Geology of the Cedar Mountains,Tooele County, Utah (Thesis and maps)

Part1 Geology of the Cedar Mountains Tooele County, Utah

Part 1 contains the title page to page 86 of thesis.

GEOLOGY OF THE CEDAR MOUNTAINS TOOELE COUNTY, UTAH By R o b e r t E u g e n e M a u r er A t h e s i s s u b m i t t e d t o t h e f a c u l t y of t h e U n i v e r s i ty o f U t a h I n p a r t i a l f u l f i l l m e n t of t h e r e q u i r e m e n ts f o r t h e d e g r e e of D o c t o r of P h i l o s o p hy D e p a r t m e n t of G e o l o g i c al a n d G e o p h y s i c a l S c i e n c es U n i v e r s i t y of Utah J u n e , 1970 T h i s T h e s i s f o r t he D o c t o r of P h i l o s o p h y D e g r ee By R o b e r t E. M a u r er h a s b e e n a p p r o v ed J a n u a r y , 1970 'pec C h a i r m a n , S u p e r v l & o i * ^ C o m m i t t ee R e a d e r , S u p e r v i s o r y C o m m i t t e e "7 is R e a d e r , S u p e r v i s o r y - C o m m i t t ee R e a d e r , S u p e r v i s o r y C o m m i t t ee R e a d e r , S u p e r v i s o r y C o m m i t t e e ~ PLEASE NOTE: S e v e r a l pages c o n t a i n colored i l l u s t r a t i o n s . Filmed in the b e s t p o s s i b l e way. UNIVERSITY MICROFILMS. ACKNOWLEDGMENTS The w r i t e r w i s h e s t o e x p r e s s h i s s i n c e r e g r a t i t u d e to D r . D a n i e l J . J o n e s f o r h e l p f u l comments r e g a r d i n g p r o b l e ms o f t h e f i e l d w o r k , f o r c r i t i c a l r e a d i n g and s u g g e s t i o n s in p r e p a r a t i o n of t h e m a n u s c r i p t , and f o r many v a l u a b le s u g g e s t i o n s d u r i n g t h e c o u r s e of t h e s t u d y . Dr. W. Lee S t o k e s i d e n t i f i e d most of t h e b r a c h i o p o d s i n a d d i t i o n to c r i t i c i z i n g t h e m a n u s c r i p t . P r o f e s s o r s A. J . E a r d l e y, Max P. E r i c k s o n , and R. E. M a r s e l l r e a d t h e m a n u s c r i p t and o f f e r e d v a l u a b l e c r i t i c i s m. D r . G r a n t S t e e l o f f e r e d h e l p f u l a d v i c e c o n c e r n i n g t he r e c o g n i t i o n of u n i t s of t h e P a r k C i t y and P h o s p h o r i a Form­a t i o n and I d e n t i f i e d t h e m a j o r p o r t i o n of t h e f u s u l i n i d s. G e o r g e Herman g a v e v a l u a b l e a s s i s t a n c e i n s e c u r i n g i d e n t i ­f i c a t i o n of f u s u l i n i d s and i d e n t i f i e d o t h e r f o r a m i n i f e ra t h a t t h e w r i t e r c o l l e c t e d from t h e l o w e r G r e a t B l u e Form­a t i o n . Dr. A u r e l e L a R o c q u e k i n d l y i d e n t i f i e d g a s t r o p o ds c o l l e c t e d by t h e w r i t e r f r om t h e N o r t h Horn ( ? ) and t he " T e r t i a r y unnamed f o r m a t i o n ". The w r i t e r t h a n k s R a l p h J . R o b e r t s f o r a n u m b e r of h e l p f u l s u g g e s t i o n s d u r i n g s e v e r a l v i s i t s t o t h e Cedar M o u n t a i n s . i i i A n u m b e r of t h e w r i t e r ' s s t u d e n t s a t V / e s t m l n s t e r C o l ­l e g e and o t h e r f r i e n d s g a v e a s s i s t a n c e i n m e a s u r i n g s e c t i o n s. T h i s h e l p i s g r a t e f u l l y a c k n o w l e d g e d from t h e f o l l o w i ng i n d i v i d u a l s : Don F o l l o w s , Duane F u l l e r , Newton G a s k i l, L a r r y J a m e s , and J o h n Ewbank. G a i l S c h m a r d e b e c k r e n d e r ed a g r e a t s e r v i c e i n h e l p i n g as f i e l d a s s i s t a n t d u r i n g t he summer of 1 9 5 8 . Reed L a P r a y a s s i s t e d t h e w r i t e r i n t he f i e l d on s e v e r a l o c c a s i o n s , p r e p a r e d a n u m b e r of t h i n - s e c t i o n s , and h e l p e d i n o t h e r w a y s. V a r i o u s a u t h o r i t i e s and p e r s o n n e l a t t h e U. S. Army Dugway P r o v i n g G r o u n d s h a v e b e e n v e r y g e n e r o u s and h e l p f ul i n p r o v i d i n g a c c e s s and a s s i s t a n c e so t h a t t h e w r i t e r c o u ld v i s i t c e r t a i n a r e a s w i t h i n t h e p r o v i n g g r o u n d s t o make g e o l o g i c a l o b s e r v a t i o n s n e c e s s a r y t o t h i s s t u d y. G u l f and S h e l l o i l c o m p a n i e s w e r e k i n d e n o u g h t o l e nd a e r i a l p h o t o s t o t h e w r i t e r f o r t h e f i e l d m a p p i n g. F i n a l l y , t h e w r i t e r o f f e r s d e e p e s t g r a t i t u d e t o h is w i f e , E l a i n e , who h a s done t h e d r a f t i n g , a c o n s i d e r a b le a m o u n t of t y p i n g , o f f e r e d s u g g e s t i o n s and a i d of g r e at v a l u e i n t h e d r a f t i n g and o t h e r t e c h n i c a l a s p e c t s of a s s e m b ­l i n g t h e t h e s i s and who h a s b e e n p a t i e n t f o r a l o n g t i m e. i v ABSTRACT The C e d a r M o u n t a i n s a r e i n n o r t h w e s t e r n U t a h i n t he n o r t h e a s t e r n p a r t of t h e B a s i n and Range P r o v i n c e . The a r e a mapped I s a b o u t 60 m i l e s w e s t of S a l t Lake C i t y , Utah a n d I n c l u d e s an a r e a of a b o u t 550 s q u a r e m i l e s. S e d i m e n t a r y s t r a t a e x p o s e d i n t h e C e d a r M o u n t a i ns r a n g e i n a g e f r om L a t e M i s s i s s i p p i a n t o R e c e n t . No M e s o z o ic b e d s o u t c r o p i n t h e C e d a r M o u n t a i n s . The s e d i m e n t a r y r o c ks h a v e b e e n d i v i d e d i n t o 10 d i f f e r e n t f o r m a t i o n s w i t h a t o t a l t h i c k n e s s i n e x c e s s of 2 0 , 7 7 5 f e e t. The P a l e o z o i c s t r a t a h a v e a t h i c k n e s s of a b o u t 1 9 , 7 00 f e e t d i s t r i b u t e d amont t h e s y s t e m s as f o l l o w s : M i s s i s s i p p i an 5 7 9 0 + , P e n n s y l v a n i a n 5 6 9 5 , P e r m i a n 8 1 9 0 + . T h i c k n e s s , in f e e t , of t h e s e r i e s of P e r m o - P e n n s y l v a n i a n age a r e : G u a d a - l u p i a n , 652+; ^ e o n a r d i a n , 4 7 7 2 ; W o l f c a m p i a n , 2 7 7 2 ; V i r g i l i a n, 2 3 9 0 ; M I s s o u r i a n ( ? ) 4 8 7 ; Des M o i n e s i a n , 1 4 7 3 ; M o r r o w a n - A t o k a n , 1 3 4 5 . Q u a r t z o s e s a n d s t o n e , medium and d a r k g r ay l i m e s t o n e , b l a c k s h a l e , and q u a r t z i t e a r e t y p i c a l of t he M i s s i s s i p p i a n s t r a t a . O v e r l y i n g b e d s of t h e O q u i r r h and " P e r m i a n unnamed f o r m a t i o n " a r e c o m p o s e d of s a n d y , c h e r t y, a n d b i o c l a s t i c l i m e s t o n e s , s a n d s t o n e s and q u a r t z i t e s . Mas­s i v e l i m e s t o n e , d a r k g r a y , t h i n - a n d m e d i u m - b e d d e d d o l o s t o n e, c h e r t and p h o s p h a t e b e d s s u c c e e d e d upward by y e l l o w - b r o wn v a n d p i n k l i m e s t o n e c o n s t i t u t e t h e h i g h e s t u n i t s of t h e P a l eo z o i c s u c c e s s i o n. A b a s a l r e d c o n g l o m e r a t e and a s a n d y , t u f f a c e o u s f o r m ­a t i o n c o n s t i t u t e t h e e a r l y T e r t i a r y s e d i m e n t a r y r o c k s and h a v e an e s t i m a t e d minimum t h i c k n e s s of 1 , 1 0 0 f e e t. U n c o n s o l i d a t e d d e p o s i t s of a l l u v i a l g r a v e l , l a c u s t r i ne c l a y and s a n d and g r a v e l , and e o l i a n s a n d c o m p r i s e t he l a t e s t T e r t i a r y and Q u a t e r n a r y m a t e r i a l s. F o l d s , domal u p l i f t s , t h r u s t f a u l t s , h i g h - a n g le r e v e r s e f a u l t s , s t r i k e - s l i p f a u l t s , t r a n s v e r s e f a u l t s and b l o c k - f a u l t s c o n s t i t u t e t h e more i m p o r t a n t s t r u c t u r e s r e c o g ­n i z e d i n t h e C e d a r M o u n t a i n s . F o l d s , t h r u s t f a u l t s , h i g h - a n g l e r e v e r s e f a u l t s and a s t r i k e - s l i p f a u l t d e v e l o p e d d a r ­i n g t h e L a r a m i d e O r o g e n y . Domal u p l i f t s a r e p r o b a b l y r e l a t ­e d t o i n t r u s i v e a c t i v i t y and c a n o n l y be d a t e d as y o u n g er t h a n f o l d i n g of E a r l y L a r a m i d e a g e . T r a n s v e r s e and b l o ck f a u l t s a r e f e a t u r e s y o u n g e r t h a n e a r l y T e r t i a r y b a s a l t ic a n d e s i t e e x t r u s i v e s. R h y o l i t e s , of p r o b a b l e i n t r u s i v e o r i g i n , a b a s a l t ic a n d e s i t e s e r i e s and b a s a l t c o m p r i s e t h e i g n e o u s r o c k s of t he C e d a r M o u n t a i n s . The r h y o l i t e and t h e b a s a l t i c a n d e s i te s e r i e s a r e c o n s i d e r e d t o be of e a r l y T e r t i a r y age w h i l e t he b a s a l t i s p r o b a b l y of M i o c e n e or P l i o c e n e a g e . P r o b a b le s o u r c e a r e a s f o r p a r t o r a l l of t h e e x t r u s i v e r o c k s a re l o c a t e d w i t h i n t h e a r e a of t h e i n v e s t i g a t i o n. V e i n d e p o s i t s of a r a g o n i t e , s a n d and g r a v e l , and g r o u n d w a t e r h a v e b e e n of e c o n o m i c i m p o r t a n c e i n t h e Cedar M o u n t a i n s . Thin b e d s of p h o s p h a t e r o c k i n t h e w e s t - c e n t r al C e d a r M o u n t a i n s w i l l n o t be of e c o n o m i c i m p o r t a n c e i n t he f o r e s e e a b l e f u t u r e. v i i TABLE OF CONTENTS P a g e INTRODUCTION 1 P u r p o s e of t h e s t u d y 1 L o c a t i o n and A c c e s s i b i l i t y 1 P r e v i o u s G e o l o g i c I n v e s t i g a t i o n s 3 F i e l d Work 5 The G e o l o g i c Map 6 STRATIGRAPHY 7 G e n e r a l S t a t e m e n t 7 M i s s i s s i p p i a n S y s t e m 11 Humbug F o r m a t i o n 11 G r e a t B l u e F o r m a t i o n 16 M a n n i n g Canyon F o r m a t i o n 25 P e n n s y l v a n i a n and P e r m i a n S y s t e m s 29 O q u i r r h F o r m a t i o n 29 U n i t 1 33 U n i t 2 39 U n i t 3 42 U n i t 4 57 U n i t 5 64 " P e r m i a n Unnamed F o r m a t i o n " 81 P a r k C i t y , P h o s p h o r i a , and G e r s t e r F o r m a t i o n s 92 P a r k C i t y F o r m a t i o n 93 G r a n d e u r Member 93 P h o s p h o r i a F o r m a t i o n 97 Meade P e a k Member 97 G e r s t e r F o r m a t i o n 101 T e r t i a r y S y s t e m 107 N o r t h Horn ( ? ) F o r m a t i o n 107 " T e r t i a r y Unnamed F o r m a t i o n " 110 Q u a t e r n a r y S y s t e m 116 v i i i P a g e STRUCTURAL GEOLOGY 121 T e c t o n i c S e t t i n g 121 L o c a l S t r u c t u r e s 124 F o l d s 124 T h r u s t F a u l t s 131 H i g h - A n g l e R e v e r s e F a u l t s 133 S t r i k e - s l i p F a u l t s 135 T r a n s v e r s e F a u l t s 136 N o r m a l F a u l t s 137 J o i n t s 138 IGNEOUS ROCKS l4l I n t r o d u c t i o n l4l R h y o l i t e 143 B a s a l t i c A n d e s i t e S e r i e s 146 Lower B a s a l t i c A n d e s i t e F l o w s and 147 A g g l o m e r a t e s M i d d l e T u f f U n i t 149 U p p e r B a s a l t i c A n d e s i t e 150 B a s a l t 155 GEOLOGIC HISTORY 158 P a l e o z o i c E r a 158 M e s o z o i c E r a 164 C e n o z o i c E r a 167 ECONOMIC GEOLOGY 171 I n t r o d u c t i o n 171 A r a g o n i t e 171 S a n d and G r a v e l 172 G r o u n d W a t e r 173 P h o s p h a t e Rock 176 REFERENCES CITED 178 i x ILLUSTRATIONS F i g u r e s Page 1 Index map t o t h e C e d a r M o u n t a i n s , T o o e l e 2 C o u n t y , Utah 2 P h o t o g r a p h of Upper Humbug and Lower G r e a t 15 B l u e F o r m a t i o n s i n t h e s o u t h e r n Cedar M o u n t a i n s . 3 P h o t o g r a p h t a k e n n e a r C o c h r a n S p r i n g w h i c h 35 s h o w s a t y p i c a l e x p o s u r e of U n i t 1 and U n i t 2 of t h e O q u i r r h F o r m a t i o n. 4 P h o t o g r a p h of U n i t 2 of t h e O q u i r r h F o r m a t i o n 35 s h o w i n g t h i c k b e d d i n g and l e d g e - f o r m i ng c h a r a c t e r . 5 Diagram p o r t r a y i n g t h e r e l a t i v e a g e s of f o s s i l 43 c o l l e c t i o n s from t h e O q u i r r h F o r m a t i o n i n t he C e d a r M o u n t a i n s. 6 P h o t o g r a p h of U n i t 3 o f t h e O q u i r r h F o r m - 45 a t i o n e a s t of Low r a i l r o a d s i d i n g s h o w i ng i t s " c l i f f - a n d - s l o p e " e r o s i o n a l c h a r a c t e r. 7 P h o t o g r a p h s h o w i n g c r o s s - b e d d i n g I n a c l i f f - 45 f o r m i n g l i m e s t o n e of U n i t 3 of t h e O q u i r rh F o r m a t i o n . 8 P h o t o g r a p h s h o w i n g s l u m p s t r u c t u r e i n a 48 c l i f f - f o r m l n g l i m e s t o n e of U n i t 3 of t he O q u i r r h F o r m a t i o n. 9 P h o t o g r a p h s h o w i n g c h e r t a g g r e g a t e s i n a 48 c l i f f - f o r m i n g l i m e s t o n e of t h e O q u i r rh F o r m a t i o n . 10 P h o t o g r a p h of "Worm T r a i l " m a r k i n g s c h a r a c - 60 t e r i s t i c of U n i t 4 a n d 5 of t h e O q u i r rh F o r m a t i o n . 1 1 P h o t o g r a p h s h o w i n g t h e " P e r m i a n unnamed 95 f o r m a t i o n " a n d t h e G r a n d e u r Member of t he P a r k C i t y F o r m a t i o n. x ILLUSTRATIONS - C o n t i n u ed F i g u r e s Page 12 P h o t o g r a p h s h o w i n g " T e r t i a r y unnamed f o r m - 111 a t i o n " i n e a s t H a s t i n g s Canyon o v e r l a i n by b a s a l t c a p r o c k. 13 P h o t o g r a p h of P l e i s t o c e n e l a k e c l a y b e d s 119 a b o u t 5 m i l e s s o u t h of Cane S p r i n g s i n t he s o u t h e r n C e d a r M o u n t a i n s. 14 P h o t o g r a p h of l a k e c l a y and b e a c h g r a v e l 119 a s s o c i a t e d w i t h t h e P r o v o l e v e l a b o u t 2 m i l e s n o r t h of Wig M o u n t a i n. 1 5 P h o t o g r a p h s h o w i n g l a g g r a v e l a b o u t 2 m i l e s 120 n o r t h of Wig M o u n t a i n. 16 P h o t o g r a p h of an a c t i v e d u n e f i e l d a l o n g t h e 120 s o u t h w e s t f l a n k of t h e C e d a r M o u n t a i n s. 17 G e n e r a l i z e d map of s t r u c t u r e i n t h e C e d a r 140 M o u n t a i n s . 