UNITED STATES DEPARTl lENT OF T H E I N T E R I O R

GEOLOGICAL SURVEY

Map a n d t a b l e showing radiometric ages o f rocks i n the Aleutian Islands and Alaska Peninsula

b y Frederic H . W i l s o n

O p e n - f i l e Report 8 1 - 4 7 1

1 9 8 1

This r e p o r t is preliminary a n d has n o t b e e n reviewed f o r c o n f o r m i t y

with U . S . G e o l o g i c a l Survey e d i t o r i a l s t a n d a r d s and

Stratigraphic nomenclature.

Map a n d t a b l e s h o w i n g r a d i o m e t r i c a g e s o f r o c k s i n

t h e A l e u t i a n I s l a n d s a n d t h e A l a s k a P e n i n s u l a

b y

F r e d e r i c H . W i l s o n

T h i s r e p o r t i s a c o m p i l a t i o n o f r a d i o m e t r i c a g e s a v a i l a b l e

t h r o u g h J a n u a r y 1981 f r o m p u b l i s h e d , u n p u b l i s h e d , a n d t h e s i s

m a t e r i a l o n t h e A l e u t i a n I s l a n d s a n d t h e A l a s k a P e n i n s u l a . T h e

d a t a b a s e f o r t h e r e p o r t i s d e s c r i b e d i n Shew a n d W i l s o n , 1 9 8 1 ;

s i r n i l i a r r e p o r t s s o u t h - c e n t r a l a n d s o u t h e a s t e r n A l a s k a ( D a d i s m a n ,

1 9 8 0 ; W i l s o n e t a l , 1 9 7 9 ) . T h e l o c a t i o n s o f l i s t e d s a m p l e s a r e

p l o t t e d , w h e r e p o s s i b l e , on P l a t e 1 , a 1:1 ,000,000 b a s e f r o m t h e

N a t i o n a l A t l a s .

T a b l e 1 c o n t a i n s s a m p l e i n f o r m a t i o n l i s t e d a l p h a b e t i c a l l y b y

q u a d r a n g l e . Data f o r e a c h s a m p l e a r e l i s t e d o n t h r e e l i n e s f o r

e a c h a g e d e t e r m i n a t i o n , The f i r s t l i n e o f e a c h l i s t i n g s h o w s t h e

q u a d r a n g l e , l a t i t u d e , l o n g i t u d e , s a m p l e n u m b e r , r o c k t y p e , d a t i n g

m e t h o d , w h e t h e r m i n e r a l o r w h o l e - r o c k d a t e d , a n d c a l c u l a t e d a g e

i n m.y. T h e s e c o n d l i n e l i s t s c o m m e n t s p e r t i n e n t t o t h e a g e

d e t e r m i n a t i o n o r s a m p l e . The t h i r d l i n e l i s t s a l l known

l i t e r a t u r e r e f e r e n c e s t o t h e a g e d e t e r m i n a t i o n .

T a b l e 2 i s a n e x p l a n t a t i o n o f a b b r e v i a t i o n s u s e d i n t a b l e 1

a n d o n t h e m a p .

R e f e r e n c e s C i t e d

A r m s t r o n g , R . L., H a r a k a l , J . E . , a n d H o l l i s t e r , V . F . , 1 9 7 6 , Age

d e t e r m i n a t i o n o f l a t e C a e n o z o i c p o r p h y r y c o p p e r d e p o s i t s o f

the North American Cordillera, & Institution of Mining and

Metallurgy: Applied Earth Science, Institution of Mining

and Metallurgy Transactions Section B, v. 85, November 1976,

, p. B239-B244.

Berry, A. L., Dalrymple, G.B., Lanphere, M.A., and Von Essen,

J . C . , 1976, Summary of miscellaneous potassium-argon age

measurements, U.S. Geological Survey, Menlo Park,

California, for the years 1972-74: U.S. Geological Survey

Circular 727, 13 p.

Ringham, D. K., and Stone, D. B., 1972, Palaeosecular variation

of the geomagnetic field in the Aleutian Islands, Alaska:

Royal Astrononical Society Geophysical Journal, v. 28, no.

4, p. 317-335.

Rrockway, R., Alexander, B., Day, P., Lyle, W., Hiles, R.,

Decker, W., Polski, W., and Reed, B.L., 1975, B r i s t o l Bay

Region, Stratigraphic correlation section, southwest Alaska:

The Alaska Geological Society, 1 sheet.

Burk, C. A., 1965, G e o l o g y of the Alaska Peninsula--island arc

and continental margin: Geological Society of America

lfemoir 99, parts 1-3, 250 p.

Cameron, C. P., and Stone, D. B., 1970, Outline geology of the

Aleutian Islands with paleomagnetic data from Shemya and

Adak Islands--National Science Foundation Grant EA-1216,

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Geophysics Institute (Report) UAG R-213, 153 p.

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Survey, 1969: U.S. Geological Survey Bulletin 1324-A, p.

A16-A22.

Citron, G.P., Kay, R.W., Kay, S.M., Snee, L.W., and Sutter, J.F.,

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7 8.

Cox, Allan, Hopkins, D. M., and Dalrymple, G. B., 1966,

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883-909.

Cox, Allan, and Tlalrymple, G. B., 1967, Geomagnetic polarity

epochs--Nunivak Island, Alaska: Earth and Planetary Science

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Dadisman, S.V., 1980, Radiometric ages of rocks in south-central

Alaska and western Yukon Territory: U.S. Geological Survey

Open-file Report 80-183, 79p., 1 map, scale 1:1,000,000.

Delong, S. E., Fox, P. J., and PlcIlowell, F. W., 1978, Subduction

of the Kula Ridge at the Aleutian Trench: Geological

Society of America Bulletin, v , 89, no. I, p. 83-95.

D e l o n g , S . E . , a n d M c D o w e l l , F . W., 1 9 7 5 , K - A r a g e s f r o m t h e N e a r

I s l a n d s , w e s t e r n A l e u t i a n I s l a n d s , A l a s k a ; i n d i c a t i o n o f a

m i d - O l i g o c e n e t h e r m a l e v e n t : G e o l o g y , v . 3 , n o . 1 2 , p .

6 9 1 - 6 9 4 .

