Keith Christiansen 93 Giant Mo

7/24/2019 Keith Christiansen 93 Giant Mo

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SEG SP-2 GIANT ORE DEPOSITS

THE GENESIS OF GIANT PORPHYRY MOLYBDENUM DEPOSITS

J. D. Keith, E. H. Christiansen Department o

Geo!o"#, $ri"ham %o&n" 'ni(ersit# Pro(o, 'tah'.S.A., )*+*

an

R. $. Carten

'. S. Geo!o"ia! S&r(e#, /a0a# Shoo! o /ines

Reno, Ne(aa

'.S.A., )13-*3

A$STRACT

Giant porph#r# mo!#4en&m eposits are 4est e5emp!iie4# the C!ima5

an Henerson eposits in Co!orao. The hi"h "raes o these eposits are

pro4a4!# inherite rom ma"mati mo!#4en&m onentrations o a4o&t * to

ppm, 6hih are hi"h or meta!&mino&s rh#o!iti ma"mas that a(era"e a4o&t 2

ppm mo!#4en&m. Hi"h ma"mati mo!#4en&m onentrations in meta!&mino&s

ro0s appear to 4e re!ate to hi"h ma"mati o5#"en &"aities 72 or 8 !o" &nits

a4o(e 9:/ o5#"en 4&er; an are orre!ate 6ith hi"h nio4i&m onentrations.

Hi"h o5#"en &"aities are !i0e!# inherite rom a!-a!0a!ine or !amproph#ri

preeessors. Hi"h nio4i&m an mo!#4en&m are re!ate to e5treme rationationo rh#o!iti ma"mas. /&h hi"her onentrations o mo!#4en&m 7 < =,ppm;

in the ore !&i 7an the &po!a ma"ma; are pro4a4!# ahie(e4# r#sta!!i>ation

in the eeper portions o a ma"ma ham4er aompanie 4# on(etion o the

e(o!(e !i?&i to the &po!a an (o!ati!e !&5in".

E5p!oration riteria or a "iant, hi"h-"rae eposit in!&e@ =; a tetoni

settin" that iniates a han"eo(er rom ompressiona! to e5tensiona! tetonis,

2; thi0 ontinenta! r&st at the time o eposit ormation ma# eno&ra"e e5treme

ierentiation an r&sta! ontamination, 8; an isotopia!!# >one ma"ma ham4er

iniati(e o a !on"-!i(e heat so&re, *; a !ar"e, s&4-(o!ani, entra!-(ent

ash

!o6ome s#stem that er&pte !ess than = km3 o rh#o!ite, an ; hi"h nio4i&monentrations 7 < 3 ppm; in a s&4a!0a!ine, ma"netite-4earin" rh#o!ite.

2)

INTROD'CTION

The "rae an tonna"e ata o eah

eposit ite in this paper, as 6e!! as the

assi"nment o eah eposit to a "enera! !ass

7Ta4!e =;, is moiie rom the s#stem

presente in Carten et a!. 7in press;. Deposits

!iste in Ta4!e I are "eo"raphia!!# !oate in

:i"&re =. Deposits onsiere in this paper

are restrite to porph#r# /o eposits 6hih

harateristia!!# o not ontain reo(era4!e

C& an porph#r# /o-C& eposits 6hih

ontain opro&t or 4#pro&t C& an "raes

o /o 6hih a(era"e "reater than .% /o .


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2)+ SEG SP-2 GIANT ORE DEPOSITSSEG SP-2 GIANT ORE DEPOSITS 2)3

Ta4!e 1. Grae an tonna"e o "ranite-re!ate /o an /o-C& eposits 7moiie ater

Carten et a!., in press;.

Produ!ion " r#$#r%#$

% Mo % &u m#!ri

D#'o$i!$ oun!r( )r*d# )r*d# !on$ u!o++,1-

GRANITE-REBATED No/ HIGH-SIBICA RH%OBITE-ABKABINE S'ITE

10 &im*2 US&O -.1 45 -.1- min#*6#

-.7- 5-4 )#oo)i

0 H#nd#r$on US&O -.57 -.18- )#oo)i

% Mor#+#r#n#

S.R. 9**#: '#r$. omm.: 155-

S.R. 9**#: '#r$. omm.:

155- un'u6i$;#d d*!*

-.8 -.1- )#oo)i un'u6i$;#d d*!*

-.141 44 -.-- )#oo)i

30 Ur*d US&O -.-5 1 min#d

Bi) B#n USMT -.-5- 1-5 -.-3 min#*6#

-.-58 34 -.-- )#oo)i


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SEG SP-2 GIANT ORE DEPOSITS 2)3

310 E*$! ?ounr*d UR?H -.1 -.-- 181 -.-3- )#oo)i ?. Ro2o J D.E. R*n!*

=ri!. omm.: 158

-.-87


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.(


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SEG SP-2 GIANT ORE D EPOSITS 2)121 SEG SP-2 GIANT ORE DEPOSITS

7Ta4!e = Carten et aI., in press;. Porph#r#

/o eposits are &rther s&4i(ie into those

assoiate 6ith hi"h-si!iCa or a!0a!ine rh#o!ites

6hih are rih in potassi&m, !&orine, an

inompati4!e trae e!ements an are

e5emp!iie 4# the C!ima5 eposit 7a!4eit apremier e5amp!e;, an those assoiate 6ith

!ess si!ii "ranitois that e5hi4it a(era"e

onentrations o !&orine an inompati4!e

e!ements.

E5amination o the "rae an tonna"e

o += porph#r# /o an /o-C& eposits 7:i".

2; iniates that a ontin&&m in eposit "raes

an tonna"es ma# e5ist ho6e(er, most

eposits onsist o to 2 mi!!ion tons o

ore, 4&t on!# =2 eposits ontain more than

2 mi!!ion tons o ore. These =2 eposits an4e onsiere "iant in terms o tonna"e, 4&t

on!# t6o eposits - C!ima5 an Henerson -

ontain o(er 2 mi!!ion tons o hi"h-"rae

ore 7:i". = an 2;. C!ear!#, the .most

eonomia!!# esira4!e mo!#4en&m eposit

m&st 4e in this !ass an 4e "iant in terms

o 4oth tonna"e 7-2 mi!!ion tons; an "rae

, .=% /o;. Proesses an ators 6hih

ontri4&te to the e(e!opment o these t#pes

o eposits 6i!! 4e emphasi>e.

The "enesis o these eposits in !i"hto more reent 6or0 on the partitionin"

4eha(ior . an ma"mati a4&nanes o

mo!#4en&m 6i!! a!so 4e re(ie6e. Inasm&h

as C!ima5-t#pe ma"mas are oten e?&ate

6ith topa> rh#o!ites, reent st&ies on the

e(o!&tion o topa> rh#o!ites 6i!! 4e e5amine

a!on" 6ith the (o!ani ro0s that are

o"eneti 6ith the C!ima5-t#pe Pine Gro(e

an 9&esta eposits in so&th6estern U!*; an

northern Ne6 /e5io respeti(e!#. T6o !ar"e

tonna"e eposits that are !ess 6e!!harateri>e, 4&t appear to not 4e C!ima5

t#pes are the 9&art> Hi11: A!as0a eposit an

/t. To!man, ashin"ton eposit proesses

that ma# ha(e ate to pro&e the !ar"e

tonna"es 6ith moerate-"rae ores 6i!! 4e

re(ie6e as 6e!!.

Se(era! st&ies in reent #ears ha(e

!ear!# emonstrate that the mo!#4en&m in

porph#r# eposits is eri(e in toto rom

the ma"ma or the res&!tin" sto0s 7Stein an

Hannah, =1) Carten et aI., =1))a, =1))4

hite et a!., =1)=;. This 4ein" the ase, some

ators that mi"ht pro&e a hi"h-"rae

eposit seem reai!# apparent. These in!&ethe initia! mo!#4en&m ontent o the parent

ma"ma an the inrease in mo!#4en&m

ontent 6ith ierentiation. The so&re re"ion

or the ma"ma an meta! has 4een propose

as resiin" in the &pper r&st 7a!!ae et a!.,

=13);, !o6er r&st 7hite et a!., =1)= Stein

an Hannah, =1);, an mant!e 7estra an

Keith, =1)=;. Re!ate ators that o&!

ontro! the "rae o the eposit in!&e ho6

eeti(e!# mo!#4en&m is se?&estere 4#

ear!# ma"mati minera!s 7Keith an Shan0s,=1)); an ho6 stron"!# it is partitione into

an .e(o!(e a?&eo&s phase 7Cane!a, =1)1a

Kepp!er an #!!ie, =11=;. An# is&ssion o

6hat ators or proesses are responsi4!e or

(ariations in tonna"e an "rae m&st 4e"in

6ith the so&re an ierentiation proesses

o the ma"ma. Proesses that ontro! the

!oation an &ration o mo!#4enite

eposition rom the a?&eo&s phase a!so

o4(io&s!# ontro! the "rae. These in!&e

m&!tip!e sto0s ormin" o(er!appin" ore4oies an steep hemia! an therma!

"raients aro&n the sto0 or p!&ton.

The tonna"es oporph#r# mo!#4en&m

eposits are a!so si"niiant!# aete 4# the

ators &st mentione. Ho6e(er, aitiona!

ators that are perhaps more iret!# !in0e

6ith the tonna"es are the si>e an 6ater

ontent o the parent ma"ma ham4er, an the

si>e an shape o the ens&in" pro&ti(e sto0

or &po!a. :or e5amp!e, i minera!i>ation

o&rs in a 4roa, sha!!o6 &po!a a!on" theroo o a !ar"e 4atho!ith, then the tota! amo&nt

o ma"mati 6ater an meta!s partiipatin" in

minera!i>ation ma# a!so 4e !ar"e, 4&t

&no&se. The ens&in" eposit o&! 4e

!ar"e, 4&t !o6 "rae.

/ost o these minera!i>ation ontro!s

ha(e 4een is&sse or re(ie6e 4# other

6or0ers. Ho6e(er, the essentia! ?&estion that


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21 SEG SP-2 GIANT ORE DEPOSITSSEG SP-2 GIANT ORE DEPOSITS +

-.3in" proesses

assoiate 6ith themM e 6i!! is&ss this

?&estion a!on" 6ith 6hat are the 4est

e5p!oration harateristis to &se in min" a

"iant eposit.

&LASSIFI&ATION AND GENERAL&HARA&TERISTI&S

/ost !assiiation shemes or

porph#r# mo!#4en&m eposits i(ie them

into t6o main "ro&ps. These in!&e

C!ima5-t#pe (ers&s ?&art> mon>onite t#pe

7hite et a!., =1)=;, "ranite (ers&s

"ranoiorite t#pes 7/&tsh!er et a!., =1)=;,

a!-a!0a!ine (ers&s a!0a!i-a!i 7an a!0a!i;

t#pes 7estra an Keith, =1)=;, an

!&orine-enrihe (ers&s !&orine-eiient

t#pes 7Theoore an /en>ie, =1)*;. One o

the t6o !asses is "enera!!# t#piie 4#

hi"h-si!ia rh#o!ites or "ranites that are rih in

potassi&m, !&orine, an inompati4!e trae

e!ements. Charateristis o this !ass are

e5emp!iie 4# the C!ima5 eposit. The other

!ass is t#piie 4# a !ess si!ii a!-a!0a!ine

"ranitoi that e5hi4its a(era"e onentrations

o !&orine an inompati4!e e!ements.

C!ima5-t#pe eposits are o primar# onern

in this paper 4ea&se the# e5hi4it 4oth

E


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SEG SP-2 GIANT ORE DEPOSITS 21=21= SEG SP-2 GIANT ORE DEPOSITS

hi"h-"raes o mo!#4en&m an !ar"e

tonna"es 7Si!!itoe, =1) hite et aI., =1)=;.

Ho6e(er, 4oth t#pes 6i!! 4e e5amine in

orer to &nerstan the proesses responsi4!e

or ormation o hi"h-"rae eposits.

The Henerson porph#r# mo!#4en&m

eposit is one o the premier e5amp!es o a

"iant mo!#4en&m eposit in terms o 4oth

tonna"e an "rae 7323 mi!!on tons o .=3=!

% /o Ta4!e =;. In aition, the most reent

st&ies 7Carten et a!., =1))a Seeor, =1));

represent a &!mination o 3 man #ears o

"eo!o"ia! in(esti"ation ma0in" it one o the

most 6e!!-st&ie porph#r# eposits in the

6or!.

/OB%$DEN'/ AND T'NGSTEN

GEOCHE/ISTR% IN IGNEO'S

ROCKS

Inasm&h as mo!#4en&m an

t&n"sten o&r in the same "ro&p o the

perioi ta4!e an e5hi4it man# simi!arities in

"eohemia! 4eha(ior, it is instr&ti(e to

ontrast an ompare the 4eha(ior o 4oth

e!ements to &nerstan the ore-ormin"

proess. :or e5amp!e, 4oth mo!#4en&m

an t&n"sten are oten se?&estere 4# the

same ma"matiphases. S&h a omparison is

essentia! 4ea&se

the partitionin" 4eha(ior o + mo!#4en&m

has not 4een in(esti"ate e5perimenta!!#

ho6e(er, this is the (a!ene that ma# 4e most

important in porph#r# s#stems an is the

(a!ene ommon!# e5hi4ite 4# t&n"sten.