18 P h o t o g r a p h of W h i t e Rock ( c e n t e r ) , p a r t of a 144 r h y o l i t e s t o c k . Tabby P e a k i n t h e d i s t a n ce i m m e d i a t e l y n o r t h of W h i t e Rock. 19 P h o t o g r a p h s h o w i n g t h e t h r e e u n i t s of t h e 144 b a s a l t i c a n d e s i t e s e r i e s a t Cane S p r i n g s. 20 P h o t o g r a p h s h o w i n g Tabby P e a k , c e n t e r s k y l i n e , 153 l o o k i n g e a s t w a r d i n t o R y d a l c h C a n y o n. 2 1 P h o t o g r a p h of Tabby P e a k s h o w i n g c o n c e n t r i c 153 a r r a n g e m e n t of a n d e s i t e c o l u m n s . View is t o w a r d t h e s o u t h. 22 P h o t o g r a p h s h o w i n g M o r o n i ' s P o s t p i l e as s e e n 154 f r om t h e e a s t . B o n n e v i l l e Lake l e v e l n e ar t h e summit a t an e l e v a t i o n of a b o u t 5120 f e e t. 23 P h o t o g r a p h s h o w i n g c o l u m n a r j o i n t i n g of 154 M o r o n i ' s P o s t p i l e. 24 P h o t o g r a p h s h o w i n g an a n d e s i t e d i k e i n S i x 157 H o r s e Canyon w h i c h e x h i b i t s h o r i z o n t a l, c o l u m n a r j o i n t i n g. x i ILLUSTRATIONS - C o n t i n u ed T a b l e s Page 1 Rocks of t h e C e d a r M o u n t a i n s A r e a 9 2 E s t i m a t e d A r e a s of O u t c r o p of B e d r o c k U n i t s 117 i n t h e C e d a r M o u n t a i n s. 3 Symbols u s e d i n C o l u m n a r S e c t i o n s 184 P l a t e s l a G e o l o g i c Map of t h e N o r t h e r n C e d a r Moun- In p o c k et t a i n s , T o o e l e C o u n t y , Utah l b G e o l o g i c Map of t h e S o u t h e r n C e d a r Moun- In p o c k et t a i n s , T o o e l e C o u n t y , Utah I I S t r u c t u r e c r o s s - s e c t i o n s of t h e C e d a r In p o c k et M o u n t a i n s . Following P a g e: I I I Columnar S e c t i o n of P a r t of t h e Humbug 15 F o r m a t i o n N o r t h of Wide H o l l o w. IV Columnar S e c t i o n of P a r t of t h e G r e a t B l u e 24 F o r m a t i o n E a s t of C o c h r a n S p r i n g. V Columnar S e c t i o n of t h e O q u i r r h F o r m a t i o n 80 w e s t of C o c h r a n S p r i n g. VI Columnar S e c t i o n of t h e O q u i r r h F o r m a t i o n 80 U n i t s 4 a n d 5 ( i n c o m p l e t e ) Near H a s t i n gs P e a k . V I I C o r r e l a t i o n of t h e O q u i r r h F o r m a t i o n i n P a r t 80 o f N o r t h w e s t e r n U t a h. V I I I Columnar S e c t i o n of t h e " P e r m i a n Unnamed 91 F o r m a t i o n " E x p o s e d B e t w e e n R y d a l c h P a s s and U. S. C o a s t and G e o d e t i c S u r v e y C e d ar T r i a n g u l a t i o n S t a t i o n. IX Columnar S e c t i o n of P a r t s of t h e P a r k C i t y , 106 P h o s p h o r i a , and G e r s t e r F o r m a t i o n s West of S u l f u r S p r i n g. x i i INTRODUCTION PURPOSE OP THE STUDY The p u r p o s e of t h e s t u d y was t o d i s t i n g u i s h t h e v a r i o us s t r a t i g r a p h i c and s t r u c t u r a l e l e m e n t s w i t h i n t h e Cedar M o u n t a i n s , t o d e t e r m i n e t h e i n t e r r e l a t i o n s of t h e s e e l e m e n t s, a n d t o c o r r e l a t e t h e i r d e v e l o p m e n t w i t h t h a t of t h e s u r ­r o u n d i n g r e g i o n. LOCATION AND ACCESSIBILITY The C e d a r M o u n t a i n s Range i s a b o u t 60 m i l e s w e s t of S a l t Lake C i t y , U t a h m a i n l y s o u t h of U. S. Highway 40 and A l t e r n a t e 50. (Pig. 1 ) . S e c o n d a r y r o a d s e n t e r i n g U. S. H i g h w a y 40 p r o v i d e t h e e a s i e s t a c c e s s t o t h e n o r t h e r n p a r t of t h e r a n g e w h i l e t h e c e n t r a l and s o u t h e r n s e c t o r s a r e r e a c h ed e a s i e s t from t h e Dugway P r o v i n g G r o u n d s r o a d w h i c h j o i ns U. S. Highway 40 a t T i m p i e J u n c t i o n . One c a n r e a c h t h e f o o t ­h i l l s of any d e s i r e d p a r t of t h e r a n g e by m e a n s of d i r t r o a d s. A s m a l l f o u r - w h e e l - d r i v e v e h i c l e can be u s e d i n t h e h i g h er f o o t h i l l s and p e r h a p s a l i t t l e h i g h e r i n some l o c a l i t i e s but m o s t of t h e a r e a s of b e d r o c k e x p o s u r e must be r e a c h e d by m e a n s o t h e r t h a n f o u r - w h e e l v e h i c l e s . A p i c k u p t r u c k o r f o u r - w h e e l - d r i v e v e h i c l e p r o v i d e s t h e b e s t t r a n s p o r t a t i o n i n t h is a r e a f o r any o f f - h i g h w a y d r i v i n g . Even r o a d s i n t h e l o w l a nd - 2 - F i g . 1 - Index map t o the Cedar Mountains, Tooele County, Utah - 3 - t h a t a p p e a r t o be e a s i l y p a s s a b l e h a v e o c c a s i o n a l d e e p r u ts a n d s o f t s a n d y s p o t s . Washouts from f l a s h - f l o o d s , e s p e c i a l ly i n l a t e summer, can make t h e l o w e r r o a d s v e r y d i f f i c u l t to t r a v e r s e . I t i s n e c e s s a r y t o g e t p e r m i s s i o n t o v i s i t a r e a s w i t h ­i n t h e Dugway P r o v i n g G r o u n d s a t t h e h e a d q u a r t e r s i n Dugway, U t a h . The Army p r o v i d e s an e s c o r t f o r a v i s i t o r d o i n g f i e ld w o r k i n t h e a r e a . Also i t i s a d v i s a b l e t o c a l l a t l e a s t a week i n a d v a n c e t o a r r a n g e any v i s i t t o t h e P r o v i n g G r o u n ds t o l e a r n w h e t h e r t h e a r e a of i n t e r e s t w i l l be a c c e s s i b l e at t h e t i m e t h e t r i p i s p l a n n e d. The C e d a r M o u n t a i n s Range i s a b o u t 45 m i l e s l o n g and 10 t o 12 m i l e s w i d e , t h e w i d t h e s t i m a t e d on t h e b a s i s of b e d r o c k o u t c r o p a r e a . It e x t e n d s from T o w n s h i p 2 N o r th i n t o T o w n s h i p 7 S o u t h ( S a l t Lake C i t y Base L i n e ) and from R a n g e 8 i n t o 11 W e s t . The a r e a i n w h i c h s u r f a c e f e a t u r es h a v e b e e n mapped i s a b o u t 550 s q u a r e m i l e s. PREVIOUS GEOLOGIC INVESTIGATIONS The e a r l i e s t r e c o r d of g e o l o g i c a l o b s e r v a t i o n s i n t he C e d a r M o u n t a i n s i s r e c o r d e d i n t h e W h e e l e r G e o g r a p h i c al a n d G e o l o g i c a l E x p l o r a t i o n s and S u r v e y s West of t h e 1 0 0 th M e r i d i a n ( H o w e l l , 1 8 7 5 , p . 2 3 9 - 4 0 ) . Howell r e c o g n i z e d t he a n t i c l i n a l n a t u r e of t h e r a n g e a s h o r t d i s t a n c e s o u t h of - 4 - S u l p h u r S p r i n g . He a l s o a p p e a r s t o h a v e r e c o g n i z e d t h e en e c h e l o n a n t i c l i n e d e v e l o p e d i n t h e G r e a t B l u e F o r m a t i o n e a st o f t h e C o c h r a n V a l l e y a n t i c l i n e i n t h e s o u t h e r n C e d a r Moun­t a i n s . K i n g ( 1 8 7 7 , p . 4 6 2 - 6 5 ) d e s c r i b e d t h e u n u s u a l , g r a y i s h - w h i t e , r o u n d e d h i l l s o u t h of C o c h r a n S p r i n g , W h i t e R o c k , as q u a r t z i f e r o u s t r a c h y t e and a l s o r e c o g n i z e d t h a t t h e r e d d i sh v o l c a n i c s i n t h a t a r e a had b e e n e m p l a c e d o v e r a s u r f a c e of some r e l i e f . He a l s o commented on t h e b a s a l t i c l a v a I n t he v i c i n i t y of H a s t i n g s C a n y o n . He d i d n o t r e c o g n i z e t h e i n t r a - r a n g e f a u l t i n g n o r t h of H a s t i n g s C a n y o n , h o w e v e r , and s u r ­m i s e d f r om t h e l i m i t e d e x p o s u r e s he was a b l e t o o b s e r v e t h at t h e s t r u c t u r e n o r t h of H a s t i n g s Canyon c o n s t i t u t e d a s y n c l i ne p l u n g i n g n o r t h w a r d. Z i r k e l ( 1 8 7 7 , v o l . 6) s t u d i e d t h e i g n e o u s r o c k s c o l ­l e c t e d as p a r t of t h e F o r t i e t h P a r a l l e l S u r v e y . He d e s ­c r i b e d a t h i n s e c t i o n of t h e w h i t e r o c k r h y o l i t e and one of r e d d i s h , a n d e s i t i c f l o w - r o c k w e s t of W h i t e Rock I n c o n s i d e r ­a b l e d e t a i l. W o o l l e y ( 1 9 1 2 ) s t u d i e d a s m a l l a r e a I n t h e v i c i n i t y of t h e U t a h C a l c i u m C o m p a n y ' s a r a g o n i t e m i n e i n West H a s t i n gs C a n y o n . He mapped a t o t a l of f i v e a r a g o n i t e v e i n s i n t he a r e a and d i s c u s s e d t h e p r o b a b l e o r i g i n of t h e d e p o s i t. I v e s , ( 1 9 4 6 ) d e s c r i b e d t h e v o l c a n i c n e c k known as - 5 - M o r o n i ' s P o s t P i l e in t h e s o u t h w e s t e r n C e d a r M o u n t a i ns a b o u t 3 m i l e s w e s t of Cane S p r i n g. J o h n s o n and Cook ( 1 9 5 7 ) r e p o r t e d t h e r e s u l t s of a r e g i o n a l g r a v i t y s u r v e y of an a r e a w h i c h i n c l u d e d t he s o u t h e r n p a r t of t h e C e d a r M o u n t a i n s . About 60 g r a v i ty s t a t i o n s w e r e o c c u p i e d i n o r i m m e d i a t e l y a d j a c e n t t o t he m o u n t a i n r a n g e . They f o u n d e v i d e n c e of a m a j o r B a s i n and R a n g e f a u l t zone a l o n g t h e s o u t h e a s t e r n m a r g i n of t he C e d a r M o u n t a i n s. B i s s e l l ( i 9 6 0 , p . 1 4 2 7 ) m e a s u r e d and d e s c r i b e d a c o m p o s i t e s e c t i o n of t h e s e d i m e n t a r y u n i t s e x p o s e d i n t he C e d a r M o u n t a i n s a s p a r t of a c o m p r e h e n s i v e s t u d y of e a s t e rn G r e a t B a s i n P e r m o - P e n n s y l v a n i a n s t r a t a . He h a s r e f e r r ed t o t h i s C e d a r M o u n t a i n s s e c t i o n i n more r e c e n t d i s c u s s i o ns ( 1 9 6 2 , 1964) of P e r m o - P e n n s y l v a n i a n g e o l o g y of t h e G r e at B a s i n . FIELD WORK The F i e l d work was b e g u n d u r i n g t h e l a t t e r p a r t of t he summer of 1 9 5 6 . Most of t h e p r o j e c t was c o m p l e t e d d u r i ng t h e 1 9 5 7 . 1 9 5 8 , 1 9 5 9 , I 9 6 0 f i e l d s e a s o n s b u t o c c a s i o n al v i s i t s w e r e made a f t e r i 9 6 0 and c o n t i n u e d u n t i l A u g u s t 2 4, 1 9 6 6 when t h e w r i t e r made h i s f i n a l o b s e r v a t i o n s i n t he C e d a r M o u n t a i n s. D u r i n g t h e 1957 t h r o u g h i 9 6 0 f i e l d s e a s o n s t h e w r i t er - 6 - u s u a l l y camped i n t h e f i e l d f o u r d a y s p e r w e e k . Most of t he t r a v e r s e s i n t o t h e m o u n t a i n o u s a r e a s had t o be made on f o o t. The m a p p i n g was a l l done on a i r p h o t o s a t an a p p r o x i m a te s c a l e of 1 : 2 0 , 0 0 0 . The O q u i r r h F o r m a t i o n s e c t i o n m e a s u r ed w e s t f r om C o c h r a n S p r i n g and t h e P a r k C i t y - P h o s p h o r i a - G e r s t e r F o r m a t i o n s e c t i o n s w e r e m e a s u r e d w i t h a f i v e - f o ot J a c o b s t a f f and B r u n t o n C o m p a s s . All o t h e r m e a s u r e d s e c ­t i o n s w e r e made w i t h a s t e e l t a p e and B r u n t o n C o m p a s s. THE GEOLOGIC MAP An a c e t a t e f i l m b a s e f o r t h e g e o l o g i c map of t he N o r t h e r n C e d a r M o u n t a i n s was p r e p a r e d by means of a r a d i al l i n e a s s e m b l y u s i n g c o n t r o l p o i n t s s e l e c t e d on t h e a i r p h o t o s. G e o l o g i c d a t a w e r e t r a n s f e r r e d t o t h e b a s e u s i n g an o p t i c al p l o t t i n g d e v i c e. The b a s e f o r t h e g e o l o g i c map of t h e s o u t h e r n Cedar M o u n t a i n s was d r a f t e d on a c e t a t e f i l m b a s e u s i n g t o p o g r a p h ic q u a d r a n g l e maps p u b l i s h e d by t h e U n i t e d S t a t e s G e o l o g i c al S u r v e y and g e o l o g i c d a t a was t r a n s f e r r e d from t h e p h o t o ­g r a p h s m a n u a l l y u s i n g t o p o g r a p h i c and c u l t u r a l f e a t u r es a s a g u i d e i n p l o t t i n g. STATIGRAPHY - 7 - G e n e r a l S t a t e m e nt R o c k s of M i s s i s s i p p i a n , P e n n s y l v a n i a n , P e r m i a n , and T e r t i a r y a g e and Q u a t e r n a r y s e d i m e n t s a r e e x p o s e d i n t he C e d a r M o u n t a i n s. A p p r o x i m a t e l y 1 9 , 7 0 0 f e e t of P a l e o z o i c s e d i m e n t a ry r o c k s d i v i s i b l e i n t o 8 d i f f e r e n t f o r m a t i o n s o u t c r o p w i t h in t h e C e d a r M o u n t a i n s . Q u a r t z o s e s a n d s t o n e , medium and d a rk g r a y l i m e s t o n e , and b l a c k s h a l e and q u a r t z i t e a r e t y p i c al o f t h e M i s s i s s i p p i a n s t r a t a . O v e r l y i n g b e d s of t h e O q u i r rh a n d " P e r m i a n unnamed f o r m a t i o n " a r e composed of s a n d y , c h e r t y, a n d b i o c l a s t i c l i m e s t o n e , s a n d s t o n e and q u a r t z i t e . M a s s i ve l i m e s t o n e , d a r k g r a y d o l o s t o n e , c h e r t , and p h o s p h a t i c b e ds s u c c e e d e d u p w a r d by t a n and p i n k l i m e s t o n e c o n s t i t u t e t he h i g h e s t u n i t s of t h e P a l e o z o i c s u c c e s s i o n. No M e s o z o i c s t r a t a o u t c r o p i n t h e C e d a r M o u n t a i n s. A b a s a l , r e d c o n g l o m e r a t e and a s a n d y , t u f f a c e o us f o r m a t i o n c o n t a i n i n g f o s s i l i f e r o u s , w h i t e , l a c u s t r i ne l i m e s t o n e c o n s t i t u t e t h e e a r l y T e r t i a r y s e d i m e n t a r y r o c ks i n t h e C e d a r M o u n t a i n s . The minimum e x p o s e d t h i c k n e ss o f t h e s e u n i t s i s a b o u t 1 , 1 0 0 f e e t . A minimum of a b o u t 800 t o 900 f e e t of e a r l y T e r t i a r y b a s a l t i c a n d e s i t i c v o l c a n ic s t r a t a o u t c r o p i n t h e s o u t h e r n C e d a r M o u n t a i n s. Some of t h e a l l u v i a l s a n d and g r a v e l d e p o s i t s w h i ch - 8 - c o v e r t h e b e d r o c k a l o n g t h e f l a n k s of t h e n o r t h e r n Cedar M o u n t a i n s a r e p r o b a b l y of l a t e T e r t i a r y a g e . The b a s a lt i n t h e H a s t i n g s Canyon a r e a i s a l s o c o n s i d e r e d t o be l a te T e r t i a r y i n a g e. C l a y and s i l t d e p o s i t s of P l e i s t o c e n e Lake B o n n e ­v i l l e o u t c r o p s o u t h of U. S. Highway 40 w h e r e I t p a s s es a r o u n d t h e n o r t h e r n end of t h e C e d a r M o u n t a i n s . G r a v el d e p o s i t s of c o n s i d e r a b l e m a g n i t u d e a r e l o c a t e d a t t h e n o r th e n d and a l o n g t h e s o u t h e a s t m a r g i n of t h e r a n g e. R e c e n t s a n d d u n e s mask a l a r g e a r e a u n d e r l a i n by T e r t i a r y v o l c a n i c s and P a l e o z o i c s t r a t a i n t h e s o u t h e a s t ­e r n C e d a r M o u n t a i n s from W h i t e Rock t o Dugway. - 9 - T a b l e 1. - Rocks of t h e C e d a r M o u n t a i n s A r e a. SYSTEM SERIES FORMATION THICKNESS ( F e e t ) Q u a t e r n a r y P l e i s t o c e n e U n c o n s o l i d a t e d ? t o R e c e n t d e p o s i ts T e r t i a r y M i o c e n e o r B a s a l t 50-100 P l i o c e n e B a s a l t i c a n d e ­s i t e s e r i es U p p e r m b r . 500+ E a r l y T e r - Middle m b r . 100-150 t i a r y Lower m b r . 250-300 R h y o l i t e ( i n t r u s i v e ) , P a l o e c e n e " T e r t i a r y unnamed f m . " 300+ o r E o c e n e North H o r n ( ? ) F m . 800+ T o t a l T e r t i a r y 2.150+ G e r s t e r Fm. *511+ G u a d a l u p i a n ( 6 5 2 + f t) P e r m i a n Phosphoria Fm. *l4l Meade P e a k Mbr. P a r k C i t y Fm. *4l9 G r a n d e u r Mbr. " P e r m i a n unnamed f m . " *3953 L e o n a r d i a n ( 4 7 7 2 f t ) O q u i r r h Fm. W o l f c a m p i a n ( 2 7 7 2 f t) U n i t 5 *1935+-2750 * 3 4 0+ U n i t 4 »2762-3000 T o t a l P e r m i a n 8,190 • 1 0 - SYSTEM P e n n s y l - v a n i a n SERIES V i r g i l i a n ( 2 3 9 0 f t) M i s s o u r i a n ( 4 8 7 f t) Des Moines-i a n ( 1 4 7 3 f t) M o r r o w a n - A t o k a n ( 1 3 4 5 f t) M i s s i s - C h e s t e r i an s i p p i a n FORMATION U n i t 3 U n i t 2 U n i t 1 T o t a l P e n n s y l v a n l an M a n n i n g Canyon Fm. G r e a t B l u e Fm. THICKNESS ( F e e t ) * 2 5 5 6 - 3 0 0 0 + * 7 1 5 - 1 4 0 0 •434 5 , 6 9 5 1 5 0 0 - 2 0 0 0 * 2 4 4 l + M e r a m e c i a n Humbug Fm. T o t a l M i s s i s s i p p i an » 1 0 l 4 + 5 , 7 9 0 E s t i m a t e d t h i c k n e s s of s e d i m e n t a r y r o c k s 20,775+ E s t i m a t e d t h i c k n e s s of v o l c a n i c r o c k s 1,050+ * F o r m a t i o n t h i c k n e s s e s m e a s u r e d i n t h e f i e l d. M I S S I S S I P P I AN SYSTEM - 1 1 - Humbug F o r m a t i on D i s t r i b u t i o n and T h i c k n e ss The Humbug F o r m a t i o n i s e x p o s e d i n t h e s o u t h e a s t e rn C e d a r M o u n t a i n s a b o u t a m i l e e a s t of W h i t e Rock ( F i g . 