Geology of the Lost Creek-Echo Canyon Area, Morgan and Summit Counties, Utah

Rocks in the vicinity of Lost Creek end Echo Canyon, Utah, were first studied and named. by Hayden (1869, p. 90) and Vea1~oll (1907, pp •. 88-96) . In the absence of positive fossil evidence, the earlier correlations were based primarily on lithologic similarities. This , coupled with the fact that description to the original type section . (Hayden, 1869, p. 90) was vague an~1 confusing, has further complicated the problem

COUNTIES, J a m e s H e n r y M a d s e n , J r. t h e s i s s u b m i t t e d t o t h e a c u l t y 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 t h e r e q u i r e m e n t s f or t h e d e g r e e D e p a r t m e n t G e o l o gy U n i v e r s i t y U t ah J u n e , GEOLOGY OF THE LOST CREEK-ECHO CANYON AREA, MORGAN AND SUMMIT COONTIES, UTAH by James Henry Madsen, Jr. A thes is submitted to the f aculty of the Univer sity of Uteh in par ti el fulfillment of the req uirement s for the de gree of MASTER OF SCIENCE Depertme nt of Geology Univ er sity of Utah June, 1959 T h i s T h e s i s f o r t h e M a s t e r ' s d e g r ee b y J a m e s H e n r y M a d s e n , J r. h a s b e e n a p p r o v e d by J u n e , 1959 C h a i r m a n , 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 ^ 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 H e a d , M a j o r D e p a r t m e nt D e a n , G r a d u a t e S c h o ol 4 2 0 C 0 7 This Thesis for the Master'. degree by James Henry Madsen, Jr. has been approved by June, 1959 ~?~~ Chairman, Supervisory Committee Reaer;uper ~ommlttee te4;n· .t2JC!)7 ACKNOWLEDGMENTS T h e o p p o r t u n i t y i s t a k e n h e r e t o e x p r e s s t h a n k s t o Dr. ? / i l l i a m s , s u g g e s t e d t h e p r o b l e m o f f e r ed c o u n s e l i n t h e f i e l d i n t h e p r e p a r a t i o n t h e manu­s c r i p t . A p p r e c i a t i o n i s a l s o e x t e n d e d o S t o k e s and D r . J . J o n e s , o f f e r e d c r i t i c i s m i n t h e 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 . S t o k e s o a i d e d i n t h e i d e n t i f i c a t i on t h e f o s s i l s. C o n f e r e n c e s w i t h Dr. J . E a r d l e y i n t h e o f i c e in t h e f i e l d w e r e e s p e c i a l l y r e w a r d i n g t h r o u g h o u t t h e i n v e s t i g a ­t i o n t h e p r o b l e m. C r i t i c a l f o s s c o l l e c t i o n s i n v e r t e b r a t e s and p l a n ts w e r e i d e n t i f i e d , r e s p e c t i v e l y , A. Dr. f o r w h c h h e l p t h e a u t h o r i n d e b t e d. G r a t i t u d e i s e x p r e s s e d t o t h e a u t h o r ' s w i f e f o r t y p i ng t h e m a n u s c r i p t. 1\CKNOWLEDGMENTS The opportunity 1s tak.en here to express thanks to Dr ~ N. C. Vlilliams, who suggested the problem and who offered counsel in the field and in the preparation of the manu­script. Appreciation 1s also extended t o Dr. Wm. L. Stokes and Dr. D. J. Jones, who offer ed critic ism in the prepar ation of the manusc ript . Dr. Stoke s a l so aided in the identitic ation of some of the foss ils .. Conterence s with Dr . A. J. Eard ley in the of f ic e and in the field were especially rewarding throughout the investiga­tion of the problem. Critical foss i l collections of inv ertebrates Bnd plants were identified, respectiv ely, by Dr. W. Cobban and Dr. R. W. Brown, for wh i ch help the author i s indebt ed . Gratitude is expressed to the author's wife f or t yping the menuscr Ipt. i TABLE OF CONTENTS P a g e INTR 0DUCTI o o o o o o o o o o o o o o o o o . o . o o 1 G e n e r a l S t a t e m e n t s D ^ . o o 0 . 0 0 . 0 . « . o o « « . « 1 L o c a t i o n A c c e s s i b i l i t y . , 0 . 0 o . . • . . . . 2 P u r p o s e S c o p e 0 o . . . . . . . . . . • . • . . . P h y s l o g r a p h y o o o o o o o o o o o o o o o o o . o o L a n d U t i l i z a t i o n . . . . . . . . . . . . . . . . . . P r e v i o u s G e o l o g c . . . . . . . . . . . . . . . e o o o o o o o o o o o o o o o o o o . . o G e n e r a l S t a t e m e n t 0 . . . . o . . . . . . . . » • . . J u r a s s i c S y s t e m . . . . . » . • . . . . . . . . • o 9 N u g g e t s a n d s t o n e o . . . . . . . . . . T w i n G r e e k i m e s t o n e . . . . . . . . . . . . . . 10 P r e u s s f o r m a t i o n , , ° • . . . . . • . . . . . . . 11 Stump f o r m a t i o n . . . . . „ . . . . . . . . . . 13 M o r r i s o n f o r m a t i o n . . . . . . . . . . . . . . . 14 C r e t a c e o u s S y s t e m . . . . . . . . . . . . . . . . « 15 K e l v i n f o r m a t i o n . . . . . . . . . . . . . . . . 15 A s p e n s h a l e . . . . . . . . . . . . . . . . . . 15 F r o n t i e r f o r m a t i o n . . . . . . . . . . . . . . 16 W a n s h i p f o r m a t i o n 0 . . . . . . . . . . . . . . 17 E c h o c o n g l o m e r a t e . . . . . . . . . . . . T e r t i a r y S y s t e m . . . . . . . . . . . . . . . . . K n i g h t f o r m a t i o n 0 . . . . . . . . . . . . . . . 29 Q u a t e r n a r D e p o s i t s . . . . . . . . . . . . . . . o 31 o o o o o o o o o o o o o o o o o o o o o o o o 33 R e g i o n a l S t r u c t u r e . . . . . . . . . . . . . . . . . 33 F o l d S o . o o o o o o o o o o o o o o o o o o o o o o 34 i i Paga INTRODUCTI ON • • • • • • • • • • • • • • • • 1 Gener al St atement e • • • • • • • • • 1 Locat ion and Acce ssibility • • • • 2 Purpose and Scope . • • • • 4 Physiogr aphy • • • • • • • • • • • • • • 5 Land Utilization • • • • • • • • • • • • • 6 Previous Geol og i c Work • • • • • • • • 8 STRATIGRAPHY • • • • • • • • • • • • 9 Gener al Stat ement . • • • • 9 Jur assic Syst em • • • 9 Nu gget sandstone . • 9 Twin Creek l imestone . • • • • 10 Preuss formation . • • • • • • • 11 Stump format ion • • • • • • • 13 Morrison f ormation . • 14 Cretaceous Syst em • • • • • • • 15 Kelvin fo rmation . • • • 15 Aspen shale • • • • • • • 15 Fr ont ier formation • • • 16 Wanship formation • • • • • • • 17 Echo Canyon con €lomerate . • • 23 Tertiary System • • • • • • • 29 Kni ght formation . • • • 29 Qua t e r nar y Deposits • • • • • • • • 31 STRUCTURE • • • • • • • • • • • • • 33 Regional Str uc ture • • • • • • • • • • • • • 33 Fold s . • • • • • • • • • • • • • • • 34 11 i i i S t e v e n s o n Canyon s y n c l i n e . C o a l v i l l e a n t i c l i n e . . . . . . . . . . . . . . . . T o o n e Canyon a n t i c l i n e . F a u l t i n g . U n c o n f o r m i t i e s 36 B a s a l W a n s h i p u n c o n f o r m i t y B a s a l K n i g h t u n c o n f o r m i t y 39 P o s t K n i g h t D e f o r m a t i o n 41 GBOMORPHOLOGY ... . . 43 D r a i n a g e . 43 L a n d f o r m s ... . 43 E r o s i o n S u r f a c e s .... 45 GEOLOGIC HISTORY ..... . . . . 47 G e n e r a l S t a t e m e n t . . . . . . . . . . . 47 J u r a s s i c ..... . . . . . . . . . . 47 E a r l y C r e t a c e o u s .; . . . > . . . . . . 48 C o l o r a d o a n ... . . . . . 4B M o n t a n a n ( ? ) ....... 50 P o s t Echo Canyon c o n g l o m e r a t e - P r e - K n i g h t . . . . . . . 50 P a l e o c e n e . . . . . . . . . . . . 52 E o c e n e . . . . . . . . . 52 L a t e T e r t i a r y . . . . 53 Q u a t e r n a r y . . . . . . . . . . 53 ECONOMIC GEOLOGY. . , 54 G e n e r a l S t a t e m e n t C o a l 54 C l a y . 55 L i m e s t o n e . 55 P e t r o l e u m . REFERENCES CITED. . . . . . .... iii Stevenson Canyon syncline • • • • • • 34 Coalville anticline • • • 34 To'one Canyon anticline. • • • • 35 Faulting • • • • • • 36 Unconformities • • • • • • 36 Basal Wanshlp unconformity. • • 36 Basal Knight unconformity 39 Post Kni ght Deformation. • • • • 41 GBOMORPHOLOGY • • • • • • • 43 Drainage • • • , • • • 43 Landforms. • · . • 43 Erosion Surfaces .. 45 GEOLOGIC HISTORY. • • • • 47 General Statement. .. 47 Jurassic • , '. -;- · • 47 Early Cretaceous • • • · · . 48 Coloradoan • • 48 Montanan (?t • • • · . 50 Post Echo Canyon conglpmerate Pre-Knight • • • • 50 Paleocene • • • 52 Eocene • • • · 52 Lata Tertiary. 53 Quaternary • 53 l!CONOMIC GEOLOGY. • , • • • • • 54 General Statement. • 54 Coal • 54 Clay • 55 Limestone. • 55 Petroleum. • • REFERENCES CITED. • • • • • 57 L I S T ILLUSTRATIONS P a g e P l 8 t e I map, s h o w i n g l o c a t i o n t he L o s t C r e e k - E c h o a r e a P l a t e I I t h e h e a d Toone C a n y o n ..View l o o k i n g n o r t h P l a t e I I I J u r a s s i c - C r e t a c e o u s N o m e n c l a t u r e C h a r t . . 