

rm p

ond.

K

imbe

rlite

mas

s is

abou

t 10

0 m

in d

iam

eter

and

has

a r

ough

ly c

ircul

ar o

utlin

e.

Bro

okin

s (1

970b

); C

ulle

rs

and

othe

rs (

1982

).

Bro

okin

s (1

970b

); C

ulle

rs

and

othe

rs (

1982

); M

eyer

an

d B

rook

ins

(197

6).

Bro

okin

s (1

970b

); C

ulle

rs

and

othe

rs (

1982

).

Ber

ends

en a

nd o

ther

s (1

985)

; M

ansk

er a

nd

othe

rs (

1985

).

Ber

ends

en a

nd o

ther

s (1

985)

; M

ansk

er a

nd

othe

rs (

1985

).

Ber

ends

en a

nd o

ther

s (1

985)

; M

ansk

er a

nd

othe

rs (

1985

).

Ber

ends

en a

nd o

ther

s (1

985)

; M

ansk

er a

nd

othe

rs (

1985

).

Tab

le 1

. Sum

mar

y o

f pe

trol

ogy,

str

uctu

ral

info

rmat

ion,

and

pri

mar

y re

fere

nces

on

alka

line

igne

ous

rock

s, c

arbo

natlt

es,

and

peri

doti

tes

in t

he n

orth

ern

Mid

cont

inen

t ar

ea

Conti

nued

Loca

lity

No.

Roc

k ty

peFe

atur

e or

st

ruct

ure

Des

crip

tion

Ref

eren

ces

KA

NSA

S C

ontin

ued

Wils

on a

nd W

oods

on C

ount

ies:

WI

1 La

mpr

oite

Silv

er C

ity d

ome,

sil

ls.

Woo

dson

Cou

ntv:

WO

1

Lam

proi

teR

ose

dom

e

WO

2N

eosh

o do

me

WO

3D

ome

Sills

of

mic

a pe

ridot

ite a

s m

uch

as 9

m th

ick

intru

de

Penn

sylv

ania

n sh

ales

. R

ock

is po

rphy

ritic

, co

nsis

ting

of e

uhed

ral

to s

ubhe

dral

phl

ogop

ite, d

iops

ide,

pot

assi

c ric

hter

ite,

anhe

dral

ser

pent

ine

pseu

dom

orph

s af

ter

oliv

ine,

and

chr

ome

spin

el in

a g

roun

dmas

s of

mos

tly

serp

entin

e.

Acc

esso

ry m

iner

als

are

pero

vski

te,

apat

ite,

and

mag

netit

e.

Sills

con

tain

a f

ew g

rani

tic x

enol

iths.

U

ltram

afic

roc

ks o

f W

ilson

and

Woo

dson

Cou

ntie

s di

ffer

fro

m t

hose

of

Rile

y C

ount

y in

tha

t th

ey a

re n

ot

exte

nsiv

ely

mic

robr

ecci

ated

and

con

tain

les

s th

an 5

pe

rcen

t xen

olith

s.

Bio

tite

K-A

r age

s ab

out

90±5

Ma.

Roc

ks d

isco

vere

d by

dril

ling

are

petro

grap

hica

lly s

imila

r to

tho

se o

f Si

lver

City

dom

e.

Mas

s in

trude

s Pe

nnsy

l­ va

nian

sha

le a

nd c

onta

ins

a fe

w g

rani

tic x

enol

iths

date

d at

abo

ut 1

,200

Ma.

M

iner

als

in u

ltram

afic

roc

ks in

clud

e 25

per

cent

or

mor

e eu

hedr

al to

sub

hedr

al p

hlog

opite

and

le

ss t

han

5 pe

rcen

t ea

ch o

f an

hedr

al o

livin

e, e

uhed

ral t

o su

bhed

ral d

iops

idic

aug

ite, a

nd p

leoc

hroi

c eu

hedr

al to

sub

­ he

dral

am

phib

ole

phen

ocry

sts

in d

olom

itize

d, s

erpe

ntin

ized

gr

ound

mas

s.

Roc

k co

ntai

ns m

inor

apa

tite,

mag

netit

e,

and

iron-

rich

chro

mite

. B

iotit

e K

-Ar a

ge 8

8±4

Ma.