2 ). O u t c r o p s o c c u r d i s c o n t i n u o u s l y a l o n g a n o r t h w e s t - t r e n d i ng b e l t a b o u t t h r e e m i l e s l o n g . The Humbug i s , i n g e n e r a l , a p o o r l y e x p o s e d u n i t w h i c h e x h i b i t s s m o o t h s l o p e s o f t en m a n t l e d w i t h i t s own t a l u s * It a p p e a r s a t t h e s u r f a ce a l o n g t h e e a s t e r n l i m b of an a n t i c l i n e c u t o b l i q u e l y on i ts w e s t e r n m a r g i n by t h e C o c h r a n S p r i n g F a u l t . The Humbug F o r m a t i o n i s b o u n d e d on t h e n o r t h , e a s t , and s o u t h by t he o v e r l y i n g G r e a t B l u e F o r m a t i o n and a l o n g i t s w e s t e r n edge b y t h e C o c h r a n S p r i n g F a u l t . The Humbug F o r m a t i o n i s l e ss r e s i s t a n t t h a n t h e G r e a t B l u e L i m e s t o n e and f o r m s low h i l ls a n d s l o p e s a l o n g i t s w e s t e r n e s c a r p m e n t . The b e s t e x p o ­s u r e s a r e j u s t n o r t h of Wide H o l l o w w h e r e an i n c o m p l e te s e c t i o n of 1 , 0 1 4 f e e t was m e a s u r e d . The b a s e of t h e f o r m a ­t i o n i s n o t e x p o s e d i n t h e C e d a r M o u n t a i n s. L i t h o l o g y The Humbug F o r m a t i o n c o n s i s t s p r e d o m i n a n t l y of f i n e - t o m e d i u m - g r a i n e d , t h i n - t o m e d i u m - b e d d e d , s a n d s t o n e s and o r t h o - q u a r t z i t e s . There a r e some medium and d a r k g r ay l i m e s t o n e b e d s i n t h e m i d d l e p a r t of t h e f o r m a t i o n . Sand g r a i n s a r e s u b - r o u n d e d and t h e s a n d s t o n e u n i t s a r e c e m e n t ed w i t h c a l c i t e . The s a n d s t o n e and q u a r t z i t e b e d s a r e u s u a l ly y e l l o w - b r o w n or g r a y on f r e s h s u r f a c e s but w e a t h e r t o s h a d es o f y e l l o w - b r o w n , b r o w n , o r a n g e , and m a r o o n. L i m e s t o n e b e d s o c c u r m a i n l y i n t h e m i d d l e p a r t of t he f o r m a t i o n and c o m p r i s e one r e l a t i v e l y r e s i s t a n t u n i t a b o ut 2 6 3 f e e t b e l o w t h e t o p of t h e f o r m a t i o n . The t h i n - to m e d i u m - b e d d e d l i m e s t o n e l a y e r s c o n t a i n n u m e r o u s t h i n h o r i ­z o n t a l b l a c k c h e r t s t r i n g e r s . C o r a l s and b r a c h i o p o d s a re common i n t h e l i m e s t o n e l a y e r s. T h r e e p r i n c i p a l l i t h o l o g i c d i v i s i o n s a r e v i s i b l e in Humbug F o r m a t i o n i n t h e C e d a r M o u n t a i n s . The l o w e r d i v ­i s i o n , b a s e n o t e x p o s e d , c o m p r i s e s t h i n - t o m e d i u m - b e d d ed s a n d s t o n e and q u a r t z i t e o v e r l a i n by a m e d l u m - t o t h i c k - b e d d e d , l e d g e - f o r m i n g q u a r t z i t e bed a b o u t 24 f e e t t h i c k. The m i d d l e d i v i s i o n c o m p r i s e s s a n d s t o n e and q u a r t z i t e b e ds w i t h o c c a s i o n a l m e d i u m - b e d d e d l a y e r s of g r a y s u b l i t h o g r a p h ic l i m e s t o n e t o p p e d by a c h e r t y l i m e s t o n e u n i t a b o u t 38 f e et t h i c k . The u p p e r d i v i s i o n i s a g a i n s a n d s t o n e and q u a r t z i te b e d s w h i c h g r a d e i n t o t h e o v e r l y i n g G r e a t B l u e F o r m a t i o n. The c o n t a c t was c h o s e n a t t h e f i r s t medium g r a y , medium-b e d d e d l i m e s t o n e c h a r a c t e r i s t i c of t h e G r e a t B l u e F o r m a t i o n. The l o w e r p a r t of t h e Humbug F o r m a t i o n I s n o t e x p o s ed I n t h e C e d a r M o u n t a i n s so t h e f o l l o w i n g m e a s u r e d s e c t i on r e p r e s e n t s a minimum t h i c k n e s s. - 1 3 - M e a s u r e d s e c t i o n of t h e Humbug F o r m a t i o n ; n o r t h s i d e of Wide H o l l o w i n s e c , 10 , T 6 S , R9W. (Township u n s u r v e y e d) C o n f o r m a b l e C o n t a ct U n i t Description Thickness T f e e t T 5 Quartzite and s a n d s t o n e , y e l l o w - b r o w n 263 a n d l i g h t - g r a y , f i n e t o m e d i u m - g r a i n e d, c a l c a r e o u s , w e a t h e r s y e l l o w - b r o w n, o r a n g e , and maroon» Some s a n d y l i m e ­s t o n e b e d s i n u p p e r 70 f e e t . F549. 4 Limestone, d a r k g r a y , t h i n - b e d d e d , 32 w e a t h e r s l i g h t - g r a y , b l a c k c h e r t in t h i n s t r i n g e r s , l e d g e. 3 Sandstone and q u a r t z i t e , y e l l o w - b r o w n , 355 t o g r a y , v e r y f i n e t o f i n e - g r a i n e d, m e d i u m - b e d d e d , c a l c a r e o u s , w e a t h e rs y e l l o w - b r o w n and g r a y ; medium g r ay a p h a n i t i c l i m e s t o n e l a y e r s n e a r t he t o p , s l o p e, 2 Quartzite, b r o w n - g r a y t o g r a y , medium- 2 4 g r a i n e d , m e d i u m - t o t h i c k - b e d d e d, w e a t h e r s y e l l o w - b r o w n and p a l e - l a v e n d a r, l e d g e o 1 Sandstone and q u a r t z i t e , y e l l o w - b r o w n , 334 m a r o o n , and p u r p l e , v e r y f i n e t o f i n e ­g r a i n e d , t h i n - t o m e d i u m - b e d d e d , b r e c - c i a t e d i n p l a c e s , some f r a g m e n t s have c o n c e n t r i c a l l y - b a n d e d c o l o r s , forms a s l o p e . B a s e c o v e r e d by Q u a t e r n a r y Minimum T h i c k n e s s 1014 Age a n d C o r r e 1 a t l on Tower and S m i t h ( l 8 9 9 s PP« 6 2 5 - 6 2 6 ) named t h e Humbug F o r m a t i o n f o r e x p o s u r e s i n t h e T I n t i c M i n i n g D i s t r i c t and - 1 4 - a s s i g n e d i t a l a t e C a r b o n i f e r o u s a g e . M o r r i s ( 1 9 5 8 , p . 20) r e p o r t e d on t h e g e n e r a l g e o l o g y of t h e E a s t T i n t i c M o u n t a i ns a n d i n d i c a t e d an u p p e r M i s s i s s i p p i a n age f o r t h e Humbug F o r m a t i o n , " s i n c e i t l i e s b e t w e e n f o r m a t i o n s t h a t a r e w e l l - d a t e d a s L a t e M i s s i s s i p p i a n , : , " F o s s i l s c o l l e c t e d from t he Humbug F o r m a t i o n i n t h e O q u i r r h M o u n t a i n s a r e c o r r e l a t ed w i t h t h e " e a r l i e r f a u n a s of t h e B r a z e r L i m e s t o n e " ( G i l l u l y, 1 9 3 2 , p , 2 8 ) , The age of t h e Humbug F o r m a t i o n I n t h e Cedar M o u n t a i n s I s i n f e r r e d t o be M e r a m e c i a n on t h e b a s i s of f o r a m i n i f e r s so d a t e d ( H e r m a n , p e r s o n a l c o m m u n i c a t i o n ) and c o l l e c t e d i n t h e l o w e r 30 f e e t of t h e G r e a t B l u e F o r m a t i on ( p . 22). The Humbug F o r m a t i o n h a s b e e n r e c o g n i z e d I n t h e L a k e ­s i d e M o u n t a i n s ( D o e l i i n g , 1 9 6 4 , p . 1 7 8 - I 8 O ) , t h e S t a n s b u ry M o u n t a i n s ( R i g b y , 1 9 5 8 , p , 45) and o t h e r n e a r b y a r e a s . The Humbug F o r m a t i o n of t h e C e d a r M o u n t a i n s i s c o r r e l a t e d w i th t h a t f o r m a t i o n i n t h e T i n t i c M i n i n g D i s t r i c t and o t h e r n e a r ­by l o c a l i t i e s on t h e b a s i s of s i m i l a r a g e , l i t h o l o g y , and s t r a t i g r a p h l c p o s i t i o n„ F i g . 2 - P h o t o g r a p h of u p p e r Humbug and l o w e r G r e at B l u e F o r m a t i o n s i n t h e s o u t h e r n Cedar M o u n t a i n s l o o k i n g e a s t. G r e a t B l u e F o r m a t i on D i s t r i b u t i o n and T h i c k n e ss T h e r e a r e a b o u t e i g h t s q u a r e m i l e s of o u t c r o p s of t he G r e a t B l u e F o r m a t i o n i n t h e s o u t h e a s t e r n C e d a r M o u n t a i ns b e t w e e n R y d a l c h Canyon and P o s t H o l l o w w h e r e i t forms a l o n g } l o w , n o r t h w e s t - t r e n d i n g r a m p a r t f a c i n g S k u l l V a l l e y. The e a s t e r n b a s e of t h e e x p o s u r e s I s c o v e r e d by a l l u v i um b u t g e o p h y s i c a l d a t a i n d i c a t e t h a t a b o r d e r f a u l t of as much a s 6 , 7 5 0 f e e l d i s p l a c e m e n t may I n t e r r u p t t h e f o r m a t io n e a r t h e m o u n t a i n f r o n t ( J o h n s o n and Cook, 1 9 5 7 , p . 5 3 ). The G r e a t B l u e F o r m a t i o n p r o t e c t s e x p o s u r e s of Humbug F o r m a t i o n w h i c h f l a n k i t s w e s t e r n b a s e n e a r W h i t e Rock. The t h i c k , e s s e n t i a l l y p u r e (97±* c a l c i t e ) l i m e s t o n e b e ds o f t h e G r e a t B l u e F o r m a t i o n r e s i s t e r o s i o n and f o rm s t e ep w e l l - e x p o s e d o u t c r o p s. The G r e a t B l u e F o r m a t i o n i s e s t i m a t e d t o be a t l e a st 2 , 4 4 l f e e t t h i c k i n t h e s o u t h e r n C e d a r M o u n t a i n s . The b a s a l 522 f e e t of a c o m p o s i t e s e c t i o n w e r e m e a s u r e d on t he w e s t s i d e of t h e m o u n t a i n i n s e c . 3 2 , 3 3 ; T 5 S , R9W ( F i g . 2) The h o r i z o n of t h e h i g h e s t bed m e a s u r e d a t t h a t l o c a l i ty was f o l l o w e d n o r t h w a r d and e s t i m a t e d t o be a b o u t 300 f e et b e l o w t h e b a s e of t h e o v e r l y i n g s t r a t a whose m e a s u r e m e nt b e g a n i n SW 1 / 4 , s e c . 1 3 , T 5 S , R10W ( u n s u r v e y e d ) and p r o c e e d e d n o r t h w a r d t o t h e h i g h e s t e x p o s e d b e d s of t he - 1 7 - G r e a t B l u e F o r m a t i o n . This u p p e r m e a s u r e d s e q u e n c e t o t a l ed 1 , 6 1 9 f e e t . The G r e a t B l u e - M a n n i n g Canyon F o r m a t i o n c o n ­t a c t i s n o t c l e a r l y e x p o s e d b u t t h e t o p o g r a p h y and o c c a s ­i o n a l e x p o s u r e s s u g g e s t t h a t t h e c o n t a c t i s n e a r t h e h i g h e st m e a s u r e d o u t c r o p of t h e G r e a t B l u e F o r m a t i o n. L i t h o l o g y L i m e s t o n e c o m p r i s e s t h e G r e a t B l u e F o r m a t i o n a l m o st t o t h e e x c l u s i o n of o t h e r l i t h o l o g i e s i n t h e C e d a r Moun­t a i n s . Every u n i t i n t h e m e a s u r e d s e c t i o n i s d e s i g n a t ed l i m e s t o n e . Color r a n g e s from medium t o d a r k g r a y and t he t e x t u r e i s u s u a l l y f i n e l y c r y s t a l l i n e or b i o c l a s t i c . C r i n - o i d and b r y o z o a n f r a g m e n t s commonly f o rm t h e m a j o r i t y of c l a s t s i n t h e d e t r i t a l u n i t s . Many s t r a t a of t h e G r e at B l u e F o r m a t i o n a r e m e d i u m - a n d t h i c k - b e d d e d and on w e a t h e r i ng p r o d u c e a r u g g e d , l e d g y t o p o g r a p h y . Gray and b l a c k c h e r t in s t r i n g e r s and n o d u l e s a r e common i n some b e d s i n t h e u p p er p a r t of t h e f o r m a t i o n . Samples of f i v e d i f f e r e n t b e d s in t h e u p p e r t h i r d of t h e G r e a t B l u e F o r m a t i o n w e r e c o l l e c t ed by t h e w r i t e r f o r Morgan P e t e r s o n E n t e r p r i s e s of S a l e Lake C i t y , U t a h . Chemical a n a l y s e s of t h e s e s a m p l e s i n d i c a t ed a n a v e r a g e CaC03 c o n t e n t of 9 6 . 9 $ . No t r u e s h a l e b e d s , i . e ., l a m i n a t e d , p e l i t i c s t r a t a , were f o u n d i n t h e G r e a t B l ue F o r m a t i o n i n t h e C e d a r M o u n t a i n s i n s p i t e of t h e f a ct t h a t t h e y o c c u r i n t h e f o r m a t i o n i n more e a s t e r l y and - 1 8 - s o u t h e r l y l o c a t i o n s ( R i g b y , 1 9 5 8 ; G i l l u l y , 1 9 3 2 ; C o h e n o u r, 1 9 5 9 ; M o r r i s , 1 9 5 7 ) . Three z o n e s t h a t c o n t a i n s i g n i f i c a nt a m o u n t s of s a n d , one w i t h w e l l - d i f f e r e n t i a t e d s a n d s t o ne b e d s , w e r e o b s e r v e d i n t h e s o u t h e r n C e d a r M o u n t a i n s . These b e d s c o n s t i t u t e U n i t s 7, 8, 1 6 , and 19 ( s e e m e a s u r ed s e c t i o n ) . D o e l l i n g ( 1 9 6 4 ) f o u n d no s h a l e i n t h e G r e a t B l ue F o r m a t i o n i n t h e N o r t h e r n L a k e s i d e M o u n t a i n s b u t r e p o r ts a " m i d d l e member" of s l a b b y , s a n d y l i m e s t o n e , 574 f e et t h i c k w i t h s a n d s t o n e a t t h e t o p. The l o w e r b o u n d a r y of t h e G r e a t B l u e F o r m a t i o n is t r a n s i t i o n a l i n t o t h e Humbug F o r m a t i o n and i s p l a c e d a t t he b a s e of t h e f i r s t g r a y l i m e s t o n e c h a r a c t e r i s t i c of t h o s e in t h e G r e a t B l u e F o r m a t i o n . The u p p e r c o n t a c t w i t h t he M a n n i n g Canyon F o r m a t i o n i s n o t e x p o s e d i n t h e Cedar M o u n t a i n s . C o m p o s i t e M e a s u r e d S e c t i o n of t h e G r e a t B l u e F o r m a t i o n in S o u t h e r n C e d a r M o u n t a i n s ( S e e p . 15 f o r d i s c u s s i o n of l o c a t i o n ) M a n n i n g Canyon F o r m a t i on C o n f o r m a b l e ( ? ) C o n t a ct U n i t Description Feet 34 Limestone, medium g r a y , w e a t h e r s s a m e , 11 f i n e l y c r y s t a l l i n e , medium t o t h i c k - b e d d e d . 33 Covered. 206 - 1 9 - U n l t Description Feet 32 Limestone, medium g r a y , w e a t h e r s s a m e , 69 m e d i u m - t o t h i c k - b e d d e d , few b l a ck c h e r t n o d u l e s , c l i f f - f o r m e r. 3 1 Limestone, medium t o d a r k g r a y , w e a t h e r s 87 m e d i um g r a y , f i n e l y c r y s t a l l i n e to d e t r i t a l , m e d i u m - b e d d e d , o c c a s i o n al c h e r t n o d u l e s , s l o p e w i t h s m a l l l e d g e s. 30 Limestone, medium t o d a r k g r a y , w e a t h e r s 28 m e d i um g r a y , d e t r i t a l t o f i n e l y c r y s t a l ­l i n e , m e d i u m - b e d d e d t o m a s s i v e , a b o ut 25% c h e r t , b e d d e d , m a r o o n , g r a y , and b l a c k . Makes one s t e e p c l i f f u n d e r c ut by a o n e - f o o t , s h a l y l i m e s t o n e b e d. 29 Limestone, medium g r a y , w e a t h e r s medium 159 g r a y , c l a s t i c t o f i n e l y c r y s t a l l i n e, t h i n t o t h i c k - b e d d e d , t h i n - b e d d e d w e a t h ­e r s t o p l a t y s l o p e s , much g r a y t o b l a ck c h e r t i n d i s c o n t i n u o u s l a y e r s , s t e e p s l o p e. 28 Limestone, medium g r a y , w e a t h e r s medium 227 b l u e - g r a y , f i n e l y c r y s t a l l i n e , medium-t o t h i c k b e d d e d , n u m e r o u s f r a c t u r e s f i l l ed w i t h w h i t e c a l c i t e , n u m e r o u s c o r a l s, s t e e p , l e d g y s l o p e. 27 Limestone, d a r k g r a y , w e a t h e r s medium t o 84 d a r k g r a y , medium t o t h i c k - b e d d e d , v e ry f i n e l y c r y s t a l l i n e , d a r k g r a y t o b l a ck c h e r t n o d u l e s. 26 Limestone, d a r k g r a y , w e a t h e r s medium t o 478 d a r k - g r a y , f i n e l y c r y s t a l l i n e , medium-b e d d e d , s m a l l c r i n o i d and b r y o z o a n f r a g ­m e n t s , o c c a s i o n a l h o r n c o r a l , p a r t ly c o v e r e d s l o p e. 25 Limestone, d a r k g r a y , w e a t h e r s medium t o 23 d a r k g r a y , m e d i u m - b e d d e d , s l o p e. 24 Limestone, d a r k g r a y , w e a t h e r s medium t o 16 d a r k g r a y , h o r i z o n t a l l y - e l o n g a t e d brown c h e r t n o d u l e s , n u m e r o u s h o r n c o r a l s, f o r m s l e d g e s. - 2 0 - U n l t Description Feet 23 Limestone, d a r k g r a y , w e a t h e r s medium 33 t o d a r k g r a y , a p h a n i t i c t o f i n e l y c r y ­s t a l l i n e , medium- t o t h i c k - b e d d e d , h o rn c o r a l s , forms s l o p e. 22 Limestone, d a r k g r a y , w e a t h e r s medium 6 g r a y a p h a n i t i c t o f i n e l y c r y s t a l l i n e, m e d i um t o v e r y - t h i c k - b e d d e d , f r a c t u r e d, l e d g e . 