The onentration o 4othmo!#4en&m an t&n"sten in the mant!e is!ess than in C=

honrites, iniatin" that a si"niiant

ration o Earths ori"ina! eno6ment o

these meta!s no6 resies in the ore 7Ne6som

an Pa!me, =1)*;. A!tho&"h mo!#4en&m an

t&n"sten "enera!!# e5hi4it stron"!#

inompati4!e 4eha(ior in r#sta!!i>in" ma"mas

&e to ormation o !ar"e o5#-anions, &ner

s&iient!# re&in" onitions 7:e-:eO;

these meta!s ma# 4e stron"!# partitione into

a !i?&i meta! phase, as apparent!# happene

&rin" ore ormation. The 4est estimates o

the mant!e a4&nane o mo!#4en&m an

t&n"sten are .1 ppm an .= ppm,

respeti(e!# 7Ne6som an Pa!me, =1)*

Ne6som et a!., =1)+; 6hereas &pper r&sta!

a4&nanes are =. ppm an 2. ppm,

respeti(e!# 7Ta#!or an /C!ennan, =1);.These ata s&""est that t&n"sten is more

inompati4!e an thereore more enrihe in

the r&st than is mo!#4en&m 74# a ator o

2 or an on!# 2 or /o;. Ne6som an

Pa!me 7=1)*; attri4&te the more stron"!#

inompati4!e 4eha(ior o t&n"sten to an

o5iation state o + , 6hereas the o5iation

state o mo!#4en&m (aries rom + to 8

&ner terrestria! onitions. T&n"sten ma#

e5hi4it an o5iation state o * in some o

the most re&e "ranitoi ma"mas 7C#"anan Cho&, =1)3 Cane!a, =1));. Ne6som

an Pa!me 7=1)*; s&""est the mo!#4en&m

(a!enes !ess than are perhaps more

ommon an e(iene o a * (a!ene has

4een o4ser(e in meta!-si!iate partitionin"

e5periments. A (a!ene o * " or

mo!#4en&m mi"ht iniate that its

"eohemia! 4eha(ior 6o&! 4e simi!ar to Ti

7simi!ar har"e an ioni rai&s;. A

orre!ation in the a4&nane o /o an Ti has

4een o4sere 4# K&roa an Sane!! 7=1*;

or some i"neo&s ro0s.

Ta0er an Cane!a 7=1)3; a!so

s&""est that the ominant o5iation state or

mo!#4en&m in si!iate ma"mas (aries rom

* to 8 4et6een ni0e!-ni0e! o5ie an

"raphite-methane 4&ers. /o!#4en&m

4eomes more inompati4!e in ma"netite an

i!menite as o5#"en &"aCit# is inrease

7Ta0er an Cane!a, =1)3 $o&ton et a!.,

=1)3;.

Assoiate a!0a!ine mai ro0s

The presene o !amproph#re i0es at

C!ima5, Henerson, 9&art> Hi!!, an Chia"o

$asin an o >one ma"ma ham4ers that are

!oore 6ith a!0a!ine mai ro0s at Pine

Gro(e, 9&esta, an Gri>>!# Pea0

7mi-Tertiar# (o!ani ie! in entra!


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Co!orao; iniate that mant!e-eri(e mai

a!0a!ine ma"mas ma# represent a portion o

the parenta! ma"ma o C!ima5-t#pe rh#o!ites.

There is no isotopi onstraint or e!iminatin"

them as a portion o the so&re materia!.

A!0a!ine i"neo&s ro0s 7minettes, !amproites,

an nephe!inites; rom the Ceno>oi (o!ani

ie!s in the E!0hea /o&ntains in Co!orao,

the Be&ite Hi!!s, #omin", an the 6estern

Co!orao P!atea&, U!*;: ha(e epsi!on N an

epsi!on Sr (a!&es 7Thompson et aI., =11=

o!!mer et aI., =1)* Tin"e# et aI., =11=; that

are not ar remo(e rom those e5hi4ite 4#

C!ima5-t#pe s#stems. Despite the "enera!!#

!o6 onentration o mo!#4en&m in the

mant!e 7.1 ppm;, mant!e-eri(e a!0a!ine

ma"mas orme 4# e5treme!# sma!! e"rees

o partia! me!tin" P = %0 ha(e s&4stantia!!#

hi"her onentrations o mo!#4en&m that

6o&! not !o6er the a(era"e mo!#4en&m

ontent o a !ar"e!# r&sta! me!t. :or

e5amp!e, Ne6som an Pa!me 7=1)*; note

that ontinenta! a!0a!i 4asa!ts ha(e hi"h

ontents o inompati4!e e!ements in!&in"

mo!#4en&m onentrations &p to *. ppm

76e!! a4o(e the r&sta! a(era"e o =. ppm;

an Ne6som et a!. 7=1)+; report as m&h as

+.8 ppm /o in a!0a!ine oean is!an 4asa!t.

Shoshonites, minettes, an me!anephe!inites

rom entra! U!*; ontain .2 to 8. ppm /o

7&np&4!ishe ata;.

The so&re re"ion or mai a!0a!ine

ma"mas on the ontinents is oten propose to

4e the metasomati>e !ithospheri mant!e.

Hattori et a!. 7=112; e5amine the meta!

ontent o ma"mati s&!ies rom

metasomati>e 7amphi4o!e-4earin"; periotite

5eno!iths rom a (ariet# o!oea!ities a

5eno!ith rom N&ni(a0 Is!an, A!as0a

7&ner!ain 4# ontinenta! r&st; ontaine

ma"mati s&!ie 4!e4s 6ith &p to + ppm

mo!#4en&m, 6hereas s&!ie 4!e4s in

5eno!iths rom other !oa!ities ontaine no

eteta4!e mo!#4en&m. Ins&iient ata are

a(ai!a4!e to spe&!ate on 6hether the

mo!#4en&m ontent o !ithospheri mant!e o

ierent Pream4rian pro(ines ma# (ar#

eno&"h to ao&nt or the o&rrene o

porph#r# mo!#4en&m pro(ines.

O5iation state an mo!#4en&m

inompat

i4i!it# in ma"mas

Perhaps the "eohemia! harateristi

inherite rom the so&re re"ion that is most

ritia! or the e(e!opment o porph#r# /o

ma"mas is the o5iation state o the ma"ma.

This parameter is &namenta! 4ea&se a

4&er para!!e! o5iation state is not easi!#

moiie &rin" ma"mati rationation

7Carmihae!, =11=;. This harateristi ma#

aet the o5iation state o mo!#4en&m

6hih in t&m aets ho6 inompati4!e it ma#

4eha(e &rin" r#sta! rationation. As

pre(io&s!# note, mo!#4en&m ma# e5hi4it

(a!enes o * an 8 4et6een ni0e!-ni0e!

o5ie an "raphite-methane o5#"en 4&ers

7Ta0er an Cane!a, =1)3;. /ost s&4&tion

re!ate 7a!-a!0a!ine; an !amproph#ri

ma"mas ha(e o5iation states ro&"h!# 2-8 an

*- !o" &nits a4o(e ni0e!-ni0e! o5ie

respeti(e!#. I the tren o inreasin"

inompati4i!it# o mo!#4en&m 6ith

inreasin" 2 note 4# Ta0er an Cane!a

7=1)3; ontin&es, then mo!#4en&m ma#

4eome e(en more inompati4!e in

a!-a!0a!ine an !amproph#ri ma"mas 6ith

hi"h o5#"en &"aities 6here mo!#4en&m

(a!enes "reater than * ma# e5ist.

E(iene o (aria4!e inompati4i!it#

or mo!#4en&m in (ario&s ro0 series sho&!

4e note here. R&4ii&m is insensiti(e to

han"es in the o5iation state o the ma"ma

an an 4e &se in (ariation ia"rams as a

monitor o ma"ma e(o!&tion. A p!ot o thea4&nane o t&n"sten (ers&s r&4ii&m in

resh (o!ani ro0s ran"in" in omposition

rom mi-oean ri"e 4asa!ts to hi"h-si!ia

rh#o!ites sho6s !inear, stron"!# inompati4!e

4eha(ior o(er a ran"e o a!most o&r

orers-o-ma"nit&e 7:i". 8;. Ho6e(er, the

enrihment o mo!#4en&m in the same ro0

series is m&h more s&4&e inreasin" on!#

t6o orers o ma"nit&e in aition, the


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218SEG SP-2 GIANT ORE DEPOSITS218 SEG SP-2 GIANT ORE DEPOSITS

enrihment tren 4ranhes aorin" to ro0

t#pe 7:i". 8;. Oean is!an 4asa!ts an

a!0a!ine ro0s e5hi4it a stron"er enrihment

tren than a!-a!0a!ine 7meta!&mino&s;

(o!ani ro0s (er# re&e stron"!#

rationate ro0s s&h as ma&sanites,on"onites, an some topa> rh#o!ites, s&h as

Spor /o&ntain, e(en sho6 sharp!# !o6er

a4&nanes o mo!#4en&m 6ith inrease

rationation, espite stron" enrihment o

t&n"sten 7&p to 8-3 ppm E. H.

Christiansen, &np&4!ishe ata Piha(ant et

aI., =1)3;. The ierenes in the 4eha(ior o

mo!#4en&m ma# 4e the res&!t o (aria4!e

o5iation states 6ith mo!#4en&m in a !o6er

o5iation state 78 "7MQ 4eha(in" more

ompati4!# than at hi"her o5iation states7+ , simi!ar to t&n"stenM; 6here mo!#4en&m

appears to 4e moerate!# inompati4!e.

The o5iation states o most porph#r#

mo!#4en&m s#stems are not 6e!! onstraine.

Keith 7=1)2; emonstrate that the o5#"en

&"ait# o the Pine Gro(e ma"ma 6as a4o&t

2 !o" &nits a4o(e ni0e!-ni0e! o5ie 7simi!ar

to most a!-a!0a!ine ro0s;. Christiansen et

a!. 7=1)+; o&n that the ma"mati o5#"en

&"ait# o the topa>-4earin" Cha!0 /o&ntain

rh#o!ite 7oma"mati 6ith C!ima5; 6as a!soa4o&t 2-8 !o" &nits a4o(e ni0e!-ni0e! o5ie.

Ho6e(er, some topa> rh#o!ites rom

6est-entra! U!*; 7in!&in" Spor /o&ntitiiJ.;

6ere o&n to 4e s&4stantia!!# more re&e,

6ith ma"mati 2 (a!&es 2 &nits 4e!o6

ni0e!-ni0e! o5ie. Thereore, this is

permissi(e e(iene that C!ima5-t#pe ma"mas

6o&! e5hi4it moest enrihment o

mo!#4en&m 6ith ontin&e rationation,

pro4a4!# a!on" the tren o other

meta!&mino&s 7apparent!# more o5ii>e;ma"mas 7:i". 8;, rather than ep!etion as

o&n in more re&e ma"mas.

:rom the inompati4!e trae e!ement

s#stematis, 6e on!&e that ma"mati

onentrations o /o in meta!&mino&s,

a!-a!0a!ine ma"mas are "enera!!# ?&ite !o6.

This is iniate 4# the a(era"e mo!#4en&m

ontent o ontinenta! r&st an "ranitois

7=. ppm, Ta#!or an /Bennan, =1);.

/ore important!#, 4ea&se the enrihment

tren o mo!#4en&m in meta!&mino&s ro0s

is re!ati(e!# !at thro&"h the "ranitoi re"ion

7:i". 8;, an appro5imate ma"mati

mo!#4en&m onentration 74et6een = an ppm 6ith an &nertaint# o on!# a e6 ppm;

an 4e inerre rom the "ranitois r&4ii&m

onentration. Rh#o!ites or "ranites 6ith

r&4ii&m onentrations o o(er 1---ppm are

rare an ommon!# are re&e t#pes that

isp!a# mo!#4en&m ep!etion 6ith

rationation. E(en i hi"h!# e(o!(e o5ii>e

"raniti ma"mas e5iste 6ith onentrations

o R4 as hi"h as 2 ppm, ma"mati /o

onentrations preite 4# this tren 6o&!

sti!! 4e !ess than + or 3 ppm. /oreo(er, as&r(e# o the mo!#4en&m ontents o

s&4a!0a!ine (o!ani ro0s 6or!6ie iniates

that onentrations in e5ess o = ppm ha(e

not 4een o&n 7Smith, =1);. This oes not

in!&e potentia!!# !ar"e enrihments o

mo!#4en&m that are inerre to o&r at the

apies o C!ima5-t#pe intr&sions 7=8,ppm,

Carten et a!., =1))a; &e to a&m&!ation o

a separate a?&eo&s phase 7is&sse !ater;, 4&t

on!# to mo!#4en&m enrihment &e to r#sta!

rationation.

