Zircon and Granite Petrology

7/26/2019 Zircon and Granite Petrology

1/14


2/14

2 0 8 J . P. P u p in : Z i r co n an d G ran i t e P e t ro log y

+ _ 5 0 ~V

5 ~ C

5 5 0 ~

6 0 0 ~ ( , . )R

6 5 0 ~ ~ - ) - ( , ~ )

7 0 0 o c c ,- ). (, ,o~

S

7 5 0 ~ ( , - ) . (. o)

M

8 0 0 o c c,oo) (,,o~

E

8 5 0 o c ~ , - ) , - ~ , , o )

9 0 0 o c s ~,oo~

P Y R M I D E S

211) {101) ~ N: 211) {101) < [211) {1011 {211) 101) . 211) 101) ~ 211 ) 101) 301 )

B

H

Q 2

Q 4

~ Q 5

@ E

AB~

1

111

116

S 1 6

A R 2

9L2

9112

S 7

S 1 7

02 2

|ABa

02

3

3

S 8

G@

8 2 3

A S 4

03

@L4

@4

S 9

9

@S 2 4

AB5

@J4

@L5

@S5

S1

S 1 5

S20

S25

P~

P2

P3

P 4

5

D

~ R 2

5

1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 6 0 0 7 0 0 8 0 0

I N D I C E

1 0 0

C

2 0 0

I

3 0 0

1t7

4 0 0

5 0 0

6 0 0

R4

7 0 0

R5

8 0 0

Fig . 1 . Main types and sub types o f the typo log ic c lass i f icat ion and co rrespond ing geo thermometr ic scale . The approx imat ive temperatu rscale p ropos ed Pup in and Turco 1972c) was cal ib rated f rom the confro n tat ion o f the typo logy zi rcon data wi th the temp eratu resnorm al ly accep ted in l i tera tu re fo r crysta l l izat ion o f p lu to -vo lcan ic rocks and minerals . In th is work , we hav e par t icu lar ly consideredThe l imi t o f s tab i l i ty o f the minerals i .e ., the musc ov i te in g ran i t ic and me tam orph ic rocks) ; the geo therm om etr ic data ob taine dwith o ther me thods i .e ., on pyroxenes f rom cha rnock i t ic and vo lcan ic rocks; on v i t reous inclusions) ; the temp eratu re ranges fogneiss anatex y ; - the tem peratu re ranges fo r the beg inn ing and the end o f the mag ma t ic crysta l l izat ion in g ran i tes , d io r i tes , gabb ro

and effusive equ ivalen ts ; the temp eratu res o f fo rm at ion o f minerals wi th which z i rcon syncrysta l l ized i .e ., f luo r i te , la te-mag mat icquar tz)

The Typology Method

The use of zircon as a possible clue to the problemof the origin of granite had been propo sed by Polder-vaart since 1950; the idea, though further developedby Polderva art and his collaborators Poldervaart1956; Larsen and Poldervaart 1957; Alper and Pol-dervaart 1957), did not receive wide acceptance be-cause the p roposed criteria of dimensional crystal sta-

tistics, criticised by Pup in 1976, pp. 314 317), didnot produce the desired solution.

The fundame ntal basis o f population study in zir-cons had been given in an earlier publication Pupinand Turco 1972a). An arran gement of given prismaticand pyramidal crystal faces constitute a populationtype. The abundance of zircon crystals related to cer-tain types has led to the setting up, in those particularcases, of more or less numero us subtypes 1 to 25).

N

C

T


3/14

J.P. Pupin: Zircon and Granite Petrology

Table1. Main and secondary types and subtypes of the typologic classification of zircon

209

Prisms Pyramids Main Subtypestypes

Supplementary pyramids:secondary types and subtypes Pinacofd

+ { 3 0 1 } + { 3 2 1 } + { 3 1 1 } + { 5 1 1 } + { 0 0 1 }

0 1 {101} A - AC{211} B - BC{301} C - -

0 2 { 1 0 1 } { 211} A B 5 A B 1 5 _ A B 5 ) A B C 1 5 5

1 {100} 1 {101} D - K{211} E - - EC{ 3 0 1 } F - -

1 {110} 1 {101} G 3 G 1 ~ . G3 ) M1 53{211} H - H C{301} I - -

1 { 1 0 0 } 2 { 1 0 1 } - { 2 11 } J 5 J 1 ~. J 5 ) N I 5 5

1 {110} 2 {1 01 }- {211} L 5 L1 ~ Ls ) O1 5 5

2 {100} - {110} 1 {101} P 5 P1 ~ t Ps ) T i l l5

{211} Q 5 Q1 5 , Q5 ) OC l f i 5{ 3 O l } R 5 R 1 ~ R ~ ) -

2 {1 0 0 } {11 0 } 2 {1 0 1 } {2 11} S 2 5 S1 ~ t S2 5 )Vla 5

Add Add Add Add AddZ Y W X an

to the to the to the to the as ter isk

main main main main to the

type: type: type: type: type:

A Z , B Z , . . . AY, B Y, . . AW, B W , . . . A X , B X , . . . A * , B * , . , .

S Y =V

Decreasing frequency of Pyram ids in nature- ->

S o , th a t r o c k s w i t h c o m p a r a b l e p e r c e n t a g e s o f th es a m e z i r c o n t y p e c a n t h e n b e e a s i l y s e p a r a t e d - s i g n if i -c a n t l y - p r o v i d e d t h a t t h e i r s u b t y p e s d i s t r i b u t i o n i sk n o w n .

T h e m a i n t y p e s s h o w 0 , 1 o r 2 p r i s m s , i .e . { 1 0 0 },{ 11 0 } i n c o m b i n a t i o n w i t h e i t h e r o n e o f t h e t h r e ep y r a m i d s { 1 01 } , {2 1 1} o r { 3 0 1 }, o r th e a r r a n g e m e n t{ 1 0 1} + { 2 11 } . M a i n t y p e s a n d s u b t y p e s c a n b e r e l a t e do n a s q u a r e b o a r d w i t h t w o v a r i a b l e s ( F i g . 1 ), d e p e n d -i n g u p o n t h e r e l a ti v e d e v e l o p m e n t o f t h e c r y st a l li n ef a c es . T h e i n i ti a l ty p o l o g i c d i a g r a m d e s i g n w a s e n -t ir e ly b a s e d o n t h e r e l a ti v e n a t u r a l a b u n d a n c e s o fz i r c o n t y p e s a n d s u b t y p e s . S t y p e , w h i c h is th e m o s ta b u n d a n t h a b i t u s t h a t c a n b e f o u n d i n e n d o g e n o u sa n d e x o g e n o u s r o c k s, f o rm s , t h e n , th e d i a g r a m s m a i np o i n t , t h e o t h e r m a i n t y p e s lo g i c a l ly a r r a n g e d a r o u n d .

S o m e m a i n t y p e s s t a y p u r e l y t h e o r e t i c a l ( i .e . : C , I ,R , F ) : t h e i r e m p l a c e m e n t w a s s u g g e s t e d a t t h e d i a -g r a m r i g h t p a r t ( F i g . 1) a s T a n d K t y p e s a r e m a i n l yl i n k e d w i t h t h e P a n d D t y p e s i n a l k a l i n e r o c k s .

T h e s e c o n d a r y t y p e s h a v e b e e n d e r i v e d f r o m t h ea b o v e m a i n t y p es f r o m w h i c h t h e y c a n b e d e d u c e db y a d d i n g o n e o r m o r e e x t r a p y r a m i d s , w i t h u s u a ll ya m i n o r d e v e l o p m e n t . T h e s e c o n d a r y t y p e s a p p e ll a -t i o n c a n b e f o u n d i n Ta b l e 1 .

R e g a r d i n g t h e m o r e c o m p l e x c a s es w h e r e a c r y s t a ls h o w s a g r e a t n u m b e r o f d i f fe r e n t p y r a m i d a l f o r m s ,t h e n o m e n c l a t u r e c a n y e t b e u se d . A b i p y r a m i d a l

c r y s t a l { 1 0 0 } { 11 0 } w i t h f o u r p y r a m i d s { 1 0 1 } { 2 11 }{ 112 } { 311 } w o u l d b e l a b e l l e d S W Z , t h e W a n d Z l et -t e rs li st e d b y a l p h a b e t i c a l o r d e r ( c o r r e s p o n d i n g t o

t h e s u p p l e m e n t a r y p y r a m i d s { 3 1 1} a n d { 1 12 } ) w i t hr e s p e c t t o t h e S p r i n c i p a l t y p e ; t h e r e l a t i v e d e v e l o p -m e n t s o f { 1 0 0} { 110 } p r i s m s a n d { 1 01 } { 2 11} p y r a -m i d s a l lo w t h e s u b t y p e c h a r a c t e r i z a t i o n ( S W Z 1 t oS W Z 2 5 ) a s f o r a c o m m o n S t y p e .

U p t o n o w, w e h a v e l is te d s o m e t h i r t y n a t u r a lt y p e s , o u t o f w h o s e e i g h t o n l y a r e f r e q u e n t ( D , G ,J , L , N , P, S , U ) .