Dril

ling

in 1

927

reve

aled

an

ellip

tical

dom

e in

Mis

siss

ippi

an

sedi

men

tary

roc

ks,

but

no i

gneo

us r

ocks

wer

e fo

und.

H

ighl

y si

liceo

us r

ecry

stal

lized

roc

ks n

ot n

orm

ally

fou

nd

in l

ocal

sec

tion

sugg

est

a de

eper

ign

eous

mas

s.

Qua

rtzite

, m

agne

tite,

pyr

ite,

chal

copy

rite,

and

che

rt

wer

e no

ted

in d

rill c

uttin

gs.

Smal

l, w

ell-d

efin

ed d

ome.

H

ighl

y sil

icifi

ed d

rill c

uttin

gs,

sim

ilar

to t

hose

fro

m N

eosh

o do

me,

con

tain

ed m

agne

tite.

D

ome

has

clos

ure

of a

bout

8 m

and

stru

ctur

al r

elie

f of

ab

out

18 m

.

Kni

ght

and

Land

es (

1932

); B

ickf

ord

and

othe

rs (

1971

) Za

rtman

and

oth

ers

(196

7)

Wag

ner

(195

4);

Fran

ks

(195

9);

Snyd

er a

nd

Ger

dem

ann

(196

5);

Cul

ler

and

othe

rs (

1985

).

Kni

ght

and

Land

es (

1932

); B

ickf

ord

and

othe

rs

(197

1);

Zartm

an a

nd

othe

rs (

1967

); Sn

yder

an

d G

erde

man

n (1

965)

; C

ulle

rs a

nd o

ther

s (1

985)

.

Kni

ght

and

Land

es (

1932

); Sn

yder

and

Ger

dem

ann

(196

5).

Kni

ght

and

Land

es (

1932

).

KE

NT

UC

KY

Cri

ttend

en C

ount

y, H

ardi

n K

nob

dike

s:

CR

1

Lam

prop

hyre

D

ikes

Cri

ttend

en C

ount

y. C

aldw

ell

Spri

ngs

dike

:

CR

2

Peri

dotit

e D

ike

Liv

ings

ton

Cou

nty:

LI 1

L

ampr

ophy

re

Dik

es

Bas

ed o

n ge

nera

lized

des

crip

tion

of d

ikes

on

cite

d m

aps.

D

ark-

gray

, fin

e- to

med

ium

-gra

ined

, ho

locr

ysta

lline

la

mpr

ophy

re,

abun

dant

bio

tite,

dol

omite

, an

d ca

lcite

, an

d m

inor

mag

netit

e, l

euco

xene

, m

arca

site

, flu

orap

atite

, an

drad

ite,

pero

vski

te,

and

goet

hite

. M

any

dike

s co

ntai

n ab

unda

nt c

hlor

ite a

nd s

erpe

ntin

e.

Qua

rtz is

pre

sent

in

and

asso

ciat

ed w

ith v

eins

. D

ike

loca

tions

on

area

ge

olog

ic m

aps

and

in o

ther

rep

orts

are

not

con

sist

ent.

Wea

ther

ed p

erid

otite

, ab

out

1.5

m t

hick

Bas

ed o

n ge

nera

lized

des

crip

tion

of a

ll di

kes

on c

ited

map

s.

Dar

k-gr

ay,

fine-

to m

ediu

m-g

rain

ed, m

uch-

alte

red,

ho

locr

ysta

lline

lam

prop

hyre

. B

ulk

of a

ltere

d ro

cks

is ca

lcite

with

abu

ndan

t chl

orite

and

ser

pent

ine,

alte

red,

da

rk-b

row

n bi

otite

, an

d ab

unda

nt n

eedl

es o

f ap

atite

; so

me

mag

netit

e an

d ilm

enite

. T

he t

hree

nor

th-tr

endi

ng

dike

s ar

e fr

om n

orth

to

sout

h, S

unde

rland

dik

e,

Lash

er-R

obin

son

dike

, and

Hut

son

dike

.

Engl

ehar

dt (

1973

); H

eyl

and

McK

eow

n (1

978)

; K

oeni

g (1

956)

; M

cDow

ell

and

othe

rs

(198

1);

Tra

ce (

1966

); W

elle

r an

d Su

tton

(195

1).

Koe

nig

(195

6).