2 1 Limestone, d a r k g r a y , w e a t h e r s medium 38 g r a y m e d i u m - b e d d e d , many w h i t e c a l c i te s e a m s , s l o p e. 20 Limestone, medium g r a y , w e a t h e r s s a m e , 35 a p h a n i t i c t o m e d i u m - c r y s t a l l i n e , m o s t ly a p h a n i t i c , many s o l i t a r y and c o l o n i al c o r a l s , l e d g y s l o p e. 19 Limestone, medium g r a y , w e a t h e r s medium 33 g r a y , f i n e t o c o a r s e l y c r y s t a l l i n e medium t o t h i c k - b e d d e d , p a r t l y e n c r i n a l , has t h i n i n t e r l a y e r s of s a n d s t o n e , v e r y - f i ne g r a i n e d , t a n , c a l c a r e o u s , froms a s l o p e. 18 Limestone, medium g r a y , w e a t h e r s medium 16 g r a y , m e d i u m - t o t h i c k - b e d d e d , p a r t ly e n c r i n a l , l e d g y s l o pe 17 Limestone, medium g r a y , w e a t h e r s medium 45 g r a y , v e r y - t h i c k - b e d d e d , becomes medium-t o t h i n - b e d d e d i n t h e t o p q u a r t e r , e n c r i ­n a l , f r e w t h i n l a y e r s of m a r o o n s a n d s t o n e. 16 Limestone, medium g r a y , w e a t h e r s medium 23 g r a y , m e d i u m - t o t h i n - b e d d e d , s a n d y l a m i n a ­t i o n s , s l o p e w e a t h e r s i n p l a c e s t o y e l l o w - b r o w n p l a t y f r a g m e n t s. 15 Limestone, medium g r a y , w e a t h e r s medium g r a y medium t o c o a r s e l y c r y s t a l l i n e, m e d i u m - b e d d e d , e n c r i n a l , f o r m s a l e d g e. lUl9 - 2 1 - U n i t Description Feet U n m e a s u r e d i n t e r v a l 300 14 Limestone, medium g r a y , w e a t h e r s medium 19 d a r k g r a y , medium t o c o a r s e l y c r y s t a l l i n e, m e d i u m - b e d d e d , f o r m s s t r o n g l e d g e s, w e a t h e r s t o a v e r y f i n e l y i r r e g u l a r s u r f a c e. 13 Limestone, d a r k g r a y , w e a t h e r s medium g r a y , 56 f i n e c r y s t a l l i n e , t h i n - t o m e d i u m - b e d d e d, s l o p e , F 5 5 3 - 1 3 , 1 4 f r om u n i t s 13 a n d 14, 12 Limestone, medium g r a y , f i n e c r y s t a l l i n e 53 t o c a l c a r e n i t i c , m e d i u m - b e d d e d , makes s m a l l l e d g e s. 1 1 Limestone, d a r k g r a y , w e a t h e r s medium g r a y , 37 f i n e c r y s t a l l i n e , forms l e d g e s , f e t id o d o r f r om f r e s h b r e a k. 10 Limestone, medium g r a y , f I n e - c r y s t a l l l n e , 39 m e d i u m - t o t h i n - b e d d e d , many s o l i t a ry c o r a l s , c h e r t y , f o r m s a s l o p e. 9 Limestone, medium g r a y , w e a t h e r s d o v e - 164 g r a y , a r e n i t i c and f i n e - c r y s t a l l i n e, m e d i u m - t o t h i c k - b e d d e d , makes l e d g e s, s e v e r a l l e n t i c u l a r c h e r t z o n e s , c r o s s - b e d d e d . 8 Limestone, medium g r a y , f i n e - c r y s t a l l i n e 31 some l a y e r s s i l t y , m e d i u m - b e d d e d , h o rn c o r a l s , f o r m s a s l o p e. 7 Limestone, medium g r a y , w e a t h e r s medium 11 g r a y , d e t r i t a l , s a n d y ( f i n e ) , c r o s s - b e d d e d. 6 Limestone, medium g r a y , f i n e - c r y s t a l l i n e , 40 t h i n t o m e d i u m - b e d d e d , forms a s l o p e. 5 Limestone, medium g r a y , w e a t h e r s d o v e - g r a y 5 m e d i u m - t o t h i c k - b e d d e d , much c r i n o i d d e b r i s, m a k e s d o u b l e l e d g e. 4 Limestone, g r a y , w e a t h e r s medium g r a y , 17 d e t r i t a l and f i n e - c r y s t a l l i n e , t h i n - b e d d e d, h o r n c o r a l s , f o r m s s l o p e F 5 5 3 - 4. - 2 2 - U n i t D e s c r i p t i o n F e e t 3 L i m e s t o n e , medium g r a y , w e a t h e r s medium g r a y , n u m e r o u s b e d s s a n d y , s m a l l l e d g es ( a b o u t 3 f e e t ) s e p a r a t e d by s h o r t s l o p e s, s a n d y b e d s makes s l o p e s , s m a l l h o r n c o r a ls a n d c r i n o i d d e b r i s , F 5 5 3 0 3. 18 2 L i m e s t o n e , g r a y , w e a t h e r s medium g r a y, t h i n - b e d d e d , s a n d y t o w a r d t o p , f o r m s a s l o p e, F 5 5 3 f r om u n i t s 1 and 2. F 6 7 4 - 1 , F 6 7 4 - 2, F 6 7 4 - 3 from u n i t s 1 a n d 2. 27 1 L i m e s t o n e , g r a y , w e a t h e r s medium g r a y , s a n d y , 5 d e t r i t a l , t h i c k - b e d d e d , forms a l e d g e. 522 C o n f o r m a b l e c o n t a ct Humbug F o r m a t i on Minimum T o t al 2 4 4 ; Age a n d C o r r e l a t i on S p u r r ( 1 8 9 5 , p . 375) named t h e G r e a t B l u e F o r m a t i o n f or e x p o s u r e s i n t h e M e r c u r D i s t r i c t of t h e O q u i r r h M o u n t a i n s. At t h a t t i m e i t s age was e s t a b l i s h e d on f a u n a l e v i d e n ce m e r e l y a s C a r b o n i f e r o u s . G i l l u l y ( 1 9 3 2 , p . 3 D i n h i s s t u dy o f t h e S t o c k t o n and F a i r f i e l d Q u a d r a n g l e s i n t h e O q u i r rh M o u n t a i n s c o l l e c t e d f a u n a l e v i d e n c e s u p p o r t i n g a L a te M i s s i s s i p p i a n age f o r t h e f o r m a t i o n . S i n c e t h a t t i m e , it h a s b e e n r e c o g n i z e d a t s e v e r a l l o c a l i t i e s i n t h e v i c i n i t y of t h e t y p e s e c t i o n and G i r t y ( N o l a n , 1 9 3 5 , p . 30) s u g g e s t ed t h e G r e a t B l u e F o r m a t i o n as t h e u n i t most n e a r l y c o r r e l a t i ve w i t h t h e O c h r e M o u n t a i n F o r m a t i o n i n t h e Deep C r e e k M o u n t a i n s. C o h e n o u r ( 1 9 5 9 , p . 93) mapped t h e G r e a t B l u e F o r m a t i o n in t h e S h e e p r o c k M o u n t a i n s and c i t e d f a u n a l e v i d e n c e f o r a - 2 3 - " b a s a l Upper M i s s i s s i p p i a n ( C h e s t e r ) a g e . " D o e l l i ng ( 1 9 6 4 , p . 183) made f o s s i l c o l l e c t i o n s from t h e l o w e r and u p p e r G r e a t B l u e i n t h e N o r t h e r n L a k e s i d e M o u n t a i n s i n d i c a ­t i v e of L a t e M i s s i s s i p p i a n a g e . RIgby ( 1 9 5 8 , p . 38) s u g g e s t e d a maximum t h i c k n e s s of 1 , 3 0 0 f e e t f o r t h e I n c o m ­p l e t e s e c t i o n of G r e a t B l u e F o r m a t i o n i n t h e S t a n s b u ry M o u n t a i n s . S a d l i c k ( p e r s o n a l c o m m u n i c a t i o n , s e e m e a s u r e d s e c ­t i o n ) e x a m i n e d f i v e f o s s i l c o l l e c t i o n s from t h e l o w er G r e a t B l u e F o r m a t i o n i n t h e C e d a r M o u n t a i n s and r e p o r t ed a s f o l l o w s: F 5 49 F 5 5 3 F 5 5 3 - 3 U n it F 5 5 3 - 4 U n it L i t h o s t r o t i o n s p . ( C o l l e c t e d 68 f e e t b e l o w t o p of Humbug F o r m a t i o n .) Q v a t i a s p. B r a c h y f r h y r i s ( ? ) s p. T r i p l o p h y l l i t e s sp. No. 3 S t r i a t i f e r a b r a z e r i a n us No. 4 T o r y n i f e r a s p. F 5 5 3 - 1 3 / 1 4 U n i t s No. 1 3 - 14 F a b e r o p h y l l u m sp. Q v a t i a sp. S p i r i f e r sp. B r a c h y t h y r i s (?) a f f . o z a r k e n s is " L a t e V i s e a n , no y o u n g e r t h a n M i d - C h e s t e r ." Herman e x a m i n e d t h r e e l i m e s t o n e s p e c i m e n s from t he l o w e r t h i r t y f e e t of t h e G r e a t B l u e F o r m a t i o n and r e p o r t ed - 2 4 a s f o l l o w s ( p e r s o n a l c o m m u n i c a t i o n ): ( u p p e r ) 674-3 E n d o t h y r a s y m m e t r i ca E n d o t h y r a h a m u la P l e c t o g y r a i r r e g u l a r is P l e c t o g y r a s p. H y p e r a m m i n a s p. H y p e r a m m i n a b o u r n i a y e l la T e t a t a x i s h o w c h e n ia 6 7 4 - 2 E n d o t h y r a s y m m e t r i ca P l e c t o g y r a s p. P l e c t o g y r a i r r e g u l a r is H y p e r a m m i n a s p. H y p e r a m m i n a t o u r n i a y e l l a (?) T e t r a - t a x i s h o w c h e n ia ( l o w e r ) 674-1 E n d o t h y r a s y m m e t r i ca E n d o t h y r a a f f . hamula E n d o t h y r a sp. Mr. Herman r e p o r t e d t h a t t h e s e f o r a m i n i f e r a l c o l l e c ­t i o n s i n d i c a t e l a t e Meramec Age. T h e G r e a t B l u e F o r m a t i o n of t h e C e d a r M o u n t a i n s is c o r r e l a t e d w i t h t h a t u n i t i n t h e n e a r b y r a n g e s on t h e b a s es o f s i m i l a r l i t h o l o g y , s t r a t i g r a p h i c p o s i t i o n , and a g e. D a t a now a v a i l a b l e r e g a r d i n g t h e o c c u r r e n c e of s h a l e and q u a r t z i t e s i n t h e G r e a t B l u e F o r m a t i o n s u g g e s t t h a t b o th t h e s e l i t h o l o g i e s d e c l i n e i n a b u n d a n c e n o r t h w a r d and w e s t ­w a r d f r o m t h e E a s t T i n t i c M o u n t a i n s , s h a l e d i s a p p e a r i n g at some p o i n t e a s t of t h e C e d a r M o u n t a i n s . The s a n d s t o n e b e ds a n d s a n d y l i m e s t o n e of t h e C e d a r M o u n t a i n s s e c t i o n a r e in a p p r o x i m a t e l y t h e same s t r a t i g r a p h i c p o s i t i o n a s t he C h i u l o s s h a l e of t h e E a s t T i n t i c and S h e e p r o c k M o u n t a i n s. M a n n i n g Canyon F o r m a t i on - 2 5 - D l s t r i b u t i o n and T h i c k n e ss The M a n n i n g Canyon F o r m a t i o n i s s p a r s e l y e x p o s e d i n t he C e d a r M o u n t a i n s , t h e t o t a l a r e a of o u t c r o p b e i n g e s t i m a t ed a t a b o u t two s q u a r e m i l e s . E x p o s u r e s a r e c o n f i n e d a l m o st c o m p l e t e l y t o t h e s o u t h e a s t e r n C e d a r M o u n t a i n s and t he l a r g e s t o n e s a r e i n C o c h r a n V a l l e y a b o u t a m i l e s o u t h e a s t of C o c h r a n S p r i n g w h e r e b l a c k s h a l e , s p a r s e l i m e s t o n e , and u n d e r l y i n g i r o n - s t a i n e d q u a r t z i t e r i s e t o t h e s u r f a c e a l o ng t h e c r e s t of t h e C o c h r a n V a l l e y A n t i c l i n e . The s e c o n d most e x t e n s i v e e x p o s u r e i s n e a r t h e m o u t h of e a s t R y d a l c h Canyon. The p e d i m e n t a l o n g t h e b a s e of t h e c e n t r a l C e d a r M o u n t a i ns b r o a d e n s a c r o s s t h e e a s i l y - e r o d e d M a n n i n g Canyon F o r m a t i on a n d p r o d u c e s t h e p r o m i n e n t t o p o g r a p h i c r e e n t r a n t which s u r r o u n d s t h e n a r r o w e n t r a n c e t o R y d a l c h C a n y o n . There a r e o t h e r s m a l l o u t c r o p s of t h e M a n n i n g Canyon F o r m a t i on a l o n g t h e v a l l e y w h i c h t r e n d s s o u t h e a s t from W h i t e Rock, n e a r S u l p h u r S p r i n g , i n w e s t R y d a l c h C a n y o n , and e a st H a s t i n g s Canyon. The w r i t e r h a s f o u n d no s u r f a c e e x p o s u r e s I n t h e Cedar M o u n t a i n s w h i c h w o u l d a l l o w a r e l i a b l e t h i c k n e s s m e a s u r e ­ment of t h e M a n n i n g Canyon F o r m a t i o n . At t h e most o b v i o us l o c a t i o n , b e t w e e n t h e G r e a t B l u e F o r m a t i o n and t h e l o w er O q u i r r h i n e a s t R y d a l c h C a n y o n , t h e f o r m a t i o n i s c u t by - 2 6 - R y d a l c h Canyon f a u l t . A d d i t i o n a l f a u l t i n g i s i n d i c a t ed b e c a u s e O q u i r r h u n i t s 1 a n d 2 do n o t a p p e a r a t t h e b a s e of t h e O q u i r r h e x p o s u r e s . F u r t h e r m o r e , a d e q u a t e l i t h o l o g ic d e s c r i p t i o n w o u l d be u n a v a i l a b l e i n t h i s a r e a b e c a u s e t he M a n n i n g Canyon i s a l m o s t c o m p l e t e l y c o v e r e d . Moyle ( 1 9 5 9, p . 66) h a s p r e p a r e d an I s o p a c h o u s map f o r t h e Manning C a n y o n and c o r r e l a t i v e f o r m a t i o n s i n c e n t r a l U t a h and e a s t e r n Nevada w h i c h i n d i c a t e s a b o u t 1 , 1 0 0 f e e t t h i c k n e ss f o r t h e M a n n i n g Canyon F o r m a t i o n i n t h e C e d a r M o u n t a i n s. F o r a n u m b e r of r e a s o n s , i t seems p r o b a b l e t h e t h i c k n e s s in t h e s o u t h e r n C e d a r M o u n t a i n s i s somewhat g r e a t e r t h an 1 , 1 0 0 f e e t . The more i m p o r t a n t c o n s i d e r a t i o n s a r e : 1) a b o u t 900 t o 1 , 0 0 0 f e e t t h i c k n e s s i s i n d i c a t e d by o u t c r o ps a n d a t t i t u d e of b e d s . . 2) l i t h o l o g y of M a n n i n g Canyon in t h e S t a n & b u r y M o u n t a i n s ( R i g b y , 1 9 5 8 , p . 49) and O q u i r rh M o u n t a i n s ( M o y l e , 1 9 5 9 , p . 6 0 - 6 1 ) s u g g e s t t h a t a l o w er l i m e s t o n e and s h a l e s e q u e n c e i s n o t e x p o s e d i n t h e Cedar M o u n t a i n s . 3) t h e f o r m a t i o n h a s p r o b a b l y u n d e r g o n e some t h i n n i n g d u r i n g p o s t - P e n n s y l v a n i a n o r o g e n y . Young ( 1 9 5 5, p . 33) e s t i m a t e d t h e M a n n i n g Canyon F o r m a t i o n In t he s o u t h e r n C e d a r M o u n t a i n s t o be b e t w e e n 1 , 5 0 0 and 2 , 0 0 0 f e et t h i c k and t h e w r i t e r a g r e e s w i t h t h i s e s t i m a t e. L i t h o l o g y G r a y t o b l a c k f i s s i l e s h a l e c h a r a c t e r i z e s t h e Manning C a n y o n F o r m a t i o n a t most e x p o s u r e s . B r o w n i s h - g r a y and - 2 7 - b r o w n q u a r t z i t e s a r e common a n d t h e r e a r e o c c a s i o n a l medium t o t h i n - b e d d e d , b r o w n i s h - g r a y , c a r b o n a c e o u s l i m e s t o n e l a y e r s. Some e x p o s e d brown q u a r t z i t e b e d s a r e t e n f e e t or more t h i ck a n d show c r o s s - b e d d i n g . The brown c o l o r i s t h e r e s u l t of u n e v e n l y d i s t r i b u t e d , p o w d e r y l i m o n l t e c e m e n t„ At C o c h r a n S p r i n g , t h e u p p e r m o s t l a y e r s of Manning C a n y o n F o r m a t i o n c o n t a i n some f i n e - g r a i n e d , g r e e n i sh q u a r t z i t e w h i c h was n o t n o t i c e d a t o t h e r l o c a l i t i e s . F i s ­s i l e b l a c k s h a l e w i t h m i n o r , t h i n q u a r t z i t e and l i m e s t o ne b e d s c o m p r i s e t h e u p p e r 600 t o 800 f e e t of t h e f o r m a t i o n. A l o w e r u n i t e x p o s e d i n C o c h r a n V a l l e y h a s t h i c k e r brown q u a r t z i t e a n d l i m e s t o n e b e d s i n a d d i t i o n t o b l a c k s h a l e. W h i l e p a r t of t h e l o w e r M a n n i n g Canyon F o r m a t i o n a p p e a r s to u n d e r l i e d i r e c t l y t h e Q u a t e r n a r y s a n d and c l a y I n s m a ll a r e a s s o u t h e a s t of W h i t e Rock, i t i s n o t e x p o s e d a n y w h e re i n t h e C e d a r M o u n t a i n s. The c o n t a c t of t h e M a n n i n g Canyon F o r m a t i o n w i t h t he u n d e r l y i n g G r e a t B l u e F o r m a t i o n I s n o t e x p o s e d i n t h e Cedar M o u n t a i n s . However, t h e a b r u p t e n d i n g of t h e h i l l y t o p o g ­r a p h y on t h e u p p e r G r e a t B l u e F o r m a t i o n a t i t s n o r t h e r n ­m o s t e x p o s u r e s i n d i c a t e s a r a t h e r s h a r p t r a n s i t i o n upward t o t h e M a n n i n g Canyon F o r m a t i o n . The f o r m a t i o n g r a d es u p w a r d I n t o t h e O q u i r r h F o r m a t i o n . The b o u n d a r y was c h o s e n a t t h e b a s e of t h e f i r s t b r o w n i s h - g r a y , f o s s i l i f e r - o u s l i m e s t o n e bed t y p i c a l of U n i t 1 of t h e O q u i r r h F o r m a ­t i o n . - 2 8 - Age and C o r r e l a t i on The M a n n i n g Canyon F o r m a t i o n was named by G i l l u ly ( 1 9 3 2 ) f o r e x p o s u r e s i n t h e s o u t h e r n O q u i r r h M o u n t a i n s and h e c o n c l u d e d t h a t t h e M i s s i s s i p p i a n - P e n n s y l v a n i an b o u n d a r y i n t h a t a r e a i s i n t h e u p p e r M a n n i n g Canyon F o r m a ­t i o n . Moyle ( 1 9 5 9 ) h a s r e s t u d i e d t h e M a n n i n g Canyon and c o r r e l a t i v e f o r m a t i o n s i n t h e s o u t h e r n O q u i r r h M o u n t a i ns a n d s e v e r a l o t h e r a r e a s I n c e n t r a l U t a h and e a s t e r n N e v a d a. He a l s o c o n c l u d e s t h a t t h e M i s s i s s i p p i a n - P e n n s y l v a n i an t r a n s i t i o n i n t h e s o u t h e r n O q u i r r h M o u n t a i n s I s i n t he u p p e r p a r t of t h e M a n n i n g Canyon F o r m a t i o n . Young ( 1 9 5 5, p . 