I t is a l s o v e r y i m p o r t a n t t o p o i n t o u t t h a t c r y s t ale l o n g a t i o n i s n o t a t a ll t a k e n i n t o a c c o u n t i n o u rp r o p o s e d t y p o l o g y .

nalytical Techniques

Zircon crystals (populations) are separated from rocks by wellknown routine procedure:moderate crushing and sieving followedby densimetric (bromoform and m ethylene iodide), magnetic andelectromag netic separations o f the heavy minerals fraction; onlythe 0.050 0.160 mm fraction, w here most of the granites zirconsgenerally are, have been here studied. T he separated populationsare then mounted on microscope glass slides with Canada balsamand studied at 250 x magnification. For each o f the 200 graniticrock samples studied up to date, the typologic distribution hasbeen determined on the ba sis of the examination of 100 to 150unbroken zircon crystals whenever possible, and the coordinates(I.A and I.T) computed (Pupin and T urco 1972b) (F ig. 2). Typo-


4/14

2 1 0 J . P. P u p i n : Z i r c o n a n d G r a n i t e P e t r o l o g y

a

I . Aj ,o o ~ ~ 1 7 6i i i I 1 ~ i

1oo I I .~I

.T I .~ . . . . . . . . . ,

800

' ~= '~- - '= :~ b

~ 2 , N 5- I0

N 2 - 5 ~ 1 0 -2 0 '/ ,

F i g . 2 a - c . Z i r c o n p o p u l a t i o n r e p r e s e n t a t i o n : a s u b t y p e s o b s e r v e d ;b t y p o l o g i c f re q u e n c y d i s tr i b u t i o n o f t h e p o p u l a t i o n ; e m e a n p o i n t( I . A , I . T ) i n t h e ( I . A , I . T ) d i a g r a m a n d c a l c u l a t e d " Ty p o l o g i c a lE v o l u t i o n a r y Tr e n d " ( T. E .T. ) o f t h e p o p u l a t i o n c . - T h e d e -t e r m i n a t i o n s o f I . A a n d I fi " i n d i c e s a r e m a d e w i t h t h e f o l l o w i n gf o r m u l a s :

8 0 0 8 0 0

I .A = ~ I .A x nl . A I .T = ~ I .T nI :TI A = 1 0 0 I T = 1 0 0

w h e r e n l. A a n d n ET a r e t h e r e s p e c t i v e f r e q u e n c i e s f o r e a c h v a l u e o fI .A o r I . T ( ~ n l . A = ~ n l . T = 1 ). - - T h e T.E . T. i s d r a w n t h r o u g h t h em e a n p o i n t ( I . A , I f i' ) w i t h a s l o p e a = ST / SA , w h i c h i s th e t a n g e n t o ft h e a n g l e b e t w e e n t h e T. E . T. a x i s a n d t h e I , A a x i s .

S t a n d a r d d e v i a t i o n o f A i n d e x = S A= ( A I / ~ Z ~ -)2 /N.

S t a n d a r d d e v i a t i o n o f T i n d e x = S T = 1 / ( T - T ) 2 / N 9N = n u m b e r o f d e t e r m i n e d c r y s t a ls

l o g i c d i s t r i b u t io n d i a g r a m s p e r m i t t h e c o m p a r i s o n o f t h e v a r i o u sp o p u l a t i o n m e a n p o i n t s ( I . A , I . ~ C ) .

P r o v i d e d t h a t t h e m a i n a g e n t s c o n t r o l l i n g t h e v a r i a t i o n s i nt y p o l o g i c al p o p u l a t i o n s a r e k n o w n ( s ee n e x t c h a p t er ) , o n e c a na p p l y t h e m e t h o d t o t h e f ie l d o f c o m p a r a t i v e p e t r o l o g y a n d d i s c u ssd i f fe r e n c es o f t y p o l o g i c d i s t ri b u t i o n a n d p o s i t i o n s o f t h e s t u d i e dp o p u l a t i o n s . O n e c a n a l so , u s i n g th e s a m e d a t a , b r i n g o u t v a r i a ti o n s

i n t h e p h y s i c o - c h e m i c a l c o n d i t i o n s o f t h e c r y s t a ll i z at i o n m e d i u mt h a t h a v e r e s u l t e d i n a s i n g l e s a m p l e z i rc o n p o p u l a t i o n . O f t e n ,i n g r a n i t i c r o c k s , t h e z i r c o n c r y s t a l l i z a t io n c y c l e is o f l o n g d u r a t i o na n d m a y e v e n c o v e r t h e e n t i r e m a g m a t i c s t a g e s (e . g ., Pu p i n 1 9 76 ,p p . 2 1 4 - 21 9 ) , s o t h a t t h e d a t a o b t a i n e d m a y n o t o n l y r e la t e t od e f i n i t e s t a g e s o f m a g m a t i c c r y s t a l l i z a t i o n b u t m a y a l s o c o v e r ,a s a m a t t e r o f f ac t , t h e w h o l e z i r c o n c r y s t a l l i z a t i o n p e r i o d , t h es u c ce s s iv e st a g e s o f z ir c o n " t y p o l o g i c a l e v o l u t i o n " b e i n g t r a p p e di n s id e o t h e r m i n e r a ls a s t h e i r g r o w t h s p r o c e e d . T h e c h r o n o l o g yo r s e q u e n c e o f a p p e a r a n c e o f c ry s t al f o r m s t h e n l e a d s t o t h ee s t a b l i s h m e n t o f in d i v i d u al " t y p o l o g i c a l e v o l u t i o n a r y t r e n d "( T. E . T. ) ( Pu p i n 1 9 76 , p p . 5 9 a n d f o l l .) . I n c o m p o s i t e g r a n i t ic b o d i e ss h o w i n g c o g e n e t i c r o c k u n i t s , i t i s p o s s i b l e t o s t u d y t h e t y p o l o g i c a le v o l u t i o n f r o m t h e f i r s t t o t h e l a s t u n i t s a n d t o d e t e r m i n e a d i f f e r -enc ia t ion T.E.T. (Pup in 1976 , pp . 141 and fo l l . ) .

100

200

I T300

400

500

600

700

800

I A

100 200 300 400 500 600 700 800I I r i I I i 1

..:~i:: i iii~ /i~ i~ i~ : ' 4

: i i i~ i i i i~ i i i : : i i i : : . i . : i : \...... :::::::::::::::::.: : : I [

III

I

I

l

~ J

Fi g . 3 . D i s t r i b u t i o n o f p l u t o n i c r o c k s i n t h e t y p o l o g i c d i a g r a m :( 1 ) d i o r i t e s , q u a r t z g a b b r o s a n d d i o r i t e s , t o n a l i t e s ; ( 2) g r a n o d i o -r i t es ; ( 3 ) m o n z o g r a n i t e s a n d m o n z o n i t e s ; ( 4 ) a l k a l i n e a n d h y p e r a l k -a l i n e s y e n i t e s a n d g r a n i t e s ; ( c ) c o r d i e ri t e b e a r i n g r o c k s

K n o w n E s s e n t i a l F a c t o r s C o n t r o l l i n g Va r i a t i o n si n Z i r c o n Ty p o l o g i c a l P o p u l a t i o n s

Resu l ts of the invest igat ions of factors kn ow n to in-f luence the g row th o f z ir con typo log y have b eenrepor t ed in va r ious pub l i ca t ions Pup in and Turco

1972c -1975; Pupin 1976; Pupin et a l. 1978).The chemical character is t ics of the crystal l izat ionmedium play a leading role in the or igin and rela t ivegrowth o f z i r con pyramids Pup in and Turco 1975 ;Pupin 1976) . Z ircons or iginat ing in an hyperalumi-nous o r hypoa lka l ine med ium show wel l deve loped{211} pyramid whereas those g rown in an hypera lka-l ine o r hypoa luminous med ium have wel l deve loped{101} pyramid; the A1/alkal ine ra t io i s therefore be-l ieved to con t ro l t he z i r con pop u la t ion index A, anobserva t ion which is conf i rmed w hen cons ider ing thep lu ton ic rocks d i s t r ibu t ion in the I .A , I.T ) d i ag ramPu pin 1976, pp. 179-180) Fig. 3) . The {301} pyr a-

mid shows a dist inct spreading propensi ty in an alka-l ine m edium wh ere i t occurs in the T [{100}, {110},{101}, {301}] and K [{100}, {101}, {301}] types inpo tass ium- r i ch a lka l ine med ium. On the o ther hand ,the {112} pyra mid pre ferent ia l ly appears in hyperalu-minous m ed ia where i t can som et imes deve lop p romi -nen tly Pup in 1976, p. 296; G irau d et al . 1979).

As the leading factor governing the re la t ive devel-opm ent o f t he z i rcon p r i sms r ea l ly i s the t em pera tu reof the c rys t a ll i za tion med ium , we have the re fo re p ro -posed tha t minera l a s a geo therm ome te r Pup in andTu rco 1972) Fig. 1) .


5/14

J.P. Pupin: Zircon and Gran ite Petrology 211

~ I . A100 89

J i , i ~ , ,

1 t

I . T

\

x

80 1 ~

a

(

d

, I\ x 1

b

\ I

: I+ t

\ - I

f I

: I

X

g h i

Fig. 4a i. Distribution of mine ral associations in granitic rocks:musco vite (a), anata se and bro okite (b), am phiboles (e) (a = alkalineamphiboles; h = hornblende), pyroxenes and olivins (d), cordierite(e), garne t (f), tourm aline (g), monaz ite (h), xenotime (i)

M us co v i te (F ig . 4a ) is p r es en t on ly in g ran i t i cr o c k s t h e z i r c o n p o p u l a t i o n i n d e x o f w h i c h s h o w sI ' < 4 5 0 , w h i c h t h e n le d t h e a u t h o r s t o p r o p o s e , i nacco rd ance w i th Lam eyre (1966), the p res enc e o f at h e r m a l t h r e s h o l d f o r t h e a p p e a r a n c e o f t h a t m i n e r a l

in g ran i t e s (P up in and Turc o 1974 a ) . A nea r ly s imi la rd i s t r ibu t ion i s no te d fo r the an a tas e + b rook i t e , g a rne tand tou rm al ine (F ig . 4b , f , g ). O n the o the r h and ,z i r c o n p o p u l a t i o n i n di c e s o f p l u t o n i c r o c k s w i t h a m -ph ibo les , py roxenes and pe r ido t s have h igh T va lues(> 500) , mark ing h igh c rys ta l l i za t ion t em pera tu re s(F ig . 4 c , d) . A n excep t ion to tha t ru le tha t one s eeson F ig . 4 is an hype ra lka l ine g ran i t e f ac ies f rom Ev is a ,Cor s ica w i th r i ebeck i t e - aegyr ine in w h ich the ve ryla te oc taed r ic type A z i r con ( I . T. = 20 0) is the o n lytype p res en t an d i s in te rg row n w i th in te r s t i t ia l f luo r i t e( P u p i n a n d Tu r c o 1 9 7 5 ) . Z i r c o n p o p u l a t i o n s f r o me u h e d r a l o r n o d u l a r c o r d i e r it e r o c k s h a v e l o w A a n d

~f indices (F ig . 4e) . This is a lso t rue for m os t o f therocks con ta in ing mon az i t e (F ig . 4h ) , w h ich i s p re fe r -en t i a l ly fou nd in typ ica l s i a li c rocks ( c rys ta ll ines ch i s t s , migmat i t e s , ana tec t i c g ran i t e s ) . X eno t ime i smo re l ike ly to be foun d (overg row ths on z i r cons ) inr o c k s w i t h a n a l k a l i n e t r e n d , t h e z i r c o n p o p u l a t i o nof w h ich s ho w s low T and h igh A ind ices (F ig . 4 i ) .