Am

os (

1967

); E

ngle

hard

t (1

973)

; K

oeni

g (1

956)

; M

cDow

ell

and

othe

rs

(198

1);

Tra

ce a

nd A

mos

(1

984)

; Wel

ler a

nd

Sutto

n (1

951)

.

MIS

SOU

RI

Cra

wfo

rd C

ount

y:

CF

1 B

recc

iate

d se

dim

en­

tary

roc

ks.

Cro

oked

Cre

ek

stru

ctur

e.Sy

nclin

al r

ing

grab

en w

ith d

efor

med

, el

liptic

al, u

plift

ed,

cent

ral a

rea.

Ex

tens

ive

brec

ciat

ion

of p

ost-P

reca

mbr

ian

rock

s in

bre

ccia

ted

zone

s, b

ut n

o ba

sic

or u

ltrab

asic

ig

neou

s ro

cks.

Sh

atte

r co

nes

com

mon

in c

entra

l ar

ea.

Loca

ted

at in

ters

ectio

n of

Cub

a fa

ult a

nd P

alm

er f

ault

zone

. Sn

yder

and

Ger

dem

ann

(196

5) i

nter

pret

ed s

truct

ure

as d

ia-

trem

e; H

endr

iks

(196

5) i

nter

pret

ed s

truct

ure

as a

stro

blem

e.

Hen

drik

s (1

965)

; O

ffie

ld

and

Pohn

(19

79);

Snyd

er

and

Ger

dem

ann

(196

5).

Tabl

e 1.

Sum

mar

y of

pet

rolo

gy,

stru

ctur

al i

nfor

mat

ion,

and

pri

mar

y re

fere

nces

on

alka

line

igne

ous

rock

s, c

arbo

natit

es,

and

peri

dotit

esin

the

nor

ther

n M

idco

ntin

ent

area

C

ontin

ued

Loca

lity

No.

Roc

k ty

peFe

atur

e or

st

ruct

ure

Des

crip

tion

Ref

eren

ces

MIS

SOU

RI

Con

tinue

dLa

cled

e Co

unty

;:

LC

1V

olca

nic

ash(

?)B

eds

Mag

netic

and

gr

avity

ano

mal

y.

New

Mad

rid

Cou

nty:

NM

1

Mic

aceo

usla

mpr

ophy

re.

New

Mad

rid a

nd D

unkl

ln C

ount

ies:

ND

1

Pem

isco

t C

ount

y:

PM 1

A

lkal

ine

igne

ous

rock

.

St.

Cla

ir Co

unty

;:

SC 1

Fa

ulte

d an

d br

ecci

ated

W

eaub

leau

cry

pto-

se

dim

enta

ry r

ocks

. ex

plos

ion

stru

ctur

e.

Vol

cani

c ro

cks

of H

azel

gree

n m

ay c

onsi

st o

f as

h an

d de

tritu

s in

terb

edde

d w

ith s

hatte

red

Upp

er a

nd M

iddl

e(?)

C

ambr

ian

Lam

otte

San

dsto

ne.

Kno

wle

dge

of o

ccur

renc

e ba

sed

on s

ingl

e dr

ill h

ole.

In

trusi

ve e

vent

thou

ght

to h

ave

occu

rred

dur

ing

Late

Cam

bria

n, c

onte

mpo

rane

ous

with

de

posi

tion

of t

he L

amot

te.

Igne

ous

rock

enc

ount

ered

in

drill

hol

e

Bur

ied

maf

ic o

r ul

tram

afic

int

rusi

on i

nfer

red

from

mag

netic

an

d gr

avity

sur

veys

.

Alk

alin

e ig

neou

s ro

ck p

enet

rate

d in

tw

o dr

ill h

oles

Zone

of

inte

nse

faul

ting

and

brec

ciat

ion

appr

oxim

atel

y 11

km

long

and

5 k

m w

ide.

Fa

ultin

g in

clud

es n

orm

al f

aults

bu

t is

chie

fly l

ow-a

ngle

thr

ust

faul

ts.

No

intru

sive

ig

neou

s ro

cks

know

n in

are

a.

Feat

ure

parti

ally

cov

ered

un

conf

orm

ably

by

undi

stur

bed

Penn

sylv

ania

n ro

cks.

Snyd

er a

nd G

erde

man

n (1

965)

.