33) r e p o r t e d a c o l l e c t i o n of f o r m s from t h e s o u t h e rn C e d a r M o u n t a i n s and i n d i c a t e d t h e p o s s i b i l i t y t h a t a t l e a st 7 / 8 of t h e f o r m a t i o n i n t h a t a r e a i s M i s s i s s i p p i a n . The w r i t e r made a c o l l e c t i o n from a l o c a t i o n on t h e C o c h r an S p r i n g A n t i c l i n e a b o u t t h r e e or f o u r m i l e s s o u t h of t he o n e made by Young. S t o k e s ( P e r s o n a l c o m m u n i c a t i o n ) i d e n t ­i f i e d t h e f o s s i l s l i s t e d b e l o w and e s t i m a t e d t h e i r a g e as C h e s t e r . F 4 4 8 B a c t r i t e s ( ? ) s p. C r a v e n o c e r a s sp. D i s c i t o c e r a s ( ? ; s p. E u m o r p h o c e r a s sp. L e i o r h y n c h u s sp. M o o r e o c e r a s sp. S i n c e S a d l i c k ( w r i t t e n c o m m u n i c a t i o n ) h a s i n d i c a t e d t h at t h r e e c o l l e c t i o n s t h e w r i t e r made f r om t h e l o w e r O q u i r rh - 2 9 - P o r m a t i o n i n t h e s o u t h e r n C e d a r M o u n t a i n s may be M i s s i s s i p ­p i a n , i t a p p e a r s t h a t a l l t h e M a n n i n g Canyon F o r m a t i o n in t h e C e d a r M o u n t a i n s may be of M i s s i s s i p p i a n a g e , Tooker a n d R o b e r t s ( 1 9 6 1 , p . 26) p r e s e n t e v i d e n c e r e g a r d i n g t he a g e of t h e l o w e r O q u i r r h F o r m a t i o n i n t h e n o r t h e r n O q u i r rh M o u n t a i n s w h i c h s u p p o r t s t h e s u g g e s t i o n t h a t t h e Manning C a n y o n F o r m a t i o n I n t h e C e d a r M o u n t a i n s may be M i s s i s s i p ­p i a n . The e v i d e n c e t h e y c i t e i n d i c a t e s t h a t a t l e a s t t he l o w e r 5 5 0 - 5 6 0 f e e t of t h e O q u i r r h F o r m a t i o n i s of M i s s i s s i p ­p i a n a g e. The M a n n i n g Canyon F o r m a t i o n h a s a l s o b e e n mapped in t h e S t a n s b u r y M o u n t a i n s ( R l g b y , 1958) and t h e s o u t h e rn L a k e s i d e M o u n t a i n s (Young, 1 9 5 5 ). PENNSYLVANIAN AND PERMIAN SYSTEMS O q u i r r h F o r m a t i on I n t r o d u c t i o n The v e r y t h i c k s e r i e s of r a t h e r m o n o t o n o u s l i m e s t o n e, s a n d s t o n e , and q u a r t z i t e b e d s w h i c h t o d a y a r e e n c o m p a s s e d in t h e O q u i r r h F o r m a t i o n p r e s e n t e d a p r o b l e m f o r g e o l o g i s ts t r y i n g t o u n r a v e l t h e g e o l o g y o r t o u n d e r s t a n d t h e m i n e r al d e p o s i t s of t h e e a s t e r n G r e a t B a s i n e v e n b e f o r e G i l l u ly ( 1 9 3 2 , p . 34) named t h e f o r m a t i o n . An i m p o r t a n t a s p e c t of t h e p r o b l e m h a s b e e n t h e c h o i c e of a m e t h o d s u i t a b l e for - 3 0 - m a p p i n g s u c h a t h i c k , a p p a r e n t l y m o n o t o n o u s a c c u m u l a t i o n of s t r a t a . One of G i l l u l y ' s ( 1 9 3 2 , p . 35) g o a l s i n s t u d y i ng t h e S t o c k t o n and F a i r f i e l d Q u a d r a n g l e s i n t h e s o u t h e rn O q u i r r h M o u n t a i n s was t o d i s c o v e r w h e t h e r c e r t a i n u n i t s of t h e O q u i r r h F o r m a t i o n i n t h e B i n g h am M i n i n g D i s t r i c t c o u ld b e t r a c e d I n t o t h e O p h i r D i s t r i c t on t h e w e s t s i d e of t he r a n g e and t h u s make I t p o s s i b l e t o d e t e r m i n e t h e r e l a t i ve a g e and s t r a t i g r a p h i c p o s i t i o n of t h e m i n e r a l i z e d b e d s. H i s i n v e s t i g a t i o n i n d i c a t e d t h a t no q u a r t z i t e b e d s i n t he L e w i s t o n P e a k a r e a were c o n t i n u o u s f o r more t h a n t h r e e or f o u r m i l e s and he d i d n o t h o l d much h o p e t h a t i n d i v i d u al l i m e s t o n e b e d s w o u l d p r o v e s u f f i c i e n t l y c o n t i n u o u s f o r c o r ­r e l a t i o n o v e r s i g n i f i c a n t d i s t a n c e s . G i l l u l y named t he O q u i r r h F o r m a t i o n f o r e x p o s u r e s i n t h e s o u t h e r n O q u i r rh M o u n t a i n s and d e t e r m i n e d t h e a g e of t h e l o w e r and m i d d le p a r t of t h e f o r m a t i o n t o be P e n n s y l v a n i a n . His s t u d i es s h o w e d t h e f o r m a t i o n t o be a t l e a s t 1 5 , 0 0 0 and p o s s i b le 1 8 , 0 0 0 f e e t t h i c k. N o l a n ( 1 9 3 5 ) mapped b e d s he r e f e r r e d t o as O q u i r r h in t h e Gold H i l l Q u a d r a n g l e . He r e p o r t e d t h a t b e d s w i t h i n t he f o r m a t i o n were l e n t i c u l a r and d i d n o t d i s t i n g u i s h any s u b ­s i d i a r y u n i t s a l t h o u g h he n o t e d t h a t d e c i p h e r i n g t h e s t r u c ­t u r e w o u l d h a v e b e e n s i m p l i f i e d had he b e e n a b l e t o map s m a l l e r u n i t s . His ( 1 9 3 0 ) u s e of t h e name O q u i r r h F c r m a - t l o n a p p e a r e d I n p r i n t b e f o r e t h e p u b l i c a t i o n of G i l l u l y Ts ( 1 9 3 2 ) p r o f e s s i o n a l p a p e r . A q u e s t i o n h a s b e e n r a i s e d a s to t h e l e g i t i m a c y of a p p l y i n g t h e t e r m O q u i r r h t o s t r a t a in t h e Deep C r e e k M o u n t a i n s ( W e l s h and J a m e s , 1 9 6 1 , p . 7; B i s s e l l , 1 9 6 2 , p . 1 0 8 7 ) . It i s n o t u s e d f o r b e d s i n t h is a r e a on t h e G e o l o g i c Map of U t a h , N o r t h w e s t Q u a r t er ( S t o k e s , 1 9 6 3 ). B i s s e l l ( 1 9 3 6 ) s t u d i e d t h e O q u i r r h F o r m a t i o n i n t he s o u t h e r n W a s a t c h M o u n t a i n s and s u g g e s t e d t h a t t h e s t r a t a in t h a t a r e a be c a l l e d t h e O q u i r r h S e r i e s , c o n t a i n i n g a l o w er K e l l e y and an u p p e r H o b b l e F o r m a t i o n . Three y e a r s l a t e r, he p r o p o s e d t h a t f u s u l i n i d s c o u l d be u s e d i n s u b d i v i d i ng U t a h P e n n s y l v a n i a n s t r a t a and s e t up a f i v e - f o l d s u b d i v i s i on of t h e O q u i r r h F o r m a t i o n b a s e d upon d i f f e r e n t f u s u l i n id f o r m s . Thompson, V e r v i l l e , and B i s s e l l ( 1 9 5 0 ) made a f u r ­t h e r c o n t r i b u t i o n t o t h e p r o b l e m of s u b d i v i d i n g the O q u i r rh F o r m a t i o n and p r o v i d e d t h i c k n e s s e s f o r t h e v a r i o u s s e r i es i n t h e s o u t h e r n W a s a t c h M o u n t a i n s . B i s s e l l ( 1 9 5 9 ) a p p l i ed t h e m e t h o d of p a l e o n t o l o g i c z o n a t i o n i n t h e O q u i r r h F o r m a ­t i o n i n t h e s o u t h e r n O q u i r r h M o u n t a i n s w h e r e he mapped a s e r i e s of u n i t s a b o u t w h i c h he s t a t e d : "For t h e most p a r t, t h e s e a r e t i m e - r o c k m e m b e r s . " B i s s e l l r e l i e d m a i n l y on s u f - u l i n i d s f o r z o n a t i o n i n t h i s w o r k . Rigby ( 1 9 5 8 ) u s e d t he t i m e - r o c k a p p r o a c h i n h i s m a p p i n g of t h e S t a n s b u r y M o u n t ­a i n s a s d i d S t i f e l ( 1 9 6 4 ) i n h i s r e p o r t on t h e g e o l o g y of - 3 2 - t h e T e r r a c e and Hogup M o u n t a i n s. B a k e r ( 1 9 4 7 ) i n v e s t i g a t e d t h e s t r a t i g r a p h y of t he s o u t h e r n W a s a t c h M o u n t a i n s i n t h e v i c i n i t y of P r o v o , Utah a n d r e p o r t e d t h a t t h e f o r m a t i o n a t t a i n e d a t h i c k n e s s of t he o r d e r of 2 6 , 0 0 0 f e e t i n t h a t a r e a . He r e c o g n i z e d a d i s ­t i n c t , g r a y l i m e s t o n e u n i t 1 , 2 4 5 f e e t t h i c k a t t h e b a s e of t h e O q u i r r h s e q u e n c e b u t d i d n o t p r e s e n t a g e o l o g i c map w i t h h i s r e p o r t . The c o n t r a s t i n l i t h o f a c i e s w h i c h he p o i n t e d o u t b e t w e e n t h e P e n n s y l v a n i a n s e d i m e n t s of t he n o r t h e r n and s o u t h e r n W a s a t c h M o u n t a i n s w e r e t h e b a s i s f or h i s r e c o g n i z i n g t h e C h a r l e s t o n T h r u s t F a u l t. S e v e r a l i n v e s t i g a t o r s i n r e c e n t y e a r s h a v e d i s t i n g ­u i s h e d l i t h o l o g i c u n i t s w i t h i n t h e O q u i r r h F o r m a t i o n and h a v e p r o d u c e d g e o l o g i c maps on t h i s b a s i s ( T o o k e r and R o b e r t s , 1 9 6 1 ) , (Welsh and J a m e s , 1 9 6 1 ) , ( D o e l l i n g , 1 9 6 4 ), ( t h i s p a p e r ). S e v e r a l s t u d i e s h a v e b e e n c o m p l e t e d ( B i s s e l l , i 9 6 0, 1 9 6 2 ) , ( B r i l l , 1 9 6 3 ) , ( R o b e r t s et a l , 1 9 6 5 ) , ( S t e e l e , i 9 6 0) w h i c h c o n s i d e r t h e r e g i o n a l a s p e c t s of t h e P e r m o - P e n n s y l v a n ­i a n r o c k s of t h e e a s t e r n G r e a t B a s i n and a d j a c e n t a r e a s. The p r o b a b l e e x t e n t , s h a p e , and t e c t o n i c c h a r a c t e r i s t i c s of t h e O q u i r r h and o t h e r s e d i m e n t a r y b a s i n s h a v e b e e n c o n ­s i d e r e d as w e l l as a number of p o s t u l a t e d h i g h l a n d a r e a s. R o b e r t s ( R o b e r t s and o t h e r s , 1 9 6 5 , p . 1926) h a s a d v i s e d t h at - 3 3 - p r e s e n t - d a y s t r u c t u r a l and s t r a t i g r a p h i c e v i d e n c e must be s t u d i e d t o g e t h e r t o g a i n a s u f f i c i e n t b a s i s f o r d r a w i ng i n f e r e n c e s r e g a r d i n g t h e p a l e o g e o l o g y of t h e r e g i o n. The O q u i r r h F o r m a t i o n I n t h e C e d a r M o u n t a i n s h a s b e en s u b d i v i d e d i n t o f i v e m a p p a b l e l i t h o l o g i c u n i t s . T o g e t h er t h e s e r e p r e s e n t a c h r o n o l o g i c r a n g e from Upper M i s s i s s i p ­p i a n C h e s t e r ( ? ) t o Lower P e r m i a n L e o n a r d ( ? ) . There a p p e a r t o be l i t h o l o g i c r e p r e s e n t a t i v e s f o r p a r t or a l l of e a c h e p o c h i n t h i s t i m e i n t e r v a l w i t h t h e p o s s i b l e e x c e p t i on o f t h e M i s s o u r i a n . The l o w e r f o u r u n i t s p l u s a p a r t i a l s e c t i o n of U n i t 5 t o t a l 6 , 8 0 7 f e e t i n t h e s o u t h e r n Cedar M o u n t a i n s . A t h i c k e n i n g t o w a r d t h e c e n t r a l C e d a r M o u n t a i ns i s i n d i c a t e d a t l e a s t i n U n i t s 2, 3 , and 4. U n i t 1 D i s t r i b u t i o n and T h i c k n e ss E x p o s u r e s of U n i t 1 a c c o u n t f o r a b o u t 2 . 5 s q u a r e m i l es c o m p a r e d w i t h t h e a p p r o x i m a t e l y 130 s q u a r e m i l e s of o u t ­c r o p s f o r t h e O q u i r r h F o r m a t i o n a s a w h o l e . This r e s u l ts p r i n c i p a l l y from t h e f a c t t h a t U n i t 1 i s much t h i n n e r t h an a n y of t h e o t h e r u n i t s i n t h e f o r m a t i o n . The more e x t e n ­s i v e o u t c r o p s of U n i t 1 a r e a s s o c i a t e d w i t h two a n t i c l i n e s. S e v e r a l e x p o s u r e s o c c u r on e i t h e r s i d e of t h e a x i s of C o c h r a n S p r i n g A n t i c l i n e and i t s s o u t h e a s t w a r d e x t e n s i o n as - 3 4 - f a r as P o s t H o l l o w . A t o t a l t h i c k n e s s of 434 f e e t was m e a s u r e d a t t h e o u t c r o p j u s t w e s t of C o c h r a n S p r i n g . The s e c o n d g r o u p of o u t c r o p s i s n e a r t h e m o u t h of W i l d c a t Can­y o n ( s e c . 2 3 , T 4 S , R10W) w h e r e a n o r t h w e s t - t r e n d i n g a n t i ­c l i n a l nose p l u n g e s t o w a r d t h e summit of t h e r a n g e , Other e x p o s u r e s a r e i n s e c . 1 9 , T 4 S , R10W; s e c . 6, T 4 S , R10W; s e c . 1, T I S , R9W. Unit 1 I s a m o d e r a t e l y r e s i s t a n t u n it a n d u s u a l l y o c c u r s as s m o o t h h i l l s a l o n g t h e m a r g i n of a f l a t l a n d e r o d e d on t h e Manning Canyon F o r m a t i o n . It is u s u a l l y p o o r l y e x p o s e d ( F i g . 3 ). L i t h o l o g y The b a s a l u n i t of t h e O q u i r r h F o r m a t i o n i s m o s t l y a c o m p o s i t e of p u r e and a r g i l l a c e o u s l i m e s t o n e b e d s w h i c h a re medium t o d a r k b l u e - g r a y , s o m e t i m e s b r o w n - g r a y In c o l o r, w h i c h w e a t h e r g r a y and y e l l o w - b r o w n . The a r g i l l a c e o u s b e ds a r e u s u a l l y t h i n n e r - b e d d e d w i t h a brown c o l o r . Sand g r a i ns a r e v e r y s c a r c e t h r o u g h o u t t h e u n i t . F r a g m e n t a l c r i n o i d s, e c h i n o i d ( ? ) s p i n e s , and o t h e r s k e l e t a l p a r t i c l e s make up a s i z e a b l e p a r t of s e v e r a l of t h e l i m e s t o n e b e d s , some of w h i c h c o n t a i n w e l l - p r e s e r v e d f o s s i l s . F o s s i l f r a g m e n t s a re much m o r e common I n t h e f l o a t of t h i s u n i t t h a n of e i t h er u n d e r o r o v e r l y i n g b e d s . Chert i s v e r y s c a r c e i n t he s t r a t a of U n i t 1. I n one a r e a , w e s t of C o c h r a n S p r i n g , t h e l o w e r c o n t a ct was f a i r l y w e l l e x p o s e d and was c h o s e n w h e r e b r o w n - g r a y, P i g . 3 - P h o t o g r a p h t a k e n n e a r C o c h r a n S p r i n g w h i ch s h o w s a t y p i c a l e x p o s u r e of U n i t 1 a n d U n it 2 of t h e O q u i r r h F o r m a t i o n . F o r e g r o u n d is a l l u v i u m - c o v e r e d Manning Canyon F o r m a t i o n. F i g . 