H e i n , J . R . , a n d McLean , H u g h . , 1 9 7 9 , P a l e o g e n e s e d i m e n t a r y a n d

v o l c a n o g e n i c r o c k s f r o m Adak I s l a n d , c e n ~ r a l A l e u t i a n

I s l a n d s , , A l a s k a : G e o l o g i c a l S u r v e y P r o f e s s i o n a l P a p e r 1 1 2 6 ~ ,

1 6 p .

H o a r e , J . PI., C o n d o n , W. F . , a n d C o x , A l l a n , a n d D a l r y m p l e , G.

B . , 1 9 6 8 , G e o l o g y , p a l e o r n a g n e t i s m , a n d p o t a s s i u m - a r g o n a g e s

o f b a s a l t s f r o m N u n i v a k I s l a n d , A l a s k a , i n S t u d i e s o n - v o l c a n o l o g y - - a m e m o i r i n h o n o r o f Howel W i l l i a m s :

G e o l o g i c a l S o c i e t y o f A m e r i c a Memoi r 1 1 6 , p . 3 7 7 - 4 1 3 .

H o p k i n s , D . M . , a n d S i l h e r m a n , M . L . , 1 9 7 8 , P o t a s s i u m - A r g o n a g e s

o f b a s e m e n t r o c k s f r o m S a i n t G e o r g e I s l a n d , A l a s k a : U.S.

G e o l o g i c a l S u r v e y J o u r n a l o f R e s e a r c h , v . 6 , n o . 4 , p .

4 3 5 - 4 3 8 .

K i e n l e , J u e r g e n a n d T u r n e r , D . L . , 1 9 7 6 , The S h u m a g i n - K o d i a k

b a t h o l i t h - - a P a l e o c e n e m a g m a t i c a r c ? , i n S h o r t n o t e s o n -

A l a s k a n g e o l o g y - - 1 9 7 6 : A l a s k a D i v i s i o n o f G e o l o g i c a l a n d

G e o p h y s i c a l S u r v e y s G e o l o g i c R e p o r t 5 1 , p . 9 - 1 1 .

L a n k f o r d , S.M., a n d H i l l , J . M . , 1 9 7 9 , S t r a t i g r a p h y a n d

d e p o s i t i o n a l e n v i r o n m e n t o f t h e D u t c h H a r b o r Member o f t h e

U n a l a s k a F o r m a t i o n , U n ' a l a s k a I s l a n d , A l a s k a : U.S . G e o l o g i c a l

S u r v e y B u l l e t i n 1 4 5 7 - B , 1 4 p .

H a n k i n e n , E . A . , a n d D a l r y m p l e , G . B . , 1 9 7 9 , R e v i s e d g e o m a g n e t i c

p o l a r i t y t i m e s c a l e f o r t h e i n t e r v a l 0-5 m.y. B.P.: J o u r n a l

o f G e o p h y s i c a l R e s e a r c h , v . 8 4 , n . R 2 , p . 6 1 5 - 6 2 6 .

M a r l o w , M . S . , S c h o l l , D . W . , B u f f i n g t o n , E . C . , a n d A l p h a , T .

R . , 1 9 7 3 , T e c t o n i c h i s t o r y o f t h e c e n t r a l A l e u t i a n a r c :

G e o l o g i c a l S o c i e t y A m e r i c a B u l l e t i n , v . 8 4 , n o . 5 , p .

1 5 5 5 - 1 5 7 4 .

M a r v i n , R . F . , a n d D o b s o n , S . W . , 1 9 7 9 , R a d i o m e t r i c a g e s :

C o n p i l a t i o n B , U.S. G e o l o g i c a l S u r v e y : I s o c h r o n / W e s t , n . 2 6 .

McLean , Hugh , E n g e l h a r d t , C . L . , a n d H o w e l , D . G . , 1 9 7 8 ,

R e c o n n a i s s a n c e g e o l o g i c map o f t h e C o l d Bay a n d F a l s e P a s s

q u a d r a n g l e s , A l a s k a : U . S . G e o l o g i c a l S u r v e y O p e n - f i l e R e p o r t

7 8 - 3 2 3 , s c a l e 1 : 2 5 0 , 0 0 0 .

t l o o r e , J . C . , 1 9 7 3 , C o m p l e x d e f o r m a t i o n o f C r e t a c e o u s t r e n c h

d e p o s i t s , s o u t h w e s t e r n A l a s k a : Geol. S o c . o f Amer ica

B u l l e t i n , v . 8 4 , p . 2 0 0 5 - 2 0 2 0 .

M o o r e , J . C . , 1 9 7 4 a , G e o l o g i c a n d s t r u c t u r a l map o f p a r t o f t h e

O u t e r S h u m a g i n I s l a n d s , s o u t h w e s t e r n A l a s k a : U.S. G e o l o g i c a l

S u r v e y M i s c e l l a n e o u s I n v e s t i g a t i o n s S e r i e s Map 1 - 8 1 5 , s c a l e

1 : 6 3 , 3 6 0 .

M o o r e , J . C . , 1 9 7 4 b , G e o l o g i c a n d s t r u c t u r a l m a p o f t h e S a n a k

I s l a n d s , s o u t h w e s t e r n A l a s k a : U . S . G e o l o g i c a l S u r v e y

M i s c e l l a n e o u s I n v e s t i g a t i o n s Map 1 - 8 1 7 , s c a l e 1 : 6 3 , 3 6 0 .

S c h o l l , D.W., M a r l o w , M . S . , MacLeod . N.S. , a n d B u f f i n g t o n , E . C . ,

1 9 7 6 , E p i s o d i c A l e u t i a n R i d g e i g n e o u s a c t i v i t y : I m p l i c a t i o n s

o f I l i o c e n e a n d y o u n g e r s u b m a r i n e v o l c a n i s m w e s t o f B u l d i r

I s l a n d : G e o l o g i c a l S o c i e t y o? A m e r i c a B u l l e t i n , v . 8 7 , p .

5 4 7 - 5 5 7 .

S c h o l l , D . W . , M a r l o w , M.S., a n d B u f f i n g t o n , E . C . , 1 9 7 3 , P l i o c e n e

a n d P l e i s t o c e n e e r u p t i v e r o c k s o f t h e w e s t e r n A l e u t i a n r i d g e

-- a b l e e d i n g s t r i k e - s l i p p l a t e b o u n d a r y ( ? ) : G e o l o g i c a l

S o c i e t y o f A m e r i c a A b s t r a c t s w i t h P r o g r a m s , v . 5 , n o . 1 , p .