12 P l a t e IV Tentative C r e t a c e o u s C o r r e l a t i on t h e C a n y o n - C o a l v i l l e a r e a. F o l l o w i n g p a g e P l a t e e a v e s f r o m t h e W a n s h i p F o r m a t i o n . P l a t e l e a v e s f r o m t h e W a n s h i p F o r m a t i o n . P l 8 t e V I I Panoramic v i e w l o o k i n g n o r t h M i ll C r e e k . Shows t h e K n i g h t f o r m a t i o n l y i ng u n c o n f o r m a b l y upon t h e Echo Canyon c o n g l o m e r a t e 26 P l a t e V I I I Nearly v e r t i c a l K e l v i n f o r m a t i o n t r u n ­c a t e d t h e f l a t - l y i n g K n i g h t f o r m a t i on o n t h e s o u t h - f a c i n g s l o p e V i e w l o o k i n g n o r t h . . . . . P l a t e "Zn f o l d i n t h e i n c o m p e t e n t C r e ek l i m e s t o n e t h e n o r t h e a s t a c i n g s l o pe H e l l a t t h e m o u t h . l o o k ­i n g s o u t h w e s t , 37 P l a t e Drag-folding i n c o n g l o m e r a t e t h e K n i g h t o r m a t i o n i n t h e e a s t s i d e t h e f a u l t. V i e w l o o k i n g n o r t h e a s t t Plate Plote II Plate III Plate TV Plate V Plate VI Plate VII Plate VIII Plate IX Plate X LIST OF ILLUSTRATIONS Index map , showing loc ation of the Lost Creek-Echo Canyon area . . . . . Chinatown a t the head of Toone Canyon_View lOOKing north . • . . . . . Jurass ic - Cretaceous Nomenclature Chart. Tentati ve Upper Crexaceous Correlation of the Echo Canyon- voalville area. Following page . . . . . • • • • . . • . Fossil l eaves from the Wanship Formation. Fossil leaves fr om the Wenship Formation. Panorami c view look.lng north up Saw Mill Creek. Shows the Knight f o rmation lying unconformably upon the Echo Canyon conglomerate . ......... . . . . Ne arly vertical Kelvin formation trun­c at ed by the flat-lying Kni ght formation on the south-facing slope of Toone Canyon View looking north . . . . • . . . . • liZ" fold 1n the incompetent Twin Creek. lime stone on the northeast f acing slope of Hell Canyon at the mouth. View look- Page 3 7 12 20 21 22 26 30 ing southwest . . . . . . . . . . . •. 37 Dr ag-fOlding in a conglomerate bed in the Knl ~h t f ormation in Toone Canyon on the east side of the Toone Canyon f ault. View lookjng northeast ...• . . ... iv , 38 V P l a t e Classic a n g u a r u n c o n f o r m i t y o o k i n g n o r t h ­e a s t C a n y o n K n i g h t f o r m a t i on a b o v e t h e Canyon o r m a t i o n b e l ow t h e p l a n e t h e u n c o n f o r m i t y 40 P l a t e X I I T e r r a c e - l i k e t o p o g r a p h i c e x p r e s s o n t he b a s a K n i g u n c o n f o r m i t y t h e w e s s i Saw M i l l C r e e k P l a t e X I I I l o o k i n g o u t h e a s a l o n g t h e Weber V a l l e y . C i t y , P u l p i t and t he m o u t h S t e v e n s o n a r e i n t h e b a c k ­g r o u n d . N o t e a l s o e m n a n t t h e Weber V a l l e y s u r f a c e i n b a c k g r o u n d , P l a t e M o u n t a i n s u r f a c e . l o o k i n g e a s t . . . P l a t e i n h e c o n g l o m e r a te w h e r e i t c r o p s 2 m i l e s n o r t h w e s t of E c h o , S p e c i m e n i s I n o c e r a m u s d e f o r m i s ? . . . P l a t e S t r a t i g r a p h i c S e c t i o n h e L o s t C r e e k, "Echo C a n y o n , C o a l v l l e A r e a F o l l o w i ng p a g e P l a t e XVII t h e L o s t C r e e k - E c ho C a n y o n a r e a P o c k et Plate XI Pl ate XII Pl ate XIII Plote XIV Plate XV Plate XVI Plate v Cl ass ic angu l ar unconformity l ooking north­east up Echo Canyon . The Knight f ormation above and the Echo Cany on f ormation below the pl ane of the unconformity ..... . . Terr ace-like topogr aphic expr ess i on of the basa l Kn i p-h t unconformity on the wes t s i de of Sew Mi ll Creek . • . . . . • . . . . . View looking s outhe as t al ong the Weber Velley . Echo City, Pul pit Rock, end the mouth of Stevens on Canyon are in the back­gr ound. Note al so r emnant of the Weber Valley surf ace in background ..... . . . • Herd Mountain surf ace .. View looking east • Sand bed in t he Echo Canyon cone1omer at e ,'!here it crops out ~ miles northwest of Echo. Specimen is Inoceramus deformis? . . . S tr . ti ~r e p hic Section of t he Echo Cenyon, Coa lv i lle Area . page . . ..... . Lost Cre ek , Following 40 42 44 46 51 60 Geologic map of the Lost Creek- Echo Canyon ar ea . . . . . . . . . . . . . . . In Pocket G e n e r a l S t a t e m e nt R o c k s i n t h e v i c i n i t y L o s t C r e e k and E c h o C a n y o n , U t a h, w e r e f i r s t s t u d i e d n a m e d b y 1 8 6 9 , p„ 9 0 ) V e a t ch 1 9 0 7 , p p . . 8 8 - 9 6 ) 0 t h e a b s e n c e p o s i t i v e f o s s i l e v i d e n c e, t h e e a r l i e r c o r r e l a t i o n s b a s e d p r i m a r i l y l i t h o l o g ic s i m i l a r i t i e s . T h i s , c o u p l e d w i t h t h e f a c t t h a t d e s c r i p t i o n of t h e o r i g i n a l t y p e s e c t i o n ( H a y d e n , 1 8 6 9 , p . 9 0 ) v a g u e and c o n f u s i n g , h a s f u r t h e r c o m p l i c a t e d t h e p r o b l e m. F o s s i l s c o l l e c t e d d u r i n g t h e p r e s e n t s t u d y p e r m i t c o r r e l a ­t i o n t h e U p p e r C r e t a c e o u s r o c k s t h e L o s t C r e e k - B c h o Canyon a r e a w i t h a d j a c e n t a r e a s . c o n g l o m e r a t e s e q u e n c e and u n d e r* l y i n g r o c k s known C r e t a c e o u s a g e a r e w e l l e x p o s e d l e nd t h e m s e l v e s t o d e t a i l e d s t u d y i n t h e L o s t C r e e k - E c h o C a n y o n a r e a. A l t h o u g h f o s s i l s a r e r a r e t h e u p p e r p a r t of t h e C r e t a c e o us s e c t i o n , s e v e r a l l o c a l i t i e s h a v e y i e l d e d f o s s i l s w h i c h h a v e a d i r e c t b e a r i n g t h e d a t i n g t h e c o n t a i n i n g r o c k s. T h e a r e a i s l o c a t e d i n t h e z o n e t r a n s i t i o n b e t w e e n t he n o r t h t r e n d i n g W a s a t c h M o u n t a i n s and t h e e a s t t r e n d i n g U i n ta A r c h , a n d , a c c o r d i n g l y , i s a r e a i n t e r e s t f r o m a s t r u c t u r a l . INTRODUCTION General Statement Rocks in the vicinity of Lost Creek end Echo Canyon, Utllll, were first studied and named .by Hayden ( 1869, p. 90) and Vea1~oll ( 1907, pp •. 88-96) . In the absence of positive fossil evidenoe, the earlier correlations were based primerily on lithologic simil arities. This , coupled with the fact that description ot the original type sec.tion .(Hayden, 1869, p. 90) was vague an~1 confusing, has further complicated the problem. 1I'0ssils collected during the present study permit correle. tion of the Upper Cr.etaceous rocks of the Lost Creek-Icho Ce,.,oa area with adjacent areas . The conglomerate sequence end under­lying rocks of Known Cretaceous age are well exposed and len~1 themselvss to detailed study in ths Lost Creek-Echo Canyon az'.e. Although fossils are rare in the upper part ot the Creteoecua section, severel loc elities have yielded fossils which hne " direct bearing on the dating of the containing rocka. The area is located in the zone of transition between tb,e north trending Wasatch Mountains snd the eaet trending Uinta Arch, and, accordingly, 1s an area of interest from 8 atructur81. 1 a s w e l l a s a s t r a t i g r a p h i c , p o i n t of v i e w. L o c a t i o n A c c e s s i b i l i ty L o s C r e e k - E c h o a r e a i s m i l e s n o r t h e a s t S a l t Lake C i t y , U t a h o I t i n c l u d e s a p p r o x i m a t e l y 220 s q u a re m i l e s w i t i n a l l or p a r t s T o w n s h i p s 4 , N o r t h R a n g e s 4 , E a s t , S a l t B a s e M e r i d i a n P l a t e I )> H e n e f e r and a r e t h e c h i e f c o m m u n i t i e i n t h e a r e a and b o t h a r e s i t u a t e d i n t h e s o u t h w e s t c o r n e r . r a i l r o a d s i d i n gs t h e U n i o n P a c i f i c R a i l r o a d , B r i m v i l l e ) and C a s t l e Rock, a r e s i t u a t e d i n t h e c e n t e r n o r t h e a s t c o r n e r t h e a r e a, r e s p e c t i v e l y o E c h o v i c i n i t y i s a c c e s s i b l e f r o m t h e w e s t v ia S6 3 0 - f r o m t h e s o u t h v i a C o a l v i l le S.. H i g h w a y 1 8 9 f r o m t h e n o r t h e a s t v i a E v a n s t o n , Uo. So H i g h w a y 3 0 - S . m a i n l i n e t h e U n i o n P a c i f ic R a i l r o a d p a r a l l e l s S0 3 0 - i n V a l l e y Canyono O t h e r t h a n t h e m a j o r h i g h w a y s and g r a v e l e d r o a d t r a v e r s ­i n g L o s t C r e e k n e a r t h e w e s t e r n m a r g i n t h e a r e a , t h e r e a r e no r e g u l a r l y m a i n t a i n e d r o a d s i n t h e L o C r e e k - E c h o v i c i n i t y . P o o r l y k e p t s t o c k r o a d s p r o v i d e a c c e s s h e r e m o t e l o c a l ­i t i e s d r a i n e d L o s t C r e e k C r e e k . p r i m i t i ve r o a d s r e s p o r a d i c a l l y r e c o n d i t i o n e d l o c a l s t o c k m e