M ore r ecen t ly, the ro le o f w a te r in the deve lop -men t o f c rys ta l f aces in z i r con , e s pec ia l ly in g ran i t i cma gm as , ha s been inves t iga ted (P up in e t a l . 1978).I n w a t e r - p o o r m a g m a s , z i r c o n c r ys t al li s es d u r i n g a ne a r l y m a g m a t i c p e r i o d ; i n m a g m a s r ic h i n w a t e r, z i r -c o n c r y s t a l l i z a t i o n b e g i n s e a r l y i n t h e m a g m a t i cp e r i o d a n d c o n t i n u e s u p t o t h e e n d w i t h t h e d e v e l o p -m en t o f tr ace e lemen ts (U , Th , Y . . . ) r i ch -hyd roz i r -con , a s i t has bee n co nf i rm ed by e lec t ron -p robe inves -t igat ion s (S ilver an d D eu tsch 1963 ; K 6h ler 1968, 1970 ;Ven ia le e t a l. 1968 ; Eff im off 1972). M etam ic t i za t io no f t h is h y d r o z i r c o n c o m m e n c e s w i t h t im e a n d r e s ul tsin overg row ths w i th a d i s t inc t ive zoned s t ruc tu re ( e .g . ,F i g . 6 a ) . T h e g r a n i te s f o r m e d f r o m s u c h w a t e r - r i c hm a g m a s d i s p l a y m o r e o r l e ss s i g n if i c a n t d e u t e r ic p h e -n o m e n a a s s o c i a t e d w i th th e g r o w t h o f s e c o n d a r y m i n -e ra l s (mus cov i t i za t ion , s e r i c i t i za t ion , t r ans fo rmat ion

o f f e r ro - m a g n e s i a n m i n e r a ls , t o u r m a l i n i z a t i o n . . .) . I nthos e g ran i t e s , w he re w e have been ab le to s how thes imul taneous c rys ta l l i za t ion o f l a t e z i r con w i th in te r -s t i t ia l qu ar tz (P up in 1976, pp . 214-219) , th e z i rconsp o p u l a t i o n s i n d e x T i s a p p r e c i a b l y l o w e r e d b y t h ela te z i r con c rys ta l l i za t ion .

W h e n a l l t h e f a c t o rs a b o v e m e n t i o n e d w h i c h p l a yp rominen t ro les in the z i r con typo log ica l d i s t r ibu t ionare cons ide red , i t is s een tha t a s s oc ia t ions in the rock sf r o m w h i c h z i r c o n s p o p u l a t i o n s h a v e b e e n s t u d i e da r e n o t r a n d o m b u t s h o w n o t e w o r t h y c h a r a c t e r i s t i c s(Fig. 4).

Pr o p o s e d Pe t r o g e n e t i c C l a s s i f i c a t i o n

O n the bas i s o f the compar i s on o f f i e ld obs e rva t ions ,p e t r o g r a p h i c a l a n d g e o c h e m i c a l d a t a o f t h e g r a n i t e se x a m i n e d w i t h t h e d i s t r i b u t i o n o f t h e i r z i r c o nt y p o l o g i c a l p o p u l a t i o n s a n d t h e ir T. E . T. , t h e f o l l o w -ing pe t rogene t i ca l c l a s s i f i ca t ion , the ma jo r pa r t o ft h e s u b d i vi s io n s o f w h i c h a r e i n a g r e e m e n t w i t h m o s to f the r ecen t b ib l iog raph ic da ta , i s p ropos ed :

A . G r a n i t e s o f c ru s t a l o r m a i n l y c r u s t a l o r i g in(orogenic grani tes 1)1 . A u t o c h t h o n o u s a n d i n t r u s i v e a l u m i n o u s l e u c o g r a -n i t e s ;2 . ( S u b ) a u t o c h t h o n o u s m o n z o g r a n i t e s a n d g r a n o -d io r i t e s ;3 . I n t ru s i v e a l u m i n o u s m o n z o g r a n i t e s a n d g r a n o -

dior i tes .B . G ran i t e s o f c rus ta l + man t le o r ig in , hy b r id g ra -

n i t e s (o rogen ic g ran i t e s )1 . Calc-alkal ine ser ies grani tes ;2 . Sub-alkal ine ser ies grani tes .

C . G r a n i t e s o f m a n t l e o r m a i n l y m a n t l e o r ig i n(anoroge n ic g ran i t e s 1)1 . Alkal ine ser ies grani tes2 . Tholei i t ic ser ies grani tes .

1 O rogenic and anoroge nic granites are employed n agree-me nt with Bonin and Lam eyre 1978


6/14

2 1 2 J . P. P u p i n : Z i r c o n a n d G r a n i t e P e t r o l o g y

A. Grani tes of Crustal or Mainly Crustal Or igin

1) Autoch thonous and Int rusive Aluminous L eucogra-nites. These rocks , s tud ied and desc r ibed by Lameyre(1966) in the f rench Cen tral M assi f (eg. : Echassi~res,

Sa in t Sy lves t re - Sa in t Goussaud , C ha teaupon sac ,Mil levaches, V i l leret , Graz i6res-Ma ges . . . . ) are h olo-leucocrat ic grani tes r ich in quar tz , two feldspars (apo tass i c one -a l b i t e - ac id o l igoc lase ) ; , b io t i te andsome p r im ary m uscov i t e . I f t he g r ani t es s tud ied byLameyre (1966) do co r r espond , as a who le , t o anent i ty, and can be found elsewhere in the wor ld (e .g . ,Br i t t any, Maures , F rance ; Ga l i cy, Spa in ; I voryCo ast ; H im ala ya a) (Pupin et a l. 1975; Pupin 1976;Pup in e t a l. 1979) , the def ini t ion m ust be d ist inct ive(Pupin 1976, p . 92) in order to a void any c onfusionwi th o ther s ho lo leucocra t i c , two micas g r an i t es wi thent i re ly di fferent pet rogenet ic s ignif icance. The leuco-g ran i tes he re s tud ied a r e hypera lum inous , wh ich o f t enf inds expression wi th a luminous si l icates (andalusi te ,s i l l imani te) or cordier i te presence; one can also f indz i rc o n , a p a ti te , m o n a z i te ( Fi g. 9 h ) + a n a t a s e + g a r -ne t + tourmal ine . Those g ran it es have obv ious ly beensub jec ted to cons iderab le hydro th erma l p rocesses(Lameyre 1973) , p romot ing economic concen t r a t ionsof ore minerals (U, Sn) (L am eyre 1975, p . 318) andare though t to be o f typ ica lly c rus ta l ex t r ac t ion , hav-ing fo rmed by the ana tex i s o f hydrous c rys t a l l i nesch is ts under low P - T cond i t ions.

The z i r con popu la t ions o f these a luminous l euco-

g ran i tes show very low A and T indices, be tw een 260a n d 3 90 , w i t h s u bt y p e s L ~ _ ~ a n d S x - 2 - a - 6 - 7 w e l lr ep resen ted (F igs. 5a , b ; 6a , b ) and a mean T.E .T.that can be seen on Fig . 7 , s tock (1) .

2) Sub)a utochth onou s Mo nzogran i tes and Granodio-rites. On the f ie ld , these grani tes can be t raced tothe migmat i t e s wi thou t any b reak , and the i r ana tec t i co r ig in i s und i spu tab le (Ve lay, F rench Cen t r a l Mass i f ;Va lmasque , Argen te r a ; Sa in te -Anne d 'Auray,Br i t t any, F rance) . I n m os t cases, t hey a r e usua l ly b io -t i te grani tes , of ten wi th cordier i te nodules indicat inghypera luminous t r end . I n accordance wi th the in t e r -

rela t ionship of or igin , the access ory minerals sui teis pract ical ly l ike that of the a lu mino us leu cograni tes(zi rcon, apat i te , anatase - brooki te , monazi te_+gar-net +_tourmal ine). The zi rcon pop ulat io ns s ti ll g ivelow A (~30 0) and ~ (~ 350 ) ind ices , wi th a goodnum ber o f sub types S~_2_~_6_7 (F igs . 5c , 6c , d ) .These grani tes ' mean T .E.T. i s c lear ly shown onFig. 7 , s tock 2 . Z ircon pop ulat io n of anatect ic gra-

:=: ~iii

Ia

iiil ~igil

b

d e

: - -__-_~. . .. . .. . .. . . ~ _ = ~ _

c

~:: : ---~~__-_ :::

~ N I _

g h

. . . . . . . . . . . . o 0 _:::: r~H~3 -- .~ ~ - - [ ] 10 -20 ~~:==-~--~77' ~ Y---:Y----=-

] 20-40

k

F i g . 5 a - k . Ty p o l o g i c d i s t r i b u t i o n o f z i r c o n p o p u l a t i o n s f r o m g r a n -i t e s : a l u m i n o u s l e n c o g r a n i t e s , s t o c k 1 [ S a i n t -S y l v e s t r e ( a ), M u r o s ,

G a l i c i a ~ ) ] ; ( s u b ) a u t o c h t h o n o u s m o n z o g r a n i t e s , s t o c k 2 [ Ve la y ( e) ,G u + r e t ( d )] ; i n t r u s i v e a l u m i n o u s m o n z o g r a n i t e s , s t o c k 3 [ M a r g e r i d e( e ) , P l a n d e l a To u r ( f) , L a So u t e r r a i n e ( g ) ] ; c a l c - a l k a l i n e s e r i e s :s t o c k 4 a [ S i d o b r e g r a n o d i o r i t e ( h ), E l b e m o n z o g r a n i t e ( i) ] a n d 4 b[ A r g e n t e r a m o n z o g r a n i t e ( j) , B a l l o n d ' A l s a c e m o n z o g r a n i t e ( k) ]

ni tes are very simi lar to those observed in migmat i tes(Alinat 1975; Pupin 1976, p. 293 and loll .) .