1 0 1 .

S h e w , N o r a , a n d W i l s o n , F . B . , 1 9 8 1 , R a d i o m e t r i c a g e f i l e f o r

A l a s k a i n C o o n r a d , W.L., e d . , T h e U n i t e d S t a t e s G e o l o g i c a l - S u r v e y i n A l a s k a , A c c o m p l i s h m e n t s 1 9 8 0 : U.S. G e o l o g i c a l

S u r v e y C i r c u l a r , i n p r e p .

S i l b e r m a n , M. L . , a n d H o p k i n s , D . M., 1 9 7 6 , P o t a s s i u m - a r g o n a g e s

o f b a s e m e n t r o c k s f r o m S t . G e o r g e I s l a n d , A l a s k a : U.S.

G e o l o g i c a l S u r v e y O p e n - F i l e R e p o r t 7 6 - 7 3 3 , l l p .

S i m p s o n , G.L., V a l l i e r , T . L . , P e a r l , J . E . , a n d Lee-Wong,

F l o r e n c e , 1 9 7 9 , P o t a s s i u m - a r g o n a g e s a n d g e o c h e m i s t r y o f

b a s a l t d r e d g e d n e a r Saint G e o r g e I s l a n d , s o u t h e r n R e r i n g

S e a : U.S . G e o l o g i c a l S u r v e y C i r c u l a r 8 0 4 - B y p . B134-B135.

v o n H u e n e , R o l a n d , C a r r , W.J., McManus, D . , a n d H o l m e s , M . , 1 9 7 1 ,

M a r i n e g e o p h y s i c a l s t u d y a r o u n d A m c h i t k a I s l a n d , w e s t e r n

A l e u t i a n I s l a n d s ; A l a s k a : U . S . G e o l o g i c a l S u r v e y T e c h n i c a l

L e t t e r 2 2 , 3 1 p . , 7 p l a t e s .

W h i t m o r e , F . C . , J r . , a n d G a r d , L . M . , J r . , 1 9 7 7 , S t e l l e r s ' s Sea

Cow ( H y d r o d a m a l i s g i g a s ) o f L a t e P l e i s t o c e n e a g e f r o m

A m c h i t k a , A l e u t i a n I s l a n d s , A l a s k a : U.S. G e o l o g i c a l S u r v e y

P r o f e s s i o n a l P a p e r 1 0 3 6 , 1 9 p . .

W i l s o n , F . H . , 1 9 7 8 , Map s h o w i n g p r e l i m i n a r y r e s u l t s o f K - A r

s t u d i e s i n t h e C h i g n i k a n d S u t w i k I s l a n d q u a d r a n g l e s ,

A l a s k a : U . S . G e o l o g i c a l S u r v e y O p e n - F i l e R e p o r t 7 8 - 1 0 6 4 , 1

s h e e t , s c a l e 1 : 2 5 0 , 0 0 0 .

W i l s o n , F.H., 1 9 8 0 , L a t e M e s o z o i c a n d C e n o z o i c t e c t o n i c s a n d t h e

a g e of p o r p h y r y c o p p e r p r o s p e c t s , C h i g n i k a n d S u t w i k I s l a n d

q u a d r a n g l e s , A l a s k a P e n i n s u l a : U.S. G e o l o g i c a l S u r v e y

O p e n - f i l e R e p o r t 8 0 - 5 4 3 , 9 9 p . , 5 p l a t e s .

W i l s o n , F . H . , D a d i s m a n , S .V. , a n d H e r z o n , P.L., 1 9 7 9 , Map s h o w i n g

r a d i o m e t r i c a g e s o f rocks i n s o u t h e a s t e r n A l a s k a : U . S .

G e o l o g i c a l S u r v e y O p e n - f i l e R e p o r t 7 9 - 5 9 4 , 3 3 p . , 1 m a p ,

s c a l e 1 : 1 , 0 0 0 , 0 0 0 .

W i l s o n , F . H . , Gaum, W.C., H e r z o n , P . L . , 1 9 8 1 , Map a n d t a b l e s

s h o w i n g g e o c h r o n o l o g y a n d w h o l e - r o c k g e o c h e m i s t r y o f t h e

C h i g n i k a n d S u t w i k Island q u a d r a n g l e s , A l a s k a : U.S.

G e o l o g i c a l S u r v e y M i s c e l l a n e o u s F i e l d S t u d i e s Map MF-1053-M,

3 s h e e t s , s c a l e 1 : 2 5 0 , 0 0 0 , i n p r e s s .

Table 1. Radiometric ages of the Aleutian I s l a n d s and Alaska Peninsula

Quadrangle Latitude Longitude Sample No* Rock. Meth. Min. Age ( m y )

Adak 51 41.2N 176 41.3E HB6-120D D I K BI 34.59

Citron e t a l , 1980

Adak 51 41.2N 176 41.3E HB6-120D D I K HO 31.80

Citron et al, 1980

Adak 51 41.4N 176 38.OE 18-1

Citron et al, 1980

Ada k 51 41.4N 176 38.OE 18-1

Citron e t al., 1980

Adak 51 42.6N 176 37,OE HB7-23B GDL K BI 33.43

Citron et a l , 1980

Adak

Adak

51 42.9N 176 38.7E HB6-10 G D I K B I 31.51

Citron e t a l , 1980

Citron e t a l , 1980

Adak 51 43.5N 176 47.83 BE8-1 G D I K B I 32.99

Citron e t a l , 1980

A&k 51 49.1N 176 26.53 K7-32A G D I K B I 13.9

Citron e t a l , 1980

Ada k

Citron et aL, 1980

Adak 51 49.8N 176 24.OW KAGl Kagalaska Is land Marlow e t a l , 1973; Citron e t a l , 1980

Adak 51 49.8N 176 24.OW KAGl Kagalaska Island Marlow et a l , 1973; Citron et a l , 1980

G D I K HO 12.39

G D I K B I 13.2

G D I K HO 13.7

Table 1. Continued

Quadrangle La t i t ude Longitude Sample No. Rock Meth. Min. Age(my)