n t h e more r e m o t e r o a d s t r a v e l e d o n l y 4 - w h e e l - d r i v e v e h i c l e s. 2 8S well as a stratigraphic, point of view . Location and Accass ibility The Los t Creek-Echo Canyon area is 35 miles northeast of Salt Lake City, Utah. I t inc ludes approximetely 220 square miles wit h in all Dr part s of Townsh ips 3, 4, and 5 North and Ranges 4, 5, 6, and 7 East, Salt Lake Base and Meridian ( Plate I). Henefer Bnd Echo are the chi ef communitie s in the a1'ea Bnd both are situated in the southwest cornel' . Two railroad s idings of the Union Pacific Railroad, Emory ( Br imville) Bnd Castle Rock, are situated in the center and northeast corner of the area, respect lvelyo Echo Canyon and vicinity is accessible from the west via Weber Canyon on U. S. Highway )O-S ; from tha south via Coalville on U . S .. Highway 189 ; and from the northeast via Evanston, Wyoming on U. S. Highway 189 and )O-.S. A main line of the Union Pacific Railroad par allel s U. S. Highway )O-S in Weber Valley and Echo Cany on . Other than the major highways and one graveled ro ad tr avers­ing Lost Creek near the western mar gin of the ar ea, there are no re gularl y maintained roeds in the Lo s t Creek-Echo Canyon vicinity. Poorly kept stock roads provide access to t he more remote local­ities drained by Lost Cr eek and Echo Canyon Creek. These primitive roads a re sporadica lly recondi ti oned by loc al stockmen and the more remote roads can be traveled only by 4-wheel-drive vehicles. 3 showing l o c a t i o n of Lost C r e e k E c h o Canyon a r e a. SALT LAKE CITY SALT LAKE, ~/ UTA H A 5 \ I C H A ( T C I I I INDEX MAP shawing lacatian af the Last Creek - Echa Canyan area. H Plate I • Evanston 4 An a r e a n o r t h w e s t of Echo C a n y o n , d r a i n e d by H e i n e r s C r e e k, i s c o n t r o l l e d c h i e f l y by t h e D e s e r e t L i v e s t o c k Company of S a lt L a k e C i t y , and a c c e s s r o a d s , n o r m a l l y c l o s e d t o t r a v e l , can be u s e d o n l y w i t h p e r m i s s i o n , , The r e m a i n i n g p a r t of t h e Echo Can­y o n and L o s t C r e e k a r e a , a l t h o u g h p r i v a t e l y owned, i s c o n t r o l l ed by t h e Echo C a n y o n - C h a l k C r e e k Range Owners P r o t e c t i v e A s s o c ­i a t i o n . The A s s o c i a t i o n m a i n t a i n s l o c k e d g a t e s a t t h e m o u t hs of a l l m a j o r t r i b u t a r i e s t o L o s t C r e e k and l o w e r Echo Canyon, and p e r m i s s i o n t o e n t e r m u s t o b t a i n e d , . G e n e r a l l y , s u c h p e r ­m i s s i o n i s r e a d i l y e x t e n d e d t h e A s s o c i a t i o n or t h e l a n d o w n e r s. P u r p o s e and S c o pe The p r i m a r y p u r p o s e of t h i s work h a s b e e n t o g a t h e r d a ta r e l a t i v e to t h e i d e n t i f i c a t i o n , c o n t a c t s , and a r e a l d i s t r i b u ­t i o n of t h e l a t e C r e t a c e o u s and T e r t i a r y f o r m a t i o n s i n t he v i c i n i t y L o s C r e e k C a n y o n , t o r e s o l v e , if p o s s i b l e , c e r t a i n p r o b l e m s of c o r r e l a t i o n . It i s h o p e d , a l s o, t h a t new l i g h t c a n be shed upon t h e d a t i n g of c e r t a i n a s p e c ts of t h e L a r a m i d e o r o g e n y. F i e l d work was b e g u n d u r i n g t h e summer of 1957 and com­p l e t e d i n t h e summer and f a l l of 1 9 5 8 , G e o l o g i c d a t a w e re p l o t t e d S o i l C o n s e r v a t i o n S e r v i c e a e r i a l p h o t o g r a p h s h a v ­i n g a s c a l e of 1 : 3 1 * 680» The p h o t o g r a p h s , f l o w n f o r t h e S o il C o n s e r v a t i o n S e r v i c e 1 9 3 8 . i n c l u d e d t h e f o l l o w i n g : 4 - 26 t o 4 - 3 4 , 4 - 1 3 0 t o 4 - 1 3 8 , 4 - 1 7 6 t o 4 - 1 8 4 , 5 - 1 7 5 t o 5 - 1 8 1 , 1 0 - 1 61 4 An area northwest of Echo Canyon, drained by Heiners Creek, is controlled chiefly by the Deseret Liv estock Company of Salt Lake City, and access roads , normally closed to travel, can be used .only with permissi on . The remaining part of the Echo Can­yen and Los t Creek area, although privately owned, is controlled by the Echo Canyon-Chalk Creek Range Owners Protective Assoc­iation . The Association mai~talns locked gates at the mouths of all major tributaries to Lost Creek Bnd lower Echo Canyon, end permission to en.ter must be obtained ., Generally, such per­missioD- 1s readily extended by the Association 01' the landowners. Purpose and Scope The primary purpos e of this work has been to gather data relative to the identif ic ation, contacts, and are al distribu­tion at the l ate Cr etaceous and Tertiary formations in the vicinity of Los t Creek and Echo Canyon, and to resolve, it possible, certain probl ems of correlation. It is hoped, also, that new light c an be shed upon the dat i ng of certain aspects of the Lar amid e or ogeny e Field work wa s begun during the summer of 1957 and com­pleted in the summer and f all of 1958. Geologic deta were plotted on Soil Conserv ation Service aerial photographs hav7 ing a scale of 1:31 , 680. The photogr aphs , flown for the Soil Conserv.etion Service in 1938, included the following: BPK 4-26 to 4-34, 4-130 to 4-138, 4-176 to 4-184, 5-175 to 5-181, 10-161 • t o 1 0 - 1 6 6 , 1 0 - 1 2 0 t o 1 0 - 1 2 6 , 4 - 7 4 t o 4 - 7 8 1 0 - 1 0 4 t o 1 0 - 1 0 9. D a t a g a t h e r e d i n t h e f i e l d t r a n s f e r r e d o S o i l C o n s e r v a t i on S e r v i c e p l a n i m e t r i c b a s e m a p s , d e n t i f i e d U t a h 4 8, f r om w h i c h i n e n t r a c i n g a l l d a t a m a d e , c o p y w h i ch c o n s t i t u t e t h e e n c l o s e d g e o l o g i c P l a t e X V I I ). P h y s i o g r a p h y d r i n a g e t h e L o s C r e e k - E c h o a r e a have d e n d r i t i c p a t t e r n c o n s i s l a r g e l y s u p e r i m p o s e d s t r e a ms t h a a v e r o d e d l o c a l l y t h r o u g h t h e T e r t i a r y s e d i m e n t s . s u c h l o c a t i o n s e x p o s e d o l d e r o c k s w h i c h i n t h i s a r e a a re J u r a s s i c C r e t a c e o u s a g e . t e r m s t h e n o r m a l e r o s i on c y c l e t h e s t r e a m s a n g e i n f r om a t e y o u t h t o e a r l y m a t u r i t y .. R i v e r i s h e t r u n k a i n a g e w h i c h L o s t C r e e k and E c h o C a n y o n C r e e k a r e t r i b u t a r y . Th e t r i b u t a r i e s L o st C r e e k a r : G u i l d e r s l e e v e C r e e k , Cedar C r e e k, T o o n e C r e e k . H e l l C r e e k , P a r a d i s e C r e e k, F r a n c i s C r e e k , T r a i l C r e e k . S i g n i f i c a n t t r i b u t a r i es Canyon C r e e k a r e ° M i l l C r e e k H e i n e r s C r e e k Aspen C r e e k , R o b i n s o n C r e e k R e e s C r e e k . H a r r i s C r e e k, H a r r i s C r e e k a n d G r a s s C r e e k a r e t r i b u t a r y t o h e R i v e r, w h e r e a s C r e e k i s t r i b u t a r y t o C h a l k C r e e k w h i c h in t u r n j o i n s t h e R i v e r w h e r i t f l o w s i n t o r e s e r v o ir P l a t e I ) . r e l i e f i n t h e a r e a i s a b o u 3 , 0 0 0 f e e t and 5 to 10-166, 10-120 to 10-126, 4-74 to 4-78 , and 10-104 to 10-109. Deta gathe red in the fie l d was tr ansfer red t o Soil Conse rv ation Service planimetric base maps, i dentified as Utah - 47 and 48, fr om which a l inen tr acing of all data was made, a copy of which consti tute s the en.closed geologic map ( Pl ate XVII). Phys iogr aphy The dr a inage ways of the Los t Creek-Echo Canyon BrBB have a dendritic pattern and consis t lar gely of super imposed streams tha t h av e eroded locall y through the Tertiary sediments" At such loc ations a r e exposed ol der r ocks which in this area ar e Jurassic and Cretaceous i n ageo In terms of the normal er osion cycle the stre ams r ange in age fr om l ate youth to early ma turity~ The Weber River is t he trunk d r ain age t o which Lost Creek a nd Echo Canyon Creek are tr lbutary o The main tributaries to Lost Creek ar e : Guildersleeve Canyon Creek, Ced ar Canyon Creek, Toone Canyon Cre ek, Hell Canyon Creek, Paradise Canyon Creek , Francis Canyon Creek, and Tr ail Cree ko Signi ficant tributaries t o Echo Cany on Creek are : Saw Mill Creek , Heiners Creek , Aspen Creek, Robins on Creek , and Rees Creeko Har ris Canyon Creek, Harris Creek , and Gr ass Cre ek are tributary to t he Weber Ri ver, whereas Meadow Cr.eek is a tributary to Chalk Cr eek which in tUrn joins the Weber River wher e it flows int o Echo reservoir ( Plate I). Maximum relief in the area is abou t 3,000 feet and r e p r e s e n t s t h e d i f f e r e n c e i n e l e v a t i o n t h e