/o!#4en&m an nio4i&m

Another e5p!anation o the moerate!#

inompati4!e 4eha(ior o mo!#4en&m is that

its ma"mati rationation is simi!ar to

nio4i&m. /o!#4en&m an nio4i&m ma#

ommon!# e5ist as ations o appro5imate!#

simi!ar si>e an har"e in ma"mas. Oean

is!an 4asa!ts an ontinenta! a!0a!ine ma"mas

7e5!&in" minettes; e5hi4it hi"heronentrations o nio4i&m than o

a!-a!0a!ine ma"mas at the same r&4ii&m

onentrations 7:i". 8;. In aition, nio4i&m

onentrations pro4a4!# erease 6ith

ontin&e e(o!&tion in ma&sanite, on"onites,

an the most e(o!(e topa> rh#o!ites

7Christiansen et a!., =1)+ Piha(ant et a!.,

=1)3 Con"on an Nash, =11=; as oes


10/37

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11/37

SEG SP-2 GIANT ORE D EPOSITS 2121 SEG SP-2 GIANT ORE DEPOSITS

:i"&re 8. Conentrations o R4 (ers&s , /o, an N6. A; Conentrations o R4 an

in resh terrestria! (o!ani ro0s are stron"!# orre!ate o(er a!most orers o ma"nit&e

sho6in" that "enera!!# 4eha(es as a stron"!# inompati4!e e!ement. /i-oean ri"e 4asa!ts

7/OR$; an oean is!an 4asa!ts 7OI$; orm istint4&t near!# ontin&o&s ie!s 7stipp!e;. The

ie! or anesites, aites, an rh#o!ites 7AD R; e5tens rom 4&t o(er!aps the &pper en o the

ie! or oean is!an 4asa!ts 7OI$;. :or rh#o!ites, on!# ata o!!ete rom "!ass# samp!es has

4een in!&e. $; Conentrations o R4 an /o in most resh terrestria! (o!ani ro0s are

stron"!# orre!ate sho6in" that /o "enera!!# 4eha(es as a moerate!# inompati4!e e!ement.

/i-oean ri"e 4asa!ts 7/OR$; an oean is!an 4asa!ts 7OI$; orm istint 4&t near!#

ontin&o&s ie!s. At a "i(en R4 ontent, the /o enrihment in anesites, aites, an rh#o!ites

7AD R; rom s&4&tion >ones or ontinenta! settin"s is !ess than in 7OI$;. Hi"h!# e(o!(e

rh#o!ites that r#sta!!i>e &ner re&in" onitions 7ma&sanites an some topa> rh#o!ites

stipp!e pattern, !o6 2 tren; ha(e e(en !o6er /o R4 ratios, apparent!# as a res&!t o

ma"mati ep!etion o mo!#4en&m. :or rh#o!ites, on!# ata o!!ete rom "!ass# samp!es has

4een in!&e. C; Conentrations o R4 an N4 in resh terrestria! (o!ani ro0s re(ea! apattern

simi!ar to that or R4 an /o in that anesites, aites, an rh#o!ites 7AD R; rom ontinenta!

an s&4&tion >one settin"s are ep!ete in N4 ompare to oean is!an 4asa!ts 7OI$; an e(en

some mi-oean ri"e 4asa!ts 7/OR$;. A!tho&"h apparent!# more inompati4!e than /o in most

ma"mas, N6 4eha(es !i0e /o in that !o6 N4 R4 ratios are o&n in hi"h!# e(o!(e rh#o!iti

ro0s iniate 4# ma"mati ep!etion o N6 in these ro0s. D ata rom Ne6som et a!. 7=1)+;,

Go(inara& 7=1)1;, Christiansen et a!. 7=1)+;, Ko(a!en0o et a=. 7=13), =1)=;, Piha(ant et a!.

7=1)3;, Con"on an Nash 7=11=;, T&r!e# an Nash 7=1)8;, /ahoo 7=1)=;, Hi!reth 7=1)=;

an o&r o6n &np&4!ishe ana!#ses.

mo!#4en&m. :or e5amp!e, the stron"!#

re&e ma&sanite "!asses a!so sho6 a

eo&p!in" o the 4eha(ior o nio4i&m an

tanta!&m res&!tin" in a (er# !o6 N4 Ta ratio

o =.3 7Piha(ant et a!., =1)3;. hether the

4eha(ior o nio4i&m an 4e asri4e to a

han"e in o5iation state rom Nto * in

re&e ma"mas is &n0no6n. $&t 6hate(er

ma"mati phases ontro! the a4&nane o

nio4i&m ma# a!so ontro! that o

mo!#4en&m..

In s&mmar#, oean is!an 4asa!ts an

ontinenta! a!0a!i 4asa!ts ma# inherit moest!#

hi"h mo!#4en&m an nio4i&m onentrations

rom their so&res. Ho6e(er, the hi"h o5#"en

&"aities inherite rom the so&re re"ions o

minettes an a!-a!0a!ine ma"mas ma# 4e o

&namenta! importane in a!!o6in"

mo!#4en&m onentrations to inrease &rin"

r#sta! rationation o ma"mas re!ate to

porph#r# mo!#4en&m eposits.

Preser(ation o ma"mati mo!#4en&m

an t&n"sten onentrations

There are se(era! reasons to 4e!ie(e

the t&n"sten an mo!#4en&m onentrations

o man# si!ii i"neo&s ro0s oten o not

represent ma"mati (a!&es. Perhaps most

important!#, 4oth e!ements are s&4stantia!!#

partitione into an a?&eo&s phase 6hen one is

e(o!(e rom a r#sta!!i>in" "raniti ma"ma

7Cane!a, =1)1a;. I an a?&eo&s phase esapes

rom a p!&ton, then the t&n"sten an

mo!#4en&m ontent o a "ranitoi 6i!! 4e

re&e 6hereas o&ntr# ro0 mi"ht 4eome

enrihe 4# eposition o these meta!s rom

that !&i. The (er# proess that ma0es

minera!i>ation possi4!e, ma0es etermination

o ori"ina! ma"mati (a!&es a!most

&nattaina4!e. In this re"ar, I(ano(a 7=1+8;

st&ie the istri4&tion o t&n"sten in 4iotite

"ranites an orre!ati(e "reisens an

on!&e that t&n"sten ontent o the ro0s is


12/37

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13/37

SEG SP-2 GIANT ORE DEPOSITS 213

:i"&re *. Conentrations o R4 (ers&s an /o or (o!ani an "ranitoi ro0s. A;

Conentrations o in resh "ranitois rom 6estern North Ameria are "enera!!# ep!ete

ompare to resh terrestria! ro0s o the same R4 ontent, in!&in" the anesites, aites, an

rh#o!ites 7ADR; ommon!# assoiate 6ith t&n"sten eposits. $; Conentrations o /o in resh

"ranitois rom 6estern North Ameria are "enera!!# ep!ete ompare to resh terrestria! ro0s

6ith simi!ar R4 onentrations, in!&in" the anesites, aites, an rh#o!ites 7ADR; ommon!#

assoiate 6ith porph#r# mo!#4en&m eposits. C; J&"in" rom the orre!ation o R4 an /o

in "!ass# rh#o!iti ro0s, the /o onentrations in the rh#o!iti ma"ma at Pine Gro(e ma# ha(e

4een as hi"h as 8 ppm. Ho6e(er, onentrations o /o in the (o!ani ro0s ran"e to as !o6 as

.2 ppm as a res&!t o post-ma"mati !osses in!&in" !oss o a (o!ati!ephase &rin" er&ption an

meteori !eahin" 7Keith an Shan0s, =1));. In!&es &np&4!ishe ata o J. D. Keith.

primari!# a &ntion o a!teration. Keith et a!.

7=1)1; mae the same on!&sion rom a

st o the CanT&n" "ranitois, North6est

Territories. :i"&re 7 i!!&strates that thet&n"sten ontent o. "ranitois rom 6estern

North Ameria 7Keith, &np&4!ishe ata;

satter a4o(e an most!# 4e!o6 the tren

esta4!ishe or resh anesites, aites, an

rh#o!ites. Keith et a!. 7=1)1; a!so e5amine

the mo!#4en&m ontent o 4arren an

t&n"sten-re!ate "ranitois rom 6esternNorth

Ameria. No orre!ation o mo!#4en&m.

ontent 6ith e"ree o ierentiation, si>e o

assoiate eposit, or other trae e!ement

onentrations 6as o&n. As 6as the ase ort&n"sten, the mo!#4en&m onentrations in

these "ranitois "enera!!# are s&4stantia!!# !ess

than those o resh anesites, aites, an

rh#o!ites 7:i". *;.

/o!#4en&m onentrations o ro0s

rom a porph#r# mo!#4en&m eposit 6o&!

a!6a#s 4e s&spet o 4ein" either enrihe

7espeia!!# 6ithin 8 m oan ore >one,

/&tsh!er et aI., =1)=; or ep!ete 4#

h#rotherma! !eahin" or !oss o a

mo!#4en&m-rih a?&eo&s phase. E(en resh(o!ani ro0s ma# e5hi4it mo!#4en&m

onentrations !o6er than pre-er&ption

ma"mati (a!&es &e to !oss o a

mo!#4en&m-4earin" a?&eo&s phase or to

!eahin"4# meteori !&is. Keith an Shan0s

7=1)); o&mente that at !east 1 o the

mo!#4en&m in the non-6e!e t& o Pine

Gro(e 6as !eahe 4# meteori 6ater in

aition, the# inerre that (er# resh

oma"mati rh#o!ite o44!es eroe rom an

e5tr&si(e ome ha !ost -3 o their

ori"ina! mo!#4en&m ontent &e to esape oma"mati (o!ati!es 7:i". *;. A!tho&"h

meas&re mo!#4en&m onentrations in resh

Pine Gro(e ro0s ran"e rom .2 to =.)2

ppm, the pre-er&ption ma"mati !e(e! ma#

ha(e 4een as hi"h as -8 ppm 7:i". 70 the

ierene ma# ha(e 4een !ost to meteori

!eahin" or e"assin" o the ash !o6 t&

short!# ater er &ption. Conse?&ent!#, it is

ii&!t to etermine the ma"mati t&n"sten

an mo!#4en&m onentrations o e(o!(e

6ater-rih "ranites an rh#o!ites./o!#4en&m has.4een o&n in &maro!i

r&sts assoiate 6ith simi!ar rh#o!iti t&s

7ies, =121;. E(en stron"!# ierentiate

rh#o!iti ma"mas s&h as those that orme

the mo!#4enite eposits at C!ima5 an

Henerson, ma# ori"ina!!# ha(e ontaine

on!# a4o&t * ppm mo!#4en&m ma"mas 6ith

!o6er r&4ii&m an nio4i&m - s&h as those

rom 9&art> Hi!! an /o&nt To!man - ma#

ha(e ori"ina!!# ha . mo!#4 en& m

onentrations !oser to -2 ppm. At&a!

ma"mati onentrations o mo!#4en&m or

these eposits ma# 4e &nattaina4!e or the

reasons &st o&t!ine. I+ s&h mo!#4en&m

nio4i&m-r&4ii&m orre!ations ha(e some

(a!iit#, then the more nio4i&m-r&4ii&m-rih

ma"mas mi"ht 4e e5pete to pro&e !ar"er

tonna"es o hi"her "rae mo!#4en&m ore.

:i"&re i!!&strates that eposits 6ith hi"her


14/37

1--- N1.-

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Miion$

VL H#nd#r$on -.57


15/37

211SEG SP-2 GIANT ORE DEPOSITS211 SEG SP GIANT ORE DEPOSITS

:i"&re . R4 an N6 onentrations in si!ii i"neo&s ro0s assoiate 6ith porph#r#

mo!#4en&m eposits in 6estern North Ameria are simi!ar to other mem4ers o the anesite,

aite, rh#o!ite "ro&p 6or! 6ie. Graniti ro0s at 'raHenerson are the most rationate

7iniate 4# their hi"h onentrations o the inompati4!e e!ements R4 an N4; an host the

hi"hest "rae /o eposit. R4, N6: an /o ore "rae erease re"&!ar!# in the se?&ene PineGro(e, 9&esta, 9&art> Hi!!, an /t. To!man.

nio4i&m an r&4ii&m onentrations o ha(e

!ar"er tonna"es o hi"h "rae ore.

PETROGENESIS O: /AG/A

REBATED TO CBI/A-T%PE

/OB%$DEN'/ DEPOSITS

Bo6er an &pper r&sta! so&res

Do the i"neo&s ro0s assoiate 6ith

"iant porph#r# mo!#4en&m eposits inherit a

speia! omposition rom their ma"ma so&re

re"ion that istin"&ishes them rom !esser

epositsM Is there a &ni?&e tetoni settin" or

epoh or their e(e!opmentM In this re"ar,

hite et a!. 7=1)=; propose that 4ea&se the

Co!orao Ro0# /o&ntain re"ion e5hi4its

man# eposits or minera! o&rrenes

enrihe in mo!#4en&m, t&n"sten, an!&orine, this iniates a !on"-term so&re

or these e!ements in the &ner!#in"

ontinenta! !ithosphere 7=.3 Ga;. The#

s&""este that C!ima5-t#pe ma"mas 6ere

"enerate 4# rationa! me!tin" o the !o6er

r&st o!!o6e 4# rationa! r#sta!!i>ation o

eah 4ath o ma"ma as it iapiria!!# rose

thro&"h the r&st. hite et a!. 7=1)=; s&""est

the ma"mas 6o&! 4e enrihe in

mo!#4en&m an other inompati4!e trae

e!ements as a onse?&ene. hat !e(e!s omo!#4en&m enrihment 6o&! 4e ahie(e

4# this proess are not speiie, 4&t the#

s&""est that C!ima5-t#pe "ranitois are rather

!i0e the topa> rh#o!ites o $&rt et a!. 7=1)2;.