4 - P h o t o g r a p h of U n it t i o n s h o w i n g t h i ck f o r m i n g c h a r a c t e r. 2 of t h e O q u i r r h F o r m a - b e d d i n g and l e d g e - - 3 6 - f o s s i l i f e r o u s l i m e s t o n e b e d s become p r e d o m i n a n t o v e r a g r e e n i s h - g r a y , f i n e - g r a i n e d q u a r t z i t e bed of t h e u p p er M a n n i n g Canyon F o r m a t i o n . U s u a l l y , t h e l o w e r c o n t a c t i s not w e l l e x p o s e d and b l a c k s h a l e s of t h e u p p e r M a n n i n g Canyon F o r m a t i o n l i e n e a r a s l o p e w h i c h e x p o s e s t h e l o w e r b e d s of U n i t 1. The u p p e r b o u n d a r y was c h o s e n i n t h e C o c h r a n S p r i ng a r e a a t t h e b a s e of a v e r y s a n d y l i g h t brown l i m e s t o n e u n it 14 f e e t t h i c k a t t h e b a s e of t h e o v e r l y i n g s e q u e n c e of t h i c k e r - b e d d e d , g r a y , s a n d y l i m e s t o n e s . A s i m i l a r bed was l o c a t e d a t t h e t o p of U n i t 1 a b o u t a m i l e s o u t h w e s t of C o c h r a n S p r i n g b u t i t was n o t p r e s e n t i n o t h e r a r e a s and t he c o n t a c t was c h o s e n a t t h e b a s e of t h i c k e r - b e d d e d , g r a y, s a n d y , s t e p l i k e , c h e r t - b e a r i n g s t r a t a of U n i t 2. Age and C o r r e l a t i on I t h a s b e e n c o n s i d e r e d g e n e r a l l y t h a t t h e b o u n d a ry b e t w e e n t h e P e n n s y l v a n i a n and M i s s i s s i p p i a n S y s t e m s is s o m e w h e r e i n t h e m i d d l e o r u p p e r M a n n i n g Canyon F o r m a t i on i n t h e e a s t e r n B a s i n and Range P r o v i n c e . Some s t u d i e s , how­e v e r , h a v e i n d i c a t e d t h a t t h e b o u n d a r y l i e s i n t h e b a s al p o r t i o n of t h e O q u i r r h F o r m a t i o n . Dr* W a l t e r S a d l i ck ( w r i t t e n c o m m u n i c a t i o n ) e x a m i n e d two c o l l e c t i o n s a b o u t 315 f e e t a b o v e t h e b a s e of U n i t 1 n e a r C o c h r a n S p r i n g and f o u n d t h e f o l l o w i n g f o r m s: - 3 7 - F 5 5 7 T r i p l o p h y l l i t e s s p. B u x t o n l a (?) F l e x a r l a cf. a r k a n s a n us Q v a t i a T?) sp~ ( s m a l l form) R e t l c u l a r i n a s p i n o sa R h i p i d o m e l l a n e v a d e n s is S c h i z o p h o r i a a f f . r e s u p i n a t a n. s p. F 5 7 7 Ramose b r y o z o a ns C o m p o s i t a s p. F l e x a r i a ( ? ) n. g e n. P u g n o i d e s q u i n q u e p l l c us R e t i c u l a r i n a s p i n o s a "(Targe f o r m s) S p l r i f e r a f f . o c c l d u o us N u c u l a n a ( ?) P e c t e n s p. P l a n i s p i r a l g a s t r o p o ds S a d l i c k ' s comment: " B o t h c a r d s ( c o l l e c t i o n s ) c o n t a i n a l i s t of s p e c i es w h i c h a r e M i s s i s s i p p i a n i n a s p e c t . However, t he p r e s e n c e of o n l y l a r g e f o r m s of R e t i c u l a r i n a and S c h i z o p h o r i a a f f . r e s u p i n o i d e s c o u l d i n d i c a t e a P e n n s y l v a n l a n a g e ; t h e m o r p h o l o g i c a l f e a t u r e s a re n o t e x a c t l y t h o s e of t h e g e n u i n e M i s s i s s i p p i an s p e c i e s . " Two o t h e r c o l l e c t i o n s from U n i t 1 w e r e i d e n t i f i e d by Dr» S a d l i c k: F 3 8 9 Rhabdomesid b r y o z o an A n t i q u a t o n i a cf. p e r n a d o sa A n t h r a c o s p i r i f e r cf. o c c i d u us I n f l a t i a s p. L e i o r h y n c h u s s p. P e l e c y p o d G a s t r o p o d F 2 6 8 F e n e s t e l l i d b r y o z o a ns S t o n y b r y o z o a ns B u x t o n l a s p. C l e i o t h e r i d i n a s p. O r b i c u l o i d e a s p. Q r t h o t e t i d n. s p. P u n c t o s p l r i f e r t r a n s v e r s us R e t i c u l a r i n a s p i n o sa P a l e o n t o l o g i c e v i d e n c e s u g g e s t s t h a t t h e l o w e s t u n it o f t h e O q u i r r h F o r m a t i o n i n t h e C e d a r M o u n t a i n s may be in p a r t Upper M i s s i s s i p p i a n . Young ( 1 9 5 5 , p . 33) r e p o r t ed t h a t S a d l i c k c o n s i d e r e d t h a t t h e r e i s a v e r y good p o s s i b i l ­i t y t h a t t h e e n t i r e M a n n i n g Canyon F o r m a t i o n i n t h e C e d a r - L a k e s i d e M o u n t a i n s r e g i o n i s of M i s s i s s i p p i a n a g e . F u r t h er m o r e , T o o k e r and R o b e r t s ( 1 9 6 l , p 0 26) d i s c u s s f a u n al e v i d e n c e c o n c e r n i n g t h e l o w e s t u n i t of t h e O q u i r r h F o r m a ­t i o n i n t h e n o r t h e r n O q u i r r h M o u n t a i n s w h i c h s u g g e s t s t h at i t may be p a r t l y M i s s i s s i p p i a n. No O q u i r r h F o r m a t i o n b e d s as o l d as U n i t 1 a r e e x p o s ed n o r t h w a r d i n t h e n o r t h e r n L a k e s i d e - T e r r a c e M o u n t a i n s ( D o e l - l i n g , 1964) or t h e T e r r a c e - H o g u p M o u n t a i n s a r e a ( S t i f e l, 1 9 6 4 ) . S t r a t a i n t h e s o u t h e r n S t a n s b u r y M o u n t a i n s ( R i g b y, 1 9 5 7 , p . 4 9 ) , t h e n o r t h e r n ( T o o k e r and R o b e r t s , 1 9 6 1 , p, 2 1 - 2 7 ) , c e n t r a l (Welsh and J a m e s , 1 9 6 1 , p . 1 1 ) , a n d s o u t h ­e r n O q u i r r h M o u n t a i n s ( B i s s e l l , 1 9 5 9 , p . 9 4 - 1 0 0 ; N y g r e e n, 1 9 5 5 ) a r e p a r t l y or e n t i r e l y t i m e - e q u i v a l e n t s of U n i t 1 in t h e C e d a r M o u n t a i n s and a r e c o r r e l a t e d w i t h i t ( s e e P l a te V I I ) . Beds c o r r e l a t i v e w i t h U n i t 1 a r e a l s o e x p o s e d i n t he P r o v o a r e a of t h e W a s a t c h M o u n t a i n s ( B a k e r , 1947) and s o u th w a r d i n t h e G i l s o n Range ( C o s t a i n , i 9 6 0 , p . 7 3 ). - 3 9 - U n i t 2 D i s t r i b u t i o n and T h i c k n e ss A w e l l - e x p o s e d o u t c r o p of U n i t 2 c o m p r i s i n g a b o u t two s q u a r e m i l e s i s s i t u a t e d j u s t n o r t h w e s t of W h i t e Rock in t h e s o u t h e r n C e d a r M o u n t a i n s . There a r e s e v e r a l p a r t i a l ly c o v e r e d o u t c r o p s of U n i t 2 i n t h e v a l l e y b e t w e e n P o s t H o l ­l ow and W h i t e Rock, Other e x p o s u r e s o c c u r i n t e r m i t t e n t ly a l o n g C o c h r a n V a l l e y t o C o c h r a n S p r i n g w h e r e a c o m p l e te s e c t i o n of 715 f e e t was m e a s u r e d o The n e x t o u t c r o p s n o r t h ­w a r d a r e a t t h e l a t i t u d e of Tabby Peak i n s e c . 1 8 , T 4 S, R10W a n d n e a r t h e m o u t h of W i l d c a t Canyon w h e r e an e a s i ly a c c e s s i b l e , c o m p l e t e s e c t i o n i s e x p o s e d o An a p p r o x i m a te t h i c k n e s s of 1 , 4 0 0 f e e t was d e t e r m i n e d f o r t h e u n i t a t t h is l o c a l i t y from t h e t o p o g r a p h i c map0 U n i t s 1 - 2 - 3 a r e mapped a s u n d i f f e r e n t i a t e d i n a s t r u c t u r a l l y c o m p l e x a r e a i n s e c. 3 0 , 3 1 , T 3 S , R10W. Unit 2 i s a l s o e x t e n s i v e l y e x p o s e d in t h e e a s t - c e n t r a l f o o t h i l l s b e t w e e n B l a c k Rock and S u l f ur S p r i n g w h e r e i t forms t h e b e d r o c k i n a s m a l l c l o s e l y f o l d ed s y n c l i n e . U n i t s 1-2 a r e shown u n d i f f e r e n t i a t e d i n o u t c r o ps e a s t of H a s t i n g s Summit ( s e c , 3 1 , T 1 S , R9W) b e c a u s e e x p o s ­u r e s a r e n o t e x t e n s i v e e n o u g h t o d i s t i n g u i s h e a c h u n i t• L i t h o l o g y Where b e d s of U n i t 2 a r e n o t v e r y s t e e p l y i n c l i n e d, t h e y o f t e n form a s t e e p , l e d g y e s c a r p m e n t ( F i g - 4 ) 0 Unit 2 -MO i s a l m o s t c o m p l e t e l y l i m e s t o n e w i t h many b e d s c o n t a i n i ng f i n e t o medium, s u b r o u n d e d t o r o u n d e d s a n d g r a i n s . The s a n d o f t e n g i v e s t h e medium t o d a r k g r a y l i m e s t o n e s a l a m ­i n a t e d a p p e a r a n c e and s a n d g r a i n s a p p e a r s u s p e n d e d i n a f i n e l y c r y s t a l l i n e l i m e s t o n e m a t r i x 0 These b e d s f i t t he d e s c r i p t i o n , " s a n d p a p e r b e d s " d e s c r i b e d by B r i l l (1963»> p 0 3 1 3 ) . D e s e r t v a r n i s h i s common e s p e c i a l l y on t h e s a n dy u n i t s . Most of t h e b e d s a r e f i n e l y c r y s t a l l i n e b u t an o c c a s i o n a l one i s b i o c l a s t i c 0 Gray and y e l l o w - b r o w n c h e rt n o d u l e s i n v a r i o u s s h a p e s a r e common and some c h e r t o c c u rs i n s e m i - b e d d e d m a s s e s . C o n c r e t i o n a r y s t r u c t u r e s , h o r i z ­o n t a l l y f l a t t e n e d , w i t h g r a y and b r o w n i s h - b l a c k , c o n c e n t r ic b a n d i n g a r e e s p e c i a l l y common i n t h i s u n i t. The u p p e r l i m i t of U n i t 2 was c h o s e n a t t h e b a s e of t h e f i r s t brown w e a t h e r i n g , t h i n t o m e d i u m - b e d d e d , s a n dy l i m e s t o n e u n i t c h a r a c t e r i s t i c of t h e s l o p e - f o r m i n g s t r a ta o f U n i t 3. The c o n t a c t i s c o n f o r m a b l e. Age and C o r r e l a t i on U n i t 2 i s n o t y o u n g e r t h a n A t o k a n and i s p r o b a b l y most l y A t o k a n . F o u r m a c r o f o s s i l c o l l e c t i o n s w e r e made from U n i t 2. One f r om t h e b a s a l s a n d y l i m e s t o n e member was e x a m i n e d by S t o k e s who r e p o r t e d: F 5 7 8 Composita ( s m a l l s p e c i e s) S p i r i f e r k e n t u c k y e n s is A n t i q u a t o n i a ( ? ) s p. - 4 1 - He c o m m e n t e d: " P e n n s y l v a n l a n b u t c a n ' t say w h i c h p a r t - p o s s i b ly A t o k a n o r a l i t t l e l a t e r e " ( w r i t t e n c o m m u n i c a t i o n) S t o k e s e x a m i n e d one b r a c h i o p o d ( F 5 7 8 ) from t h e b o t t om p a r t of U n i t 2 a n d i d e n t i f i e d i t as A n t i q u a t o n i a sp . ( w r i t t e n c o m m u n i c a t i o n ) . A h o r n c o r a l from l o w e r U n i t 2 i s s t i l l b e i n g s t u d i e d . The l o w e r of two o c c u r r e n c e s of C h a e t e t e s s p . i n t h e C o c h r a n S p r i n g m e a s u r e d s e c t i o n i s in t h e u p p e r m o s t bed of U n i t 2. Dott ( 1 9 5 4 , 1955) r e p o r t e d t he e v i d e n c e t h a t t h i s form m i g h t be u s e f u l as an A t o k a n m a r k er h o r i z o n b u t B i s s e l l ( 1 9 5 9 , p . 108) h a s f o u n d t h a t i t may i n some i n s t a n c e s r e p r e s e n t e a r l y Des M o i n e s . The o c c u r ­r e n c e of M i l l e r e l l a sp a , a b o u t o n e - h u n d r e d f e e t a b o v e t he t o p of U n i t 2, l i m i t s an a g e n o t y o u n g e r t h a n A t o k a n6 M a c r o f o s s i l s a r e n o t p l e n t i f u l n o r e a s i l y e x t r a c t ed f r om t h e b e d s of U n i t 2, C o r a l s c o m p r i s e a h i g h e r p r o p o r ­t i o n of t h e f a u n a t h a n i n U n i t 1. T h e r e a r e no s t r a t a e x p o s e d i n t h e T e r r a c e and Hogup M o u n t a i n s ( S t i f e l , 1964) w h i c h a r e c o r r e l a t i v e w i t h U n i t 2 i n t h e C e d a r M o u n t a i n s and p r o b a b l y n o n e i n t h e G r a s sy M o u n t a i n s ( D o e l l i n g , 1 9 6 4 , p . 2 1 1 ) . Unit 2 i s c o r r e l a t ed w i t h t h e A t o k a n and p e r h a p s p a r t of t h e Morrowan s e d i m e n ts i n t h e S t a n s b u r y M o u n t a i n s ( R i g b y , 1 9 5 8 ) . It i s a l so c o r r e l a t e d w i t h p o r t i o n s of t h e l o w e r O q u i r r h F o r m a t i o n of t h e n o r t h e r n ( T o o k e r and R o b e r t s , 1 9 6 1 ) , c e n t r a l (Welsh a n d J a m e s , 1961) and s o u t h e r n O q u i r r h M o u n t a i n s ( B i s s e l l, 1 9 5 9 ; N y g r e e n , 1 9 5 8 , P l a t e V I I ). U n i t 3 D i s t r i b u t i o n and T h i c k n e ss U n i t 3 9 w i t h a b o u t f o r t y - f i v e s q u a r e m i l e s of o u t ­c r o p s , a c c o u n t s f o r more of t h e e x p o s e d b e d r o c k t h a n any o t h e r u n i t i n t h e O q u i r r h F o r m a t i o n ( T a b l e 1 ) . The low r i d g e w h i c h f o r m s t h e m o u n t a i n f r o n t s o u t h of P o s t H o l ­l ow i s u n d e r l a i n by U n i t 3 a n d s m a l l e x p o s u r e s of t he u n i t c o n t i n u e s o u t h e a s t w a r d a l m o s t t o t h e Dugway P r o v i ng G r o u n d s e n t r a n c e . It a l s o f l a n k s t h e w e s t s i d e of t he l o n g v a l l e y f o r m e d by t h e u p p e r p o r t i o n s of Wide and P o st H o l l o w s . It o u t c r o p s e x t e n s i v e l y on t h e w e s t and n o r t h ­w e s t f l a n k s of C o c h r a n S p r i n g A n t i c l i n e w h e r e i t i s p a r t ly c o v e r e d by v o l c a n i c s . West of C o c h r a n S p r i n g a c o m p l e te s e c t i o n 2556 f e e t t h i c k was m e a s u r e d . E x t e n s i v e o u t c r o ps o f U n i t 3 o c c u r w e s t of C e d a r T h r u s t F a u l t from Cedar S p r i n g n o r t h w a r d t o Lone M o u n t a i n . Unit 3 f o r m s s e v e r al l o w , p o o r l y e x p o s e d o u t c r o p s on t h e b r o a d p e d i m e n t t h at f l a n k s t h e w e s t - c e n t r a l C e d a r M o u n t a i n s . , It forms t h e n o r t h - t r e n d i n g f o o t h i l l a b o u t a m i l e n o r t h of S u l f u r S p r i n g on t h e e a s t s i d e of t h e r a n g e and i t I s a l s o t h e b e d r o c k in t h e u p t h r u s t b l o c k i m m e d i a t e l y s o u t h of H a s t i n g s Summit. - 4 4 - T h e r e i s a g o o d , c o m p l e t e s e c t i o n i n s e c . 1 4 , 1 5 , T 4 S , R10W n e a r t h e m o u t h of W i l d c a t Canyon and a t h i c k n e s s of 2 , 7 00 f e e t was d e t e r m i n e d h e r e u s i n g mapped c o n t a c t s and t he U . S . G . S Tabby P e a k 7 . 5 M i n u t e S e r i e s t o p o g r a p h i c s h e e t. The n o r t h e r n m o s t e x p o s u r e s of U n i t 3 a r e e a s t of Low R a i l ­r o a d s i d i n g and i n Skunk R i d g e n o r t h of U. S. Highway 40. E s t i m a t e d minimum t h i c k n e s s of 3>000 f e e t was c a l c u l a t ed f o r U n i t 3 e a s t of Low R a i l r o a d s i d i n g u s i n g t h e U. S. Army Map S e r v i c e , T o o e l e , U t a h q u a d r a n g l e map f o r t o p o ­g r a p h i c c o n t r o l, L i t h o l o g y I t i s e a s y t o r e c o g n i z e U n i t 3 f r om a d i s t a n c e b e c a u se I t e r o d e s t o a c o a r s e " c l i f f and s l o p e " t o p o g r a p h y . The m o u n t a i n f r o n t e a s t of Low S t a t i o n on t h e w e s t P a c i f ic r a i l r o a d w h e r e t h e b e d s d i p e a s t a t a b o u t 25 t o 35 d e g r e es p r e s e n t s a v e r y i m p r e s s i v e e x a m p l e of t h e a p p e a r a n c e of U n i t 3 i n o u t c r o p ( F i g . 6 ) . T h i s e x p o s u r e i s e a s i l y v i s i b le s o u t h of t h e h i g h w a y when a p p r o a c h i n g t h e C e d a r M o u n t a i ns f r om t h e w e s t on U. S. Highway 4 0 . B i s s e l l ( 1 9 5 9 , p . 109) r e f e r s t o c o r r e l a t i v e s t r a t a i n t h e s o u t h e r n O q u i r rh M o u n t a i n s i n d i c a t i n g t h a t t h e b e d s of h i s C e d a r F o r t mem­b e r of t h e O q u i r r h F o r m a t i o n make c o c k s c o m b r i d g e s w h e re t h e y a r e e x p o s e d a s t h e l i m b of a f o l d . The c l i f f - f o r m i ng m e m b e r s of U n i t 3 a r e u s u a l l y medium g r a y and t h i c k - b e d d ed P i g . 6 - P h o t o g r a p h of U n i t 3 of t h e O q u i r r h F o r m a t i on e a s t of Low r a i l r o a d s i d i n g s h o w i n g i t s " c l i f f - a n d - s l o p e " e r o s i o n a l c h a r a c t er F i g . 7 - P h o t o g r a p h s h o w i n g c r o s s - b e d d i n g i n a c l i f f - f o rm i n g l i m e s t o n e of U n i t 3 of t h e O q u i r r h F o r m a t i on t o m a s s i v e . T e x t u r a l l y , t h e y r a n g e from b l o c l a s t i c t o f i n e ly c r y s t a l l i n e . V a r y i n g a m o u n t s of s a n d and s i l t a r e o f t en o b s e r v e d , t h e s i l t o c c u r r i n g w i t h t h e f i n e l y c r y s t a l l i ne l i m e s t o n e . These b e d s o f t e n h a v e a number of I n t r a f o r m a t i o n - a l s t r u c t u r e s s u c h a s c r o s s - s t r a t i f i c a t i o n and s l u m p. ( F i g s . 7, 8)0 The brown and g r a y , s l o p e - f o r m i n g , t h i n n e r - b e d d e d l i m e s t o n e u n i t s u s u a l l y d e v e l o p s l o p e s w i t h s l a b by y e l l o w - b r o w n , p a l e o r a n g e , p a l e r e d , and l a v e n d e r c o b b l e s. B r o w n , g r a y , and b l a c k c h e r t i s common. It i s s o m e t i m es c o n c e n t r a t e d i n n o d u l a r m a s s e s ( F i g . 