l o w e s t p o i n t on t h e R i v e r w h c h i s 59 3 5 0 f e e t n e a r H e n e f e r , and h e p o i nt h i g h e s t e l e v a t i o n a t 8 , 3 5 0 f e e t i n t h e s o u t h e a s t c o r n e r of t h e e a , t h e s h o u l d e r P o r c u p i n e M o u n t a i n„ B a d l a n d t o p o g r a p h y i s c h a r a c t e r i s t i c and L o s t C r e e k , w h e t a n o r e d c l i f f s e d g e s f o r m t h e w a l ls t h e c a n y o n s r e a s , a s l o w e r H e i n e rs C r e e k t h e h e a d p r o m i n e n t p i n n a c l e s r i se t o f e e t f r o m t h e c a n y o n l o o r * s m a l l b a s i n - s h a p e d a r a t t h e h e a d T o o n e C a n y o n, o c a l l y c a l l e d C h i n a t o w n " , d i s ­p l a y s an a s s e m b l a g e s h e e r c l i f f s c o n g l o m e r a t e c a p p ed p i n n a c l e s d e m o i s e l l e s e q u a l l y a s c o l o r f u l t h o s e i n t he B r y c e C a n y o n a r e a s o u t h e r n U t a h , h a v e s i m i l a r l y s h a p e d a p i d h e a d w a r d e r o s i o n c o n t r o l l e d j o i n t s d i f f e r e n t i a l c e m e n t a t i o n P l a t e I I . ) ,. L a n d U t i l i z a t i on L a n d i n t h e L o C r e e k a r e a s i s u s ed p r i m a r i l y f o r g r a z i n g c a t t l e s h e e p , t h i s i n i n s t a n c e s c o n s t i t u t e s t h e o n l y r e v e n u e o l a n d o w n e r s. L o c a l l y , s m a l l c r o p s c o r n , g r a i n , p r o d u c e a r e h a r v e s t e d, b u t t h e l a r g e s t p a r t of t h e f a r m a b l e l a n d i s p l a n t e d i n hay c r o p s t o p r o v i d e w i n t e r f e e d f o r s t o c k. t i m b e r i s h a r v e s t e d l o c a l l y , b u t r e s o u r c e s a re l i m i t e d n e g l i g i b l e e c o n o m i c i m p o r t a n c e. R e c r e a t i o n a l a c i l i t i e s a r e g e n e r a l l y l a c k i n g i n t h e a r e a. 6 represents the difference in elev ation of the lowest point on the Weber River wh i ch 1s 5,350 feet near Henefer , a nd t he po int of bighest elev at ion at 8,350 feet in the southeast corner of the a r ea, on the shoulder of Porcupine Mountain . Badland topogr aphy is cha r acteristic of Echo Canyon and Lost Creek, whe r e tan t o radc liff s and l edges form the wal l s of many of the canyons . In some a re as , such as lower He iners Creek and the he ad of Toone Canyon, prominent pinnacles rise 30 to 75 feet from the canyon f loor. A small basin-shaped ar ea at the head of Toone Canyon, l ocal ly called " Chinatown" , dis­plays en assembl age of sheer cliff s and conglomerate capped pinnacles and demoiselle s equally as colorful as tho se in the Bryca Canyon Brea of sou thern Utah, and have simil arly been shaped by r apid he adward erosion controlled by joint s and differen-tial cementation ( Plate II) •. Land Utili zation Land in the Echo Canyon and Lo s t Creek areas is used primarily for summer grazing of cattle and sheep, and this use in many in sta nce~ constitutes the only revenue t o l andowners. Locally, small crops of corn, gr ain, and pr oduce ar e harvested , but the a r gest part t he farmable and is planted in crops to pr ov_i de winter feed for stock . Some timber is harvested locally, but resources are limited and of negligible economic importance. Recreational f acilities are generally lacking in the area. P l a t e U at t h e h e a d north. Plat. 1\ Chinatown at the head of Toone Canyon. View looking north. P r e v i o u s G e o l o g i c Work The e a r l i e s t g e o l o g i c e x p l o r a t i o n i n t h e r e g i o n c o m p r i s i ng L o s t G r e e k w a s c a r r i e d t h e P o w e l l ( 1 8 7 6 ), H a y d e n 1 8 7 1 ) , end K i n g 1 8 7 7 ) s u r v e y s . s u r v e y s d e a lt m a i n l y w i t h t h e b r o a d e r a s p e c t s t h e g e o l o g y t h e a r e a. U i n t a M o u n t a i n s , and t h e i r i m m e d i a t e e n v i r o n s , l o ng of h i s t o r i c i n t e r e s t t o g e o l o g i s t s , w e r e s t u d i e d a f t e r t h e t u rn o f t h e c e n t u r y B e r k e y 1 9 0 5 ) , 1 9 1 3 ) , S c h u l t z ( 1 9 1 8 ), a n d l a t e r B r a d l e y 1 9 3 6 ) F o r r e s t e r ( 1 9 3 7 ). More r e c e n t l y , d e t a i l e d s t u d i e s h a v e b e e n made by E a r d l ey 1 9 4 4 ; 1 9 5 1 a ; 1 9 5 2 ). c o a l d e p o s i t s t h e a r e a w e r e i n v e s t i g a t e d T a ff ( 1 9 0 6 ) ; Wegemann ( 1 9 1 5 ) , who d i d t h e f i r s t d e t a i l e d g e o l o gy of t h e C o a l v i l l e a n t i c l i n e ; C l a r k 1 9 1 9 ) , w h i l e w o r k i ng f o r t h e U n i t e d S t a t e s G e o l o g i c a l S u r v e y p r e p a r e d r e p o r t on t h e L o s t C r e e k c o a l f i e l d* U n p u b l i s h e d w o r k i n t h e i m m e d i a t e a r e a h a s b e e n d o n e g r a d u a t e s t u d e n t s t h e U n i v e r s i t y U t a h i n c o n j u n c t i on w i t h M a s t e r s t h e s i s p r o j e c t s . s t u d e n t p r o j e c t s i n c l u de t h e s e s E g b e r t 1 9 5 5 ) J o h n s o n 1 9 5 2 ) , L a n k f o r d ( 1 9 5 2 ), L a r s o n ( 1 9 5 1 ) , P e t e r s o n ( 1 9 5 0 ) , R a n d a l l 1 9 5 2 ) , S c h i c k ( 1 9 5 5 ), S t a r k 1 9 5 3 ) , 1 9 5 3 ) . t h e s e i n v e s t i g a t i o ns w e r e d o n e u n d e r t h e d i r e c t i o n W i l l i a m s t he U n i v e r s i t y of U t a h G e o l o g y D e p a r t m e n t i s p r e p a r i n g r e p o r t t h e a r e a i n c l u d e d t h e C o a l v i l l e Q u a d r a n g l e. 8 Previous Geologic Work The earliest geologic exploration in the region comprising Lost Creek and Echo Canyon was carried on by the Powell (1876), Hayden ( 1871), and King ( 1877) surveys. These surveys de alt mainly with the broader aspects of the geology of the area. The Uinta Mountains, ~ nd their immediate environs, long or historic interest to geologists, were studied arter the turn or the century by Berkey ( 1905), Weeks ( 1913), Schultz (1918), and later Bredley ( 1936) and Forrester (1937). More recently, detailed studies have been made by Eardley ( 1944; 1951a; 1952). The coal deposits of the area were investigated by Taft (1906); Wegemann (1915), who did the first detailed geology ot the Coalville anticline; and Clark ( 1919), while working for the United St ates Geological Survey prepared a report on the Lost Creek coalfield. Unpublished work in the immediate area has been done by graduate students of the University of Utah in conjunction with Masters thesis projects. These student projects include theses by Egbert ( 1955) , Johnson ( 1952), Lankford (1952), Larson .(.1951), Peterson (.1950), Rand all ( 19 52 ), Schick (1955), ./ Stark ( 1953), and Wood ( 1953). Some of these investigations were done under the direction of Dr. N. C. Williams of the University or Utah Geology Department who is preparing a report on the area included in the Coalville QUadrangle. G e n e r a l S t a t e m e nt T e r t i a r y o c k s t h e s u r f a c e m o s t t h e L o st C r e e k - E c h o a r e a , o l d e r r o c k s a r e e x p o s e d o n l y w h e r e e r o ­s i o n h a s r e m o v e d t h e y o u n g e r o c k s . E x p o s u r e t h e o l d e r r o c ks a r e t o o l i m i t e d e x t e n t o o f e w i n t o p e r m i t a c c u ­r a t e a c i n g c o r r e l a t i o n f r o m p l a c e t o p l a c e. E x p o s u r e s i n c l u d e t h e t r a t i g r a p h i c s u c c e s s i o n r e c o g n i z ed i n a d j a c e n t r e a s , w i t h m i n o r e x c e p t i o n s , f r o m t h e N u g g e t s a n d ­s t o n e J u r a s s i c g e , t h r o u g h C r e t a c e o u s o r m a t i o n s , and i n t o t h e T e r t i a r y » u p p e r p a r t t h e K e l v i n f o r m a t i o n t h e s h a l e , a l t h o u g h p r o b a b l y p r e s e n t d e p t h , a r e n ot e x p o s e d . o c k t y p e s n c l u d e c a r b o n a t e d e p o s i t s , b u t e l a s ­t i c s r e p r e s e n t a t i v e v a r i o u s s u b a q u e o u s s u b a e r i a l e n v i r o n ­m e n t s m o s t t h e s e c t i o n0 J u r a s s i c S y s t em N u g g e t s a n d s t o n e o E x p o s u r e s h e J u r a s s i c s a n d s t o n e , a p p r o x i m a t e l y 1 , 1 0 0 f e e t i n t h i c k n e s s , a r e p r s e nt i n t h e L o s C r e e k a r e a o c a l i t i e s : (1) i m m e d i a t e l y e a st STRATIGRAPHY General Statement Tertiary r ocks make up the surface of most of the Lost Creek-Echo Canyon area, older rocks ar e exposed only where ero_ sion has remov ed the younger r ocks. Exposure s of the older rocks are too limited in extent and t oo few in number to permit a ccu­rate t r acing and correlation from place to pl ace. Exposures