Adak 51 51.6N 176 37.8W ADAK14 AND K HO 4.9 North Adak I s l and Marlow e t all 1973

Adak 51 54.ON 177 03.OW RDH AND K WR .O Kanaqa I s l and Marlow e t all 1973; Bingham and Stone, 1972

Adak 51 54.ON 177 06.OW ADAK12 AND K WR .13 Kanaga I s l and Marlow e t a l , 1973; Bingham and Stone, 1972

Adak 51 54.ON 177 06.OW ADAX12 AND K WR 24 Kanaga I s l and Marlow et a l l 1973; Bingham and Stone, 1972

Adak 51 54.ON 177 06.OW KAN BAS K WR 18

Bingham and Stone, 1972

Ada k 51 54.6N 176 37.8~ ADAKll ZEN0 K HO 2 4 North Adak I s l and Marlow et a l l 1973

Adak 51 54.6N 176 37.8W ADAKlS AND K HO 5.25 N ~ r t h Adak I s l and Marlow e t all 1973

Adak 51 55.ON 176 34.OW A D A M AND K WR 5. North Adak Island Cameron and Stone, 1970

Adgk 51 55.ON 176 34.OW ADAK5 AND K WR 5. North Adak I s l and Cameron and Stone, 1970

Adak 51 55.ON 176 34.OW ADAKG AND K WR 5. North Adak I s l and Cameron and Stone, 1970

Adak 51 55.ON 176 34.OW ADAK7 AND K WR 5. North Adak I s l and Cameron and Stone, 1970

Adak 51 55.8N 176 37.6~ 802-802 AND K PL 14.4 andesite s i l l Hein and McLean, 1979

Table 1. Continued

Quadrangle La t i t ude Longitude Sample No.. Rock Meth. Min. Age(my1

Adak 51 55.8N 176 37.6W ADAKlO AND K WR 5.1 North Adak Xsland Marlow et a l l 1973; Cameron and Stone, 1970

Adak 51 57.5N 176 34.OW ADAK2 BAS K WR .oo North Adak I s l and . Cameron and Stone, 1970

Adak 51 58.2N 176 34.2W ADAKl BAS K WR .o North Adak I s l and Marlow et aL, 1973; Cameron and Stone, 1970

Adak 51 58.2N 176 34.28 ADAKl KEPT BAS K WR .O North Adak I s l and Marlow e t a l l 1973

Atka 52 22.8N 174 09.6W ATKAl AND K WR 19 Atka Island Marlow e t a l l 1973; Bingham and Stone, 1972

Atka 52 22.8N 174 09.6W ATKA2 AND K WR 24 Atka I s l and Marlow e t a l l 1973; Bingham and Stone, 1972

Attu 52 27.6N 173 41.4E 50D4 DAC K B I 12.2 Porphyr i t ic dike, McDonald Cove, Agattu I s l and s c h o l l e t a l l 1976

Attu 52 27.6N 173 41.4E 50D4 DAC K HO 15.2 Porphyr i t ic dike, McDonald Cove, Agattu I s l and Scholl e t a l l 1976

Attu 52 27.6N 173 41m4E 50D4 DAC K PL 10.7 Porphyr i t ic dike, McDonald Cove, Agattu I s l and Schol l e t a l l 1976

Attu 52 27.6N 173 41.4E 5004 DAC K PL 13.2 Porphyr i t ic dike, McDonald Cove, Agattu I s l and Schol l e t a l l 1976

Attu 52 28.2N 173 41.3E 50D4 DAC K WR 14.2 Agattu I s l and DeLong and McDowell, 1 9 7 5

A t t u 52 43.2N 174 06.6E ATTU6 DAC K AM 15.0 Shemya I s l and Marlow et a l , 1973; Cameron and Stone, 1970

Table 1. Continued Quadrangle La t i t ude b n g i t u d e Sample No. Rock Meth. Min. ~ ~ e ( r n y )

Attu 52 43.88 174 07.2E ATTU3 BAS K WR 12.3

Shemya I s l and Marlow e t a l , 1973; Cameron and Stone, 1970

Attu 52 48.1N 173 06.5E 49P53 BAS K WR 31.9 Attu I s l and DeLong and McDowell, 1975

Attu 52 48.2N 173 09.OE 50P295 Q D I K WR 26.5 Attu I s l and DeLong and McDowell, 1975

Attu 52 48-48 172 56.53 4966 AMPH K WR 29.9 Attu I s l and DeLong and McDowell, 1975

Attu 52 49.3N 173 1009E 50P293 BAS K WR 28.9 Attu I s l and DeLong and McDowell, 1975

Attu 52 49.88 173 07.OE 50P286 AND K HO 8.35 Massacre Bay Formationr Lookout H i l l , Attu I s land; l oca t ion i n error i n source* Scholl e t a l , 1976

Attu 52 49.8N 173 07.OE 50P286 AND K WR 7.4 Attu I s l and DeLong and McDowell, 1975

Attu 52 50.ON 173 21.9E 49W36 DAC K WR 5.9 Attu I s l and DeLong and McDowell, 1975

Chignik 56 00.2N 160 02.3W 78AYb90 AND K WR 3 . 5 3 Milky River Formation, mean of 2 determinat ions Wilson e t a l , 1981

Chignik 56 01. lN 158 30.3W 78AWs95 Q DI K BI 7.86

Wilson, 1980; Wilson e t a l l 1981

Chignik 56 Ol.lN 158 30.3W 78AWs95 Q DI K HO 10.08

Wilson, 1980; Wilson et a l , 1981

Chiqnik 56 01.4N 159 20.2W 78AWslll LBAS K WR 39.1 mean of 2 determinat ions Wilson et al, 1981

Table 1. Continued Quadrangle L a t i t u d e Longitude Sample No. Rock Meth. Min. Age(my)

Chiqnik 56 01.7N 159 11.2W 77AWs112b LBAS K WR 48 Mean of 3 de te rmina t ions Wilson, 1980; Wilson e t a l , 1981

Chignik 5604.ON 1 5 6 2 9 . 5 8 77AWs100 GDI K B I 7.78 Mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t a l , 198 1

Chignik 5604.ON 1 5 8 2 9 . 5 1 77AWs100 G D I K 80 9.86 Mean o f 2 de te rmina t ions WiL~on, 1978; 1980; Wilson e t al, 1981