E5tensi(e ata on the mo!#4en&m ontent o

topa> rh#o!ites are not a(ai!a4!e, 4&t Keith

an Shan0s 7=1)); o&n that resh topa>

rh#o!ite rom so&th6estern 'tah 6ith nio4i&m

an r&4ii&m onentrations simi!ar to those

at Henerson ontaine 8.8 7- .2; ppm

mo!#4en&m. T&r!e# an Nash 7=1)8; o&n

rom 2 to + 7- =.; ppm mo!#4en&m in

(itroph#res rom topa> rh#o!ite !a(as at

Sme!ter Kno!!, 'tah. There is no e(iene

that topa> rh#o!ites "enera!!# ontain hi"her

onentrations o mo!#4en&m than these

(a!&es.

Stein 7=1)); in(esti"ate the !ea,

stronti&m, s&!&r, an o5#"en isotope ratios

an rare earth-e!ement ompositions o ores,

an o (o!ani an p!&toni ro0s rom the

Co!orao minera! 4e!t the "enesis o

C!ima5-t#pe s#stems 6as o parti&!ar

onern. Her ata 6ere interprete to iniate

that a!! the Baramie-Tertiar# intermeiate to

e!si ma"mas 7in!&in" a!-a!0a!ine; ha a

!o6er r&sta! ori"in ho6e(er, C!ima5-t#pe"ranites 6ere propose to ha(e ori"inate

rom a &ni?&e !o6er r&sta! so&re 7not

re!ate to a!-a!0a!ine ma"matism;. The

ma"mati harateristis ritia! to

C!ima5-t#pe minera!i>ation a?&ire rom this

&ni?&e so&re are not speiie.

In their re(ie6 o the Henersoneposit, Carten et *I. 7=1))4; s&""est that a

&ni?&e ma"ma that ontaine hi"h

onentrations o ore omponents 6as not

re?&ire to orm the eposit. The# ar"&e that

the initia! onentration o mo!#4en&m in the

ore-re!ate ma"ma is not as ritia! to ore

ormation as the t#pe an &ration

o rationation proesses in a hi"h-!e(e!

ma"ma ham4er.

The a(era"e mo!#4en&m ontent o

the !o6er an &pper r&st is estimate to 4e

.) an =. ppm respeti(e!# 7Ta#!or an


16/37

8 SEG SP GIANT ORE DEPOSITSSEG SP-2 GIANT ORE D EPOSITS 8/Bennan, =1);. One o the trst attempts to

eme a speia! mo!#4en&m-rih so&re or

C!ima5-t#pe eposits 6as ana!#sis o the

mo!#4en&m ontent o Iaho Sprin"s

:ormation an the Si!(er P!&me Granite

ahone# 7=1+); o&n an a(era"e o ppm

an 2-8 ppm /o in these respeti(e ro0

t#pes. On this 4asis, a!!ae et a=. 7=13);

s&""este that the t&n"sten an mo!#4en&m

o the C!ima5 an Henerson eposits 6ere

eri(e rom these &pper r&sta! host ro0s.

Ho6e(er, !ater isotopi st&ies 7hite etaI.,

=1)= Stein, =1)); ha(e emonstrate

that C!ima5-t#pe ma"mas an ore eposits in

the Co!orao minera! 4e!t o&!

not ha(e inorporate an# appreia4!e

amo&nt o these &pper r&sta! ro0s.

/ost reent 6or0ers ha(e propose

that the ma"ma so&re o C!ima5-t#pe s#stems

an topa> rh#o!ites is in the !o6er r&st

7hite et aI., =1)= Christiansen an i!son,

=1)2 Christiansen et aI., =1)) Stein, =1));

a!tho&"h enrihe &pper mant!e has 4een

propose a!so 7estra an Keith, =1)=;.

hite et a!. 7=1)=; note that the initia!

)3Sr)+Sr (a!&es or &na!tere C!ima5an

Henerson ro0s (aries 4et6een .3 -

.3=. Stein 7=1)); o&n si"nitant!# hi"her

an 6ie!# (ar#in" (a!&es o .3) to .3*

or C!ima5 an Henerson ro0s. Cha!0

/o&ntain rh#o!ite is a re!ati(e!# &na!tere

topa>-4earin" e5tr&si(e ome that is

oma"mati 6ith the C!ima5 rh#o!ites ,Bur! et

aI., =1)2;. Stein 7=1)); reporte a )3Sr)+Sr

(a!&e o .3) or Cha!0 /o&ntain an-

the ompositions o 8 samp!es rom

Henerson. Epsi!on N or these samp!es

ran"e rom -1. to -1.1. These (a!&es are

inistin"&isha4!e rom the hi"h en epsi!on

N o Pream4rian 7=.+ to =.) Ga; 4asement

ro0s, s&""estin" to :armer an DePao!o7=1)*; that the "raniti ma"mas 6ere eri(e

e5!&si(e!# rom mi-Protero>oi r&st.

Ho6e(er, it sho&! 4e note that DePao!o

7=1)=; o4ser(e that Protero>oi r&st in

Co!orao o&! ha(e ha epsi!on N as !o6 as

-=* &rin" the mi!e Tertiar#. I s&h r&st

6as in(o!(e in the "enesis o C!ima5-t#pe

rh#o!ites then a si"nitant mant!e omponent

6ith hi"her epsi!on N m&st ha(e 4een

present e(en in this ma"ma s#stem.

/oreo(er, the o&rrene o i"neo&s ro0s6ith epsi!on N (a!&es as !o6 as -=8 7Johnson

an :ririh, =11; in the same re"ion an

4roa!# oe(a! 6ith Henerson is onsistent

6ith the in(o!(ement o si"nitant

mant!e-eri(e ma"ma at Henerson. As

note 4e!o6, Johnson et a=. 7=1)1; a!so

propose a simi!ar mi5e 7mant!e an r&sta!;

herita"e or the ma"mas that !e to the

ormation o the 9&esta eposit.

Tetoni settin"

Si!!itoe 7=1); s&4i(ie porph#r#

mo!#4en&m eposits into rit-re!ate an

s&4&tion-re!ate eposits that orrespon

air!# 6e!! to C!ima5-t#pe an the other

ate"ories respeti(e!#. Se(era! a&thors ha(e

reo"ni>e that e6 /o eposits o&r in

.3= - .3== or C!ima5 samp!es. :&se #o&n" is!an ar settin"s 7i.e. Canianian,

ash-!o6 !u++ assoiate 6ith the C!ima5-t#pePine Gro(e eposit in U!*;: 6hih is

&ner!ain 4# Protero>oi r&st o the same a"e

as C!ima5, has an initia! )3Sr)+Sr (a!&e o

.311 7Christiansen an i!son, =1)2;.

A!tho&"h sparse, N isotopi ata ma#

re(ea! more a4o&t the so&re7s; o C!ima5

t#pe rh#o!ites, 4ea&se the# are pro4a4!# !ess

aete 4# h#rotherma! a!teration an

6a!!-ro0 ontamination than Sr isotope

ratios. :armer an DePao!o 7=1)*; reporte

Ta4!e =;, an a!most a!6a#s in areas &ner!ain4# at !east thin ontinenta! r&st 7Si!!itoe,

=1) estra an Keith, =1)= Christiansen

an i!son, =1)2;. A!tho&"h some ha(e

!aime that C!ima5-t#pe s#stems orre!ate

6ith thi0er ontinenta! r&st, others s&""est

that the# are inepenent o r&sta! thi0ness

7estra an Keith, =1)=;. Perhaps the most

ommon!# s&""este tetoni settin" or

C!ima5-t#pe s#stems is &rin" the han"eo(er

rom ompressiona! to e5tensiona! tetonis


17/37

SEG SP-2 GIANT ORE D EPOSITS 8=8= SEG SP GIANT ORE DEPOSITS

7Si!!itoe, =1) estra an Keith, =1)=

/&tsh!er et aI., =1)= hite et aI., =1)=

$oo0strom, =1)=;. Some a&thors preer to

onsier this settin" as atetoni or 4a0-ar

spreain" rather than simp!# rit-re!ate.

The han"eo(er tetoni settin" hasa!so reent!# 4een o&mente or the Co&!ee

D am intr&si(e s&ite 7Car!son an /o#e, =11;

that hosts the C&-rih /t. To!man eposit

6hose ore-re!ate "ranite porph#r# !ear!#

e(o!(e rom a ominant (o!&me o

"ranoiorite 7Car!son an /o#e, =11;.

A it io na ! !# , a p os t -o ro"en i ,

e5tension-re!ate settin" has 4een propose or

the 9&art> Hi!! eposit 7H&son et a!. , =1)=;.

The @u*r! Hi!! intr&si(e omp!e5 6as

emp!ae in the Coast 4atho!ith ater it ha4een e5tensi(e!# &p!ite an eroe. A

re"iona! e5tension-re!ate oint s#stem

ontro!s emp!aement o man# !amproph#re

i0es as 6e!! the 9&art> Hi!! intr&sions.

Ho6e(er, the initia! )3Sr)+Sr (a!&es o .3=

or the 9&art> Hi!! intr&sions o not ier

si"niiant!# rom those o the o!er

s&4&tion-re!ate p !&ton i ro0s.

Aitiona!!#, the 9&art> Hi!! intr&sions sho6

minima! enrihment o ?-: !&orine, an

other inompati4!e e!ements 7H&son et a!. ,=1)=;.

Cr#sta! rationation rom a!-a!0a!ine

preeessors

D espite a&m&!ation o a !ar"e

amo&nt o ata on the petro"eneti an

isotopi e(o!&tion o C!ima5-t#pe rh#o!ites, a

n&m4er o ierin" so&re ro0s are

permissi4!e. 9&esta an Pine Gro(e sho6

man# petro"eneti simi!arities. Pine Gro(e728-22 /a :i". =; is !oate in the Inian

Pea0 (o!ani ie! that pro&e ominant!#

hi"h-K a!-a!0a!ine aiti ash !o6s rom 82

to 23 /a 7$est et a!., =1)1;. /ore than

, 0m8 o ash !o6 t& 6as er&pte.

Sma!!er (o!&mes o hi"h-K a!-a!0a!ine

rh#o!ite, trah#anesite, an minor aite

6ere er&pte near the Inian Pea0 (o!ani

ie! at =)-28 /a an are ro&"h!#

ontemporaneo&s 6ith the ineption o

e5tension in the area 7$est et aI., =1)3;. The

Pine Gro(e porph#r# mo!#4en&m eposit

o&rs in the eroe (ent o an ash-!o6 ome

omp!e5 &st east o the rim o the InianPea0 a!era omp!e5. Initia! er&ptions 4e"an

6ith hi"h-si!ia rh#o!ite an !ater er&ptions

sim&!taneo&s!# (ente rh#o!iti an aiti

ma"ma. Hi"h-si!ia rh#o!ite s&4se?&ent!#

i!!e the (ent to orm omes an intr&e to

sha!!o6 !e(e!s to orm a C!ima5-t#pe eposit.

The o-er&pte aiti ma"ma e5hi4its a moe

an maor-e!ement omposition (er# simi!ar to

the (o!&mino&s aiti ash-!o6s that 6ere

emp!ae &rin" the O!i"oene an to other

intermeiate (o!ani ro0s o the same a"e728-2= /a; to the 6est 7$est et ai., =112;.

Short!# ater omp!ete r#sta!!i>ation o the

ma"ma ham4er, trah#anesiti ma"ma

intr&e the (ent an other portions o the

r&st an o(ere the t& o Pine Gro(e

aross the re"ion. Keith 7=1)2; emonstrate

that + rationation o aiti ma"ma,

&sin" o4ser(e phenor#st proportions an

ompositions, o&! pro&e the maor

e!ement omposition o the Pine Gro(e

rh#o!ite. The a(ai!a4!e Sr isotopi ata are

onsistent 6ith this iea no si"niiant

ierenes e5ist 4et6een the Sr-isotopi

ompositions o the Pine Gro(e ma"ma an

the o!er aites o the Inian Pea0 (o!ani

ie!.

Johnson an Bipman 7=1));

in(esti"ate the ori"in o the meta!&mino&s

an a!0a!ine (o!ani ro0s o the Batir

(o!ani ie!, host o the 9&esta eposit 7:i".

=;, in the Rio Grane rit near the

Co!orao-Ne6 /e5io 4orer. /a"matism in

the Batir ie! 722 - 2). /a an ==-= /a;

is appro5imate!# oe(a! 6ith C!ima5-t#pe

s#stems 7i.e. C!ima5, Henerson, /t.

Emmons; arther north a!on" the Rio Grane

rit. In aition, the a"e o ma"matism spans

the ineption o ritin" in the area 72+ /a;.

/o!#4en&m minera!i>ation is assoiate 6ith

6anin" sta"es o a!era ma"matism. The


18/37

82 SEG SP GIANT ORE DEPOSITS82SEG SP3 GIANT ORE DEPOSITS

;i);#$! )r*d#$ o+ or# *r# *$$oi*!#d =i!; !;#

Su';ur Gu; 'u!on ,3< M*0 !;*!

in!rud#d !;# $ou!;#rn rim o+ !;# @u# !*

*d#r* ,o;n$on #! *. : 15850. o;n$on *nd

Li'm*n ,15880 $u))#$!#d !;*! - %

+r*!ion*!ion o+ * '*r#n!* m*)m* $imi*r !o

!;# &*6r#$!o L*k# mono)r*ni!#: * $i);!(

od#r r#$ur)#n! 'u!on: oud 'rodu# !;#

m*Cor*nd !r*###m#n! om'o$i!ion o+ !;#

Su';ur Gu; 'u!on. T;#( $u))#$! !;*! *

6*$# #%# in!#rm#di*!# om'o$i!ion m*)m*:

#2#m'i+i#d 6( !;# m*Cori!( o+ !;# o*

o*ni *nd 'u!oni rok$: '#r$i$!#d in !;#

*r#* +or m.(. T;# in+#rr#d mono)r*ni!#'*r#n! i$ #r( $imi*r !o !;# d*i!# o#ru'!#d=i!; !;# r;(oi!i Pin# Gro%# m*)m* *nd !;#6*$# ## om'o$i!ion o+ !;# Indi*n P#*ko*ni +i#d ,B#$! #! *I.: 15850.