include the s tr atigraphic succe ssion as reco gnized in adj acent a reas, with minor excepti ons , from the Nugget sand ­stone of Lower Jurassic a ge, through Cr etaceous f ormations , Bnd into the Terti ary. The upper part of the Kelvin formation and the Aspen shele, although probably present a t depth, are not exposed. The r ock types i nclude some carb onate deposits , but cl as­tics representative of various subaqueous and sub aerial envir on­ments make up most of the section . Jurassic System Nugget sandstone o Exposure s of t he Lower Jurassic Nugget sapdstone, approximately 1,100 feet in thickne ss , are pr e sent in the Los t Craek area a t two l ocalities : immediately .ast 9 t h e j u n c t i o n T r a i l F r a n c i s C r e e k s w i t h L o s t C r e e k and 2 ) s o u t h t h e c o n f l u e n c e T r a i l F r a n c i s C r e e k s * t h e s e l o c a l i t i e s t h e N u g g e t s a n d s t o n e o n s i s t s of t a n t o o r a n g e, w e l l c e m e n t e d , a e o l i a n a n d t o n e s h a v i n g d i s t i n c t c r o s s - b e d d i n g. c o n t a c t t h e N u g g e t w i t h t h e u n d e r l y i n g C h i n l e ? ) is n o t d e f i n i t e l y e x p o s e d i n t h e a r e a , b u t a t l o c a l i t y 2, r e d d i s h s h a l e y b e d s a r e p o o r l y e x p o s e d r e p r e s e n t t he b a s a l p a r t t h e N u g g e s a n d s t o n e. F o s s i l s a r e r a r e i n t h e N u g g e s a n d s t o n e , b u t i t s i d e n t i ty i s r e a d i l y e s t a b l i s h e d t h e b a s i s t h e c h a r a c t e r i s t i c c o l o 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 w i t h r e f e r e n c e t o t h e o v e r ­l y i n g C r e e k l i m e s t o n e. t y p e s e c t i o n t h e N u g g e t a n d o n e , i n i t i a l l y d e s ­c r i b e d V e a t c h 1 9 0 7 , P* 5 6 ) , s n e a r N u g g e t S t a t i o n , Wyoming. T h e r e i t h a s m e a s u r e d t h i c k n e s s , 9 0 0 f e e t .. T w i n C r e e k l i m e s t o n e . . o n l y e x p o s u r e t h e C r e ek l i m e s t o n e i n t h e a r e a o c c u r s a l o n g t h e a l l e y L o C r e e k f r om t h e m o u t h t o t h e T r a i l C r e e k f o r k . H e r s , t he T w i n C r e e k i s w h i t e t o g r a y w e a t h e r i n g s h a l e y l i m e s t o n e c o n ­t a i n i n g some r e d b e d s and c a l c a r e n i t e s . a r e n i t e s n o r m a l ly s t a n d o u t a s t o p o g r a p h i c a l l y r e s i s t a n t r i b s , t h e e x p o s u r e s a r e o b s c u r e d t a l u s s l o p e s s i l v e r - l i k e f r a g ­m e n t s f r o m t h e o v e r l y i n g s h a l e y l i m e s t o n e. The b a s a l c o n t a c t t h e C r e e k i s n o t s h a r p and w e ll d e f i n e d , a p p e a r s i n s t e a d t o be g r a d a t i o n a l , o v e r t h i c k n e ss 10 of the junction of Trail and Franc is Creeks with Lost Creek and ( 2) south of the confluence of Treil and Francis Creeks. At these localities the Nugget sandstone c onsists ot ten to or enge, well cemented, aeolian s and s tones having distinct cross- bedding . The contact of the Nu gget with the underlying Chinle ( 7) is not d~flnltely expos ed in the area , but at loc ality 2 , some reddi sh shaley beds are poorly exposed and may represent the beeel pert of the Nugge t sendstone. Fossils ere rare in the Nugge t sendstone , but its identity 1s readily established on the basis of the characteristic colol', lithology , and stretigraphic position wi th refer ence to the over­lying Twin Creek limestone. The type section of the Nugget s and s t one, initi ally des­cribed by Veatch ( 1907, p. 56), i s ne ar Nu gget Station, Wyoming . There it has a measured thickness of 1 , 900 feet. Twin Creek limestone.. The only exposure of the Twin Creek limestone in the aree occurs along the v alley of Lo s t Creek from the mouth of Toone Canyon to the Trail Creek fork.. Hers, the Twin Creek is a white to grey - weathering shaley limestone con­taining s ome redbed s end calc arenites. The arenites normally stand out as topographically resistant ribs , but more commonly, the exposures Bre obs cured by talus slopes of sil:ver-like fra g­ments from the overlyinp shal ey limestone. The basal cont act of the Twin Creek is not sharp end well de~1ned, but app ear s ins te ad to be gr adational, ov er a thickness 1 1 a b o u t f e e t , t h e r o s s b e d d e d s a n d s t o n e s h e N u g g et t o t h e m a r i n e l i m e s t o n e t h e G r e e k , i n d i c a t i n g t h a t t he i n u n d a t i o n t h e C r e e k e a s l o w e n o u g h t o a l l o w t i me f o r r e w o r k i n g l e a t h e u p p e r f e e t t h e N u g g e t .. I n t e n s e o l d i n g t h e C r e e k l i m e s t o n e i n t h e a r e a of e x p o s u r e a l o n g L o s C r e e k t h e e x p o s u r e s u n s u i t a b l e for a c c u r a t e s e c t i o n m e a s u r e m e n t c o n s e q u e n t l y , r e f e r e n c e is o t h e n e a r e s t a v a i l a b l e s e c t i o n , w h i c h i s m i l e s o t he w e s t n e a r t h e C r o y d e n , s e c t i o n , 3 , 1 4 0 f e e t t h i c k, m e a s u r e d d e s c r i b e d t h e r e E a d l e y 1 9 4 4 , P« 0- f o s s i l h o r i z o n n e a r t h e u p p e r i m i t t h e C r e ek c o n t a i n s a b u n d a n , w e l l p r e s e r v e d s p e c i m e n s P e n t a c r i n us a s t e r i s c u s p e l e c y p o d f r a g m e n t s0 C r e e k l i m e s t o n e f i r s t d e s c r i b e d V e a t 1 9 0 7 , p . i n s o u t h w e s t e r n s p r e s e n t l y c o n s i d e r ed t o M i d d l e U p p e r J u r a s s i c i n I m l a y , 1 9 4 7 , p - 2 3 1 ) . It i s c o r r e l a t i v e , p a r t , t h e f o r m a t i o n i n U t a h t h e S u n d a n c e " I m l a y , 1 9 5 2 , p„ 963)- P l a t e I I I ) , P r e u s s f o r m a t i o n ^ . o n l y e x p o s u r e t h e P r e u s s f o r m a t i on r e c o g n i z e d i n t h e a r e a i s i n T o o n e t r i b u t a r y t o L o st C r e e k , t h i c k n e s s t h i s e x p o s u r e c a r e f u l l y s c a l e d from a e r i a p h o t o g r a p h s i s f e e t . P r e u s s c o n f o r m a b l y o v e r l i es t h e C r e e k f o r m a t i o n t h e c o n t a c t i s e a s i l y d i s c e r n e d b e ­c a u s e m a r k e d c o l o r d i f f e r e n c e b e c a u s e t h e l e s s r e s i s t ­a n t P r e u s s s r e a d i l y t r i p p e d t h e r e s i s t a n t r o c k s 11 of about 30 feet, from the c rossbedded sandstones of t he Nugget to the marine limestone of the Twin Cre ek , indicating that the inundation by the Twin Creek s ea was slow enough to allow time for reworking of a t lea s t the upper few fe et of the Nugget .. Intense f olding of the Twin Creek li me st one in the area of exposure along Los t Creek makes the ex pos ur es unsuitable for accurate section meas urement and, consequently, reference 1s made t o the nearest avail able section, which is 8 miles t o the west ne ar the town of Cr oyden . The section, 3,140 feet thick, was measur ed and descr ibed there by Ea r dl ey ( 1944 , p. 836) •. A fos sil hor izon near the upper l imit of the Twin Creek contains abund an t , well pr.es.erved specimens of Pen t ac rinus astel'i scus and pelecypod fragments . The Twin Creek limest one was first described by Veat ch ( 1907 , p. 56) in southwestern Wyoming and i s presently considered to be Middle. and Upper Jur assic in age ( Imla y, 1947, p. 231). It is a correlative, in part , of the Carmel formation in Utah and the "Lower Sund ance" of Wyoming ( Iml ay, 1952, p. 963) ( Plate III) . Preuss format ion.. The onl y exposure of the Preu ss formation recognized in the area is in To one Canyon, a tributary to Los t Creek. The thickness of this exposure as car efully scaled from aeria l photographs is 370 feet . The Preuss conformably overlies the Twin Creek formation and the contact is eas ily discerned be­CBuse of a marked color difference and because the less resist­ant Preuss i s readil y s trip ped off the more resis t an t rocks of P l a t e J U R A S S I C - C R E T A C E O U S N O M E N C L A T U R E C H A RT IDAHO Mansfield (1927) W.WYOMING V e a t c h l 9 0 7 ) THRUST S t o k e s 1955) Paper) MOUNTAINS S t o k e s , e t al.(!955) ASPHALT S t o k e s , e t al.