Chignik 5609.7N 15824.OW 77AWs179 G D I K BI 7.65 Mildly hydrothermal ly a l t e r e d g r a n o d i o r i t e ; mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t a l , 1981

Chignik 5609.7N 15824.OW 77AWs180 PEG K B I 7.37 Mean of 2 de te rmina t ions Wilson, 1978; 1980; Wilson e t a l , 1981

Chignik 5609.7N 15824.OW 77AWs96B PEG K KS 6.53 Mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson et a l l 1981

Chignik 56 11.7N 158 19,OW 77AWs122 DAC K HO 22.37 Minimum age, impure s e p a r a t e wi th i n c l . of p l a g i o c l a s e , mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t aL, 1981

Chignik 56 12.7N 158 19.9W 78AWs98 LBAS K WR 21.18 mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson et al, 198 1

Chignik 56 13.2N 158 23.3W 77AWs125 TON K B I ' 6-03 Mean of 2 de te rmina t ions Wilson, 1978; 1980; Wilson et a l , 1981

Chignik 56 13.2N 158 23.3W 77AWs125 TON K HO 6.33 Cor rec ted age is mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

Chignik 56 13.5N 158 28.5W 77AMs001 AND K HO 27.1 P r o p y l i t i c a l l y a l t e r e d d ike ; mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t a l , 1981

Chignik 56 13.6N 158 28-98 77AWs137 Q D I K B I 21.3 C h l o r i t i z e d , a l t e r e d q u a r t z dkor i t e - smal l p l u t o n i n t r u d i n g v o l c a n i c p i l e Wilson, 1978; 1980; Wilson e t a l , 1981

Table 1. Continued

Quadrangle L a t i t u d e Longitude Sample No. Rock Meth. Min. Age(my)

Chignik 5613.8N 15829.0w 77AW~183 OTHER K WR 21.2 Q u a r t z - s e r c i t e a l t e r e d v o l c a n i c rock ; mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t a l , 1981

- Chignik 56 17.1N 158 35.2W 78AWs134 DAC K WR 26.23 m a n of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t al, 198 1

Chignik 56 18.ON 158 22.8W 77AWs176 AND K BO 16.5 Minimum age, mean of 2 de te rmina t ions d e t e r m i n a t i o n s Wilson, 1980; Wilson e t al, 1981

Chignik 56 18.5N 158 24.5W 77AWs190b AND K HO 8 -97 mean o f 2 d e t e r m i n a t i o n s Wilson e t a l , 1981

Chignik 56 20.ON 158 30.0W 77Aws186 CG K BI 89.8 Cobble from Chignik Formation, minimun age, m a n of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l l 1981

Chi gnik 5629.5N 15848.QW 78AWs125 DAC K HO 1.88 Corrected age is mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

Chignik 5630.ON 15843.4W 78ADt187 DAC K WR 1.94 mean of 2 de te rmina t ions Wilson e t all 1981

Chignik 56 30.1N 158 40.5W 78AYb57 DAC K PL 1.80 mean of 2 de te rmina t ions Wilson e t a l ; 1981

Chignik 5630.4N 15823.5W 77AWs235 OTHER K CH 3.5 Hydrothermally a l t e r e d a rkose of Naknek Formation, mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson et a l , 1981

Chignik 56 30.5N 158 24.1W 77AWs243 OTHER K CH 3.92 Hydrothermally a l t e r e d Naknek Formation Wilson, 1980; Wilson e t air 1981

Chiqnik 56 30.5N 158 24.1W 77AWs243 OTHER K SE 3 .83 H y d r o t h e m a l l y a l t e r e d Naknek Formation, c o r r e c t e d age, mean of 2 de te rmina t ions Wilson, 1980; Wilson e t a l , 1981

Chignik 56 30.5N 158 24.1W 77AWs243 OTHER K WR 3.72 H y d r o t h e m a l l y altered Naknek Formation Wilson, 1980; Wilson e t a l , 1981

Table 1 . Continued Quadrangle Latitude Longitude Sample No. Rock Meth. Min. Aqe(my)

Chignik 5630.6N 15824.OW 77A~s21S DAC K HO 2.15 mean of 2 de te rmina t ions Wilson, 1980; Wilson e t al, 1981

Chignik 56 30.7N 158 39.9W 78~Yb58 AND K PL 1.72 mean of 2 d e t e r m i n a t i o n s Wilson e t a l l 1981

Chignik 56 31.ON 158 23.5W 77AWs152 DAC K BX 3.65 H y d r o t h e m a l l y a l t e r e d d a c i t e ; mean of 2 de te rmina t ions Wilson, 1978; 1980; Wilson et aL, 1981

Chignik 5631.ON 15824.OW 77AWs251 OTHER K B I 3.67 A l t e r e d d a c i t e ? ; mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t al, 1981

Chiqnik 56 31.ON 158 42.OW 77ACx4 OTHER K WR 1.38 Hydrothermally a l t e r e d v o l c a n i c rock, mean of 2 de te rmina t ions Wilson, 1980; Wilson e t a l l 1981

Chignik 56 32. N 158 23. W Chignikl OTHER K SE 3.4 Hydrothermal mineral ; age r e c a l c u l a t e d with 1976 c o n s t a n t s Armstrong et all 1976; Wilson, 1980

Chiqnik 56 58. ON 158 40.6W Chignik2 UNXD K UN 42.