I n th i s second g roup cou ld be inc luded theG u6r e t t ype g ran it es (F rench Cen t r a l Mass if ) , t he

pecu l i a r ity o f which has been emphas ized by D id ie rand Lameyre (1971) . These grani tes , which arethough t to be fo rme d by c rus t a l r eac t iva t ion (K ur tbas

et a l. 1969; R anch in 1970) , show indeed a pecul iarfeature by having zi rcons wi th co mp lex and osci lla-to ry zona t ion o f {101} and {211} pyram ids (Pup in1976, p. 71) (Figs. 5d, 6e) . T his fact m ay point ou ta succession of crystal l izat ion phases in a med iumwith recurrent chemical proper t ies , suggest ing prob-ab le po lypha sed ana tex i s dur ing a long basemen t evo-lution.

2 T h e y a r e o f t e n l e u c o m o n z o g r a n i t e s3 S t u d y i n p ro g r e ss , j o i n t a u t h o r s h i p w i t h D e b o n a n d L e F o r t

3) Int rusive Aluminous Monzograni tes and Granodio-rites. They a r e p orphyro id g ran i t es wi th charac te r is t i cid iomorph ic co rd ie r i t e and cogna te g r anod io r i t e s (La


7/14

J.P. Pupin : Zircon and Granite Petrology 213

Fig. 6a-r . Zircon crystals fromgranitic rocks with their subtypesand stock classifications. Zircon sfrom aluminous leucogranites,stock 1 [Echassi6res (a; St;0.150 mm); Ferk6, Ivory Coast (b;Sx 2; 0.25 0ram )];(sub)autochthonous monzogranites,stock 2 [Sainte-Anne d'Au ray (c;Sz; 0.140 ram); Velay (d; SZ2;

0.160 mm) ; Gu~ret (e; S 30.110 mm)]; intrusive alumin ousmonzogranites, stock 3 [Margeride(f; 6; 0.145 mm ); Plan de la Tour(g; S,; 0.235 ram)I; calc-alkalineseries granites, stock 4a [Sidobregranodiorite 0a; Sla; 0.180 mm) andmonzo granite (i; L5 ; 0.170 mm);Monte Capanne, Elba monzogranite(j; G~; 0.220 ram)I; stock 4b[Argentera monzog ranite (k; U2~ ;0.210 mm l; GI ; 0.120 mm);Ballon d'alsace monzogran ite (in;St9; 0.130 mm)]; stock 4c[Saint-Guiral monzog ranite (n; 20;

0.180 mm) ; Panticosa g ranodiorite(o; 19; 0.155 ram),leuco grano diorite (p; S20 ;0.120 ram) and mo nzogranite (q;G1; 0.110 ram); Aar monzogranite(r; P2; 0.170 mm)]

Souterraine, Margeride, Laubies, Saint-Cierge-laSerre, Tournon, French Central Massif ; Rouet, Tan-neron and Plan de la Tour, Maures, France; Hima-laya). They are classified with essentially crustal gra-nites because, from a petrographic point of view,

apart from a little higher basicity, they display con-spicuous analogies with the above mentioned alumi-nous leucogranites. They are granites with quartz,potash feldspar, oligoclase-andesine, biotite, second-ary m usco vite + cordierite + mona zite (Fig. 9 g) + zir-con + ap atite + anatase (very rarely titanite) _+ garnet-_+tourmaline. Water still shows a strong influence(secondary) muscovitization and sericit ization, bioti techloritization, cordierite pinitization ...). The zirconpercentage remains low (Pupin 1976, p. 222), and thezircon-monazite association can often be seen(Fig. 9g). As for the leucogranites, these aluminous

monzogranites-granodiorites can be found along pre-ferential structures in the orogenic areas (i.e., Rouet-Plan de la Tour area, south-eastern France; Marger-ide-Tournon area, French Central Massif) , and areoften co nn ec ted with aluminous leucogranites(Margeride) or with Gu~ret type granites (La Souter-raine, French Central Massif) . Yet, a fundamentalpoint distinguishes these granites from those of thefirst two groups, i.e. the fact that there are basicmicrogranular xenoliths (Didier 1964, 1973), indicat-ing l i tt le mantle con tribution (hybridization), if oneagrees that those xenoliths in the greater part of intru-sive granites were remnents of basic magm a (Leterrierand Debon 1978; Orsini 1979).

The zircon populations still show low A and ~ in-dices (250 to 440) (Figs. 5e-g; 6f, g; 9i) and a meanT.E.T. which is shown on Fig. 7, stock 3.


8/14

100 200i 1

lOO

{ 2 o o

I T

300

400

500

600

700

8 0 0

I A3 0 0

I

-Mu

400

2 1 4

500 600 700 800200

200.

i T

~ I . A

5 0 0

J . P. P u p i n : Z i r c o n a n d G r a n i t e P e t r o l o g y

5 0 0

Fi g . 7 . a D i s t r i b u t i o n o f m e a n p o i n t s a n d m e a n T. E . T. o f z i r c o n p o p u l a t i o n s f r o m : G r a n i t e s o f c ru s t a l o r m a i n l y c r u s t a l o r i g i n : (a l u m i n o u s l e u c o g r a n i t e s ; (2 ) ( s u b ) a u t o c h t h o n o u s m o n z o g r a n i t e s a n d g r a n o d i o r i t e s ; (3 ) i n t ru s i v e a l u m i n o u s m o n z o g r a n i t e s a n d g r a n or i t e s. - G r a n i t e s o f c r u s t a l + m a n t l e o r i g i n , h y b r i d g r a n i t e s :4a, b, c) ca lc -a lka l ine se r i e s g ran i t e sdark doted area=granodiorites+m o n z o g r a n i t e s ;clear do ted area=monzogran i tes+alkal ineg r a n i t e s ) ; ( 5) s u b - a l k a l i n e s e r ie s g r a n i te s . - G r a n i t e s o f m a n t l e o r m a i n l ym an t l e o r ig in : (6 ) a lka l in e se r i e s g ran i t e s ; (7 ) tho le i i t i c s e r i e s g ran i t e s . -M u , l i m i t o f t h e m u s c o v i t e g r a n i t e s ( I . T < 4 5 0 ) ;Ch, m a g m a t i cc h a r n o c k i t e s a r e a . I f s t o c k 4 e x a c t l y r e p r e s e n t t h e r e p a r t i t i o n k n o w n u p t o n o w o f t h e g r a n i t e s o f t h e c a l c - a lk a l i n e s e r i e s , s t o c k s2 , 3 , 5, 6 a r e t h e a r e a s o f th e m e a n p o i n t s g r e a t e r f r e q u e n c i e s o f t h e c o r r e s p o n d i n g z i r c o n p o p u l a t i o n s , g r a p h i c a l l y d r a w n . F o r s t o c kt o 3 , w h i c h o v e r l a p b r o a d l y e a c h o t h e r , t h ethree curved bands I-3m a r k t h e r e l a ti v e p o s i t i o n s o f t h e a r e a s o f r e p a r t i t i o n o f th em e a n p o i n t s a n d o f th e g l o b a l ty p o l o g i c a l e v o l u t i o n a r y t r e n d o f p o p u l a t i o n s ; t h e g r e a t m a j o r i t y o f t h e m e a n p o i n t s o f t h e z i r cp o p u l a t i o n s o f a s t o c k l i e o n t h e c o r r e s p o n d i n g c u r v e d l i n e a n d i n s i d e it s c o n c a v i t y. To i l l u s t ra t e t h i s f a c t , a n e x a m p l e i s ta k e n w4 5 g r a n i t e s a m p l e s f r o m s t o c k s 1 , 2 , 3 i n t h e F r e n c h C e n t r a l M a s s i f (F i g . 7 b ) : 9 1 o f t h e m e a n p o i n t s a r e s i t u e d o n t h e c u r v e i n s i d e i t s c o n c a v i t y f o r e a c h s t o c k . M o r e o v e r , a f u n d a m e n t a l f i e l d a rg u m e n t t o d i s t i n g u i s h t h e s t o c k 3 f r o m t h e s t o c k s 1 - 2 i s e x i s te n c e o n l y i n t h e s t o c k 3 o f b as i c m i c r o g r a n u l a r x e n o l it h s , b R e p a r t i t io n o f m e a n p o i n t s o f z i rc o n p o p u l a t i o n s f r o m g r a n it i c r oo f s t o c k s l , 2 , 3 i n t h e F r e n c h C e n t r a l M a s s i f ( 45 s a m p l e s ; r e s p e c t i v e l y 1 0, 1 0 a n d 2 5 f o r s t o c k s 1 , 2, 3 )

B. Grani tes of Crusta l+ M ant le Or iginHy br id G ran it es )

1) Calc-Alkaline Series Granites.G enera l ly thes e in -t ru s ive g ran i t e s fo rm a ve ry l a rge rock g roup theun i t s o f w h ich a r e v e ry d ive r s if i ed . I f the g ran i t e so f the s tocks 1 ,2 ,3 a r e b roa d ly p res en t in the F ren chC e n t r a l M a s s i f , t h e c a l c - a l k a l i n e m e m b e r s a r e f o u n d

i n l a rg e q u a n t i t y i n t h e o ld p y r 6 n 6 o - c o r s o - s a r d ea r e a . I n t h e o u t c r o p , t h e b o d i e s c a n b e f o r m e d o fo n l y a s in g le p e t r o g r a p h i c e n t i t y ( i. e. , M o n t e C a p a n n em o n z o g r a n i t e , E l b a ; P o n t - d e - M o n t v e r t m o n z o g r a n i t eF r e n c h C e n t r a l M a s s i f ). M o r e o f t e n h o w e v e r, t h e ya r e c o m m o n l y c o m p l e x , s o m e t i m e s c o n c e n t r i c i n p a t-t e rn , w i th tw o o r more cogene t i c un i t s ( i . e . , S idobreg r a n o d i o r i t e - m o n z o g r a n i t e , F r e n c h C e n t r a l M a s s i f ;P a n t i c o s a q u a r t z g a b b r o - g r a n o d i o r i t e - l e u c o g r a n o -d io r i t e - m onz ogra n i t e , P y r6n~ es , F ran ce) (D id ie r1964 ; D ebon 1975) . A l l thes e g ran i t e s s how bas icm i c r o g r a n u l a r x e n o l it h s in v a r y i n g q u a n t i ti e s a n d a r e

s o m e t i m e s a s s o c i a t e d w i t h b a s i c ro c k s ( g a b b r o , q u a r t zgabbro , d io r i t e , qua r tz d io r i t e ) .