(l955) C o r r e l a t i o n of Late C r e t a c e o u s f o r m a t i o n s d e t a i l P l a te CO o LU O < Ixl or o fm. a> c c o T y g e e ss D r a n e y B e c h l e r eg. P e t e r s o n E p h r a im eg. S t u m p fm. o CO CO < or P r e u ss. F r o n t i e r fm. A s p e n fm. B e a r fm. <o F r o n t i e r fm. fm. CL a> c c o CD Draney B e c h l e r eg. P e t e r s o n E p h r a im eg. fm. P r e u s s fm. Frontier fm. A s p e n Kelvin fm. M o r r i s o n fm. S t u m p fm. P r e u s s fm. fm. A s p e n fm. Kelvin fm. M l l l l l l l l l i r T M o r r i s o n fm. S t u m p fm. P r e u s s fm. Mancos F r o n t i e r M a n c os D a k o t a C e d a r fm B u c k h o r n eg. 111111111 n M o r r i s o n fm. C u r t i s fm. E n t r a d a fm. C r e e k fm. C r e e k fm. Creek Creek fm, Nugget ss N u g g e t fm. N u g g e t fm. N u g g e t s s. N u g g e t fm. N a v a j o fm. Pl ate III JURASSIC- CRETACEOUS NOMENCLATURE CHART S.E. IDAHO S.w. WYOMING WYOMING TOONE CANYON N.W.UINTA ASPH ALT RIDGE THRU ST BELT MOUNTAIN S Mansl ield (1927) Veatch ( 1907) Stokes (1955) (This Paper) Stokes,et 01.(1955) Stokes, et 01.(1955) Correlati on 01 Lat e Cr eta ceous fo rmations shown in det a il on Plate ~ ~ ~~ ~ ~ ~ ~ ~ (/) Frontier 1m. .c; Upper Mancos => Fro ntier 1m. Front ier I",. Frontier 1m. ~ 0 ~ Frontier Wayan 1m. c ss. u W c Aspen 1m. Aspen sh. Aspe n 1m. c u :::0 Lower Mancos Wayan 1m. 00: Bear River 1m. Da kota ss. f- Tygee ss . w e0>. Droney Is. a. Droney Is. . Ke lvin 1m. Ke lvin 1m. Cedar Mountain 1m - 0> a:: -.. Bec hler cg. -- Bec hle r cg. Buc kh orn cg. Peterson Is. .. u (;'. Peterson Is. '" (c!) Ephraim cg. ~ (cc!) Ephraim cg. Morrison fm. Mor rison fm . Morrison tm . ~ Stump 1m. (j' Stump 1m. Stump 1m. Stump 1m. Cur tis 1m. ~ .. u - (J) Preu s s ss . Preu ss 1m. Pr euss 1m. Preuss 1m. Entrada 1m. (/) 00: 0:: Twin Creek Is. Twin Cre ek 1m. Twin Creek 1m. Twin Cr eek Is. Twin Cr eek 1m. Carmel fm. =..>, Nu gget s s. Nugget 1m. Nugget 1m. Nugget ss . Nugget 1m. Nava jo 1m. 13 t h e C r e e k l i m e s t o n e .. The P r e u s s c o n s i s t s of t h i n - b e d d e d , r e d s a n d s t o n e s and s i l t - s t o n e w h i c h w e a t h e r r a p i d l y t o f o r m s o f t s l o p e s w h i c h r e t a in t h e c h a r a c t e r i s t i c r e d c o l o r. The t y p e s e c t i o n of t h e P r e u s s f o r m a t i o n i s i n s o u t h e a s t e rn I d a h o n e a r t h e n o r t h e r n b o r d e r of B e a r Lake County, w h e r e i t was f i r s t named by M a n s f i e l d and Roundy ( 1 9 1 6 , p . 8 1 ) - I t i s a c o r r e l a t i v e of t h e E n t r a d a s a n d s t o n e i n s o u t h e r n U t a h and t he l o w e r B e c k w i t h f o r m a t i o n of s o u t h w e s t e r n Wyoming a s d e s c r i b e d by V e a t c h ( 1 9 0 7 , p . 57) ( P l a t e I I I ) . Stump f o r m a t i o n . . The Stump f o r m a t i o n c r o p s out o n l y i n a s m a l l a r e a a b o u t one m i l e e a s t of t h e m o u t h of Toone Canyon w h e re a p p r o x i m a t e l y 420 f e e t a r e e x p o s e d . The b a s a l c o n t a c t of t he Stump f o r m a t i o n w i t h t h e c h a r a c t e r i s t i c red s a n d s and s i l t s of t h e u n d e r l y i n g P r e u s s f o r m a t i o n i s e a s i l y r e c o g n i z e d , a l t h o u gh p o o r l y e x p o s e d in t h e d e s c r i b e d a r e a. I n n e a r b y a r e a s s u c h a s P e o a ( M o r r i s , 1 9 5 3 , p . 20) s o u th of t h e W a n s h i p r e s e r v o i r , t h e Stump f o r m a t i o n i s d i v i s i b l e i n to 3 u n i t s : ( 1 ) an u p p e r member of g r e e n i s h g r a y g l a u c o n i t i c l i m e ­s t o n e , (2) a m i d d l e member w h i c h c o n s i s t s of l i g h t r e d and y e l l ow s h a l e and s o f t s a n d s t o n e , and (3) a l o w e r member c o n s i s t i n g of g r a y t o y e l l o w - g r a y s a n d s t o n e. The c e p h a l o p o d , P a c h y t e u t h i s d e n s u s , i s a c h a r a c t e r i s t ic f o s s i l i n t h e Stump f o r m a t i o n (A ' h o m a s and K r e u g e r , 1 9 4 6 , p . 1278) i n n e a r b y a r e a s , but n o n e w e r e f o u n d a t t h e Toone C a n y o n o u t c r o p. , " 13 the Twin Creek limestcne., The Preuss consists cf thin-bedded, red sandstcnes and silt­stcne s which weather rapidly to. ferm seft slepes which retain the characteristic red celer. The type secticn cf the Preuss fermatien is in scutheastern Idaho. near the nerthern border cf Bear Lake Ceunty, where it was first named by Mansfield and Reundy (1916, p. 8l)~ It is a cerrelative cf the Entrada sandstene in seuthern Utah and the lewer Beckwith fcrmGtien ef seuthwestern Wycming as described by Veatch (1907, p_ 57) (Plate III). Stump formaticn~ The Stump fcrmaticn crcps cut enly in a small area abcut cne mile east cf the mcuth ef Teene Canycn where approximately 420 feet are expesed. The basal centact ef the Stump fermatien 'Nith the -characteristic red sands Bnd silts cf the underlying Preuss fcrmatien is easily recegnized, althcugh peerly expesed in the described area. In nearby areas such as Peca (Morris, 1953, p. 20) south of the Wanship reservoir, the Stump fcrmaticn is divisible into. 3 units: (1) an upper member cf greenish gray glauccnitic lime­stone, (2) a middle member which consists of lif,htred and yellow shale and scft sandstcne, and (3) a lcwer member ccnsisting of gray to. yellow-gray sBndstone~ The cephalopod, Pachyteuthis densus,is a characteristic fessil in the Stump fcrmation ('l'hcmas and Kreuger, 1946, p. 1278) in nearby areas, but ncne were fC:-1nd at the Toone Canyon outcrcp. c o r r e l a t e s w i t h t h e C u r t i s f o r m a t i o n e a s t - c e n t r a l U t a h and w i t h p a r t t h e l o w e r B e c k w i t h f o r m a t i o n in s o u t h w e s t e r n V e a t c h , 1 9 0 7 , p„- 5 7 ) » t y p e s e c t i o n of t h e i s n e a r P e a k i n C a r i b o u C o u n t y s o u t h e a s t e rn I d a h o M a n s f i e l d R o u n d y , 1 9 1 6 , p . 8 1 ) .. M o r r i s o n o r m a t i o n . C o n f o r m a b l y o v e r l y i n g t h e i s the M o r r i s o n f o r m a t i o n ^ M o r r i s o n f o r m a t i o n i s p o o r l y e x p o s e d in T o o n e and i t s i d e n t i f i c a t i o n i s b a s e d u p o n ; i t s s t r a t - i g r a p h i c p o s i t i o n , 2) c h a r a c t e r i s t i c w h i t e n o d u l a r l i m e s t o ne b e d , 3) Q c o l o r s i m i l a r i t y r e d w i t h one d e s c r i b ed i n t h e M o r r i s o n f o r m a t i o n a t i t s p l a c e o u t c r o p i n t h e Peoa s e c t i o n M o r r i s , 1 9 5 3 , p<> )„ t h i c k n e s s 4 8 0 f e e t f o r the e x p o s e d M o r r i s o n o r m a t i o n i n s c a l e d f r o m a e r i al p h o t o g r a p h s . p r o n o u n c e d c o l o r c h a n g e m a r k s t h e b a s a l c o n t a c t t he M o r r i s o n f o r m a t i o n w i t h t h e u n d e r l y i n g f o r m a t i o n . u p p er c o n t a c t i s n o t a s w e l l d e f i n e d , h o w e v e r , c h o s e n a r b i ­t r a r i l y i n a s m u c h a s t h e r e i s g r a d a t i o n i n t o t h e c o n g l o m e r a t ic K e l v i n f o r m a t i o n . c o n t a c t s e l e c t e d i s j u s t b e l o w t h e l o w e st c o a r s e c o n g l o m e r a t e i n t h e K e l v i n f o r m a t i o n. w h i t e n o d u l a r l i m e s t o n e i n t h e M o r r i s o n f o r m a t i o n p r o b a b l y c o r r e l a t i v e of t h e w h i t e m a r k e r b e d s d e s c r i b ed G r a n g e r and S h a r p , 1 9 5 2 , p . e a s t S a l t Lake C i t y* W0 To. L e e 1 9 2 0 ) named t h e t y p e s e c t i o n t h e M o r r i s o n f o r m ­a t i o n f o r i t s e x p o s u r e n e a r M o r r i s o n , C o l o r a d o ., 14 The Stump correlates with the Curtis formation of east­central Utah end with part of the lower Beckwith fonnstion 1n southwestern Wyoming ( Veatch, 1907, p. 57). The type section of the Stump is near Stump Peak in Caribou County of southeastern Idaho ( Mansfield and Roundy, 1916, p. 81). Morrison f orma tion. Conformably overlying the Stump 1s the Morrison formation o ' The Mor rison formation is poorly exposed 1n To one Canyon end its identification is basad upon; 1) its str at­i graphic position, 2 ) a characteristic white nodular limestone bed, and 3} a color simil erity of a red bed with Doe described 1n the Morrison format ion at its place of outcr op in the Pece section ( Morris, 1953, p. 21 ). A thickness of 480 feet for the exposed Morrison f ormation in Toone Canyon was scaled from aerial photographs . A pronounced color chan ge marks the basal contact of the Morrison forma ti on with the underlying Stump formation . The upper contact is not as well defined, however, and must be chosen arbi­trarily inasmuch 88 ther e is a gr ad e tion into the conglomeratic Kelvin forma tion. The contact selected is just below the lowest coarse conglomerate bed in the Kelvin form ation o The white nodul er limestone in the Morrison formation is probably a correlative of one or the white marker beds described by Granger Bnd Sha rp , ( 195 2 , p . 