A ri!i* u#$!ion!;*!$;oud6# *$k#d

i$ =;#!;#r !;# '#!ro)#n#!i 'ro#$$#$#2#m'i+i#d 6( Pin# Gro# *nd @u#$!*

m*)m*!i$m o'#r*!#d *! o!;#r &im*2!('#'or';(r( Mo $($!#m$. Book$!rom ,15810$!*!#$ !;*! !;# &im*2!('# d#'o$i!$ in !;#&oor*do min#r* 6#! our *on) !;# *2#$ o+$i);!( od#r **k*in# 'u!on$ ,mo$!(#$$ !;*n 7- M*0 . T;#r# *r# *6ou! 3-mo(6d#num 'ro$'#!$ =i!; u' !o -. 1 %MoS min#r*i*!ion in: !;# min#r* 6#! *ndmo$! o+ !;#$# *r# *$$oi*!#d =i!; 6ro*d(**k*in# i)n#ou$ rok$ *nd *''#*r !o 6#$u6du!ion r#*!#d. H# no!#$ !;*! !;# &im*2ik# r;(oi!# 'or';(ri#$ o+ !;#9in+i#d 'ro$'#! ,3


19/37

88SEG SP3 GIANT ORE DEPOSITS88 SEG SP-2 GIANT ORE DEPOSITS

*r# *$o 'o$$i6#. For #2*m'#: !;# 8* M*

Gri1( P#*k Tu++: o*!#d *''ro2im*!#( )

km $ou!;=#$! o+!;# &im*2 d#'o$i!: *ri#$ in

om'o$i!ion +rom ;i);$ii* r;(oi!# *! !;#

6*$# !o o=$ii* r;(oi!# *! !;# !o' o+ *

$in)# #rod#d ooin) uni! !=o ;#!#ro)#n#ou$

!u++ *(#r$ *$o on!*in d*i!# !o m*+i *!i!#+i*mm# ,o;n$on *nd Fridri;: =11;. Ini!i*1

84Sr8Sr r*!io$ r*n)# +rom .3=3 !o *$ o= *$

.311 *nd #'$ion Nd *u#$ *r( 6#!=##n

13.- *nd -==.8 $imi*r *ri*!ion$ *r##2;i6i!#d 6( P6 *nd - i$o!o'#$. o;n$on *ndFridri; 7=11; 'oin! ou! !;*! !;# mo$! m*+iom'o$i!ion 73 =!% Si0 i$ !oo m*+i !o 6# *'*r!i* m#! o+ ru$!* rok$ !;i$ m*)m*!iom'o$i!ion i$ 6#$! #2'*in#d 6(

*''ro2im*!#( =!% r($!* +r*!ion*!ion o+6*$*!i m*)m*: *om'*ni#d 6( - !o *=!% *$$imi*!ion o+ Pro!#rooi ru$!. T;#mor# $iii 'or!ion$ o+ !;# m*)m* =#r#mod##d !o ;*# +orm#d 6( r($!*

+r*!ion*!ion *om'*ni#d 6( *!#$!*)# ru$!**$$imi*!ion . E%id#n# +or !ate-sta"e*$$imi*!ion inud#d i$o!o'i di$#uii6rium6#!=##n =;o#rok +i*mm# *nd #*r( *nd*!#r($!*iin) ';#nor($!$ $#'*r*!#d +rom!;# $*m# +i*mm#. T;#( no!# !;*! =i!;ou! !;#+or!ui!ou$ #ru'!ion o+ !;# mor# m*+i 'or!ion$o+ !;# m*)m* ;*m6#r: !;#( =oud ;*#dr*=n !;# #rron#ou$ onu$ion !;*! !;# !u++=*$ )#n#r*!#d 6( 1--% ru$!* m#!in). T;#;i);$ii* 'or!ion o+ !;# Gri1( P#*k Tu++

=ou1d +i! a!! o+ !;# i$o!o'i ri!#ri* +ord#ri*!ion +rom * &im*2!('# $our#

,S!#in: =1)) S!#in *nd &rok: =11;, in $'i!#o+ i!$ in+#rr#d m*n!# ;#ri!*)#.

Isotopia!!# >one m*)m*ham4ers

Pu!oni *nd o*ni rok$ r#*!#d !o!;# @u#$!* *d#r* *nd 'or';(r( mo(6d#numd#'o$i! *$o $;o= #id#n# o+ d#ri*!ion +rom;#mi*( *nd i$o!o'i*( on#d m*)m*;*m6#r$. T;# @u#$!* *d#r* +orm#d u'on

#ru'!ion o+ < -- km3 o+ !;# ;i);$ii*'#r*1k*1in# Am*1i* Tu++ ,o;n$on *nd

Li'm*n: =1));. Pr#*d#r* in!#rm#di*!#

om'OSI!Ion o*ni rok$ ;*# r#*!i%#1(

uni+ormini!i*1 84Sr8Sr r*!io$ o+*''ro2im*!#(

.3 ,id#n!i* !o !;# in!#rm#di*!# **$ o+

!;# S*n u*n o*ni +i#d Li'm*n #! *. :

=13) o;n$on #! *I. : =11;. Ini!i*1

84Sr8Sr

r*!io in !;# Am*1i* Tu++ inr#*$#$

mono!oni*( =i!; d#r#*$in) Sr ontent+rom .33 !o .31), !;# Sr'oor !u++r#'r#$#n!in) !;# #*r( #ru'!ion$ . L*!#$!*)#roo+=*rd *$$imi*!ion o+ Pro!#rooi rok$ i$'ro'o$#d *$ !;# 'r#+#rr#d #2'*n*!ion o+ !;#inr#*$in) ini!i* 84Sr8Sr r*!io$ oninin)#id#n# o+ !;i$ mod# i$ !;# roo+=*rdinr#*$# in !;# 'ro'or!ion o+ iron$ =i!;Pro!#rooi or#$ r#*!i# !o T#r!i*r( iron$=i!; no Pro!#rooi or#$ . T;#Momin#r*i#d Su';ur Gu; 'u!on #2;i6i!$ *n*n*o)ou$ !r#nd o+ d#r#*$in) ini!i*

84Sr+8Sr r*!io$ ,+rom . 3) !o .3+3; =i!;

inr#*$in) Sr on!#n!. T;# in+#rr#d '*r#n!

,&*6r#$!o L*k# 'u!on0 ;*$ *n ini!i* 84Sr8Sr

r*!io o+ .38 ,o;n$on #! *I. : 155-0.

L*!#$!*)# roo+=*rd on!*min*!ion m*( *$o

*u$# $om# o+ !;# *r)# *ri*!ion$ in ini!i*

84Sr8Sr no!#d in !;# &im*2: H#nd#r$on: *nd

M!. Emmon$ r;(oi!#$ ,S!#in: =1));. S!#in

*nd &rok 7=11; r#C#! !;*! 'o$$i6ii!(

6#*u$# !;# in+#rr#d 'ro'or!ion$ o+ =*rok

n##d#d !o 'rodu# !;# *ri*!ion$ *r#

$u6$!*n!i*( di++#r#n! +or !;# Nd: Sr: *nd P6

i$o!o'i on$!r*in!$. Ho=##r: o;n$on #! *.

7=11; #noun!#r#d #r( $imi*r i$o!o'iinon$i$!#ni#$ in mod#in) !;# *!#$!*)#*$$imi*!ion o+ !;# Su';ur Gu; ,@u#$!*0'u!on.

No! * ;i);## m*)m* ;*m6#r$ or'o$!*d#r* 'u!on$ $;o= #id#n# o+

*!#$!*)# *$$imi*!ion. I+ *!#$!*)# roo+=*rd*$$imi*!ion i$ * ommon 'ro#$$ in&im*2!('# m*)m* ;*m6#r$: !;#n =;*!'ro#$$ i$ r#$'on$i6# +or *u$in)*$$imi*!ion U!im*!#(: !;# *n$=#r i$ r#*!#d!o ;#*!: =;#!;#r 6( r($!*i*!ion or 6(und#r'*!in) or inC#!ion o+ n#= m*)m*. T;#+*! !;*! &im*2!('# m*)m*$ m*( $;o=on$i$!#n! i$o!o'i #id#n# o+ *!#$!*)#*$$imi*!ion o+ roo+ rok$ $;oud no! 6#


20/37

8* SEG SP-2 GIANT ORE DEPOSITSSEG SP-2 GIANT ORE DEPOSITS 8

s&rprisin" inasm&h as one o the most 6ie!#

reo"ni>e harateristis o this eposit t#pe

is the o&rrene o m&!tip!e intr&sions an

ore 4oies that are "enera!!# emp!ae 4#

assimi!ation an stopin".

Chonrite-norma!i>e rare-earth

e!ement patterns rom C!ima5, Henerson,

9&esta, an Pine Gro(e 7is&sse in a !ater

setion; sho6 e(iene o some r#sta!!i>ation

an rationation o the parent ma"mas

4et6een intr&si(e &nits this o&! 4e one

so&re o heat or assimi!ation. A!! o&r

o these eposits 6ere apparent!# e(e!ope

&rin" the han"e rom s&4&tion-ontro!!e

to e5tensiona! tetonis. Thompson et a!.

7=11=; s&""este that e5tension-re!ate mai

ma"ma assoiate 6ith the Rio Grane rit

p!a#e a s&4stantia! ro!e in e5tenin" the !ie

o pre-rit (o!anism appro5imate!# 4# 8

m.#. :or e5amp!e, the S&!ph&r G&!h p!&ton

728-2 /a;, 6hih hosts the 9&esta eposit,

ma# ha(e e(o!(e rom pre-rit ma"mas that

6ere 0ept a!i(e 4# 4asa!ti ma"matism

re!ate to ritin" 72+ /a;. Thereore,

&nerp!ate mai ma"ma at 9&esta ma# ha(e

4een responsi4!e or the "ra&a! e!e(ation in

initia! )3Sr)+Sr assoiate 6ith roo6ar

assimi!ation.E(iene or e5tension-re!ate

trah#anesite &nerp!atin" o the Pine Gro(e

ham4er is perhaps e(en more on!&si(e in

s&4stantiatin" a ro!e or e5tension-re!ate

ma"mas. Trah#anesiti ma"mas 6ere

!ear!# assoiate 6ith e5tensiona! tetonis

rom 22 to =) /a aross the

Pio he- / ar#s(a ! e (o ! an i 4e ! t .

Trah#anesite ma"ma o-er&pte 6ith the

t& o Pine Gro(e an intr&e the (ent &st

ater ina! onso!iation o the ma"maham4er. Keith an Shan0s 7=1)); s&""este

that the trah#anesiti ma"ma ma# ha(e

pro(ie the heat to a!!o6 the 6ater-rih Pine

Gro(e ma"ma to asen to s!i"ht!# hi"her

!e(e!s in the r&st 6itho&t so!ii#in".

hite et a!. 7=1)=; an Stein an

Cro0 7=11; point o&t that assimi!ation o

hi"h!# raio"eni o&ntr# ro0s aro&n

C!ima5 an Henerson o&! not ha(e 4een a

(er# si"niiant ma"ma moi#in" proess.

Ho6e(er, e(en a tri(ia! amo&nt o

assimi!ation 7-2 o Si!(er P!&me Granite,

$oo0strom et aI., =1)); ma# e5p!ain the

monotoni inrease in initia! )3Sr)+Sr (a!&es

4et6een oma"mati rh#o!ite intr&sions. e

o not propose that !ate-sta"e assimi!ation is

ain" an#thin" speia! to the ma"ma

ham4er, 4&t it ma# point to a on)i#d heat

so&re at the 4ase o the s#stem that permits

e5tene r#sta! rationation, (o!ati!e !oss,

an perhaps (o!ati!e !&5in" 6itho&t rapi!#

so!ii#in" the entire ham4er. Isotopi

>onation o the hi"h-!e(e! ma"ma ham4er

ma# 4e one si"nat&re o that heat so&re.

hite et a!. 7=1)=; a!so note that

4asa!ti (o!anism is not assoiate, on a !oa!

sa!e, 6ith C!ima5-t#pe s#stems. Ho6e(er,

e!si ro0s at C!ima5, Henerson, an

Chia"o $asin are ontemporaneo&s 6ith

minor (o!&mes o ross-&ttin" 4iotite-rih

!amproph#re i0es 7$oo0strom, =1)=

$oo0strom et aI., =1));. Aitiona!!#, mi!!#

a!0a!ine to transitiona! 4asa!ts 72*-2 /a;

interm"er 6ith 4asin-i!! seimentar# ro0s

o the $ro6ns Par0 :ormation 6est o

the Co!orao minera! 4e!t 7Thompson eta!.,

=11=;. $oo0strom 7=1) =; s&""ests that the

!amproph#res represent a ierent t#pe o

4imoa! s&ite. Some ha(e s&""este that

!o6er therma! inp&t ma# res&!t in se!eti(e

partia! me!tin" o !ess rerator# p!&ms in a

p!&m p&in" mant!e 6ith the res&!tin" me!t

4ein" isotopia!!# enrihe an o a!0a!ine

ainit# 7Thompson et aI., =11 = Perr# et aI.,

=1)3;. C!ima5, Henerson, ai! Chia"o

$asin are s&iient!# remo(e rom areas os&4stantia! ritin" that rit-re!ate therma!

inp&t ma# ha(e 4een !o6, 4&t s&iient to

e5ten the !ie o the ma"ma ham4ers.