Gulf 1 P o r t Heiden w e L L , core 1 11,832-11858', approximate Locat ion Brockway et a l l 1975; Wilson 1980

Chignik 56 58.ON 158 40.6W Chignik3 U N I D K UN 36. G u l f 1 Por t Heiden well, 14,000' , approximate l o c a t i o n Brockway et all 1975; Wilson, 1980

F a l s e Pass 54 29.ON 162 3 8 - 4 1 75089 G D I K B I 62.0 Approximate l o c a t i o n , Sanak I s l a n d ; age r e c a l c u l a t e d wi th 1976 c o n s t a n t s Kienla and Turner , 1976; Wilson, 1980

F a l s e Pass 54 29.ON 162 38.4W S-70 G D I K B I 61.4 Sanak P lu ton ; age recaLcula ted w i t h 1976 constants; addl r e f McLean et a l , 1978 Berry e t al, 1976; KienLe and Turner , 1976; Wilson, 1980; Moore, 1973, 1974a

G a r e l o i I s l a n d 51 14.6N 179 07.6W A-A20 DIA K WR 29.0 Amatiqnak I s l a n d Delong e t all 1978

G a r e l o i I s l a n d 51 17.8N 179 07.2W A-A31 BAS K WR 23.7 Amati ynak Is. Delong e t a l l 1978

Table 1. Continued Quadrangle L a t i t u d e Longitude Sample No. Rock Meth. Min. Age(my)

G a r e l o i I s l a n d 51 23.ON 178 59.8W A-U22 BAS K WR 42.3

Ulak I s l a n d Delong et all 1978

G a r e l o i I s l a n d 51 23.4N 178 59.OW A-U23 D I K WR 33.1 Metad ior i t e : Ulak Is* Delong e t al., 1978

Kiska 51 55.ON 177 22.OE A-K14 BAS K WR 29.0 Kiska I s l a n d Delonq e t a l l 1978

Kiska 52 06.2N 177 33.OE KISKAl AND K WR 5.5 Kiska I s l a n d , approximate l o c a t i o n von Huene e t a l l 1971; Marlow et 91, 1973; DeLong e t a l , 1978

O f f s h o r e 52 36.ON 174 48.OE B-29-1 DAC K HO 1.4 Hornblende d a c i t e dredged a t 750x11 from west of Buldir I s l a n d S c h o l l e t a l l 1973

O f £shore 52 36.6N 174 48.6E B-29-1 DAC K HO .61 Dredge s t a t i o n Marlow e t a l , 1973; S c h o l l et a l l 1976

Offshore 52 3 6 . 6 N 174 48-63 B-29-1 DAC K HO 2.10 Dredge s t a t i o n Marlow e t a l l 1973; S c h o l l e t a l , 1976

O f f s h o r e 55 42.ON 165 12.OE OFFSHI BAS K WR 4.6 Augi te b a s a l t dredged a t 1600m S c h o l l e t a l , 1973

O f f s h o r e 56 23.ON 169 37.5W DR5-34 BAS K WR .77 Dredge site sou th of St. George Is., approximate l o c a t i o n Simpson e t al., 1979

O f f shore 56 23.ON 169 37.5W DR5-8 BAS K WR -84 Dredge s i te sou th of St. George Is., approximate l o c a t i o n Simpson et a l l 1979

P o r t Moller 55 03.2N 160 02.5W 405M D I K MU 57.4 Shumagin b a t h o l i t h ; age recaLcula ted with 1976 c o n s t a n t s Burk, 1965; Kien le and Turner , 1976; Wilson, 1980

Port Moller 55 05.ON 160 O O . O W 75092 GDI K BI 60.7 Approx. l o c a t i o n Nagai Is. Kien le and Turner , 1976; Wilson, 1980

Tabla 1. Continued

Quadrangle L a t i t u d e Longitude Sample No. Rock ~ e t h . Min. ~ ~ e ( r n y )

P o r t Moller 55 06.8N 160 01.7W 4068 D I K B I 58.4 Shumagin b a t h o l i t h ; age r e c a l c u l a t e d w i t h 1976 c o n s t a n t s Burk, 1965; Kien le and Turner , 1976; Wilson, 1980

P o r t Moller 55 06.8N 160 01.7W 406M D I K MU 65.6 Shumagin b a t h o l i t h ; age r e c a l c u l a t e d w i t h 1976 c o n s t a n t s Burk, 1965; Kien le and Turner , 1976; Wilson, 1980

P o r t Moller 55 37. N 160 41. W Moller-1 Q D I K B I 6.2 Secondary minera l Armstrong et a l , 1976

P r i b i l o f I s l a n d s 56 34.ON 169 29.OW P66 BAS K WR 2.19 St. George Is land Cox e t a l , 1966; Cox, 1966

P r i b i l o f I s l a n d s 56 34.5N 169 30.OW GI99 Q D I K PL 55.0

Silberman and Hopkins,1976; Hopkins and Si lberman, 1973

P r i b i l o f I s l a n d s 56 34.5N 169 30.OW GI99 Q D I K SE 49.5

Silberman and Hopkins, 1976; Hopkins and Silberman, 1978

P r i b i l o f I s l a n d s 56 34.5N 169 30.OW G2OO Q D K AW 52.7

Si lbennan and Hopkins, 1976; Hopkins and Silberman, 1978

P r i b i l o f I s l a n d s 56 34.5N 169 30.OW G200 Q DI K CH 57.2

Silberman and Hopkins, 1976; Hopkins and S i l b e m n , 1978

P r i b i l o f I s l a n d s 56 34.5N 169 30.OW ISOCHRON Q D I K I C 51.7

Silberman and Hopkins, 1976; Hopkins and Silberman, 1978

P r i b i l o f I s l a n d s 56 35.ON 169 34.OW P67 BAS K WR 2.10 S t . George I s l a n d Cox et a l , 1966; Cox, 1966

P r i b i l o f I s l a n d s 56 36.ON 169 27.OW PI2 BAS K WR 2.12 St. George I s l a n d Cox and Dalrymple, 1967; Hoare e t a l l 1968; Mankinen and Dalrymple, 1979

P r i b i l o f I s l a n d s 56 36.ON 169 27.OW PI3 BAS K WR 2.15 St. George I s l a n d Cox and Dalrymple, 1967; Boare e t al, 1968; Mankinen and Dalrymple, 1979

Table 1. Continued Quadrangle Lat i tude Longitude Sample No. Rock Meth. Min. ~ge(my)

Prib i lof Is lands 5635.5N 169 28.OW PI0 BAS K WR 2.13 S t . ~ s o r g e . I s l a n d Cox et a l , 1966; Cox, 1966

Prib i lof Is lands 56 35.5N 169 28.OW PI1 BAS K WR 1.80 St. George Island Cox e t a l l 1966; Cox, 1966

Prib i lof Is lands 56 35.5N 169 28.OW PI1 BAS K WR 1 .83 St. George Island Cox and Dalrymple, 1967; Hoare et a l , 1968; Mankinen and Dalrymple, 1979

Prib i lof Is lands 56 36.ON 169 28.OW PI5 BAS K WR 2.14 St. George Is land Cox et al, 1966; Cox, 1966