I f th e m a j o r e l e m e n t s c h e m i s t ry a l o n e w e r e c o n s i d -e red , i t is o f t en d i f f i cu l t to s e para te thes e g ran i t e sf r o m t h e a l u m i n o u s o n e s c o n s i d e r e d e a r l i e r a b o v e(P up in 1976 , p . 78 ) ; z i r cons s tudy how ever o f f e r s aneas y d i s c r imina t ion (P up in and T urco 1975) .

The l a rge a r ea as s oc ia ted w i th th i s g ran i t e s e r i e s

in the ( I .A , I . T. ) d iag ram (F ig . 7 , s tock 4 ) has be end i v i d e d i n t o t h re e m a i n s t o c k s ( 4 a - c ) d e p e n d i n g u p o nt h e m e a n a s p e c t o f th e i n d i v i d u a l a n d d i f f e r e n c ia t i o ntendenc ies T. E . T. :

- S t o c k 4 a : b i o t i te g r a n o d i o r i te - b i o t i t e + s e -c o n d a r y m u s c o v i t e m o n z o g r a n i t e - b io ti te _ + s e c o n d -a r y m u s c o v i t e a l k a li n e g r a n it e ( e g ., M o n t e C a p a n n e ,E lba ; S idobre , F ren ch C en t r a l M a s s i f ) (F igs . 5h , i ;6 h- j ) .

Stock 4b .. b i o t i t e + a m p h i b o l e g r a n o d i o r i t e -b i o t it e + a m p h i b o l e m o n z o g r a n i t e - b i o t it e + s ec o n d -a r y m u s c o v i te m o n z o g r a n i t e - b i o t i t e + s e c o n d a r y


9/14

J.P. Pupin: Zircon and Granite Petrology 215

N i l : : : : : :, ~m::2 i

b c

I ) E E ~

d e

m u ~ m I

_ _ ~ ~ ~

f

iiii Iit

h i

] 2-5,~

] 5-10 /,

10-20 ~,

.~ I~: : : l :: : : l [ ]2o-4o ~

k

Fig. ga-k . Zircon crystals from granitic rocks w ith the ir subtypesand stock classifications. Typo logicdistribution of zircon popula-

tions from granites calc-alkaline series stock 4 c [Panticosa grano-diorite (a), leucogranodiorite b) and mon zogranite (e)]; sub-alka-line series, stock 5 [Traoui6ros d), La Clart6 (e) and Kerleo-Canton(f) mo nzogranites]; alkaline series, stock 6 [Tolla hypersolvus (g),transsolvus (h) and subsolvus (i) g ranites; E visa hyperalkaline al-bitized granite (j)]; tholeiitic series, stock 7 [Inzecca trondhjemite(k)]

m u sc o v i t e a lk a l in e g r a n i t e ( e g . , Ba l lo n d ' A l sa c e ,Vo s g e s, F r a n c e ; Vi l l e f r a n c h e d e R o u e r g u e , C h a r b o n -n i 6 r e s l e s Va r e n n e s , F r e n c h C e n t r a l M a s s i f ;A r g e n t e r a , S o u t h A l p s, F r a n c e - P u p i n a n d T u r c o1 9 7 4 b - ) ( F i g s . 5 j , K ; 6 k - m ) .

- S t o c k 4 c : b io ti te _ + a m p h i b o l e + p y r o x e n e g r a -n o d i o r i t e b io ti te _ + a m p h i b o l e + p y r o x e n e m o n z o g r a -n i t e - b i o t i t e + s e c o n d a r y m u s c o v i t e a l k a li n e g r a n i t e( e g . , Pa n t i c o sa , e a s t e r n Ca u te r e t s , Py r 6 n 6 e s , F r a n c e

D e b o n 1 9 7 5 - ; B o r d b re s , P y r6 n 6 es , F r a n c e F o r g -h a n i 19 6 5 - ; B o n o , B u d d u s o , S a r d i n i a , I t a l y H e r -m i t r e 1 9 7 5 - ; A a r, S w i t z e r l a n d ; A i g o u a l , S a i n t - G u i r a l -L i r o n , P o n t d e M o n t v e r t , B o r n e , F r e n c h C e n t r a lM a s s i f ) ( F i g s . 6 n - r ; 8 ~ c ) .

T h e a s so c i a t i o n w i th b a s i c r o c k s i s e sp e c i a l l y f r e -q u e n t i n t h e s t o ck 4 c , w h e r e t h e n u m b e r o f m i c -r o g r a n u l a r b a s i c x e n o l i th s s e e m s t o b e g r e a t e r. Z i r c o n

i t s e l f is m o r e a b u n d a n t i n t h is t y p e o f s t o c k ( P u p i n1976 , p . 223) , a l tho ug h in the th ree a , b , c , s tock s ,t h e z i r c o n p e r c e n t a g e s d e c r e a s e f r o m g r a n o d i o r i t i cr o c k s t o t h e m o r e d i f f e r e n t i a t e d o n e s . A t t h e e n do f t h e d i f f e r e n t i a t i o n ( o r a t t h e e n d o f c r y s t a l l i z a t io n

o f th e m o r e d i f f e r e n t i a t e d r o c k s ) , a l l th e s e s t o c k s c o n -verg e on the G type [{110} {101}] (Fig . 1 ) , thus a l lo w-in g a f a i r l y e a sy d i s t i n c t i o n b e twe e n th e f i n a l h o lo l e u -c o c r a t i c m o n z o g r a n i t e s a n d a l k a l in e g r a n i t e s o f t h e s ese r ie s w i th q u a r t z , p o t a s h f e ld sp a r, a lb i t e - a c id i co l i g o cl a s e, b i o t i t e + s e c o n d a r y m u s c o v i t e + a n a t a s e +z i r c o n + a p a ti te _ + g a r n e t + t o u r m a l i n e + m o n a z i t e( r a r e ) + x e n o t i m e , b u t w i t h o u t c o r d i e r i t e , a n d t h e a l u -m in o u s l e u c o g r a n i t e s o f t h e s to c k 1 ( F ig . 7 ) . I n t h eg r a n o d i o r i t i c r o c k s , s p h e n e i s o f t e n a b u n d a n t , t o -g e t h e r w i t h z i r c o n a n d a p a t i t e .

2 S u b a l k a l i n e S e r i e s G r a n i t e s .A n e x a m p l e o f t h i s

se r ie s h a d b e e n s tu d i e d b y Ba r r i6 r e ( 1 9 7 7 ) i n t h e P lo u -m a n a c ' h c o m p l e x o f n o r t h e r n B r i t t a n y ; B a r ri 6 r e d ids tr e ss t h e p r i m a r i l y m a n t l e o r i g i n o f t h e r o c k s a n dth e d i s t i n c t i o n o f th i s a n d th e c a l c - a lk a l in e se r ie s .T h e r o c k a s s o c i a t i o n in t h e P l o u m a n a c ' h i s a s f o l l o w s :m o n z o g r a n i t e a n d s y e n o g r a n i t e w i t h q u a r t z - m i c r o -l in e o l i g o cl a s e - b i o t i te h o r n b l e n d e ( Tr a o u i e r o s- L a C l a rt 6 ) , b i o t i te m o n z o g r a n i t e ( C a n t o n ) , b i o t i te -+ s e c o n d a r y m u s c o v i t e l e u c o m o n z o g r a n i t e ( Wo a sWe n ) . T h e se r i e s f i r s t r o c k s a r e a s so c i a t e d w i th b a s i cr o c k s ( g a b b r o s , d io r i t e s , q u a r t z d io r i t e s ) .

T h e o b s e r v e d c h a r a c t e r i s t i c f e a t u r e s o f t h e z i r c o n

ty p o lo g y ( Pu p in e t a l . 1 97 9) ( F ig s . 8 d - f ; 9 a , b ) g iv ea s to c k 5 (F ig . 7 ) t h a t n o t o n ly f a l l b e tw e e n th e c a l c -a lk a l in e a n d a lk a l in e se r i e s , b u t a l so o v e r l a p t h e c a l c -a l k a l in e s e ri e s ( s t o c k 4 c i n p a r t ) . Z i r c o n p o p u l a t i o n so f th e s u b a l k a l i n e s e r i es w i t h h i g h e r a n d l o w e r Tin d ic e s a r e r e sp e c t iv e ly l o c a t e d a t t h e a lk a l in e se r i e sh y p e r so lv u s a n d su b so lv u s g r a n i t e s l e v e l s i n t h e ( I .A ,I . T. ) d i a g r a m . A t t h e e n d o f d i f f e r e n t i a t i o n ( o r a tt h e e n d o f c r y s t a l li z a t i o n o f t h e m o r e d i f f e r e n t i a t e dr o c k s ) , t h e s to c k c o n v e rg e s o n th e G ty p e ( F ig . 1 ).

O t h e r m o n z o g r a n i t e s o f th e s a m e c o n s a n g u i n i tya r e n o w k n o w n ( i. e. , C a l d a s d e R e y e s , G a l i c ia , S p a i n- P u p i n 19 7 6 ; K a l t u n g o , N i g e r i a E n u 1 97 8) .