14) east of Salt Lake City. VI. T. Lee ( 1920) named the type section of the Morr ison form­ation for its exposure near Morrison , Colorado .. 1 5 C r e t a c e o u s S y s t em K e l v i n f o r m a t i o n . l o w e r K e l v i n f o r m a t i o n i s e x p o s e d in T o o n e C a n y o n , h u t t h e u p p e r p a r t t h e s e q u e n c e h a s b e e n o m i t t ed b y f o l d i n g f a u l t i n g . a p p r o x i m a t e t h i c k n e s s t h e K e l v in i s e e t M o r r i s , 1 9 5 3 , . . 2 2 ) .. T h e b a s a l c o n t a c t t h e K e l v i n f o r m a t i o n , w h e r e e x p o s e d in t h e P e o a s e c t i o n , i s a r b i t r a r i l y a k e n a s t h e b a s e c h e r t c o n ­g l o m e r a t e 1 9 5 2 , p . 9 ) , w h i c h c o n f o r m a b l y o v e r l i e s the M o r r i s o n f o r m a t i o n, C o n g l o m e r a t e s w i t h f r a g m e n t s r a n g i n g i n s i z e f r o m s m a l l p e b ­bles t o v e r y l a r g e p e b b l e s f a i r l y w e l l c e m e n t e d i n a r e d s a n d y m a t ­r i x , t o g e t h e r w i t h i n t e r b e d d e d s a n d s t o n e s and s i l t s t o n e s c o m p r i se t h e K e l v i n f o r m a t i o n a t i t s e x p o s u r e i n T o o n e C a n y o n. M a t h e w s 1 9 3 1 , p - and d e s c r i b e d t h e K e l v i n forma­t i o n f o r i t s e x p o s u r e E m i g r a t i o n C a n y o n e a s S a l t C i t y, t h e t y p e l o c a l i t y t h e K e l v i n f o r m a t i o n i s p r e d o m i n a n t l y c o n ­g l o m e r a t e s e q u e n c e ; i t b e c o m e s l e s s c o n g l o m e r a t i c c h a r a c t e r ­i s t i c a l l y h a s a h i g h e r p e r c e n t a g e s a n d s t o n e and s i l t s t o n e t h e v e a s t . . K e l v i n i s c o n s i d e r e d t o r e p r e s e n t s e r i e s c o a l ­e s c i n g a l l u v i a l a n s w h i c h w e s t e r n s o u r c e i n t h e h i g h l a n ds f o r m e d d u r i n g t h e Cedar H i l l s o r o g e n y ( E a r d l e y , 1 9 5 1 , P* 3 2 5 ), The K e l v i n i s a l i k e l y c o r r e l a t i v e of t h e E p h r a i m and B e c h l er c o n g l o m e r a t e s of s o u t h w e s t e r n Wyoming. A s p e n s h a l e * s h a l e i s n o t e x p o s e d i n t h e immed­i a t e a r e a s t u d y , b u t i s p r o b a b l y p r e s e n t a t d e p t h * I t i s, 15 Cretaceous System Kelvin formation. The lower Kelvin formation 1s exposed in Toone Canyon, but the upper part of the sequence bas been omitted by folding and faulting . An approximate thickness of the Kelvin is 2700 f eet ( Morris, 1953, p •. 22) . The basal contact of the Kelvin forma tion, where exposed in the Pece sectIon, is arbltI' arl1y t aken as the base of a chert con­glomerata (Mount, 1952, p. 9), which conformably overlies the Morrison formation . Conglomerates with fra gments ranging in size from small peb­b~ to very large pebbles fairly well cemented 1n B red sandy mat­rix, together with interbedded sandstones Bnd siltstones comprise the Kelv in formation at its exposure in Toone Canyon. Mathews ( 19 31, p. 48) named end described the Kelvin forma­tinn for its exposure in Emi gr ation Canyon eas t of Selt Lake City. At the type 10c a11 ty the Kel vin format ion is predominan tly a con­glomerate sequence; it becomes less conglomeratic and char acter­istically has 8 higher percentage of sandstone end siltstone to the \ eest .. The Kelvin is considered to repr esent a series of coal­escing alluvial f ans which had a western source in the highlands formed during the Hills orogeny Eardley, 1951, p. 325). Kelvin is likely correlative the Ephraim Bechler conglom,erates southwestern Aspen shale. The Aspen shale is not exposed in the immed­iate area of study , but is probably present at depth .. It is, h o w e v e r , w e l l r e p r e s e n t e d a b o u t m i l e s t o t h e s o u t h i n t h e v i c i n ­i t y C o a l v i l l e , U t a h w h e r e i t h a s m e a s u r e d t h i c k n e s s 99 f e e t 1953? P« 1 6 ) . Where t h e f o r m a t i o n i s e x p o s e d, s o u t h t h e a r e a t h e p r e s e n t s t u d y , i t i s r e a d i l y d i s ­t i n g u i s h e d f r om t h e u n d e r l y i n g o v e r l y i n g f o r m a t i o n s i ts d a r k g r a y c o l o r , s h a l e y c h a r a c t e r , a b u n d a n t t e l e o s t f i sh s c a l e s . V e a t c h ( 1 9 0 7 , p . 64) named t h e t y p e s e c t i o n of t h e Aspen f o r m a t i o n f o r i t s e x p o s u r e n e a r Aspen S t a t i o n of t h e U n i o n P a c i f ic R a i l r o a d i n s o u t h w e s t e r n Wyoming. The Toone Canyon a r e a would be v e r y n e a r s h o r e i n r e l a t i on t o t h e Aspen s e a and, c o n s e q u e n t l y , the s h a l e f a c i e s n o t e d t o t he s o u t h i n t h e v i c i n i t i e s of. C o a l v i l l e and R o c k p o r t ( V e a t c h , 1 9 0 7, p p . . 1 0 3 - 1 0 5 ) , may w e l l be a b s e n t or a t b e s t , r e l a t i v e l y t h i n . It may, a c c o r d i n g l y , l a c k t h e c h a r a c t e r i s t i c f i s h s c a l e s , i n t he v i c i n i t y of Toone C a n y o n . C o r r e l a t i v e s of t h e Aspen f o r m a t i on a r e t h e Mowry s h a l e and p a r t of t h e l o w e r Mancos f o r m a t i o n in o t h e r a r e a s» F r o n t i e r f o r m a t i o n a E x p o s u r e s of t h e F r o n t i e r f o r m a t i o n a re r e s t r i c t e d t o t h e s o u t h e r n m a r g i n of t h e mapped a r e a a l o n g u p p er G r a s s C r e e k C r e e k . T h e s e a r e i n c o m p l e t e s e c t i o n s , but c o n t i g u o u s a r e a s c o n t a i n c o m p l e t e s e c t i o n s t h a t b e e n s t u d i ed b y p r e v i o u s r e c e n t i n v e s t i g a t o r s 1 9 5 3 , PP» 1 6 - 2 3 ) * m e a s u r e d 2 , 1 3 2 f e e t b e d s n o r t h e a s t C o a l v i l l e , w h i c h a s s i g n e d t o t h e F r o n t i e r f o r m a t i o n. 16 however, well represented about 12 miles to the south in the vicin­ity of Coalville, Utah where it has a measured thickness of 99 feet (Wood, 1953, po. 16). Vihere the Aspen formation is exposed, south of the mapped area of the present study, it is readily dis­tinguished from the underlying and overlying formations by its dark gray color, shaley characrt.er, and abundant teleost fish scales. Veatch (1907, po 64) named the type section of the Aspen formation for its exposure near Aspen Station of the Union Pacific Railroad in southwestern Wyoming. The Toone Canyon area would be very near shore in relation to the Aspen sea and, consequently, the shale facies noted to the south in the vicinities of Coalville and Rockport (Veatch, 1907, pp .. 103-105), may well be absent or at best, relatively thin. It may, accordingly, lack the characteristic fish scales, in the vicinity of Toone Canyon. Correlatives of the Aspen formation are the Mowry shale and part of the lower Mancos formation in other areas .. Fr on tier forma ti on .. Exposur es of the Frontier formati on are restricted to the southern margin of the mapped area along upper Grass Creek and Meadow Creek. These are incomplete sections, but contiguous areas contain complete sections that have been studied by previous recent investigators (Wood, 1953, pp. 16-23) .. Wood measured 2,132 feet of beds northeast of Coalville, which he assigned to the Frontier formation. S t u d e s t h e b e d s m m e d i a t e l y o v e r l y i n g h e s h a l e in h e C o a l v i l l e a r e a w e r e made by n u m b e g e o l o g i s i n c l u d i n g: S t a n t o n 8 9 3 ) , V e a t c h 1 9 0 7 ) , Wegemann 9 1 5 V e a t c h ( 1 9 0 7, Po. 1 0 3 ) c o r r e l a t e d the C o a l v i l e s e c t i o n w i t h t h e F r o n t i e r f o r m ­a i o n s o u t h w e s t Wyomingo age of t h e F r o n t i e r o r m a t i o n was e s a b l i s h e d by e a r ly w o r k e s S t a n o n , 1 8 9 3 , p , 4 0 V e c h , 1 9 0 7 7 p » 6 9 ; Wegemann, 1 9 1 5 , I 6 4 ) C o l o r a d o a n , h e b a s i s t h e f o s s i l a u n a f l o r a „ L o c a l l y , h e u p p e r p a r t t h e F r o n t i e r q u e n c e i s m i s s i ng b e c a u s e e r o s i o n n o n d e p o s i t i o n s s o c i a t e d w i t h l o c a f o l d ­i n g p r i o r t o a t e C o l o r a d o a n t i m e , E v i d e n c e t h i s o c d e ­f o r m a t i o n s p a r t i c u l a r l y e v i d e n t a s t t h e W a n s h i p r e s e r v o ir i n C r a n d a l l and Dry C a n y o n s w h e e t h e F r o n t i e r f o r m a i o n , s t a n d ­i n g n e a r l y v e r t i c a l , i s t r u n c a t e d h e e s s e n t i a l l y h o r i z o n t al b e d s y o u n g e r g e* W a n s h i p o r m i o n . O v e r l y i n g t h e F r o n t i e r f o r m a t i o n w i th l o c a l n g u l a r d i s c o r d a n c e i s s e o u e n c e s a n d s o n e s s n a l e s w h i c h N„ 0o W i l l i a m s o r i t s o u t c r o p e a s t W a n s h i p, U t a h . Though n o t y e t f o r m a l l y p r o p o s e d , t h e t e r m i s g e n e r a l ly a c c e p t e d by w o r k e r s in n o r t h e a s t e r n U t a h. An u n i n t e r r u p t e d e c t i o n t h e W a n s h i p o r m a t i o n s n o t p r e s ­e n t w i t h i n t h e a r e a , b u t h e e n t i r e u n i t i s r e p r e s e n t e d c o m p o s i t e v a i o u s e x p o s u r e s . Wood, 1 9 5 3, p » 3 0 - 3 1 ) m e a s u r ed t h e f o l l o w i n g s e c t i o n w i t h p l a n e t a b l e end a l i d a d e a c r o s s l o w er 17 Stud i es of the beds i mmedia tely overlying t he Aspen sha le in t he Coa lville area were Jl'IlJde t.