Prib i lof Is lands 56 36.ON 169 28.OW PI9 S t . George Is land Cox e t al, 1966; Cox, 1966

Prib i lof Is lands 56 36.ON 169 28.OW P20 St. George Is land Cox e t a l , 1966; Cox, 1966

BAS K WR 1 a92

BAS K WR 1.81

Prib i lof Is lands 56 36.0N 169 30.OW P21 BAS K WR 1.64 St. George Island Cox and Dalrymple, 1967; Hoare e t al, 1968; Mankinen and Dalrymple, 1979

Prib i lof Is lands 56 37.ON 169 33.OW P2 BAS K WR 2.00 St. George Island Cox and Dalrymple, 1967; Hoare e t all 1968; Mankinen and Dalrymple, 1979

PribiLof Is lands 56 37.ON 169 33.OW P3 BAS K WR 1.99 St. George Is land Cox e t al, 1966; Cox, 1966

Prib i lof Is lands 56 37.ON 169 33.OW P3 BAS K WR 2.01 St. George Island Cox and Dalrymple, 1967; Hoare et a l , 1968; Mankinen and Dalrymple, 1979

Pr ib i lo f Is lands 56 37.ON 169 34.OW P5 BAS K WR 1.89 St. George Is land Cox e t a l , 1966; COX, 1966

Prib i lof Is lands 56 37.ON 169 34.OW P5 BAS K WR 1.91 S t . George Is land Cox et a l , 1966; Cox, 1966; Mankinen and Dalrymple, 1979

Table 1. Continued Quadrangle Lat i tude Longitude Sample No. Rock Meth. Min. ~ g e ( m y )

PribiSof Is lands 57 08.ON 170 17rOW P52 BAS K WR .1 st. Paul Is land Cox e t a l , 1966; Cox, 1966

Prib i lof Islands 57 12.ON 170 25.0W P38 BAS K WR - 3 3 St. Paul Is land Cox and Dalrymple, 1967; Hoare e t a l , 1968; Mankinen and Dalrymple, 1979

P r i b i l o f I s l a n d s 57 12.ON 17025.OW P38 BAS K WR 36 St. Paul Island Cox e t al, 1966; cox, 1966

Prib i lof Is lands 57 13,ON 170 24.OW P35 BAS K WR .10 St. Paul Is land Cox e t a l , 1966; Cox, 1966

Prib i lof Is lands 57 13.ON 170 24.OW P35 BAS K WR . I 3 st. Paul Island Cox e t d l , 1966; Cox, 1966; Mankinen and Dalrymple, 1979

Pr ib i lo f Is lands 57 13.ON 170 24.OW P35 BAS K WR .20 St. Paul I s land Cox et a l , 1966; Cox, 1966

Rat Is lands 51 21.9N 179 20r7E WJC87A66 AND K HO 2.7 Dike Carr e t a l , 1970

Rat Islands 51 22.6N 179 22.53 Rat1 OTHER P SH .13 S t e l l e r ' s sea cow, South Bigh t , approximate loca t ion Whitmore and Gard, 1977

R a t I s lands 51 22.8N 179 25-23 69AMCll GDI K BI 15.8 Amchitka Is land Marlow e t a l , 1973; Carr et al, 1970

R a t I s lands 51 23.4N 179 12.6E WJC1-67 BAS K WR 10.2 Arnchitka Is land Marlow et al, 1973; Carr et al, 1970

Rat Islands 51 25.6N 179 13.8E 69AMC12 AND K WR 8.9 M c h i tka Is land Marlow e t a l , 1973; C a r r e t al, 1970

R a t Is lands 51 28.8N 179 02.4E 69AMC17 AND K WR 13.2 Amchitka Is land Marlow et aL, 1973; Carr e t al, 1970

Table 1. Continued Quadrangle L a t i t u d e Longitude Sample No. Rock Meth. Min. ~ge(my)

Rat I s l a n d s 51 31.2N 179 01.8E 69AMC2 AND K WR 14.1 Amchitka I s l a n d Marlow e t al, 1973; C a r r e t a l , 1970

Rat Is l a n d s 51 36.0N 178 48.OE 69AMC15 AND K WR 12.4 Amchitka I s l a n d Marlow e t a l , 1973; C a r r e t al., 1970

Simeonof Is. 54 S5.ON 159 14.4W 62AGz7 GD1: K BI 59.9 Light-gray, medium g r a i n e d b i o t i t e g r a n o d i o r i t e , approximate Location Moore, 1974a; Marvin and Dobson, 1979; Wilson, 1980

Stepovak Bay 55 08.9N 159 32.OW 75088 GDI K B I 60.2 Approximate l o c a t i o n , B i g Koniu j i I s l a n d ; age r e c a l c u l a t e d w i t h 1976 c o n s t a n t s KienLe and Turner , 1976; Wilson, 1980

Stepovak Bay 5557.ON 15921.OW 77AWs102 LBAS K WR 40.3 mean of 2 d e t e n n i n a t i o n s Wilson e t a l , 1981

Sutwik Is. 56 02.7N 156 41.3W 75086 G D I K . BI 59.3 Approximate l o c a t i o n , Chowiet Island; age r e c a l c u l a t e d w i t h 1976 c o n s t a n t s Kien le and Turner , 1976; Wilson, 1980

Sutwik IS. 56 19.8N 157 39.6W 77AWs134 DAC K HO 10.10 Hornblende p l a g i o c l a s e porphyry, unaltered sample; mean of 2 de te rmina t ions Wilson, 1978; 1980; Wilson e t a l , 1981

Sutwik Is. 56 30.4N 157 43.1W 78AWs42 AND K HO 32.8 Cor rec ted age which i s mean of 2 de te rmina t ions Wilson e t a l , 1981; Wilson 1980

Sutwik Is. 56 30.4N 157 43.2W 78AWs43 OTHER K WR 33.9 Hydrothermally a l t e r e d v o l c a n i c rock , c o r r e c t e d age i s mean o f 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l l 1981

Sutwik Is. 56 30.4N 157 49.4W 78AWs58 DAC K WR 34.44 mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 198 1

Sutwik Is. 56 31.6N 157 11.7W 78AWs32 AND K WR 30.71 mean of 2 de te rmina t ions WiLson, 1980; Wilson et a l l 1981