C . G r a n i te s o f M a n t l e o r M a i n l y M a n t l e O r i gi n

1 A l k a l i n e S e r i e s G r a n i t e s.T h e s e a r e a l k a l i n e a n dh y p e r a l k a l i n e g r a n it e s f o u n d i n s u b v o l c a n i c , a n o r o g e -n i c c o m p l e x e s ( o f te n s o - c a ll e d r i n g g r a n i t e s ) , T h eh o t a n d d r y m a g m a s p r o d u c t i v e o f t h es e m a n t l e-o r ig in g r a n i t e s ( Bo n in a n d L a m e y r e 1 9 7 8 ) , g iv e r i set o h y p e r s o l v u s g r a n i te s ( Tu t t l e a n d B o w e n 1 9 58 ), w i t hc h a r a c t e r i s t i c s t r i n g p e r th i t e s . C o l o u r e d m i n e r a l s a r ei r o n r i c h ( f a y a l i t e , f e r r o - a u g i t e , h e d e n b e rg i t e , a e g i -


10/14


11/14

J . P. P u p in : Z i r co n an d G ran i t e P e t ro lo g y 217

100p

100 f

200 1

3 0 0 4I T

400

500

600

700

800

I.A200 300 400 500 600 700 800

Fig . 10 . Dis t r ib u t ion o f some non g ran i t ic g roups o f endogenou srocks : A.B.)alkal ine basal ts wi th gem-qual i ty z i rcons ; A .R. ) a lka-l ine ser ies rhyo l i tes f rom anorogen ic complexes;C.A.R.)calc-alkal ine ser ies rhyo l i tes o rogen ic) ; M) migmat i tes ; t ) t rachyande-sites; T) tonalite s

stocks 5 and 6 in the area of the alkaline rhyolitestha t are related to the anorogenic complexes (Fig. 10),and which are considered to be either entirely or sub-stantially of mantle origin.

G e n e r a l V i e w s a n d i s c u s s i o n

Before summarising the fundamental points of thepreceeding presentation, some comments will be madeon Fig. 10 which contains some non granitic groupsof rocks :

migmatites (M) (Pupin 1976, p. 297; 21 samples)show rathe r low T indices (300-400) (c rystallizationtemperature ~650-700 ~ C) and occupy main ly theareas of essentially crustal granites (1 to 4a);

tonalites and qua rtz gabbro diorites (T) (Pupin1976, p. 179; 25 samples) locate at the root of thecalc-alkaline stocks (less differentiated rocks) and un-der anatectic granites (they, themselves, can beformed from the anatexis of amphibolitic gneiss andamphibolites). The convergence of the zircon popula-tions position of quartz diorites derived from thesetwo processes can also be exp lained by the geochem-ical convergence of the magmas thus obtained: thesialic crust-mantle hybridization of the calc-alkalinestock can, in a way, be found again in the anatexisof gneiss and amphibolitic series through the mainly

mantle origin of most of the amphibolites (ancientalkaline or tholeiitic basalts or basic tufts);

magmatic charnockites (Ch) (Pupin 1976, p. 351;6 samples from Ivory Coast and Rogaland, Norway)locate right under the quartzitic tonalites - gabbros- diorites group and the calc-alkaline stock4c(Fig. 7), which shows the greatest number of basicrocks associations of granites. A convergence of theserocks with the basic calc-alkaline series rocks of verydeep origin is therefore indicated which could be usedas an argument for regarding them as being formedin typical magmatic calc-alkaline area;

calc a lk a l in e rhyol i tes (C.A.R.) (Tessier et al.1978; 15 samples from Corsica and French CentralMassif) cover all the lower pa rt of stock 4; theobserved difference when compared with the crystal-line equivalents can be explained as resulting fromthe break in zircon crystallization consequent on ra-

pid cooling in rhyolites (vitreous mesostase rhyolites),whereas crystallization is not similarly interrupted ingranites (Pupin 1976, p. 269);

- the same observation can be made for the alkaline rhyolites (A.R.) related to the anorogenic subvol-canic complexes (Pupin 1978 ; Tessier et al. 1978 ; 26samples from Corsica and Est6rel, France); attentionis especially drawn to their localization, right at theroots of stocks 5 and 6, and also to the already men-tioned position of the tholeiitic plagiogranite. Theplace of the ring shaped anorogenic complexes withinthe areas of plate spreading and especially in the intra-continental rifts zone could be found again with thesubalkaline series granites (eg., the red hercynian gra-nites alignment Aber Ild ut - Morlaix bay - Plouma-nac h Fla man vil le- Barfleur in northern Brittanyand Contentin , France ; Barri6re 1977);

- the genesis of the gem-quali ty zircons from alkaline basalts is not well explained yet (Pupin 1976,p. 271), but it is worth noting that their populationfields (5 have been studied from Madagascar, Cambo-dia, Tasmania and Velay, France) accord very wellwith stocks 5 and 6 (A.B. Fig. 10).

In the Fig. 7, the distribution of the different gen-etic types of granites comes out with an ex treme logic:

the sialic origin granites with low A and T indicesand the mantle origin granites with high A andindices. In between, the hybrid granites are essentiallyrepresented by the calc-alkaline rocks. This type ofdistribution pattern is diagramatically represented inFig. 11.

The association with basic bodies (gabbros, dio-rites...) is likely to be found in the granites ofstocks 4c to 7, where variation of the lithologic typesinvolves the existence of often more complicatedbodies, in the same way tha t the basic microcrystallinexenoliths which are not found in stocks 1 and 2 be-


12/14

218 J.P. Pupin: Zircon and Granite Petrology

1 2 3 5 6 7

f i i i i i i i i i i i i 7 1 i iFig. 11. S chem atic diagram sum marizing origin of ma terial fordifferent stocks o f g ranites(1 to 7)

Ch iapp a s ub s o lvus a lka l ine g ran i t e , Cor s ica ( e = 65~I t i s a l s o pos s ib le to have a look a t the popu la t ionsea r ly z i r cons [w i th a p reva i l ing { 100} p r i s m] ; on theaverage thos e c rys ta l s s how la rge r { 211} py ram idsin the ca lc - a lka l ine s e r ie s g ran i t e s than in the a lka l ine

one .

Z i r c o n Ty p o l o g y a n d t h e I n it i al R a t i o so f S r s 7 S r S 6 i ll G r a n i t i c R o c k s

c o m e v i si b le in s t o c k 3 a n d a r e n u m e r o u s i n d e e d i nt h e 4 c s t o c k . T h e a b u n d a n c e o f m i c r o g r a n i te s d y k e sand bod ies a l s o inc reas es f rom s tock l to 6 .

The z i r con pe rcen tage in g ran i t e s inc reas es f roms tock 1 (w here i t is e s pec ia l ly low ) to s tock s 6 -7 (un -c o m m o n l y r ic h ) . T h e a n a t e c t i c p h e n o m e n a s e e m s t ob e p r o d u c t i v e o f a z i r c o n i u m s e g r e g a t i o n i n s i d e t h es ia li c c rus t , by ex t r ac t ing f rom i t s ome m el t s impover-i s hed in tha t e l em en t (P up in 1976, p . 222) . Th e pa r t i a lm e l t i n g o f t h e m a n t l e w h i c h w a s i n v o k e d b y B o n i na n d L a m e y r e ( 19 78 ) t o a c c o u n t f o r t h e a l k a l i n em a g m a f o r t h e f o r m a t i o n o f h y p e r s o l v u s g r a n i t e i sa l so c a p a b l e o f c o n c e n t r a t i n g a p p r e c ia b l e q u a n t i t yo f z i r c o n i u m i n a s m u c h a s t h is e l e m e n t i s n o r m a l l yp r e s e n t in n o t i c e a b le q u a n t i t y in b a s ic m a g m a s ( C h a oand Fleisher 1960) .

The z i r co n inc lus ions (P up in 1976) a r e a l s o d i f f e r -e n t a c c o r d i n g t o th e s t o c k c h o s e n . G e n e r a l l y z ir c o n so f the 1 -2 -3 s tocks a r e inc lus ions po or a nd a re s imi la r

t o t h o s e f o u n d i n m i g m a t i te s . I n c l u s io n s b e c o m e m o r enumerous and d ive r s i f i ed in the o the r s tocks (4 to7 ) : examples o f inc lus ions in s ubvo lcan ic rocks a r es tocky mic ro l i t e s , nega t ive c rys ta l s and v i t r eous ma te -rials .

I t g r a n i te s d o a p p e a r a s c o m p l e x r o c k s o n t h ew h o l e , t h e g e n e t ic s c h e m e c o m p i l e d o u t o f z ir c o n ss tudy g ives a f a i r ly c lea r p ic tu re w h ich s hou ld ena b leu s t o d e a l m o r e e a s il y w i t h t h e p r o b l e m s r e l a te d t ot h a t t y p e o f r o c k . O n e c a n re a d i l y s e e t h a t t e r m m o n -zog ran i t e s in the 1 , 2 , 3 , 4a , b , c , 5 s tocks do n o th a v e t h e s a m e m e a n i n g , e v e n i f m o s t o f t h e m , a tf ir s t s i g h t, a p p e a r t o b e c o m m o n b i o t it e g r a n i te s . T h i s

i s a l s o true fo r g ran od io r i t e s , o r fo r tw o-m ica g ran i t e sw i t h a n a l k a l i n e t e n d e n c y, t h e p e t r o ge n e s i s o f w h i c hcan b e ve ry d i f f e r en t : s tock 1 o r s tocks 4a , b , c , 5 ,6 ends .

The mos t c r i t i ca l po in t i s the d i s c r imina t ion be -tw een the ends o f s tocks converg ing on the G type .In tha t cas e , the ind iv idua l popu la t ions T. E . T. canbe ve ry us e fu l , s ince the i r r e s pec t ive s lopes changew i t h t h e i r b e l o n g i n g t o s u c h o r s u c h s t o c k ( P u p i n1976) ; eg ., 4 a s toc k : S ido bre m on zo gra ni te (e = 35 ~ ;4 b s t o c k : A r g e n t e r a m o n z o g r a n i t e ( ~ = 4 7 ~ 4 cs t o c k : A a r m o n z o g r a n i t e ( c~ = 60 ~ 6 s t o c k : L a

A s a w ho le , the re i s s ome co r r e la t ion be tw een theg e n e t i c s c h e m a d e r i v e d f r o m t h e t y p o l o g i c s t u d y o fz i r con popu la t ions and the s r a7 / s rS 6 r a t io s , bu t inde ta i l , t he coherence o f the r e s u l ts i s no t a lw ays ve ryg o o d .