9 ) . The r e l a t i ve a b u n d a n c e of t h e c l i f f - f o r m i n g and s l o p e - f o r m i n g s t r a t a as d e s c r i b e d i n t h e s e c t i o n m e a s u r e d a t C o c h r a n S p r i n g i s 5 0 / 5 0. The r e c u r r e n c e of s i m i l a r l i t h o l o g i c u n i t s t h r o u g h o ut m o s t of U n i t 3 i s c l e a r l y of a c y c l i c c h a r a c t e r . I n d i v i d u al d e t a i l s of s p e c i f i c s e q u e n c e s v a r y , b u t one w h i c h seemed to b e g e n e r a l l y r e p r e s e n t a t i v e was m e a s u r e d and d e s c r i b e d t o be a t a l o c a t i o n a b o u t 2 . 5 m i l e s w e s t of B r o w n ' s S p r i n g: U n i t Description Thickness 3 Limestone, medium t o d a r k g r a y ; 50 w e a t h e r s l i g h t brown and l i g h t g r a y; t h i n t o m e d i u m - b e d d e d ; some t h i n, s h a l y z o n e s ; f o r m s s l o p e. 2 Limestone, medium g r a y ; w e a t h e r s l i g h t 22 g r a y and l i g h t b r o w n ; f i n e l y s a n d y, t h i n t o m e d i u m - b e d d e d ; b r o w n , I r r e g u ­l a r l y s h a p e d c h e r t n o d u l e s and s a n dy c o n c r e t i o n s g i v e a s p o t t e d a p p e a r a n c e; f o r m s s m a l l l e d g e s. - 4 7 - U n i t Description Thickness 1 Limestone, medium g r a y ; w e a t h e r s medium 55 g r a y and w i t h a j a g g e d s u r f a c e ; medium t o t h i c k - b e d d e d ; s e v e r a l l a y e r s b i o c l a s - t i c ; some f i n e - s a n d y , brown l a y e r s ; some l e n t i c u l a r l y b e d d e d c h e r t w i t h 2 - 3 I n ch d i s c o n t i n u o u s l e n s e s ; b o t t o m few f e et f i n e l y s a n d y and b r o w n - w e a t h e r i n g ; b o t t om s u r f a c e of t h e u n i t i r r e g u l a r , c l i ff f o r m e r . The c l i f f - f o r m i n g u n i t s d i s a p p e a r a b o u t 500 t o 600 f e et b e l o w t h e t o p of U n i t 3. S e v e r a l of t h e more p r o m i n e n t l i m e ­s t o n e b e d s i n t h i s i n t e r v a l a r e u n i f o r m l y f i n e l y c r y s t a l l i ne a n d s a n d y . The b a s e of U n i t 4 was c h o s e n i n t h e C o c h r an S p r i n g s e c t i o n b e l o w a l i g h t b r o w n - w e a t h e r i n g s a n d s t o n e w i th some i n t e r b e d d e d g r a y l i m e s t o n e . F a r t h e r n o r t h i n t h e Tabby P e a k a r e a t h e c o n t a c t was p l a c e d w h e r e p r o m l n a n t g r a y l i m e ­s t o n e - b e a r i n g s t r a t a g a v e way t o l i g h t b r o w n , p l a t y - w e a t h e r - i n g s a n d s t o n e b e d s and i n t e r l a y e r e d l i g h t brown and g r ay s a n d y l i m e s t o n e s. Age and C o r r e l a t i on Most of t h e d a t a from 66 f o s s i l c o l l e c t i o n s f o r w h i ch p a l e o n t o l o g i s t s e s t i m a t e d g e o l o g i c age a r e c o n s i s t e n t w i th a n i n t e r p r e t a t i o n t h a t U n i t 3 s p a n s t h e t i m e f r om l a te A t o k a n t o m i d d l e V l r g i l i a n . The c o l l e c t i o n l o c a t i o n s a re shown on P l a t e s l a and l b and F i g u r e 5 shows g r a p h i c a l ly t h e a g e s i n d i c a t e d by f o s s i l c o l l e c t i o n s f o r e a c h u n i t of t h e O q u i r r h F o r m a t i o n ( a l s o P l a t e V ) . F53, F 5 4 , F55 in F i g . 8 - P h o t o g r a p h s h o w i n g s l u m p s t r u c t u r e i n a c l i f f - f o r m i n g l i m e s t o n e of U n i t 3 of t h e O q u i r rh F o r m a t i o n i n t h e s o u t h e r n C e d a r M o u n t a i n s. F i g . 9 - P h o t o g r a p h s h o w i n g c h e r t a g g r e g a t e s i n a c l i ff f o r m i n g l i m e s t o n e of t h e O q u i r r h F o r m a t i o n. s e c . 1 4 , T1S, R10W a r e a n o m a l o u s , r a n g i n g I n t o u p p e r V l r - g i l i a n and l o w e r W o l f c a m p i a n . While b e d s c o n t a i n i n g t h is s u i t e a r e on t r e n d w i t h b e d s f a r t h e r n o r t h w h i c h a r e d a t ed m i d d l e Des M o i n e s i a n , t h e b e d r o c k a t t i t u d e i n t h e a r e a of t h e c o l l e c t i o n s I n c r e a s e s t o as much a s 72 d e g r e e s t o w a rd t h e s o u t h e a s t and I t I s p o s s i b l e t h a t some b e d s a s h i gh s t r a t i g r a p h i c a l l y as b a s a l U n i t 4 o c c u r a t t h i s l o c a t i o n. F 5 0 , P 5 1 , and F 5 2 , e a s t of Low S t a t i o n , may i n d i c a t e a s m a l l t h i c k n e s s of U n i t 4. However, t h e e x a c t age of t h e se b e d s may u l t i m a t e l y be r e v i s e d s i n c e F50 and F 5 2 , w h i ch a r e d a t e d a s u p p e r V i r g i l i a n on f u s u l i n i d s , b r a c k e t a m a c r o f o s s i l c o l l e c t i o n j u d g e d t o be of Morrowan or A t o k an a g e . F378 r e p r e s e n t s a c o m p o s i t e m i c r o f o s s i l and m a c r o - f o s s i l c o l l e c t i o n and i s one of a s e r i e s of c o l l e c t i o ns w e s t of B l a c k Rock i n t h e e a s t - c e n t r a l C e d a r M o u n t a i n s. The a g e b a s e d on m i c r o f o s s i l s i s V i r g i l i a n and t h a t b a s ed o n m a c r o f o s s l l s i s Morrowan* F427 i s from t h e k l l p p e n o r th o f Q u i n c y S p r i n g . The c o l l e c t i o n I s from a l i t h o l o g lc s e q u e n c e t h a t i s c h a r a c t e r i s t i c U n i t 3. I n a d d i t i o n t o t h e c o l l e c t i o n s whose r e l a t i v e s t r a t i - g r a p h i c p o s i t i o n s a r e shown w i t h t h e O q u i r r h F o r m a t i on m e a s u r e d s e c t i o n s ( P l a t e s V, V I ) , t h e f o l l o w i n g c o l l e c t i o ns a r e l i s t e d I n t h e s t r a t i g r a p h i c s e q u e n c e I n w h i c h t h e y w e re c o l l e c t e d . The l o w e s t u n i t s t r a t i g r a p h i c a l l y i n t he s e q u e n c e I s a t t h e b o t t o m . The p a l e o n t o l o g i s t who made t he i d e n t i f i c a t i o n i s l i s t e d a f t e r t h e f o s s i l names and s u g g e s t ed a g e ( s e e a c k n o w l e d m e n t s ). S e q u e n c e No. 1 U n i t 3 P 1 32 F 1 44 F 1 43 F 1 42 F l 4 l F 1 40 F 1 35 F u s u l l n i d , t w o - l a y e r w a l l , m i d d l e V i r g i l, S t e e l e T r i t i c i t e s s p . , m i d d l e V i r g i l , S t e e le T r i t i c i t e s s p . , Steele T r i t i c i t e s s p . , m i d d l e V i r g i l , S t e e le T r i t i c i t e s a f f . c u l l o m e n s i s . , m i d d le V i r g i l , S t e e le F u s u l i n i d , t w o - l a y e r w a l l , m i d d l e V i r g i l, S t e e l e P r o d u c t i d b r a c h i o p od L i n o p r o d u c t u s s p. C o m p o s i t a s p. B r y o z o a n s (2 g e n e r a) S t o k e s c o m m e n t e d , " p r o b a b l y m i d d le P e n n s y l v a n l a n b u t c o l l e c t i o n i s i n s u f ­f i c i e n t f o r e x a c t d e t e r m i n a t i o n ." S e q u e n c e No. 2 U n i t 4 F 3 8 0 T r i t i c i t e s cf. T. m e d i o c r i s v a r . a n g u s t u s, m i d d l e V i r g i l , S t e e le T r i t i c i t e s s p. U n i t 3 F 3 7 9 T r i t i c i t e s i n d e t . , V i r g i l , S t e e le P 3 7 8 T r i t i c i t e s i n d e t . , V i r g i l , S t e e le A n t i q u a t o n i a s p. C o m p o s i t a s p. D i c t y o c l o s t u s a m e r i c a n us D i c t y o c l o s t u s s p. E c h i n o c h o n c h u s s p. R e t l c u l a r l n a s p i n o sa S p i r i f e r opimus " M o r r o w a n " , S t o k es ( ? ) U n c o n f o r m i ty F 3 7 7 F u s u l i n e l l a of. n e v a d e n s l s , l o w e r to u p p e r Des M o i n e s i a n , S t e e le F 3 7 5 Derbya s p . , M a u r er F 3 7 4 F u s u l i n a cf. F. w e l n t z i , l o w e r to m i d d l e Des M o i n e s i a n , S t e e le F373 F u s u l i n a c f . F. l e ei F u s u l i n a cf. F. w e i n t z i , l o w e r to m i d d l e Des M o i n e s i a n , S t e e le U n i t 2 F 3 7 2 Composita s p. P r o d u c t i d D i t y m o p y g e ( ? ) s p. " M o r r o w a n " , S t o k es S e q u e n c e No. F 4 6 l T r i t i c i t e s m e d i o c r i s , l o w e r t o m i d d le V i r g i l i a n , S t e e le T r i t i c i t e s a f f . c u l l o m e n s is F 4 2 6 A n t l q u a t o n i a a f f . A. p o r t l o c k e n s ls A n t i q u a t o n i a n. s p . a f f . h e r m o s a n us D e r b y a s p. N e o s p i r i f e r cf. c a m e r a t us P r o d u c t u s a r k a n s a n u s ( s i m i l a r t o) " p r o b a b l y M o r r o w a n , A t o k a n , or e a r l y Des M o i n e s i a n " , S a d l l ck F427 Composita s p. L i n o p r o d u c t u s s p. " P r o d u c t u s " a r k a n s a n us "Not y o u n g e r t h a n M o r r o w a n " , S a d l l ck F 4 2 8 C a n i n i a s p . , S a d l l ck ( s a m e h o r i z o n as F428 (?) C a n i n i a s p . , M a u r er S e q u e n c e No0 4 F 6 5 4 Taonurus ( ? ) s p . , S a d l l ck F 6 5 3 (same l o c a t i o n a s F654) T r i t i c i t e s meeki (?) O z a w a i n e l l a ( s a g i t t a l s e c t i o n) T e t r a t a x i s " p r o b a b l y l o w e r W o l f c a m p i a n " , Holcomb - 5 F 4 0 2 T r i t i c i t e s c u l l o m e n s i s , m i d d le V i r g i l i a n , S t e e le F 4 0 1 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n, S t e e l e ( ? ) U n c o n f o r m i ty F40Q F u s u l i n e l l a n e v a d e n s i s ( ? ) , u p p e r - l o w er ( ? ) Des M o i n e s i a n , S t e e le S e q u e n c e No. 5 P30 P u s u l l n l d , f o u r - p a r t w a l l , p r o b a b ly m i d d l e Des M o i n e s , S t e e le F u s u l l n e l l a cf. a l t a , m i d d l e Des M o i n e s, S t 6 6 l e P 2 5 P u s u l l n a s p . , m i d d l e Des M o i n e s , S t e e le F 2 3 P r l s m o p o r a s p . , M a u r er The f o l l o w i n g a r e a d d i t i o n a l c o l l e c t i o n s from U n i t 3 n ot c o l l e c t e d as p a r t of a s t r a t i g r a p h i c s e q u e n c e: F40 U n i d e n t i f i e d b r y o z o a ns P u n c t o s p i r i f e r c o m p e s t r is A r c h i m e d e s s p. " M o r r o w a n o r A t o k a n " , S t o k es F43 L i n o p r o d u c t u s cf. p r a t t e n l a n us " A t o k a n or y o u n g e r " , S t o k es P 1 0 8 D i c t y o c l o s t u s s p. L i n o p r o d u c t u s s p. I n d e n t i f i e d by S t o k es F 1 3 1 Mesolobus m e s o l o b us N e o s p i r i f e r s p. D i c t y o c l o s t u s s p. "Des M o i n e s " , S t o k es F 1 4 5 T r i t i c i t e s m e d i o c r i s s u b s p . a n g u s t u s, m i d d l e V i r g i l i a n , S t e e le F 1 7 2 T r i t i c i t e s c u l l o m e n s i s ( ? ) , m i d d le V i r g i l i a n , S t e e le P l ? 4 T r i t i c i t e s aff. s e c a l i c u s , m i d d le V i r g i l i a n , S t e e le P 1 7 6 T r i t i c i t e s a f f . s e c a l i c us T r i t i c i t e s a f f - c u l l o m e n s is m i d d l e V i r g i l i a n , S t e e le P177 T r i t i c i t e s s p . , V i r g i l i a n , S t e e le P s e u d o f u s u l l n e l l a s p . ( c o u l d be P u s u li n e l l a ) , S t e e le P 1 8 8 T r i t i c i t e s a f f . c u l l o m e n s i s , m i d d le F 1 9 4 T r i t i c i t e s s p . , u p p e r ( ? ) V i r g i l i a n, S t e e l e F219A S y r l n g o p o r a s p. B r y o z o a n s D i c t y o c l o s t u s a m e r l c a n us L i n o p r o d u c t u s p r a t t e n i a n us P u n c t o s p l r i f e r c o m p e s t r is " A t o k a n " , S t o k es P219B A n t l q u a t o n l a c f . h e r m o s l a na B e e c h e r l a ( ? ) n. s p. C a l l o p r o t l n a (?) n e b r a s k e n s is C r u r y t h y r i s s p. H u s t e d i a n, s p. K r o t o v i a ( ? ) s p. L e i o r h y n c h u s cf. r o c k y m o n t a n us L i n o p r o d u c t u s s p. " p r o b a b l y Des M o i n e s " , S a d l l ck P 2 2 2 Composita s p. D i c t y o c l o s t u s s p. L i s s o m a r g i n l f e r a nuda (?) S c h l z o p h o r i a r e s u p i n o i d es " l o w e r A t o k a n " , S t o k es F 2 3 1 G a s t r o p od D e r b y a s p. S p l r l f e r o c c i d u us " A t o k a n " , S t o k es F 3 0 3 F u s u l i n a s p. F u s u l l n e l l a s p. " l o w e r Des M o i n e s " , S t e e le F31Q T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le F 3 1 6 Composita (two s p e c i e s) S p i r i f e r o c c i d u us S p i r i f e r opimus " M o r r o w a n - D e s M o i n e s i a n " , S t o k es F 3 4 0 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le F 3 4 2 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le F 3 4 4 Bryozoan C o m p o s i t a sp o L i n o p r o d u c t u s p r a t t e n i a n us P u n c t o s p i r i f e r c o m p e s t r is S c h i z o p h o r i a r e s u p i n o i d e s (?) " A t o k a n " , S t o k es F 3 9 2 F u s u l i n a cf. P. w e i n t zi F u s u l l n e l l a a f f . F. a l ta F u s u l l n e l l a cf. F. n e v a d e n s is F394 F u s u l i n a a f f . P. w e l n t z l , l o w e r t o u p p er Des M o i n e s i a n , S t e e le F 3 9 5 F u s u l l n e l l a a f f . F. n e v a d e n s i s , l o w e r to u p p e r Des M o i n e s i a n , S t e e le F 3 9 6 F u s u l l n e l l a a f f . F. n e v a d e n s i s , l o w e r to u p p e r Des M o i n e s i a n , S t e e le F 4 6 0 Myallna s p. B u x t o n i a s p. F 4 8 8 M i l l e r e l l a s p . , Morrowan o r A t o k a n , Lambson F 4 8 9 F u s u l l n e l l a s p . , A t o k a n , Lambson F 4 9 1 C h a e t e t e s s p . , M a u r er F 4 9 3 E o s c h u b e r t e l l a s p. F u s u l l n e l l a s p. " l o w e r t o u p p e r Des M o i n e s i a n ", S t e e l e S t o k e s " A t o k a n Lambson F 4 9 5 F u s u l i n a n, s p . ( ? ) , S t e e le F u s u l i n a sp* F u s u l l n e l l a s p. b a s a l Des M o i n e s i a n , Lambson - 5 5 - F 4 9 6 F u s u l i n a a f f . F0 r o c k y m o n t a na F u s u l i n a n 0 s p. S t e e l e F u s u l i n a sp . , Des M o i n e s i a n , Lambson F 4 9 7 F u s u l i n a r o c k y m o n t a n a , l o w e r Des M o i n e s i a n, S t e e l e F u s u l i n a s p , , Des M o i n e s i a n , Lambson F 4 9 8 F u s u l i n a a f f . P. l o n s d a l e n s is F u s u l i n a r o c k y m o n t a na F u s u l i n a n. s p. m i d d l e Des M o i n e s i a n , S t e el F u s u l i n a s p . , u p p e r Des M o i n e s i a n, Lambson F 5 0 0 F u s u l i n a s p , I n d e t . , m i d d l e t o u p p e r Des M o i n e s i a n , S t e e le F u s u l i n a s p . , u p p e r Des M o i n e s i a n, Lambson F504 T r i t i c i t e s s p . i n d e t . , l o w e r t o m i d d le V i r g i l i a n , S t e e le T r i t i c i t e s s p . , b a s a l M i s s o u r i a n , Lambson F 5 0 5 T r i t i c i t e s e x . g r . T. c u l l o m e n s i s , m i d d le V i r g i l i a n , S t e e le T r i t i c i t e s s p . , M i s s o u r i a n , Lambson F 5 0 6 T r i t i c i t e s c u l l o m e n s i s , m i d d l e V i r g i l i a n, S t e e l e T r i t i c i t e s s p . , M i s s o u r i a n , Lambson F507 T r i t i c i t e s n. s p . , m i d d l e V i r g i l i a n , S t e e le T r i t i c i t e s s p . , M i s s o u r i a n , Lambson F 5 H T r i t i c i t e s n. s p . , m i d d l e V i r g i l i a n , S t e e le F 5 1 2 T r i t i c i t e s c u l l o m e n s i s , m i d d l e V i r g i l i a n, S t e e l e T r i t i c i t e s sp . , u p p e r M i s s o u r i a n o r b a s al V i r g i l i a n ( ? ) Lambson F 5 7 1 T r i t i c i t e s of m e d i o c r i s v a r . a n g u s t us ( ? ) , V i r g i l i a n , Lambson T u b e r t i n a s p. I v a n o v i a s p. F 5 7 2 T r i t i c i t e s ef. c u l l o m e n s i s , V i r g i l i a n, Holcomb F 5 7 9 P r l s m o p o r a s p . , S a d l l ck - 5 6 - F 5 8 0 "Horn c o r a l s I n bad c o n d i t i o n " , S a d l i ck F u s u l i n a k n i g h t i , u p p e r m o s t Des M o i n e s i a n, Lambson and H o r t on F 5 8 l A n t l q u a t o n l a cf, c o l o r a d o e n s l s , S a d l i ck F 5 8 7 F u s u l i n a k n i g h t i , u p p e r m o s t Des M o i n e s i an Lambson and H o r t on F 5 8 9 S y r i n g o p o r a s p . , M a u r er F u s u l i n i d s e q u e n c e s c o l l e c t e d a t f o u r d i f f e r e n t l o c a l i ­t i e s i n t h e C e d a r M o u n t a i n s and e x a m i n e d by S t e e l e ( w r i t t en c o m m u n i c a t i o n ) s u g g e s t t h a t t h e r e i s o n l y a s l i g h t t h i c k n e s s, i f a n y , of M i s s o u r i a n s t r a t a I n t h i s a r e a 0 The f o u r a r e as a n d c o l l e c t i o n s I n v o l v e d a r e: 1 . East of Low S t a t i o n (NW C e d a r M o u n t a i n s ) , F 2 9 , F52 2 . N o r t h of Tabby Peak ( s e c . 