Gro

hsko

pf (

1955

); H

eyl

and

McK

eow

n (1

978)

.

Hild

enbr

and

and

othe

rs

(197

7).

Bro

ck a

nd H

eyl

(196

1);

Hey

an

d M

cKeo

wn

(197

8).

Snyd

er a

nd o

ther

s (1

965)

; Sn

yder

and

Ger

dem

ann

(196

7).

St.

Fran

cois

and

Ste

. G

enev

ieve

Cou

ntie

s:

SF 1

Pe

ridot

ite

Avo

n di

atre

mes

SF 2

Pe

ridot

ite

Ste.

Gen

evie

ve C

ount

y:

SG 1

Pe

rido

tite

Out

crop

s(?)

Salin

e C

reek

dik

e

Stod

dard

and

NQW

Mad

rid C

ount

ies:

ST 1

-

Bloo

mfie

ld p

luto

n

Rey

nold

s C

ount

y:

RE 1

La

pilli

tuffs

, alte

red

volc

anic

mat

eria

l.D

iatre

mes

(?)

Intru

sive

mat

eria

l co

nsis

ts o

f pr

imar

y an

d se

cond

ary

calc

ite,

chie

fly s

econ

dary

qua

rtz,

pleo

chro

ic b

iotit

e, m

agne

tite,

po

tass

ium

fel

dspa

r, an

d pl

agio

clas

e.

Bio

tite

is co

mm

only

al

tere

d to

chl

orite

. A

cces

sory

min

eral

s in

clud

e ap

atite

an

d ga

rnet

. C

alci

te is

pse

udom

orph

ic a

fter

oliv

ine

and

pyro

xene

or a

mph

ibol

e.

Lapi

lli r

epor

ted.

B

iotit

e ag

es:

K-A

r 37

7+19

Ma,

Rb-

Sr 3

99±2

3 M

a (d

ated

mat

eria

l fro

m

S1/2

NW

1/4S

W1/

4 se

c. 1

8, T

. 35

N.,

R. 8

E).

Isol

ated

out

crop

s of

per

idot

ite

Kid

wel

l (1

947)

; Za

rtman

and

ot

hers

(19

67).

Hey

l an

d M

cKeo

wn

(197

8).

Kid

wel

l (19

47);

Zartm

an a

nd

othe

rs (

1967

).D

ark-

gree

nish

-gra

y pe

rido

tite

with

phe

nocr

ysts

of

alte

red

oliv

ine,

aug

ite,

and

biot

ite.

Incl

usio

ns o

f gr

anite

, qu

artz

ite, a

nd d

olom

ite u

sual

ly le

ss th

an 1

5 cm

in d

iam

eter

. C

hlor

ite i

s co

mm

on a

ltera

tion

prod

uct.

Acc

esso

ry m

iner

als

incl

ude

mag

netit

e, a

patit

e, a

nd g

arne

t. Se

cond

ary

quar

tz

pres

ent.

Dik

e is

1.5

m w

ide,

app

roxi

mat

ely

0.4

km lo

ng,

and

belie

ved

to b

e in

trude

d al

ong

east

-wes

t-tre

ndin

g fa

ult.

Bio

tite

ages

: K

-Ar 3

88±1

9 M

a,

Rb-

Sr 3

96±2

8 M

a.

Loca

ted

at S

E co

mer

sec

. 12

, T.

35 N

., R.

7 E

., in

bed

of

Salin

e C

reek

wes

t of

roa

d.

Loca

tion

show

n on

fig

ure

2.

Maf

ic o

r ul

tram

afic

int

rusi

on i

nter

pret

ed f

rom

mag

netic

and

H

ilden

bran

d an

d ot

hers

gr

avity

fie

lds.

(197

7).

Vol

cani

c ro

cks

at B

ee F

ork,

del

inea

ted

by 5

0 or

mor

e dr

ill

hole

s, c

onsi

st o

f la

pilli

tuf

fs, w

hich

gra

de l

ater

ally

into

be

dded

vol

cani

c as

h an

d vo

lcan

idas

tic f

acie

s in

Upp

er

Cam

bria

n B

onne

terr

e D

olom

ite.

Lapi

lli tu

ffs

cont

ain

alte

red

volc

anic

mat

eria

l with

rel

ict o

livin

e, p

hlog

opite

, an

d py

roxe

ne p

heno

crys

ts.