In s&mmar#, 6hen on!# hi"h-si!ia

rh#o!ite is er&pte or e5pose or

e5amination, the petro"enesis is am4i"&o&s

7Christiansen an i!son, =1)2 Johnson an

:ririh, =11;. Inasm&h as hi"h-si!ia

rh#o!iti ma"mas !ie near the ternar#


21/37

SEG SP-2 GIANT ORE DEPOSITS 88+ SEG SP-2 GIANT ORE DEPOSITS

minim&m, a (ariet# o so&re materia!s an

petro"eneti paths ma# #ie! essentia!!# the

same 4&!0 omposition. e see no reason

that topa> an C!ima5-t#pe rh#o!ites o&! not

4e e(e!ope 4# either partia! me!tin" o

!o6er r&sta! e!si "ran&!ite 7Christiansenet a!. ,

=1)) Stein, =1)) Stein an Cro0, =11

hite et aI., =1)=;, ierentiation . o

s&4&tion-re!ate hi"h-K a!-a!0a!ine

ma"mas 7Keith et aI . , =1)+ estra

an Keith, =1)=;, or e5treme rationation

o rit-re!ate 4asa!ti ma"ma si"niiant!#

ontaminate 4# !o6er r&st . Ho6e(er,

rh#o!ites "enerate4# these proesses ma# not

4e e?&a!!# apa4!e o "eneratin" a "iant

eposit.

&ON&ENTRATION AND

TRANSPORTATION ME&HANISMS .

a!!ae et a!. 7=1+); emphasi>ethat

=-=2 km3 o ma"ma is neee to s&pp!#

the mo!#4en&m o&n in the C!ima5 ore

4oies. Carten et a! . 7=1))a; on!&e that

enrihment o ore omponents in t4e .&po!a

o&rsprior to the onset o r#sta!!i>ation an

that the initia! onentration o mo!#4en&m

in the parent ma"ma ham4er is not as

si"niiant to ore ormation as the t#pe an

&ration o proesses that e!i(er

mo!#4en&m to the &po!a. Intermin"!e

4arren an pro&ti(e sto0s at Henerson

ha(e the same isotopi omposition 7:armer

an DePao!o, =1)*; an pro4a4!# represent

s&essi(e ra&"hts rom a !ar"e, persistent

ma"ma ham4er that 6as onti"&o&s 6ith

eah intr&sion. Carten et a!.7=1))a; a!so

on!&e that either (ariations in resiene

time or (ariations in the eiienies o

rationation proesses o&! ao&nt or the

intermin"!in" o4arren an pro&ti(e sto0s .

Cr#sta!!i>ation

Cane!a 7=1)1a; states that partitionin"

o mo!#4en&m into an a?&eo&sphase is most

eiient 6hen an initia!!# r# me!t

rationates at sha!!o6 epth or 6hen me!t

e(o!(es 6ater at "reat epth, he s&""ests that

in either ase e(o!&tion o (apor &rin"

r#sta!!i>ation 7seon 4oi!in"; is more

eeti(e in remo(in" /o rom the me!t than

an# reasona4!e irst 4oi!in" senario.Ho6e(er, there is no reason to 4e!ie(e the

C!ima5!('# rh#o!iti ma"mas are r# C=

H2; an o not e(o!(e an a?&eo&s phase

&nti! the !ast e6 perent o the ma"ma

r#sta!!i>es. Keith an Shan0s 7=1));

o&mente a hi"h 6ater &"ait# an ontent

or the Pine Gro(e rh#o!ites most rh#o!iti

ma"mas are pro4a4!# sat&rate or near!#

sat&rate 6ith 6ater 6hen the# er&pt. In

aition, rh#o!ites that appear to ha(e er&pte

rom Pine Gro(e, 9&esta, C!ima5, anHenerson ha(e !ess than 8 phenor#sts.

The a!ternati(e Cane!a 7!1)1a;

proposes or "eneratin" a mo!#4en&m-rih

ma"ma--e(o!(in" an a?&eo&s phase at "reat

epth--ma# ha(e some app!iation to

r#sta!!i>ation o rier, intermeiate-or-mai

ma"ma at the roots o a stratiie ma"ma

s#stem. I 4&o#ant !&is that e(o!(e as a

res&!t o r#sta!!i>ation at epth an e5trat

mo!#4en&m rom the ma"ma the# tra(erse

an then o!!et eiient!# in a hi"h-!e(e! &p o! a , then the# ma# or m a

mo!#4en&m-rih ma"ma an onse?&ent!#

ontri4&te to ore ormation.

Some ha(e propose that !itt!e

aitiona! r#sta!!i>ation or ierentiation o

the parent ma"ma ham4er o&rre rom the

time o emp!aement o one sto0 to the ne5t

7Keith an Shan0s, =1)) Carten et aI.,

=1))a;. :or e5amp!e, >ironi&m an nio4i&m

onentrations are appro5imate!# the same or

a!! sto0s at Henerson. Ho6e(er, re!ati(e!#onstant onentrations o these e!ements are

perhaps not &n&s&a! or meta!&mino&s

ma"mas r#sta! rationation an o&r an

maintain re!ati(e!# onstant (a!&es or

>ironi&m, nio4i&m, an mo!#4en&m.


22/37

8+ SEG SP-2 GIANT ORE DEPOSITS

>*ri*!ion$ in *'orm#!'*r!i!ionin)

In orthoma"mati h#rotherma! !&is,

/o oes not appear to 4e omp!e5e an

transporte 6ith either CI or : in at,

Kepp!er an #!!ie 7=11=; o&n that

mo!#4en&m is most stron"!# partitione into

an a?&eo&s phase 7KDF .; 6hen CI an

: are a4sent. Conse?&ent!#, i o&r

on!&sions re"arin" the ma5im&m

enrihment, - ppm, o mo!#4en&m in

ma"mas are orret, none o the

e5perimenta!!# etermine (aporme!t

partition oeiients or mo!#4en&m 6o&!

pro&e an e5treme!# mo!#4en&m-rih ore

!&i 7one 6ith tho&sans o ppm /o; rom a

6ater-rih rh#o!iti me!t at sha!!o6 epths

7Kepp!er an #!!ie, =11= Ta0er

an Cane!a, =1)3; .

Bo6enstem et a!. 7=11=; in(esti"ate

the opper ontent o me!t in!&sions in ?&art>

phenor#sts rom the pera!0a!ine rh#o!ites

rom Pante!!eria. The# o&n 8 ppm opper in

matri5 "!ass an in me!t in!&sions 6ith

rat&res to the r#sta! s&rae. Non-e"asse

me!t in!&sions ontaine 2 ppm opper an

me!t in!&sions that a!so ontaine !ar"e (apor

4&44!es ontaine &p to 8 ppm opper.

The# a!&!ate that the (aporme!t partition

oeiients or opper ma# 4e 6e!! o(er

= this (a!&e is m&h hi"her than those

etermine e5perimenta!!# 7- Cane!a an

Ho!!an, =1)*;. Bo6enstem et a=. 7=11=;

propose that the stron"er partitionin" o

opper into the !&i phase o&! 4e &e to

more a(ai!a4!e CI in the !&i phase than in

the e5periments. This mi"ht ha(e 4een a&se

4# a hi"h CO2H2 ratio, renerin" HeU more

issoiate. The# a!so emphasi>e thatr($!*i*!ionindu#d (o!ati!e sat&ration

7seon-4oi!in"; ma# not 4e neessar# or the

pro&tion o C&-rih !&is. E5so!(e

(o!ati!es 6ere present in pante!!erite ma"ma

6ith on!# = r#sta!s an in rh#o!ite rom

the a!!e# o Ten Tho&san Smo0es 6ith on!#

2 phenor#sts 7Bo6enstem et aI. , =11=;.

Simi!ar!#, there are se(era! reasons

6h# the (aporme!t partitionin" oeiients o

mo!#4en&m in nat&ra! s#stems ma# 4e

si"niiant!# hi"her than e5perimenta!!#

etermine (a!&es. :or instane, porph#r#

mo!#4en&m s#stems ha(e 2 onitions o

a!-a!0a!ine ro0s 7a4o&t 2 !o" &nits a4o(e

NNO; that are 6e!! a4o(e the 2s

in(esti"ate e5perimenta!!# the trens o the

e5perimenta! ata s&""est that mo!#4en&m

sho&! 4e e(en more stron"!# partitione into

the a?&eo&s phase &ner s&h hi"h 2

onitions. Cane!a 7=1)14; a!so spe&!ates

that i the o5iation state o mo!#4en&m in

the a?&eo&s phase is hi"her than in the me!t,

then the tenen# o mo!#4en&m to enter the

(apor phase ma# 4e ompo&ne.

Keith an Shan0s 7=1)); re(ie6e the

e(iene that e5tension-re!ate trah#anesiti

ma"mas 6ere episoia!!# inete into the

4ase o the Pine Gro(e ma"ma ham4er. I

s&h ma"mas are inete into the 4ase o a

aiti or rh#o!iti ma"ma ham4er, the#

6o&! ?&enh or r#sta!!i>e an re!ease

(o!ati!es that o&! 4e !&5e thro&"h the

ma"ma ham4er. Bamproph#ri ma"mas or

!ess primiti(e K-rih mai ma"mas that are

"enera!!# (o!ati!e-rih, ma# ha(e interate

6ith C!ima5, Henerson, 9&art> Hi!!, an

other porph#r# mo!#4en&m s#stems to

pro&e simi!ar (o!ati!e !&5in".

I s&h a mo!#4en&m-transportin"

ma"mati !&i phase e5iste an 6as

CO2-rih, then e(iene o CO2 in

hi"h-temperat&re !&i in!&sions sho&!

perhaps4e o&n. Binnen an i!!iams-Jones

7=11; note that a?&eo&s-ar4oni !&i

in!&sions are ommon in !&orine-eiient

mo!#4en&m eposits, 4&t are sare in

!&orine-rih eposits. Ho6e(er, hite et

a=. 7=1)=; note that a ar4onate a&"hterminera! is present in some !&i in!&sions

rom Henerson. Seeor 7=1)); o&n

simi!ar a&"hter minera!s in !&i in!&sions

rom a rhoohrosite-4earin" a!teration

assem4!a"e at Henerson . Th&s, CO2-rih

!&i in!&sions ha(e 4een o4ser(e at C!ima5

an Henerson, 4&t are not a4&nant

7Seeor, =1)) Ha!! et a!. =13*;.

H#persa!ine !&i in!&sions are


23/37

SEG SP GIANT ORE DEPOSITS

r*r# in !;# Fd#+ii#n! d#'o$i!$: 6u! ommon in&im*2!('# $($!#m$ ,Linn#n *nd 9ii*m$on#$: 155-0 . T;#$# d*!* $u))#$! !;*!o*!i# +u2in) 6( * &Ori; +uid ';*$# in&im*2!('# $($!#m$ m*( no! 6# * $i)ni+i*n!'ro#$$.

An*($i$ o+ o*ni )*$ #mi$$ion$

+rom*!i# o*no#$ indi*!#$ !;*! $u+urou$)*$#$ *r# #mi!!#d u'on !;# in+#rr#d *rri* o+

n#= m*)m* *! !;# 6*$# o+ * m*)m* ;*m6#r.

A! !;#+- ondi!ion$ o+ **k*in# m*)m*$:

S- *nd HS =oud 6# 'r#$#n! =i!; *6ou!

$u6A#Mu* +u)*i!i#$ ,9;i!n#(: 15880. T;# o=

$ou6ii!( o+ S- in m*)m*$ m*( *o= * +u2

o+ S-6#*rin) o*!i#$ !o ri$# !;rou); *

on#d m*)m* ;*m6#r *nd '#r;*'$ $*#n)#

mo(6d#num. Mo(6d#num i$ no! om'#2#d

=i!; $u+ur 6u! !;# '*r!i!ionin) 6#;*ior o+

mo(6d#num r#*!i# !o * +uid ';*$# !;*! i$

ri; in *n o2idi#d $u+ur $'#i#$ ;*$ no! 6##nin#$!i)*!#d. Ind##d: +u2in) o+ Sri; +uid$

!;rou); * m*)m* i$ 'ro6*6( re?&ire !o

*oun! +or *r)# *moun! o+ m*)m*!i $u+ur

*$$oi*!#d =i!; * )i*n! 'or';(r( mo(6d#num

d#'o$i!. T;# o= $ou6ii!( o+ $u+ur in

;i);$ii* r;(oi!i m#!$ *r)u#$ +or $u; *

'ro#$$: 6u! m*$$ 6**n# *u*!ion$ !o !#$!

!;i$ $#n*rio =oud ino# mu; un#r!*in!(.