1 6 , T 4 S , R10W), F 4 0 0, F 4 0 1 3 . N o r t h of W i l d c a t Canyon ( s e c 0 1 2 , T 4 S , R10W) F 3 7 7, F 3 88 4 . West of C o c h r a n S p r i n g ( S o . C e d a r M o u n t a i n s ) F 5 0 0, F504 P a l e o n t o l o g i c and g e o l o g i c e v i d e n c e , s u g g e s t s t h a t t h e r e a re n o more t h a n a b o u t 80 f e e t of M i s s o u r i a n s t r a t a i n t he O q u i r r h F o r m a t i o n s e c t i o n a t C o c h r a n S p r i n g e F u s u l i n i d s from t h e l o c a l i t y n o r t h of W i l d c a t Canyon s u g g e s t t h a t t h e re w o u l d be no more t h a n a b o u t 5 0 - 7 5 f e e t of M i s s o u r i a n a t t h at l o c a t i o n . Lambson ( 1 9 6 1 ) w o r k i n g w i t h p o r t i o n s of t he same f o s s i l c o l l e c t i o n s from t h e C o c h r a n S p r i n g a r e a exam­i n e d by S t e e l e , ( 1 9 6 1 ) d a t e d t h e f u s u l i n i d s s u c h t h at M i s s o u r i a n b e d s r a n g e t h r o u g h 450 f e e t of t h e s e c t i o n m e a s ­u r e d a t C o c h r a n S p r i n g. U n i t 3 c a n be c o r r e l a t e d w i t h p a r t s of t h e O q u i r rh - 5 7 - F o r m a t l o n i n t h e G r a s s y , t h e S t a n s b u r y , and t h e n o r t h e r n, c e n t r a l , and s o u t h e r n O q u i r r h M o u n t a i n s ( P l a t e V I I ) . Unit 3 i s a l s o c o r r e l a t i v e w i t h p a r t of t h e E l y L i m e s t o n e of t he C o n f u s i o n B a s i n (Hose and R e p e n n i n g , 1959) and p a r t of t he l o w e r O q u i r r h F o r m a t i o n i n t h e s o u t h e r n W a s a t c h M o u n t a i ns ( B a k e r , 1 9 * 7 ). U n i t 4 D i s t r i b u t i o n and T h i c k n e ss The s o u t h e r n m o s t e x p o s u r e of U n i t 4 i s on t h e s o u t h e a st s i d e of P o s t H o l l o w w h e r e i t i s p r e s e r v e d i n a s m a l l s y n - c l i n e o This u n i t i s l e s s r e s i s t a n t t h a n e i t h e r U n i t 3 or o v e r l y i n g U n i t 5 a n d as a r e s u l t I t o c c u p i e s c o r r m p a r a t i v e ly l o w e r t o p o g r a p h i c r e g i o n s. The l a r g e s t e x p o s u r e of U n i t 4 i n t h e C e d a r M o u n t a i ns i s a l o n g t h e w e s t f l a n k of C o c h r a n S p r i n g A n t i c l i n e and s o u t h w a r d w h e r e i t forms t h e s o u t h w e s t e r n m o s t o u t c r o p s of t h e r a n g e p r o p e r , The n o r t h e r n e d g e of t h i s o u t c r o p a r ea p r o v i d e s t h e " s a d d l e " f o r t h e r o a d w h i c h c r o s s e s t h e r a n ge s o u t h of Tabby P e a k . A c o m p l e t e s e c t i o n of U n i t 4 m e a s u r ed a l o n g a t r a v e r s e w e s t from C o c h r a n S p r i n g t o t a l l e d 2 , 7 62 f e e t . A b a n d of U n i t 4 t r e n d s e a s t a c r o s s t h e r a n g e n o r th o f Tabby P e a k . C a l c u l a t i o n of t h e t h i c k n e s s h e r e u s i n g t he t o p o g r a p h i c map i n d i c a t e s i t i s a p p r o x i m a t e l y 3 3 0 0 0 f e et - 5 8 - t h i c k . There I s a l s o an o u t c r o p of U n i t 4, a b o u t f i ve s q u a r e m i l e s i n a r e a , w h i c h t r e n d s n o r t h b e t w e e n W i l d c at C a n y o n and S u l f u r S p r i n g . Two o t h e r f a i r l y e x t e n s i v e o u t ­c r o p s a r e i n t h e p i e d m o n t a r e a b e t w e e n Lone M o u n t a i n and t h e w e s t e r n b a s e of t h e m o u n t a i n s . In t h e n o r t h e r n Cedar M o u n t a i n s U n i t 4 o c c u p i e s a s t r i p a l o n g t h e e a s t s i d e of S t r a i g h t Canyon w h i c h t r e n d s n o r t h and c u r v e s n o r t h e a s t w a rd t o f o rm t h e v a l l e y c r o s s e d by U. S. Highway 4 0 - 5 0 and t he W e s t e r n P a c i f i c R a i l r o a d l i n e . A n o t h e r p r o m i n e n t o u t c r op i s a b o u t a m i l e e a s t of H a s t i n g s P e a k. L i t h o l o g y The l i t h o l o g y of U n i t 4 i s p r i m a r i l y of two c o n t r a s t i ng t y p e s . The f i r s t i s f i n e l y c r y s t a l l i n e , t h i n - t o medium-b e d d e d l i m e s t o n e w h i c h w e a t h e r s t o a s m o o t h , d o v e - g r ay s u r f a c e . F r e s h s u r f a c e s a r e medium t o d a r k g r a y . These b e d s f o rm s m a l l l e d g e s . There i s a r e l a t i v e l y h i g h f r a c t i on o f d a r k , c a r b o n a c e o u s m a t e r i a l w h i c h i s s o m e t i m e s v i s i b le a s b l a c k s p e c k s on a f r e s h s u r f a c e „ O x i d a t i o n of t h is m a t t e r upon w e a t h e r i n g p r o b a b l y a c c o u n t s f o r t h e s t r o ng c o l o r c o n t r a s t o f t e n n o t i c e d b e t w e e n f r e s h and w e a t h e r ed s u r f a c e s o This f i r s t c h a r a c t e r i s t i c r o c k t y p e c o n t r a s ts s h a r p l y w i t h t h e u n d e r l y i n g U n i t 3 w h o s e c a r b o n a t e b e d s a re f r e q u e n t l y b i o c l a s t i c and f r e e of u n o x i d i z e d c a r b o n a c e o us m a t e r i a l . The s e c o n d r o c k t y p e of U n i t 4 c o n s i s t s of - 5 9 - l i g h t b r o w n , b r o w n , g r a y , and m a r o o n t o l a v e n d e r - w e a t h e r ­i n g f i n e s a n d s t o n e l a y e r s and s a n d y and s i l t y l i m e s t o n e s. No t r u e s h a l e s , i . e . l a m i n a t e d , f i s s i l e , p e l i t i c b e d s , have b e e n o b s e r v e d i n t h i s u n i t . F r e s h c o l o r I s u s u a l l y brown a n d g r a y . These l a y e r s a r e t h l n - t o m e d i u m - b e d d e d , p l a t y - w e a t h e r i n g and g e n e r a l l y p r o d u c e p o o r l y e x p o s e d , t a l u s - c o v e r e d s l o p e s . "Worm t r a i l " m a r k i n g s a r e a common b e d d i ng p l a n e f e a t u r e of U n i t 4 a l t h o u g h t h e s e a r e n o t r e s t r i c t ed t o t h i s u n i t a l o n e ( F i g . 1 0 ) . They a r e f o u n d a l s o i n t he t h i n n e r - b e d d e d p o r t i o n s of U n i t 5. The l o w e r c o n t a c t of U n i t 4 was c h o s e n a t t h e b a s e of t h e s e r i e s of b e d s w i th t h e c h a r a c t e r i s t i c d a r k - g r a y , f i n e l y c r y s t a l l i n e l i m e ­s t o n e s and i n t e r b e d d e d t h i n - t o m e d i u m - b e d d e d s a n d s t o n e s. The c o n t a c t a p p e a r s t o be g r a d a t i o n a l . E s p e c i a l l y i n t he C o c h r a n S p r i n g a g e a , i t c o i n c i d e s w i t h a t o p o g r a p h i c s l o pe w h i c h c a n be f o l l o w e d i n m a p p i n g . The u p p e r c o n t a c t of U n i t 4 was p l a c e d a t t h e b a s e of a s e q u e n c e of l i g h t brown a n d g r a y s a n d s t o n e b e d s w h i c h d i f f e r from t h o s e b e l o w in t h a t t h e y a r e t h i c k e r - b e d d e d , o f t e n more f r i a b l e , s o m e t i m es q u a r t z i t i c , and f r e q u e n t l y h a v e d e s e r t v a r n i s h . E l o n g a t ed c a v i t i e s l e f t a f t e r t h e l e a c h i n g of f u s u l i n i d s a r e f r e q u e n t ly s e e n i n t h e s e b e d s . The f i n e - g r a i n e d , g r a y l i m e s t o n e b e ds c h a r a c t e r i s t i c of U n i t 4 a r e l a c k i n g i n t h e o v e r l y i n g b e ds o f U n i t 5. S i l t s t o n e and s a n d s t o n e b e d s of U n i t 4 become F i g . 10 - P h o t o g r a p h of "worm t r a i l " m a r k i n gs c h a r a c t e r i s t i c of U n i t s 4 a n d 5 of t h e O q u i r r h F o r m a t i o n. - 6 1 m o r e a b u n d a n t c o m p a r e d t o l i m e s t o n e i n t h e c e n t r a l and n o r t h ­e r n p a r t of t h e r a n g e . There a r e s e v e r a l l i m e s t o n e c o n g l o m ­e r a t e b e d s , i n w h i c h t h e c l a s t s r e a c h c o b b l e s i z e , i n t he s t r a t a mapped a s U n i t s 4 a n d 5 u n d i v i d e d n o r t h of H a s t i n gs S u m m i t . C o m p l i c a t i o n s i n s t r u c t u r e a s w e l l a s s t r a t i g r a p hy made I t i m p o s s i b l e f o r t h e w r i t e r t o d i s t i n g u i s h U n i t 4 from U n i t 5 i n t h i s l o c a l i t y. Age a n d C o r r e l a t i on S t u d i e s of f u s u l i n i d c o l l e c t i o n s from U n i t 4 i n d i c a te a n a g e of m i d d l e W o l f c a m p i a n t o m i d d l e V i r g i l i a n . Macro-f o s s i l s a r e much more s c a r c e i n U n i t 4 a n d a l s o i n U n i t 5 t h a n i n t h e l o w e r u n i t s of t h e O q u i r r h F o r m a t i o n . The f o l ­l o w i n g a r e r e s u l t s of s t u d i e s of c o l l e c t i o n s made from U n i t 4: (The p a l e o n t o l o g i s t who made t h e i d e n t i f i c a t i o n is i n d i c a t e d a f t e r t h e g e o l o g i c a g e ). F77 T r i t i c i t e s c u l l o m e n s l s - T r l t l c l t e s a f f . m e d l o c r l s a n g u s t us U p p e r V i r g i l i a n , S t e e le F79 T r i t i c i t e s s p . , V i r g i l i a n , S t e e le F 8 0 T r i t i c i t e s c u l l o m e n s is T r i t i c i t e s s p . i n d e t. U p p e r V i r g i l i a n , S t e e le F84 T r i t i c i t e s s p . i n d e t . , S t e e le F85 T r i t i c i t e s s p . i n d e t . , u p p e r V i r g i l i an o r l o w e r W o l f c a m p i a n , S t e e le - 6 2 - P 1 8 3 T r i t i c i t e s a f f . c u l l o m e n e l s , m i d d le V i r g i l i a n , S t e e le F 1 8 4 T r i t i c i t e s a f f . c u l l o m e n s i s , m i d d le V i r g i l i a n , S t e e le P 2 6 6 T r i t i c i t e s a f f . c u l l o m e n s i s , m i d d le V i r g i l i a n , S t e e le P 2 6 7 T r i t i c i t e s a f f . c u l l o m e n s is T r i t i c i t e s s p. M i d d l e V i r g i l i a n , S t e e le P 2 6 9 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le P 2 9 9 S c h w a g e r i n a cf, n e o l a t a , m i d d l e Wolf­c a m p i a n , S t e e le P s e u d o s c h w a g e r l n a s p. P 3 1 1 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le F 3 1 3 T r i t i c i t e s s p . i n d e t . , m i d d l e t o u p p er V i r g i l i a n , S t e e le F 3 1 9 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le P 3 8 0 T r i t i c i t e s cf. T. m e d i o c r l s v a r . a n g u s t us T r i t i c i t e s s p. m i d d l e V i r g i l i a n , S t e e le P 3 8 2 T r i t i c i t e s cf. T^ m e d i o c r i s v a r . a n g u s t us T r i t i c i t e s a f f . T . " c u l l o m e n s is m i d d l e V i r g i l i a n , S t e e le P 3 8 3 T r i t i c i t e s a f f . T. c u l l o m e n s i s , m i d d le V i r g i l i a n , S t e e le P 3 8 5 T r i t i c i t e s s p . , Upper V i r g i l i a n , S t e e le P 4 0 1 T r i t i c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le P 4 0 2 T r i t i c i t e s c u l l o m e n s i s , m i d d l e V i r g i l i a n, S t e e l e - 6 3 - T r i t 3 c i t e s s p . , m i d d l e V i r g i l i a n , S t e e le T r i t i c i t e s s p V i r g i l i a n ( ? ) , Lambson T r i t i c i t e s m e d i o c r l s , l o w e r t o m i d d le V i r g i l i a n , Lambson and H o r t on T r i t i c i t e s c f . c u l l o m e n s i s , V i r g i l i a n, Hoicomb T r i t i c i t e s c f . r o c k e n s i s . l o w e r Wolf­c a m p i a n ( ? ) , Lambson a n d H o r t on O m p h a l o t r o c h u s ( ? ) s p . , W o l f c a m p i a n, S a d l i c k P s e u d o p s c h w a g e r i n a ( ? ) s p . ( s a g i t t a l ), l o w e r W o l f c a m p i a n , Holcomb S c h w a g e r i n a c f . w e l l s e n s l s , l o w e r Wolf­c a m p i a n , Holcomb T r i t i c i t e s m e e k l ( ?) O z a w a i n e l l a ( s a g i t t a l) T e t r a t a x i s s p. P r o b a b l y l o w e r W o l f c a m p i a n , Holcomb T a o n u r u s ( ? ) s p . , S a d l i ck U n i t 4 c a n be c o r r e l a t e d w i t h p o r t i o n s of t h e O q u i r rh F o r m a t i o n i n t h e T e r r a c e and Hogup M o u n t a i n s , t h e G r a s s y, S t a n s b u r y , n o r t h e r n , c e n t r a l , and s o u t h e r n O q u i r r h Mount­a i n s ( P l a t e V I I ) . I t a l s o a p p e a r s t o be c o r r e l a t i v e w i th t h e u p p e r p a r t of t h e E l y L i m e s t o n e F o r m a t i o n of t h e Con­f u s i o n B a s i n (Hose and R e p e n n i n g , 1959) and t h e u p p e r p a rt o f t h e O q u i r r h F o r m a t i o n of t h e s o u t h e r n W a s a t c h M o u n t a i ns ( B a k e r , 1 9 4 7 ). F 5 1 3 F 5 6 0 F 5 6 9 F 5 8 8 F644 F 6 4 5 F 6 46 F 6 5 3 F 6 54 - 6 4 - U n i t 5 D i s t r i b u t i o n and T h i c k n e ss The b a s a l few h u n d r e d f e e t of U n i t 5 o u t c r o p i n a b e lt a l o n g t h e s o u t h w e s t e r n m a r g i n of t h e C e d a r M o u n t a i n s and c o n s t i t u t e t h e y o u n g e s t s t r a t a m e a s u r e d i n t h e t r a v e r se w e s t w a r d from C o c h r a n S p r i n g t o t h e f o o t of t h e m o u n t a i n s. U n i t 5 a c c o u n t s f o r 340 f e e t of t h e O q u i r r h F o r m a t i on m e a s u r e d s e c t i o n i n t h i s a r e a . Most of t h i s o u t c r o p l i es w i t h i n t h e U. S, Army Dugway P r o v i n g G r o u n d s . Unit 3 makes u p s e v e r a l s m a l l o u t c r o p s i m m e d i a t e l y w e s t of U n i t 5 a s a r e s u l t of a s o u t h e r n e x t e n s i o n of t h e C e d a r T h r u s t . A n o t h er U n i t 5 o u t c r o p t r e n d s e a s t a c r o s s t h e c r e s t of t h e r a n ge a b o u t one and o n e - h a l f m i l e s n o r t h of Tabby P e a k . An i n c o m p l e t e s e c t i o n of U n i t 5 f o r m s an o u t c r o p a r e a of s e v e r a l s q u a r e m i l e s i n t h e n o r t h - c e n t r a l C e d a r M o u n t a i ns b e t w e e n H a s t i n g s Summit and U. S. Highway 4 0 - 5 0 . Unit 5 u n d e r l i e s H a s t i n g s P e a k , h i g h e s t i n t h e n o r t h e r n C e d ar M o u n t a i n s w i t h an e l e v a t i o n s l i g h t l y h i g h e r t h a n 6 , 6 0 0 f e e t. An i n c o m p l e t e s e c t i o n of t h i s u n i t was m e a s u r e d i n t h is a r e a i n s e c 3 1 , 3 2 , TIN, R9W. L i t h o l o g y U n i t 5 i s composed p r e d o m i n a n t l y of l i g h t b r o w n , and g r a y s a n d s t o n e s w h i c h w e a t h e r l i g h t g r a y - b r o w n . The s a n d ­s t o n e s a r e f i n e - g r a i n e d w h i c h i s c h a r a c t e r i s t i c of a ll - 6 5 - s a n d s t o n e and q u a r t z i t e u n i t s i n t h e O q u i r r h F o r m a t i o n. D e s e r t v a r n i s h i s a common f e a t u r e of t h e b e d s i n U n i t 5. B e d d i n g t e n d s t o be medium t o t h i c k i n t h e l o w e r p a r t of t h e u n i t b e c o m i n g more p r e d o m i n a n t l y t h i c k i n t h e u p p er p a r t . Some of t h e s a n d s t o n e s a r e q u a r t z i t i c and form l e d g e s b u t many t e n d t o d i s i n t e g r a t e and become p a r t ly b u r i e d i n b l o c k y r u b b l e . While t h i n - b e d d e d , s h a l y z o n es a n d t h i n g r a y l i m e s t o n e u n i t s a r e s e e n o c c a s i o n a l l y , t h e re i s l e s s l i t h o l o g i c v a r i a t i o n i n U n i t 5 t h a n i n any of t he o t h e r mapped s u b d i v i o n s of t h e O q u i r r h F o r m a t i o n . The l o w e r c