Evid

ence

for

fiv

e er

uptiv

e ce

nter

s in

vic

inity

of

Bee

For

k.

Max

imum

kno

wn

thic

knes

s of

vol

cani

c ro

cks

is 45

m.

Hey

l an

d M

cKeo

wn

(197

8);

Kis

vars

anyi

and

How

e (1

983a

, b,

c, d

, e);

Kis

vars

anyi

and

oth

ers

(198

1).

Tabl

e 1.

Sum

mar

y of

pet

rolo

gy,

stru

ctur

al i

nfor

mat

ion,

and

pri

mar

y re

fere

nces

on

alka

line

igne

ous

rock

s, c

arbo

natlt

es,

and

peri

dotit

esin

the

nor

ther

n M

idco

ntin

ent

area

C

onti

nued

Loca

lity

No.

Rock

type

Feat

ure

or

stru

ctur

eD

escr

iptio

nR

efer

ence

s

MIS

SOU

RI C

ontin

ued

Was

hing

ton

Cou

ntv:

WA

1

Tuff

aceo

us s

iltst

one

and

lapill

i tuf

fs,

carb

onat

ite.

Bed

ded

pyro

clas

tic

rock

s, di

atre

me(

?).

WA

2

Tuffi

site

Dia

trem

e(?)

Pyro

clas

tic r

ocks

at

Den

t B

ranc

h co

nsis

t of

phl

ogop

ite,

alte

red

oliv

ine

and

pyro

xene

, gar

net,

amph

ibol

e, il

men

ite,

mag

netit

e, a

nd p

erov

skite

. N

o m

elili

te n

oted

in g

roun

d-

mas

s. Cr

ysta

lline

cal

cite

of

poss

ible

car

bona

titic

orig

in

is pr

esen

t. Sm

all a

mou

nt o

f mill

erite

iden

tifie

d in

tuffs

. Py

rocl

astic

roc

ks c

rop

out

in d

itch

abou

t 10

0 m

wes

t of

inte

rsec

tion

of S

tate

Sup

plem

enta

ry H

ighw

ay C

and

Den

t B

ranc

h, (

sec.

3, T

. 35

N.,

R. 2

E.)

and

exte

nd f

or a

bout

0.

8 km

sou

th a

nd 2

.5 k

m n

orth

of

Hig

hway

C a

long

Den

t B

ranc

h.

Pyro

clas

tic m

ater

ial t

houg

ht to

hav

e be

en d

epos

­ ite

d in

sha

llow

-mar

ine

envi

ronm

ent a

nd r

ewor

ked

into

bed

­ de

d se

dim

enta

ry ro

cks.

Infe

rred

to b

e La

te C

ambr

ian

age.

Vol

cani

c ro

cks

at F

urna

ce C

reek

, di

scov

ered

in d

rill h

oles

, co

nsis

t of

lapi

lli o

f hi

ghly

alte

red

gree

n to

bla

ck b

asic

ig

neou

s ro

ck,

alon

g w

ith f

ragm

ents

of

gran

ite,

rhyo

lite,

sa

ndst

one,

and

san

dy d

olom

ite.

Lapi

lli c

onta

in c

hlor

ite,

carb

onat

e, p

hlog

opite

, m

agne

tite,

and

qua

rtz.

Dril

ling

indi

cate

s fu

nnel

-sha

ped

crat

er w

ith d

iam

eter

of

2.4

km in

U

pper

and

Mid

dle(

?) C

ambr

ian

Lam

otte

San

dsto

ne. U

pper

C

ambr

ian

Bon

nete

rre

Dol

omite

lies

und

istu

rbed

on

top

of

Hey

l and

McK

eow

n (1

978)

; K

isvar

sany

i an

d ot

hers

(1

981)

; Wag

ner a

nd

Kisv

arsa

nyi (

1969

).

Kisv

arsa

nyi

and

How

e,

(198

3a);

Snyd

er a

nd

Ger

dem

ann

(196

5);

Kisv

arsa

nyi

and

othe

rs

(198

1).

volc

anic

roc

ks, i

ndic

atin

g em

plac

emen

t dur

ing

Late

Cam

bria

n.