Con(etion an (o!ati!e

!&5in"

T;#r# *r# $##r* r#*$on$ !o $u$'#!!;*! !;# 'ro#$$ o+ m#!* #nri;m#n! ino#$on#!ion *nd o*!i# +u2in) !;rou); **r)# oum# o+ !;# ;*m6#r. ?#i!; #! *.,1580 doum#n! !;*! *r)# 6ok$ o+6io!i!#ri; ,


24/37

8) SEG SP-2 GIANT ORE DEPOSITSSEG SP-2 GIANT ORE DEPOSITS 8)

&rin" !&i o!!etion, then the !ar"er, or

hi"her "rae, the eposit o&! 4e. Certain!#

a sin"!e, 6e!!-sit&ate (ent 6o&!4e optima!.

Smith 7=131; pointe o&t that entra!

(ent (o!anoes o not er&pt more than a4o&t

= 0m8 o ash !o6 t& !ar"er er&ption

(o!&mes are re!ate to a!eras 6here

m&!tip!e (ents are pro4a4!# in(o!(e, as is

the ase o the 0m8 Ama!ia T& e5pe!!e

rom the 9&esta a!era. Se(era! res&r"ent

7or s!i"ht!# #o&n"er; p!&tons o&r a!on" the

rin" rat&re an e!se6here a!! o the

intr&sions are (aria4!# minera!i>e 6ith

mo!#4enite 7Johnson et aI., =1)1;. In

aition, the mo!#4enite-4earin" S&!ph&r

G&!h an $ear Can#on p!&tons onnet at

epth 7Beonarson et aI., =1)8;, 4&t on!#

the S&!ph&r G&!h p!&ton is ore-"rae.

/&!tip!e (ents or a!era-re!ate s#stems

ma# not 4e as !i0e!# topro&e a sin"!e "iant

eposit.

The = @= ratio o ham4er (o!&me to

er&ption (o!&me 7Smith, =131; s&""ests that

a entra! (ent (o!ano that er&pts the

ma5im&m = 0m8 o&! see no more than

1--- 0m8, 4&t m&h !ess ma# 4e re?&ire

onsierin" that = 0m8 o ma"ma strippe

o 8 ppm o mo!#4en&m 6o&! s&pp!# a!! themeta! neee to orm the Henerson eposit.

CHARACTERISTICS O: THE

DEPOSITIONAB SITE

There is no e(iene to iniate that

C!ima5-t#pe s#stems more eiient!# eposit

mo!#4en&m rom a ma"mati ore !&i than

other t#pes 4&t the# ma# o it in a sma!!er

(o!&me o ro0 t7; pro&e a hi"her "rae.

Carten et a!. 7!1))a; ientiie one o theprimar# ontro!s or the eposition o

mo!#4enite at Henerson as the presene o

K-e!spar a!on" (ein mar"ins. estra an

Keith 7=1)=; note a !inear orre!ation

4et6een K>O ontent o h#rotherma!!#

a!tere ro0 an "rae, K2-rih sto0s ma#

ha(e e?&i!i4rate 6ith a !ar"er (o!&me o

ma"mati 6ater prior to onso!iation, an

there4# ori"ina!!# ontaine a "reater amo&nt

o mo!#4en&m 7hite et a!., =1)=;.

Ho6e(er, on a me sa!e, mo!#4enite

r#sta!s are preerentia!!# eposite a!on"

K-e!spar r#sta!s re!ati(e to ?&art> or other

minera!s. Seriite separates mo!#4enite rom

the K-e!spar. The hi"h moa! a4&nane o

K-e!spar in some C !ima5-t#pe sto0s ma#

4e, in part, a epositiona! ontro! to their

"rae.

C!ima5-t#pe eposits ma# a!so 4e

hi"h-"rae &e to eposition rom a p&re!#

ma"mati a?&eo&s phase that 4e"ins

eposition at the ma"ma-6a!!ro0 interae.

The ore-!&i or :-eiient eposits ma# 4e

a mi5t&re o ma"mati an meteori 6ater

an, at eposits s&h as Tro&t Ba0e, m&st

ha(e oo!e at !east a e6 h&nre e"reesprior to minera!i>ation 7Binnen an

i!!iams-Jones, =11;. This amo&nt o

oo!in" an mi5in" ma# res&!t in eposition

o(er a !ar"er (o!&me o ro0 res&!tin" in

!o6er "raes. Deposition o mo!#4enite rom

the ore !&i in 4oth C!ima5- an

:-eiient-t#pe eposits is re!ate to

ereasin" temperat&re anorpH 7Binnen an

i!!iams-Jones, =11;.

Proesses that ontro! the !oation an

&ration o mo!#4enite eposition rom thea?&eo&s phase 6o&! a!so o4(io&s!# ontro!

the "rae. These 6o&! in!&e m&!tip!e

sto0s ormin" o(er!appin" ore 4oies an

hi"h hemia! an therma! "raients aro&n

the sto0 or p!&ton.

S'//AR% /ODEB AND

EPBORATION CRITERIA

:rom the ore"oin" is&ssion it is

apparent that the most si"niiant proess 7orpro4!em; in the ormation o C!ima5-t#pe

eposits is sa(en"in" a e6 ppm

mo!#4en&m rom a !ar"e ham4er e(ent&a!!#

to #ie! an ore !&i 6ith tho&sans o ppm

mo!#4en&m. A /o-rih ma"ma 6o&! 4e

orme in the &po!a &rin" this proess &e

to e?&i!i4ration 6ith the !&i ater its arri(a!

an prior to re!ease &rin" minera!i>ation.


25/37

SEG SP-2 GIANT ORE DEPOSITS 8181 SEG SP-2 GIANT ORE DEPOSITS

The o!!o6in" proesses appear to ha(e ate

to"ether to pro&e a mo!#4en&m-rih

&po!a o ma"ma@

=. Cr#sta!!i>ation a!on" the 6a!!s or

!oor o the ma"ma ham4er 6o&!

ao&nt or the "ra&a!!# re&e RE$

ontent o the ma"ma 4et6een

s&essi(e intr&sions. The s&essi(e!#

eeper '-shape REE patterns are not

&ni?&e to C!ima5-t#pe s#stems, 4&t

ha(e 4een note in oma"mati

intr&sions rom other non-minera!i>e

"ranitois 7Johnson et a! . , =1)1; .

Gra&a! a&m&!ation o 6ater an

!&orine a!on" the ham4er roo ma#

!o6er the so ! i&s , pre(entr# s t a! !i >ation , an pe rmi t

assimi!ation.

2. 'nerp!ate or inete mai

ma"mas ma# p!a# se(era! ro!es. The#

ma# me!t the !o6er r&st an mi5 6ith

!o6er r&sta! me!ts to pro(ie an

o5ii>e m a "m a i n 6hih

mo!#4en&m 6o&! 4e ha(e

inompati4!# &rin" rationation.

The# ma# pro(ie heat or@ a;on(eti(e transport o isso!(e an

&nisso!(e (o!ati!es to the &po!a,4;

assimi!ation o roo ro0s an the

ores o o!er sto0s, ; e5tension o

the !ie o the ham4er to a!!o6

"eneration o a !ar"e (o!&me o

rh#o!iti ma"ma an emp!aement o

m&!tip!e intr&sions. The# ma# a!so

s&pp!# some !&5 o !ess so!&4!e,

espeia!!# s&!&ro&s , "ases .

E5amination o the histories o most

(o!anoes re(ea!s that the# ten to 4e

omp!e5 rather than simp!e , 6ith the

ommon o&rrene o repeate inetions

o ma"ma, stora"e o ma"ma at ierent

!e(e!s, an ma"mati e"assin" o&rrin"

&rin" perios o re!ati(e ?&iesene or

ati(it# . Ore eposits 6o&! 4e ar more

ommon i simp!epassi(e

r#sta!!i>ation o moest!# 6ater-rih ma"ma

near the s&rae pro&e an ore eposit. In

terms o inrease omp!e5it# 4e#on simp!e

r#sta!!i>ation o &po!a ma"ma, this moe!

on!# s&""ests that on(etion ais the

transport o (o!ati!es pro&e 4#

r#sta!!i>ation a!on" the 6a!!s an !oor an

rom &nerp!ate mai ma"ma. The

proesses o on(etion an (o!ati!e !&5in"

ma# ha(e he!pe transorm /o-poor ma"ma

78 ppm; into /o-rih ma"ma 7 < =ppm;,

an enrihment that other6ise 6o&! 4e

impossi4!e 4# r#sta! rationation a!one

. Simi!ar proesses ma# ha(e operate in the

parent ma"ma ham4ers o man# porph#r#

/o s#stems, a!tho&"h the e(iene or

theseproesses oten annot 4e o&n inminera!i>e &po!as a!one. Geohemia! ata

re(ie6e here s&""est that initia!!# hi"h

inompati4!e trae e!ement a4&nanes ma#4e

m&h !ess a a&se o minera!i>ation than

the a4o(e proesses. Ho6e(er, !&orine an

6ater ma# 4e important positi(e ee4a0

parameters as their onentrations inrease,

the# re&e the (isosit# o the ma"ma an

a!!o6 more rapi on(etion an a&m&!ation

o ore !&i omponents in the &po!a.

E5p!oration riteria or a "iant,hi"h-"rae eposit in!&e@

= . a tetoni settin" that iniates a

han"eo(er rom ompressiona! to

e5tensiona! tetonis,

2. thi0 ontinenta! r&st at the time

o eposit ormation ma# eno&ra"e

e5treme ierentiation an r&sta!

ontamination,

8. an isotopia!!# >one ma"ma

ham4er iniati(e o a !on"-!i(e

heat so&re,

*. a !ar"e, s&4-(o!ani, entra!-(ent

ash !o6ome s#stem that er&pte !ess

than = 0m8 o rh#o!ite, an


26/37

. hi"h nio4i&m onentrations 7 < 3

p p m ; i n a s & 4 a ! 0 a ! i n e ,

ma"netite-4earin" rh#o!ite.

ACKNOBEDGE/ENTS

Re(ie6s o this paper 4# J. :. H.Thompson an A. H. C!ar0 are "rate&!!#

a0no6!e"e . e appreiate the patiene

an he!p&!ness o the eitors - espeia!!#

$en hitin" . This 6or0 6as s&pporte 4#

NS: "rant EAR-)1*33* to JDK.

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$o#!e, H., an Beith, H. $., =1)8, Geo!o"#

o the Tro&t Ba0e mo!#4en&m

eposit, $.C .. Canaian Inst. /in.

/eta!! . $&!! . (o!. 3+, no. )*1, p. = =

-

=2*.

$ro6n, P. , an Kah!ert, $. , =1)+, Geo!o"#

an minera!i>ation o the Re

/o&ntain porph#r# mo!#4en&m

eposit so&th-entra! %&0on. Canaian

E Inst. /in. /eta!!. , Speia! o!&me

83, p. 2))-213.

$&rt, D./., Sherian, /. :., $i0&n, J.. ,

an Christiansen E.H. , =1)2, Topa>

rh#o!ites--Distri4&tion, ori"in, an

si"niiane or e5p!oration. Eon.

Geo!., (o!. 33,p. = ) =)-=)8+.

Cameron, D.E. , $arrett, B. :. , an i!son,

J.C . , =1)+, Diso(er# o the Si!(er

Cree0 mo!#4enite eposit, Rio,

Co!orao. Amerian Inst. /in.

/eta!!.Petro!. En". , Trans. , (o!. 2),

p. 211-2=.

Cane!a, P.A., =1)1a, /a"mati ore-ormin"!&is, Thermo#nami an mass


27/37

SEG SP-2 GIANT ORE DEPOSITS 8==SEG SP-2 GIANT ORE DEPOSITS8==

transer a!&!ations . o meta!

onentrations. in hitne# , J.A. ,

an Na!rett, A.J . , es . , Ore

eposition assoiate 6ith ma"mas.

Re(ie6s in Eon. Geo!. , (o! . *, p.

28-22= .

Cane!a, P. A . , =1)14, :e!si ma"mas,

(o!ati!es, an meta!!o"enesis. in

hitne#, J.A . , an Na!rett, A.J.

, es. , Ore eposition assoiate

6ith ma"mas. Re(ie6s in Eon. Geo!

. , (o!.

*, p. 228-288 .

Cane!a, P.A. an Ho!!an, H.D., =1)*, The

p artitionin" o opper an

mo!#4en&m 4et6een si!iate me!ts

an a?&eo&s !&is. Geohim.

Cosmohim. Ata , (o! . *), p. 838-

R 8).

Car!son , D.H. , an /o#e, :.J. , =11, The

Co!(i!!e i"neo&s omp!e5@ Pa!eo"ene

(o!anism, p!&tonism, an e5tension

in northeastern ashin"ton . in

Anerson , J.B. , e. , The nat&re an

ori"in o Cori!!eran ma"matism.

Geo!. So. Ameria, /emoir =3*, p.

83-81*.

Carmihae! , I.S. E. ,= 11=, The reo5 stateso 4asi an si!ii ma"mas@ a

re!etion o their so&re re"ionsM.

Contri4 . /inera! . Petro! . , (o!.

=+, p.

=21-=* = .

Carten,R. $. , Gera"ht#, E.P. , a!0er,$./. ,

an Shannon, J.R. , =1))a, C#!i

e(e!opment o i"neo&s eat&res an

their re!ationship to hi"h-temperat&re

h#rotherma! eat&res in the

Henerson porph#r# mo!#4en&meposit Co!orao. Eon. Geo!. , (o!.