G r a n i t e s f r o m t h e v e r y r o o ts o f a l k a li n e a n d s u b -a lka l ine s tocks 6 a nd 5 have the low es t S rS 7 /S r s 6 r a -

t io s [0.703 0 .707 fo r the hy per s o lvu s a lka l ine -pe ra lka -l ine g ran i t e s f rom Ev is a and To l la , Cor s ica (Bon in1 97 2) ; 0 .7 0 5 f o r t h e m o n z o g r a n i t e f r o m P l o u m a n a c ' h ,Br i t t an y (Bar r i6 re 1977)] . S ame va lues a r e fou nd fo rthe p lag iog ran i t e s f rom the oph io l i t i c complexes o fTr o o d o s , C y p r u s : 0 . 7 0 4 0 . 7 0 6 ( C o l e m a n a n d P e t e r -m an 1975). T he g ran i t e s o f the ca lc - a lka l ine s e ri e s(4 ) have h igher s t ron t ium i s o tope r a t io s : 0 . 706-0 . 708f o r m o n z o g r a n i t e s - g r a n o d i o r i t e s f r o m T h i e rs , P o n t -d e - M o n t v e r t , B o r n e , A i g o u a l , P i 6 g u t- P lu v i e rs , C o n f o -l en s , F r e n c h C e n t r a l M a s s i f ( D u t h o u 1 9 77 ; M i a h l e1 9 80 ); 0 . 7 1 ~ 0 . 7 1 2 f o r th e m o r e r e c e n t g r a n it e s f r o m

A e g e a n S e a ( A l t h e r r a n d W e n d t 1 9 78 ).T h e a l u m i n o u s g r a n i t e s f r o m s t o c k s 1 t o 3 s h o wgen eral ly h ighe r S rS7/Sr 86 ra t io s :

- S t o c k 3 . 0 . 708 to 0 . 714 (M arger ide monzogran -i te ; C ou tur i6 e t a l. 1971 ; Va che t te e t a l . 1979) ; 0 .709( P l a n d e l a To u r a n d R o u e t g r a n i t e s ; R o u b a u l t e t a l.1970) ; 0 . 719 ( co rd ie r i t e bea r ing monzogran i t e s f romL o w e r H i m a l a y a ; L e F o r t e t a l. 1 9 8 0) :

- S t o c k 2 . 0.709 to 0 .718 for the migmati t icg r a n it e f r o m Tr e b a n , F r e n c h C e n t r a l M a s s i f ( D u t h o u1977) , bu t 0 .706 fo r the m igm at i t i c g ran i t e f ro m Velay(Vachet te e t a l . 1971) :

- S t o c k 1 : 0 . 7 0 9 to 0 .717 fo r mo s t o f the a lumi -

n o u s l e u c o g r a n i t e s f r o m t h e F r e n c h C e n t r a l M a s s i f( S a i n t - M a t h i e u , B l o n d , C o g n a c , s m a l l s t o c k s i n t h eM a rger ide ) , bu t r e s pec t ive ly 0. 705 an d 0 .707 fo rC h a t e a u p o n s a c a n d S a i n t - S y l v e s t r e l e u c o g r a n i t e s i nthe s ame a rea (C ou tu r i6 e t a l . 1971 ; D u th ou 1977) .

F or the s tock s 5 to 7 , the Sr87/Sr s6 ra t ios areak in to the man t le va lues (0 . 702-0 . 704) , and moret y p i c a ll y s ia l ic ( > 0 . 7 1 0 ) f o r a l u m i n o u s g r a n i te s o fthe s tocks 1 to 3 ; in te rm ed ia te va lues can be fou ndf o r s t o c k 4 w h e r e t h e c o n t a m i n a t i o n b e t w e e n s ia l icc rus t and man t le i s f a i r ly w e l l deve loped . N ever the -less, the low SrST/Sr 86 ra t ios (0 .705, 0 .707) ob taine d


13/14

J.P. Pupin: Zircon and Granite Petrology

from some aluminous leucogranites and the autoch-thonous granite from Velay show that in graniticrocks, these ratios must be carefully interpreted.

Recent geochronological data on hypovo lcanic al-kaline rocks from Nigeria and Niger (Van Breemen

et al. 1975 ; Bowden et al. 1976 ; in: Ducrot et al. 1979)have shown high Sr isotope ratios (0.706 to 0.752)for magmas of very deep origin, probably due toa contamination from the crust. Bonin and Lameyre(1978) have also proposed three different possibilitiesto explain these high values: (i) an overheated basicintrusion induce the melt of the continental crust;(ii) contamination with Sr from the sur rounding rocksor fro m circulating waters in those; (iii) duration ofmagma transit from its source to its actual position.

The similarity of typologic data from a same ba-tholith over great distances (one hundred kilometersin the Margeride, French Central Massif) is a funda-mental argument to consider that zircon populationsreflect very accurately the origin o f the magma . Post-magmatic geochemical variations induced locally bydeuteric processes are withou t any effect on the zirconpopulations.

Aluminous leucogranites and hypersolvus alkalinegranites are respectively two very specific entitiesamong granitic rocks and are very well defined whatwith the petrography (main and accessory minerals)and what with the field (lithologic associations, en-claves, geodynamic setting). These specificities arealso found in the very well defined repartition of

their zircon populations (I.A, I.T ~ 300, 300 for alu-minous leucogranites; 650, 700 for hypersolvus alka-line granites). On the contrary, the great variationsin the initial ratios of SrST/Sr s6 do not seem to reflectthe same very remarkable specificities.

o n c l u s i o n

Zircon is an exceptionally significant common min-eral of rocks. The study of a granite s zircon popula-tion 4 can provide extremely valuable data about itspetrogenesis. The zircon s crystallization period,

thereby the magma s water content, chemical andtemperature variations of the crystallization mediumcan be estimated. The determination of the stock rela-tionship of a rock gives data about the parent magma.The zircon population distribution in the (I.A, I.T)diagram also allows the foreseeing of the mineral as-

4 The metho d s apprentices hip can be made in the Laboratoirede P6trologie-Min+ralogie of Nice (France) in a few days. Thereare no great difficulties and, with some habit, one or two daysare enough, beginning with the rough rock, to achieve the typolog-ical distribution of zircon populations

219

sociations, mainly subordinate, likely to be associatedwith the zircon. Apart from shedding light on thequestion of granite petrology, zircon also gives acriterion for dealing with the problems of comparativepetrology and for resolving the question of the possi-

ble petrogenetic relationship of juxtaposed graniteoutcrops.

AcknowledgementsThe author is very grateful to Professor G.H.Turco, Nice, for many fruitful discussions during all the periodof his research. Thanks are also due to Professors A.A. Kayode,Ife, Nigeria, and J.E. Dietrich, Nice, for the english translationof the earlier french version of the manuscript. Careful1 reviewby D. Gebauer and M. Grunenfelder are gratefully acknowledged.

R e f e r e n c e s

Alinat M (1975) Le zircon dans les roches de la s~rie m6tamor-phique de l anticlinal de Tulle (Corr~ze, Massif Central fran-~ais). Applica tions p~trog6n~tiques. Th~se Doc t 3e cycle, U nivNice (France), 196 pp

Alper A, Poldervaart A (1957) Zircons from the Animas stockand assoc iated rocks, New Mexico. Econ Geol 52:8, 952-971

Altherr R, Wendt I (1978) Mioz~ine barro w-Meta morph ose undgranit ischer Pluto nism us in der Zentralfig/iis. Bund GeowissRohst, DFG We 345/23 (1):90 pp

Barri6re M (1977) Le complexe de Ptouma nac h, Massif armori-cain. Th~se Doct Etat, Univ Brest (France), 291 pp

Bonin B (1972) Le complexe granitique de la r~gion de Tolla-Cauro(Corse). Thbse Doct 3e cycle, Univ Paris (France), 127 pp

Bonin B (1975) II y a granites et granites ... La Recherche 6(57) : 570-573

Bonin B, Lamey re J (1978) R6flexions su r la posi tion et l originedes complexes magmatiques anorog~niques. Bull Soc G6ol Fr7, XX (1):45-59

Bowden P, Van Breemen D, Hutchinson J, Turner DC (1976)Palaeozoic and mesozoic age trends for alkaline ring complexesin Niger and Nigeria. Nature 259 (5541): 297-299

Chao ECT, Fleischer M (1960) Abundance o f zirconium in igneousrocks. 21th Int Geol Congr Report 1:106-131

Coleman RG, Peterman ZE (1975) Oceanic plagiogranites. JGeoph ys Res 80 : 1099-1108

Couturi6 JP, R oques M, Vachette M (1971) Age cal6donien tardifdu g ranite de la Margeride (Massif Central frangais) et figehercynien des leucogranites qui le traversent. C R Acad ScParis 272 [D]:3235-3238

Deb on F (1975) Les massifs granitoi des ~ structure concentriquede Cau terets-Panti cosa (Pyrenees occidentales) et leurs enclaves.Th~se Doct Etat, Univ Nancy (France), Mem Sc Terre33:420 pp

Didier J (1964) Etude p~trographiqu e des enclaves de quelquesgranites du Massif Central fran~ais. Th6se Doc t Etat, UnivClermont-Ferrand (France), Ann Fac Sc 23:254 pp

Didie r J (1971) Grani tes and their enclaves. Elsevier Publ Cie3, 393 pp

Didier J, Lameyre J (1971) Les roches granitiques du Massif Cen-tral. Symposium J Jung, Cl ermont- Ferrand , 133 156

Ducrot J, Lancelot JR, Reille JL (1979) Datation en MontagneNoire d un t~moin d un e phase majeure d amincis sement crustalcaract~ristique de l Europe pr~varisque. Bull Soc G~ol Fr XXI(4):501-505

Duthou JL (1977) Chronologie Rb-Sr et g6ochimie des granito-ides d un segment de la cha~ne varisque. Relations avec le m~ta~morphis me: Le Nord Limousin (Massif Central franqais). Th~seDoct Etat, Ann Sc Univ Clermont, 63 (30): 294 pp


14/14

2 2 0 J . P. P u p in : Z i r co n an d G ran i t e P e t ro lo gy

Eff im off I (1972) Chem ical and mor pho log ical v ar ia t ions o f z i rconsf ro m th e B o u ld e r b a th o l i t h , M o n tan a . D i s s U n iv S t L aw ren ceCincinnat i , 166 pp

E n u E [ (1 9 7 8 ) C o n t r ib u t io n ~ l ' 6 tu d e s6 d im en to lo g iq u e d es fo rm a-tions cr4tac6es darts Ia /aaute vall~e de la B6nou~ (r6gion deChain , Nig4r ia nord -o r ien tal ) . Th~se Doct 36 cycle , U n iv Nice(France) , 178 pp