NEB

RA

SKA

John

son

and

Paw

nee

Cou

ntie

s:

JO 1

C

arbo

natit

ePl

ugC

arbo

natit

e ne

ar E

lk C

reek

dis

cove

red

by d

rillin

g ov

er p

osi­

tive

grav

ity a

nd m

agne

tic a

nom

alie

s. Ty

pica

l Pen

nsyl

va-

nian

sed

imen

tary

roc

ks u

nder

lain

by

iron-

rich

carb

onat

ites,

w

hich

con

tain

dol

omite

, ank

erite

, hem

atite

, chl

orite

, phl

og­

opite

, bar

ite,

and

quar

tz, w

ith le

sser

am

ount

s of

pyr

ite,

chal

copy

rite,

gal

ena,

and

ser

pent

ine.

G

eoph

ysic

al d

ata

indi

cate

a o

'lind

rical

mas

s w

ith r

adiu

s of

1.6

km

nea

r top

. A

vera

ge u

rani

um c

onte

nt o

f ca

rbon

atite

is 1

1.54

ppm

.

Har

lem

(19

82);

Trev

es

and

othe

rs (

1982

); B

rook

ins

and

othe

rs

(197

6).

Ric

hard

son

and

Nem

aha

Cou

ntie

s:

RN

1G

ravi

ty a

nd

mag

netic

ano

mal

y.N

orth

-sou

th-t

rend

ing

ellip

tical

gra

vity

ano

mal

y of

ar

ea a

nd 4

mill

igal

s re

lief.

Ver

tical

mag

neto

met

er s

urve

y re

veal

ed c

ircul

ar n

egat

ive

anom

aly

of a

bout

200

gam

mas

.

Saye

ed a

nd o

ther

s (1

972)

.

TE

NN

ESS

EE

Lake

Cou

ntv:

LA 1

A

lkal

ine

igne

ous

rock

.D

rill

hole

s pe

netr

atin

g al

kalin

e ig

neou

s ro

ckB

rock

and

Hey

l (1

961)

; H

ey

and

McK

eow

n (1

978)

.

WIS

CO

NSI

N

Mar

atho

n C

ount

y:

MA

1

Nep

helin

e sy

enite

, sy

enite

, fe

nite

, gr

anite

.

Pier

ce C

ount

y;

PI 1

Fa

ulte

d se

dim

enta

ry

rock

s, br

ecci

a pi

pe.

Com

posi

te

bath

olith

.

Rock

Elm

bre

ccia

pi

pe o

r cry

pto-

ex

plos

ion

stru

ctur

e.

Syen

ite c

ompl

ex a

t Wau

sau.

C

once

ntric

ally

zon

ed p

luto

ns

cons

istin

g of

(1)

out

er z

ones

of

feni

tized

vol

cani

c ro

cks,

(2)

disc

ontin

uous

zon

es o

f gn

eiss

ic n

ephe

line

syen

ite,

(3)

inne

r zo

nes

of s

yeni

te,

and

(4)

two

plut

ons

havi

ng

core

s of

gra

nite

tha

t in

vade

roc

ks o

f zo

nes

1-3.

A

bout

1,

500

mill

ion

year

s ol

d.

Gre

enbe

rg a

nd B

row

n (1

985)

; La

Ber

ge a

nd

Mye

rs (

1983

); Lo

ckw

ood

(196

7, 1

970)

.

Roc

k El

m s

truct

ure

is ne

arly

circ

ular

fea

ture

with

dia

met

er o

f C

ordu

a (1

985)

. ab

out 6

.5 k

m.

It ha

s rin

g bo

unda

ry fa

ult,

uplif

ted

cent

ral

area

, and

sed

imen

t-fill

ed r

ing

basi

n.

Cen

tral a

rea

has

appa

r­

ently

bee

n in

trude

d by

bre

ccia

pip

e co

ntai

ning

qua

rtz, f

elsit

e po

rphy

ry,

and

pota

ssiu

m f

elds

par

with

min

or g

rani

te,

cher

t, an

d am

phib

olite

. N

o as

soci

ated

sho

ck m

etam

orph

ic f

eatu

res

foun

d.

Gol

d an

d di

amon

ds h

ave

been

fou

nd w

ithin

Roc

k El

m

stru

ctur

e, w

hich

is o

f M

iddl

e to

Ear

ly O

rdov

icia

n ag

e._

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