)8, p. 2++-21+.

Carten ,R.$ . , Gera"ht#, E. P. , a!0er,$./. ,

an Shannon, J.R. , =1))a, C#!i

"eneration o 6ea0!# an ston"!#

minera!i>in" intr&sions in

the Henerson porph#r#

mo!#4en&m eposit, Co!orao @

Corre!ation o i"neo&s eat&res 6ith

hi"h-temperat&re h#rotherma!

a!teration. Eon . Geo!. , (o!.

2++-21+.

Carten,R.$. , a!0er,$. /. , Gera"ht#,


28/37

SEG SP-2 GIANT ORE DEPOSITS 8=2SEG SP-2 GIANT ORE DEPOSITS8=2

an G&no6, A. J., =1))4,

Comparison o ie! 4ase st&ies o

the Henerson porph#r#

mo!#4en&m eposit, Co!orao ,

6ith e5perimenta! an theoretia!

moe!s o porph#r# s#stems. in

Ta#!or, R.P, an Stron", D. : . , es .

, Reent a(anes in the "eo!o"#

o "ranite-re!ate minera! eposits .

Canaian Inst. /in . /eta!! . , Speia!

o!&me 81, p. 8=-8++.

en , R.$. , hite, . H., an Stein, H.!. ,

in press, Hi"h-"rae "ranite-re!ate

/o s#stem @ C!assiiation an ori"in

. Geo!. Asso . Canaa, Speia!

Paper, I AGOD Coneren e - -

D epos i t /oe!in" Pro"ram.

stiansen, E.H. , an i!son, R.T. , =1)2,

The !assiiation an "enesis

o sto06or0 mo!#4en&m

eposits--A is&ssion. Eon. Geo!.,

(o!. 33.p.

=2-=22.

stiansen, E.H. , $&rt, D. /., an

Sherian /.:., =1)+, The "eo!o"#

o topa> rh#o!ites rom the

6estern 'nite States . Geo! . So.

Ameria, Speia! Paper2, )2p.

Christiansen, E. H ., St&0!ess, =.S . ,

:&n0ho&ser, /.J., an Ho6e!!, K. A. ,

=1)), Petro"enesis o rare-meta!

"ranites rom ep!ete r&sta!

so&res--an e5amp!e rom the

Ceno>oi o 6estern 'tah, 'SA. in

Ta#!or, R.P, an Stron", D.:., es . ,

Reent a(anes in the "eo!o"#

o "ranite-re!ate minera!

eposits. Canaian !nst. /in. /eta!!

. , Speia! o!&me 81,p. 83-82= .

Con"on, R.D. , an Nash, .P. , =11= ,

Er&pti(e pe"matite ma"ma@ Rh#o!ite

o the Hone#om4 Hi!!s, 'tah .

Amerian /inera!. , (o!. 3+, p.

=2+=-=23).

C#"an, G.B. , an Cho& , I-/in",

=1)3, Ca!i4ration o the 2-8

4&er. EOS, (o!. +),p. *= .

DePao!o, D.J. , =1) =, N in the Co!orao

:ront Ran"e an imp!iations orr&st


29/37

ormation an mant!e e(o!&tion inthe

Protero>oi . Nat&re , (o! . 21= ,p.

=18- =1+.

:armer, G.B. , an DePao!o , D. J . ,

=1)*, Ori"in o /eso>oi anTertiar# "ranite in the 6estern

'nite States an imp!iations or

pre-/eso>oi r&sta! str&t&re 2. N

an Sr isotopi st&ies o

&nminera!i>e an C&- an /o-

minera!i>e "ranite in the

Pream4rian raton. Jo&r. Geoph#s.

Res . , (o!. )1,p. =,=*=-=,=+.

Ganster, /.. , Do6sett, :. R . , an Ranta,

D.E. , =1)=, Geo!o"# o the /o&nt

Emmons eposit Va4s .W . Amerian

Inst. /in. /eta!! . Pet. En" . ,

Ann&a! /eetin" Pro"ram, p . 2= .

Ge#ti , A. , an Shon6ant, H.K. , =131,

$or(i0a--a possi4!e porph#r#

mo!#4en&m o&rrene 6ith the Os!o

rit,Nor6a# . Eon. Geo! . , (o!. 3*,

p.

=2= =-=22.

Ge#ti, A., an Thomasson, $., =1)*,

/o!#4en&m an preio&s meta!

minera!i>aiton at :!amme e!,

So&th East Green!an. Eon. Geo!. ,

(o!. 31 ,

p . =12=-=121

.

Gi!es , D.B. , an Thompson, T. $.,

=132, Petro!o"# an

minera!i>aion o a mo!#4en&m-

4earin" a!0a!i sto0, Sierra $!ana,

Ne6 /e5io . Geo! . So . Ameria

$&!! . , (o! . )8, p. 2=21-

2 =*).

Go(inara&, K. , =1)1, =1)1 ompi!ation

o 6or0in" (a!&es an samp!e

esription or 232 "eostanars.

Geostanars Ne6s!etter, (o!. = 8,

Speia! Iss&e,p.

=-= =8.

Ha!!, .E. , :rieman, 1 . : anNash, J.T.,

=13*, :!&i in!&sion an !i"ht sta4!e

isotope st o the C!ima5

mo!#4en&m eposits, Co!orao

. Eon. Geo!. , (o!. +1,p. ))*-1 = .

Hattori, K. , Arai, S. , :ranis, D./. , an

C!ar0e, D.$ . , =112, ariations o

sierophi!e an ha!ophi!e trae

e!ements amon" mant!e-eri(e


30/37

s&!phies etete 4# in- sit&

miro-PIE ana!#sis. EOS, (o!. 83 , '.

8** .

Heint>e, B. , =1) , Geo!o"# an

"eohemistr# o the

p or ph #r# sto 06or0

mo!#4en&m eposit at Tam4oras, Ba

Ne"ra one 7Per&; . Eon. Geo!. ,

(o!.

), p. 2 =1-223.

Hi!reth, ., =1)=, Graients in si!ii

ma"ma ham4ers @ Imp!iations

or !ithospheri ma"mati sm .

Jo&r . Geoph#s . Res. , (o!. )+, p.

=, =8-

=, =

12.Ho!!ister , .: . , = 1 3)4 ,

Porph#r# mo!#4en&m eposits . in

S&t&!o(, A . , e . , Internationa!

mo!#4en&m en#!opaeia =33)-

=13) , o!&me = . Santia"o, Chi!e,

Intermet P&4!iations,p. 23-2)).

H&son, T., Ar!;: J. G. , an /&th, K.G. ,

=1)=, Geohemistr# o intr&si(e

ro0s assoiate 6ith mo!#4enite

eposits , Kethi0an 9&aran"!e,

so&theastern A!as0a . Eon. Geo!. ,

(o!. 3+, p.

=22- =282.

Ih!en, P. /. , Tronnes, R. , an o0es, :./. ,

=1)2, /inera!i>ation, 6a!! ro0

a!teration an >onation o ore epositsassoiate 6ith the Drammen Granite

in the Os!o Re"ion , Nor6a# .

in E(ans, A. /. , e. ,

/eta!!i>ation assoiate 6ith ai

ma"matism. Chihester, John i!e# ,

p. = ==-=8+.

I(ano(a, G.:. , =1+8 , Content o tin,

t&n"sten, mo!#4en&m, in "ranites

en!osin" tin-t&n"sten eposits.

Geohemistr#, (o!. ), p. *12-.

Johnson, C./. , an :ririh, C.J. , =11,Non-monotoni hemia! an -: Sr,N, an P4 isotope >onations an

hetro"eniet# in the mai- to

si!ii-omposition ma"ma ham4er o

the Gri>>!# Pea0 T&, Co!orao.

Contri4 . /inera! . Petro! . , (o!. = ,

p.

+33-+1.

Johnson, C. /. , an Bipman, P.. , =1)),

Ori"in o meta!&mino&s an a!0a!ine


31/37

SEG SP-2 GIANT ORE DEPOSITS 8=88=8 SEG SP-2 GIANT ORE DEPOSITS

(o!ani ro0s o the Bati (o!ani

ie!, northern Rio Grane ri+!: Ne6

/e5io. Contri4. /inera!. Petro!.,

(o!. =, p. =3-=2).

Johnson, C./., C>amans0e, G.K., an

Bipman P. ., =1)1, Geohemistr#

o intr&si(e ro0s assoiate 6ith

the Batir (o!ani ie!, Ne6 /e5io,

an ontrasts 4et6een e(o!&tion o

p!&toni an (o!ani ro0s. Contri4.

/inera!. Petro!., (o!. =8, p. 1- =1.

Johnson , C. /., Bipman, P..,

an C>amans0e, =11, H, , Sr, N,

an P4 isotope "eohemistr# o the

Bati (o!ani ie! an o"eneti

intr&sions, Ne6 /e5io, an re!ations

4et6een e(o!&tion o a ontinenta!

ma"mati enter an

moiiations o the !ithosphere.

Contri4. /inera!. Petro!. , (o!. = *,

p. 11- =2*.

Keith, J.D., =1)2, /a"mati e(o!&tion o the

Pine Gro(e porph#r# mo!#4en&ms#stem, so&th6estern U!*;. &np&4!.Ph.D. thesis, Dni(.

isonsin, /aison, isonsin,

2*+ p.

Keith, J.D., Shan0s, D.e., III,

Arhi4a!, D. A., an :arrar, E.,=

1)+, o!ani an intr&si(e histor# o

the Pine Gro(e porph#r#

mo!#4en&m s#stem,

so&th6estern U!*;. Eon. Geo!., (o!.

)=, p. 8-33.

Keith, J.D. , an Shan0s, .C., III,

=1)), Chemia!e(o!&tion an

(o!ati!e &"aities o the Pine Gro(e

porph#r# mo!#4en&m an ash-!o6

t& s#stem,

so&th6estern U!*;. in Ta#!or, R.P,an Stron", D. :., es., Reent

a(anes in the "eo!o"# o

"ranite-re!ate minera! eposits.

Canaian Inst. /in. /eta!!., Speia!

o!&me 81, p. *2-*28.

Keith, I.D., (an /i!e!aar, ., C!ar0,

A. H. , an Ho"son, C.I., =1)1,

Granitoi te5t&res, ompositions, an

(o!ati!e &"aities assoiate 6ith the

ormation o t&n"sten-ominate s0arn

eposits. in hitne#, I. A.,an

Na!rett, A. J. , es., Ore eposition

assoiate 6ith ma"mas. Re(ie6s in

Eon. Geo!., (o!. *, p. 28-2.

Kepp!er, H., an #!!ie, P. I., =11=, Partitionin" o C&, Sn, /o,D, U:an Th 4et6een me!t an a?&eo&s

!&i in the s#stem hap!o"ranite-H2-

HC! an hap!o"ranite-H2-H:.

Contri4. /inera!. Petro!., (o!. =1, p.

=81- =

.

Kir0ham, R. ., /Carn, C., Prasa, N.,

Sore"aro!i, A. E., o0es, :./., an

ine, G ., =1)2, /o!#4en&m in

Canaa, Part 2@ /OB%:IBE--An

ine5-!e(e! omp&ter i!e o

mo!#4en&m eposits an o&rrenes

in Canaa. Geo!. S&r(. Canaa, Eon.

Geo!. Report 88, 2)p.

Knitte!, D. , an $&rton, C.K., =1), Po!o!Io

Is!an 7Phi!ippines;@ /o!#4en&m

minera!i>ation in an is!an ar. Eon.

Geo!., (o!. ), p. 2 =8-2 =).

Kooiman, G.J.A., /Beo, /.J., an

Sin!air, .D. , = 1)+,

Porph#r# t&n"sten-mo!#4en&m

ore4oies, po!#meta!!i (eins an

rep!aement 4oies, an tin-4earin"

"reisen >ones in the :ire

To6er one, /o&nt P!easant,

Ne6 $r&ns6i0. Eon. Geo!., (o!.

)=,p. =8+-=838.

Ko(a!en0o, . I., Antipin, .S., Kon&so(a,

. ., Smirno(a, %e.., Petro(, B.B.,

!a#0in, N. . , K&>netso(a, A.I.,

Kost#&0o(a, %e.S., an Pisars0a#a,

.A., =13), Partition oeiients o

!&orine, nio4i&m, tan ta!&m,

!anthan&m, #tter4i&m, #ttri&m, tin an

t&n"sten in on"onite. Geohemistr#

Inti., (o!. =, p. 28-2.

Ko(a!en0o, . I., Samo#!o(, . S. , an

Gore"!#a, A.., =1)=, o!ani

on"onites enrihe in rare e!ements.

Do0!a# A0aemia Na&0 SSSR, (o!.

2*+,p. )-+=.

K&roa, P.K. , an Sane!!, E.$., =1*,

Geohemistr# o mo!#4en&m.

Geohim. Cosmohim. Ata, (o!. +,


32/37

8=* SEG SP-2 GIANT ORE DEPOSITS

p. 8-+8.

Beonarson, R.., D&n!ap, G., Star?&ist,

.B. , $ratton, G.P., /e#er, J.. ,

Os4orn, B .., At0in, S.A., /o!!in",

P.A., /oore, R.:., !more, S.D.,

=1)8, Pre!iminar# "eo!o"# an

mo!#4en&m eposits at 9&esta, Ne6

Documents

Keith Christiansen 93 Giant Mo