Sutwik IS. 56 32.5N 157 2O.OW 77AWs74 DAC K B I 34-50 Hydrothermally a l t e r e d b i o t i e d a c i t e ; mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; wi l son e t a l l 1981

Table 1. Continued Quadrangle L a t i t u d e Longitude Sample No. Rock Meth. Min. Age(my)

Sutwik IS. 56 33.ON 156 59.6W 78AWs31 AND K WF! 30.33 mean of 2 de te rmina t ions Wilson, 1980; Wilson e t a l , 1981

Sutwik Is. 56 36.1N 157 58.9W 78AWs61 DAC K WR 34.39 mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

Sutwik Is. 56 37.5N 157 34.5W 78AWs18 LBAS K WR 37.3 mean of 2 de te rmina t ions Wilson e t a l , 1981

Sutwik IS. 56 38.2N 157 27.9W 77AWs46 AND K HO 39.1 P r o p y l i t i c a l l y a l t e r e d a n d e s i t e porphyry; m a n of 2 de te rmina t ions Wilson, 1978; 1980; Wilson e t a l , 1981

Sutwik IS. 56 38.2N 157 28.9W 77AWs40 LBAS K HO 35.0 Hornblende l euco-basa l t porphyry; mean of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t al., 1981

Sutwik Is. 56 38.3N 157 35.5W 77AWs30 AND K HO 3 6 . 3 Hornblende a n d e s i t e porphyry from a l t e r e d zone; m a n of 2 d e t e r m i n a t i o n s Wilson, 1978; 1980; Wilson e t a l , 1981

Sutwik IS. 56 38.7N 157 25.OW 78AWs17 LBAS K HO 34.2 mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

Sutwik Is. 56 43.ON 157 49.5W 78AWs20 DAC K WR 36.6 mean of 2 d e t e r m i n a t i o n s Wilson e t a l , 1981

Sutwik IS. 56 47.3N 157 11.8W 78AWs24 AND K HO 33.5 mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

Sutwik Is. 56 47.9N 157 13.7W 78AWs27 OTHER K HO 36.7 Mafic i n c l u s i o n ( a u t o l i t h ) i n d a c i t e , mean of 2 d e t e r m i n a t i o n s Wilson e t a l , 1981

Sutwik Is. 56 49. IN 157 56-31 78AWs35 DAC K HO 34.47 mean of 2 d e t e n n i n a t i o n s Wilson, 1980; Wilson e t aL, 1981

Sutwik Is. 56 51.2N 156 S3.8W 77ADt19 AND K PL 15-33 mean of 2 d e t e r m i n a t i o n s Wilson et a l , 1981

Table 1. Continued

Quadrangle L a t i t u d e Longitude Sample No. Rock Meth. Min. Age(my)

Sutwik Is. 56 55.ON 157 14,OW 78ADt34 AND K WR .62 Yanta rn i Volcano, mean of 2 d e t e r m i n a t i o n s Wilson e t a l , 1981

Sutwik Is. 56 56.58 157 57.OW 78AWs5 AND K PL 48.1 mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

Sutwik Is. 56 59.ON 157 07.5W 78AWsll DAC K HO 19.25 Minimum age due t o proximity to Quaternary volcano, mean of 2 d e t e r m i n a t i o n s Wilson, 1980; Wilson e t a l , 1981

T r i n i t y Is. 5655.ON 15413.OW 62AMe120 Q D I K BI 60.8 South p a r t Kodiak Island Marvin and Dobson, 1979

T r i n i t y Is. 56 55.ON 154 13.OW 62AMe120 Q D I K MU 61.9 South p a r t Kodiak I s l a n d Marvin and Dobson, 1979

Ugashik 57 00.3N 156 40.4W 77AWs9 AND K WR 9.25 mean of 2 de te rmina t ions Wilson, 1980; Wilson et a l , 1981

Ugashik 57 26.ON 157 44.3W Ugashikl U N I D K UN 33. Great Bas ins 1 Ugashik w e l l , c o r e 1 , 5364-5391' Brockway e t a l , 1975; Wilson, 1980

Ugaahik 57 26.ON 157 44.3W Ugashik2 UNID K UN 39. Great Basins 1 Ugashik w e l l , c o r e 2, 8083-8095' Brockway e t a l , 1975; Wilson, 1980

Umnak 53 28.2N 168 04.8W CCR BAS K WR .O Umnak I s l a n d Marlow e t al., 1973; Bingham and Stone, 1972

Umnak 53 28.2N 168 04.8W UMNAKl BAS K WR . I 3 Umnak I s l a n d Marlow et a l , 1973; Bingham and Stone, 1972

Umnak 53 31.8N 168 06.OW ASH1 BAS K WR 1.7 Umnak I s l a n d Marlow e t a l , 1973; Bingham and Stone, 1972

Umnak 5331.8N 16806.OW ASH2 BAS K WR 2.1 Umnak I s l a n d Marlow et a l , 1973; Bingham and Stone, 1972

Table 1. Continued Quadrangle Latitude Longitude Sample N o . Rock Meth. Min. Age(my)

Unalaska 53 37.8N 166 55.8W 54SN197 GDI K BI 3.4

Unalaska Island Marlow et all 1973

Unalaska 53 37.8N 166 55.88 54SN197 GDI K HO 11.1 Unalaska Island DeLong and McDowell, 1975; Marlow e t al., 1973; Lankford and Hill, 1979

Unalas ka 5348.ON 16630.OW uNAI GDI K UN 13.

Unidentified rock type, mineral, and location, Captains Bay Pluton Lankford and H i l l , 1979

TABLE 2 - ABBREVIATIONS mTyp

AMPH Anphibolite

AND Andesite

BAS Basalt

I3AC Cacite

DI Diori te

DIA Diabase

GDI Grandiorite

GR Granite

Mineral Phase

AM Anphibole

AW Anorthoclase

BI Biotite

CH Chlorite

HO Hornblende

IC Isochron

KS Pot ass ium feldspar

Dating Method

LBAS Leuco-basal t

OTHER Other

PEG Pegmatite

Q DI Quartz diorite

TON Tondlite

UNID Unidentified

Z E N 0 Zenolith

MU Muscovite

PL Plagioclase

SE Sericite

SH Shell material

WR Whole rock

UN Unknown

P F%U, PbTh, etc.