F o rg h a n i A H (19 65 ) S u r l a s t ru c tu re an n u la i r e d u m ass i f 6 ru p t ifd e B o rd & es , H au tes -P y r~ n d es , C R A cad S c P a r i s260 :6943 6945

G irau d JD , P u p in JP, Tu rco G (19 79 ) L a m ic ro d io r i t e q u a r t z iq u ed 'Alghero (Sardaigne) . Relat ions avec le vo tcan isme calco -alca-Iin cenozo i 'que sarde. R 6un An n Sc Terre , Lyon (France) , p 221

Herm it te D (1975) La morph o log ie des z i rcons dons les in t rusion sca[co-alcal ines du cen tre-r to rd de la Sardaigne. Th6se Doct 3hcycle, Un iv Marsei l le (F rance) , 159 pp

Jauzein P, Pup in JP, Bon in B (1979) Les z i rcons des t rondh jemitescorses: typo log ie - im pl icat ions . R~un A nn S c Terre , L yon(France) , p262

K 6 h le r H (1 9 6 8 ) Idb e r Z i rk o n e m o ld an u b i sch e r G ran i t e . D i s s U n ~ vM / i n c h e n

K 6 h le r H (1 97 0) D ie A n d eru n g d e r Z i rk o n m o rp h o lo g ie m i t d emD i ffe ren ti a t io r t sg rad e in es G ran i t s . N eu es Jah rb M in e ra l , M o -n a t sh 9 : 4 0 5 -4 2 0

K u r tb as K , M arq u a i r e C , R an c h in G (1 96 9 ) D i ff+ ren c ia t i on s p 6 tro -g raph iqne s e t g6och imiques dons te massi f g ran i t ique de Cm 6retet les massi fs annexes de ta Marche occiden tale . C R AcadSc Par is 268 [D1:2396-2398

Lam eyre J (1966) Leucog ran i tes e t mu scov i t i sa t ion dans le Mass i fC en t r a l f r an ~a i s . T h 6 se D o c t E t a t , U n iv C le rm o n t -F e r r an d(F ran ce ) , A n n F ac S c 2 9 :2 6 4 p p

Lameyre J (1973) Les marques de I ' eau dans les leucogran i tesdu Mas si f Cen tra l f ran~ais . Bu l l Soc G6o l F r 15 :288-295

L am ey re J (1 97 5) R o ch es e t m in 6 raux . 2 . - L es fo rm a t io n s , D o in(~d). Paris, pp 135-352

L ar sen L H , P o Id e rv aa r t A (19 57 ) M easu rem en t an d d i s t r i b u tio no f z ir co n s i n so m e g ran i t ic ro ck s o f m ag m at i c o r ig in. M in e ra l

. M ag 3 1 :5 4 4 -5 6 4Le For t P, Debon F, Sonet J (1980) La cein tu re des g ran i tes

co rd i6 r i te d u ) )B as -H im a lay a< Ty p o lo g ie e t f i ge R b - S r d um ass i f d e M an se rah (P ak i s t an ) . R ~ n n A n n S c Te r r e , M arse i l le(France) , p 218

Leterr ier J , De bon F (1978) Caract~res ch imiques com par6s desroches g ran i to i 'des e t de leu rs enclaves microgrenues . Impl ica-t ions g~n~t iques . Bu l l Soc G6o t F r 7 , XX (1 ) :3 -10

M ar t in R F, B o n in B (19 76 ) W ate r an d m ag m a g en esi s : t h e a s so c i a-t ion hyperso lvus g ran i te-subso lvus g ran i te . Can M ineral14 : 228-237

Miah le J (1980) Le mas si f g ran i t ique de la Born e (C6vennes) . Th6seDo ct 36 cycle, U n iv Clerm ont-F erran d (France) , 130 pp

Oh nenste t ter D, O hnen stet ter M (1976) Mod61e de fonct ionnem ert td 'une r ide m6dio -oc6an ique ~ par t i r de l '6 tude p&ro log ique

des oph io l i tes co rses . Bu l l Soc G+ol F r 18 (4 ) :88 894Orsin i J (1979) Con tr ibu t io n h la connaissa nce des g ran i to i 'des~ard i-o rog~n iques du ba thoI i te co rso -sarde. Les enclaves som-bres de l ' associat ion p lu ton ique calco -alcal ine . Travaux LabSc Terre Marsei l le (F rance) C3 , I04 pp

Po lde rvaar t A (1950) S tat is t ical s tud ies o f z i rcon as a cr i ter ionin g rar t i t izat ion . Natu re 165 :574-575

Pold ervaa r t A (1956) Z irco n in rocks . 2 . - Igneous rocks . A mJ Sci 254 :521-554

Pup in JP (1976) S ign if icat ion des caractg res morpho log iques duzircon commun des roches en p6 tro log ie . Base de la m6thodetypo log ique. App l icat ions . Th6se Do ct E tat , U n iv Nice(France) , 394 pp

Pup in JP, Bo n in B , Tessier M, Tu rco G (1978) R61e de l 'eausur les caract6 res morpho log iques e t la cr is ta l l i sa t ion du zi rcondar ts les g ran i tes . Bu l l Soc G6o l F r 20 (5 ) :721-725

Pup in JP, Casanova R , Turco G (1975) Les z i rcons de quelquesgr~n i to ides p r~cam briens de C6 te d ' Ivo ire . Bu l l Sn isse MineralPetr 55/1 : 35-50

Pup in JP, Dup u is C , Turco G (1979) Le z i rcon et l 'o r ig ine man tel l i -que de cer ta ins g ran i tes : le po in t ap r6s l '6 tude du com plexed e P lo u m an ac ' h - I l e G ran d e (B re t ag n e sep t en tr i o n al e ) . R & mAn n Sc Terre , Lyon (France) , p 387

Pup in JP, Tnrco G (1972a) Une typoIog ie o r ig inale du z i rconaccesso ire . Bu l l Soc Fr Mineral Cr is ta l log r 95 :348-359

P u p in JP, Tu rco G (1 9 7 2 b ) A p p l ica t i o n d es d o n n 6 es m o rp h o lo g i -ques du z i rcon accesso ire en p6 tro log ie endog6ne. C R AcadSci Par is 275 [D]:799-802

Pnp in JP, T urco G (1972c) Le z i rcon accesso ire en g6o thermom 6-tr ie . C R Acad Sci Par is 274 [D]:2121-2124

P u p in JP, Tu rco G (1 9 7 4 a) C o n t r6 1 e th e rm iq u e d u d + v e lo p p em en tde Ia muscov i te dans les g ran i to~des e t morpho log ie du z i rcon .C R A cad Sci Par is 278[DJ :2719 2722

Pupin JP, T urco G (197 4b) App l icat ion ~ t quelques roches endog6-n es d u M ass i f fr an co - i ta l i en d e l ' A rg en te ra -M erca n to u r d ' u n etypo log ie o r ig inale du z i rcon assesso ire . E tude com parat ive avecl a m 6 th o d e d es R M A . B u l l S o c F r M in e ra l C r is t a l lo g r 9 7: 5 6 9

Pup in JP, Turco G (1975) Typo log ie de z i rcon accesso ire dansles roches p lu ton iques d io r i t iques , g ran i t iques e t sy6n i t iques ,Facteu rs essen t ie ls d+term inan t les var ia t ions typo log iques , p6 :t ro log ie I (2 ) : 139-156

Ran ch in G (1970) La g6och imie de l 'u ran ium et la d i ff6 renciationg ran i t iq u e d an s I a p ro v in ce n ran i fb re d u N o rd -L im o u s in . T h 6 seD o c t E ta t , U n iv N an c y (F ran ce ) , 48 3 p p

Read H H (1957) The g ran i te con troversy. Murley (6d)R o u b au l t M , B o rd e t P, L eu tw e in F, S o n e t J, Z im m erm an n JL

(1970) Ages abso lus des fo rm at ions cr is ta l lophy l l iennes desmassi fs des Ma ures e t du Tann eron . C R Acad Sci Par is 271[D]: 1067-1070

Si lver LT, D eu tsch S (1963) U ran ium -lead iso top ic var ia t ions in

zi rcons: a case s tudy. J Geo l 7 i :721-758Tessier M, Pup in JP , Tu rco G, V el lu t in i P (1978) Le z i rcon , u r t

argum ent pour d is t inguer Ies rhyo l i tes o rog6n iques des rhyo l i tesdes complexes annu la i res : l ' exemple co rso -p roven~al . C R AcadSci Par is 287 [D]:407~410

Tut t le OF, Bowen NL (1958) Orig in o f g ran i te in the l igh t o fe x p e ri m e n ta l s tu d ie s i n t h e s y st e m N a A I S i 3 O s - K A I S i 3 O s -S i O 2 - H 2 0 . G e o l S o c A m M e m 7 4 :1 - 15 3

Vachet te M, Roques M, Cou tu r i6 JP (1971) Age hercyn ien p r6cocedu m assi f de g ran i te du Velay (M assi f Cen tral f rangais) e t g tgecaI6don ien des migmat i tes en panneaux dons ce massi f , C RAca d Sci Par is 272 [D]: 3116-3119

Vac het te M, V iale t te Y, Co u tu r i6 JP (1979) Age nam urien dugran i te de la Marger ide. C0rts+quenses , R6un Ann Sc Terre ,Lyon (France) , p 452

Van Breem en O, Hutch inson J , Bow den P (1975) Age and o r ig ino f t h e n ig e r i an m eso zo ic g ran i te s . A R b - S r i so to p i c s tu d y.Co n tr ib Mine ral P et ro l 50 : 157 172

Ven iale F, Pigor ini B, Soggetti F (1968) Petrologic al significanceof the accesso ry z i rcon in the g ran i tes f rom Baven o M, Orfa noand Alzo (N orth I ta ly ) . In t Geo l Cong r R eport , 23 ~ sess Cze-chosl 13 : 243-268

Received October 30 , 1979 ; Accep ted May 28 , 1980

Zircon and Granite Petrology

Documents

Transcript of Zircon and Granite Petrology