\' a numbe r of ge olori s t s includ i ng: St an ton ( 1 893), Ve atch ( 1907 ), and "Iegemann ( 1 915 ) ; vea tch (19 07, pO' 10)) correlated t he Coa lvil l e sec tion with the Fr onti er form­a t ion of southwest fyami ng. The a ge Of the Fr ontier f or mation wa s es t a bli shed e arly wo rke r s ( St an t on, 1893, .. 40 ; Ve a t ch, 1907, o 69: and We gemE.lnn~ 1915, p . 164 ) as Col or adoan , on t he ba sis of the fossil f auna and fl ora .. Locally , t he upper Art of the Frontier s e quenc e 1s mi ss ing because of erosion or nond ep os iti on a ssociat ed with loca l fold­ing prior to l a t e Coloradoan time o Evidence of this l oc a l de­formation i s particul arly evident e ast of the Wanshl p reserv oir in Cr and el l end Dr y Canyons whe r e the Fr ontier for ma t ion, s t and ­ing ne arl y vertic al , 1s trunc ated by t he essentially horizonta l bed s of younger a ge ... Wanship f orm a t ion. Overlying the Frontier forma ti on with lo cal a neul e.r discord ance is a seouence of se nds t ones and sha l es which was named by N. C. Wil liams f or its outc rop east of Wanship, Utah. Thourh not as ye t for mally proposed, the term is generally ccepted wor ke s in northeastern Ut ah • . An uninterr upted s ection of the i'la nship f ormation i s not pr es­en t within the mapped area, but t he entfre unit i s re presen t ed in a composite of va r ious exposures .. Vlooo, ( 1953, .. 30- 31) measured the fo110'.. ..l in? s ection with plane table and alid ade Bc r oss ower 1 8 G r a s s V a l l e y H o l l o w , w h i c h l i e i m m e d i a t e l y s o u t h l o w er E c h o C a n y o n: Almy f o r m a t i o n * c o n g l o m e r a t e t h i s p a p e r) W a n s h i p f o r m a t i o n ( C o n t a c t r e c o g n i z e d by c h a n g e i n Top c o l o r and l i t h o l o g y f r o m b u f f and l i g h t g r a y s a n d s , t o r e d d i s h c o n ­g l o m e r a t e s ) U n i t Description Feet 8 b u f f t o g r a y t o w h i t e , c a l c a r ­e o u s , f r i a b l e , medium t o c o a r s e g r a i n e d, p o r o u s , t h i n b e d d e d . W e a t h e r s b r o w n , I n - t e r b e d d e d w i t h a r e n a c e o u s s h a l e s and p e a - t o n u t - s i z e d c o n g l o m e r a t e s . . P o o r l y e x p o s e d - . 1 , 2 50 7 Covered* P r o b a b l y i n t e r b e d d e d s a n d s t o n es and a r e n a c e o u s s h a l e s s i m i l a r u n i t 8 . 2 5 0 t a n t o g r a y , m a s s i v e , m e d i u m to f i n e g r a i n e d v e r y c a l c a r e o u s , f r i a b l e, s l i g h t l y p o r o u s . . C o n t a i n s f e w c h e r t n o d ­u l e s . C o n t a i n s I n o c e r a m u s p . . F o r m s h o g ­b a c k r i d g e s e p a r a t i n g C a r r u t h L e w is C a n y o n s . 205 b u f f , t h i n b e d d e d , w i t h i n t e r ­b e d d e d s h a l e s * P o o r l y e x p o s e d . 1,080 w h i t e t o g r a y , v e r y c a l c a r e o u s, w e l l c e m e n t e d . t o f i n e g r a i n e d m a s s i v e . W e a t h e r s g r a y t o t a n . h o g ­b a c k r i d g e b e t w e e n H o l l o w G r a ss V a l l e y C a n y o n , and b e t w e e n L e w i s Canyon a n d V a l l e y *... . 2 30 t h i n b e d d e d s a n d s t o n e , w i t h c o al a t t h e b a s e . P o o r l y e x p o s e d ^ 2 b u t p r o b a b l y s h a l e and t h i n b e d d ed s a n d s t o n e 770 p o o r l y s o r t e d , f e r r u g i n ­o u s . P e b b l e s a r e p e a s i z e d t o i n c h e s i n d i a ­m e t e r , and a r e c o m p o s e d q u a r t z i t e and s a n d ­s t o n e * S a n d y , c a l c a r e o u s m a t r i x . T o t a l , 9 5 0 18 Grass Valley and Dry Hollow, which lie immediately south of lower Bcho Canyon: Unit e 6 5 4 3 1 Almoc formation. (Echo Canyon conglomerate of this paper) Wanship formation (Contact recognized by change in color and lithology fr.om buff and light gray sands, to reddish con­glomerates) Descri.ption Sandstone, buft to gray to white, calcar­eous, friable, m~dium to coar"se grained, porous, thin bedded. Weathers brown, In­terbedded with arenaceous shales Bnd pea- Top Feet te nut- sized conglomerates .. Poorly exposed ... 1, 250 Cover ed. Probably interbedded sand stones aod arenaceous shales similar to unit 8 ....... 1,250 Sandstone, tan to gray, massive, medium to fine grained very calcareoUs, friable, slightly porous. Contains a few chert nod-ules. Contains Inoceramu s sp .. Forms hog-back rid ge separating Carruth and Lewis Canyons 0 ' , ••••••••••••••••••• •• ••• • •••••••••••• 205 Sandstones, buff, thin bedded, with inter-bedded shales. Poorly e"posed • • • ....••.•. • •. l, 080 Sandstone, white to gray, very calcareous, well cemented. Medium to fine grained and massive. Weathers gray to tan. Forms hog-back ridge between Dry Hollow and Gress Valley Canyon, Bnd between Lewis Canyon and Weber Valley ..... . .... . .... . ...... ......... 230 Shales and thin bedded sandstone, with coal at the base. Poorly e"posed ................... 105 ,/ Covered, but probably shele end thin bedded sand stone ......... . ......... .. . ... ............ 770 Conglomerate, brown, poorly sorted, ferrugin­ous. Pebbles are pea sized to 6 inches in dia­meter, Bnd are composed of quartzite Bnd sand­stone. Sandy, calcareous mstrix • • .. • .. . ..• • •• .. 60 Total ... . .... . .............................. 4 t 950 1 9 h e r e i n d e f i n e d t h e W a n s h i p f o r m a t i o n c o m p r i s e s a b a s al c o n g l o m e r a t e member o v e r l a i n s e q u e n c s h a l and s a n d s t o ne u n i t b a s a l o n g l o m e a t e t h e W a n s h i p f o r m a i o n in a r e a s i s t h e b e i d e n t i f y i n g t h e l o w e r l i m i t t he f o r m a t i o n and s p e c i a l l y so w h e r e t h e i m i l a l i t h o l o g i e s t he u n d e r l y i n g F r o n t i e r f o r m a t i o n a r e a l s o e x p o s e d. E a s t and s o u t h e a s t W a n s h i p , U t a h , m a r k e d a n g u l a r u n c o n ­f o r m i t y i s e x p o e d b e t w e e n t h e W a n s h i p and F r o n t i e r f o r m a t i o n s, w h e r e a s , i n t h e a r e a e a s t C o a l v i l l e , U t a h t h e a n g u l a r d i s c o r ­d a n c e i s n o t e d g e n e r a l y o n l y o v e r d i s t a n c e s t h a n m i l e . The b a s a l W a n s h i p o n g l o m e r a t e u n i t d e s c r i b e d by Wege-mann 9 1 5 , p - f r o m h i s t r a t i g r a p h i c s e c t i o n a t C o a l v i l l e, U t a h W i l l i a m s , p e r o n a c o m m u n i c a t i o n ) .. T r e x l e r 1 9 5 7 , p . d e s c r i b e d f o u r u n i t s w h i c h c o m p r i se t h e F r o n t i e r f o r m a t i o n i n t h e C o a l v i l l e r e a o l l o w s ( d e s c e n d ­i n g o r d e r ): 4 ) f e e t m a r i n e s a n d s t o n e a l e s w i t h 6 3 5 - f o ot n o n m a r i n e e q u e n c e i n t h e l o w e r h a l f ; e a r l y N i o b r a C o n i a c a n ) Fauna,, 3 ) e e t n o n m a r i n e a n d s t o n e and c l a y s t o n e s w i t h 7 5 - f o o t c o n g l ome r a t e f e e t f r o m t h e b a s e . 2 ) e e t m a r i n e a n d s t o n e s h a l e d a t e d e a r ly C a r l i l e T u r o n i a n ) and t e C r e e n h o r n T u r o n i a n ) a g e s; c o a l s a s o c i a t e d w i t h s a n d s t o n e s n e a r t h e b a s e. 1 ) e e t d o m i n a n t l y o n m a i n e s a n d s c l P r o b a b l y C e n o m a n i a n ). p p e r m o s t t h e s e u n i t s u n i t c o n s i s t s 2 4 0 f e et m a r i n e a n d s t o n e s h a l e o n t a i n i n g a r l y N i o b r a r a f a u na 19 As herein defined the Wanshlp fom ation comprises B basal conglomer ate membe r overlain by a sequenc e of shal e Bnd s end stone unit s . The basal c ongl ome r ate member of the Wanship forma t i on in many areas is the be s t means of identify ing the lower limit of the formation end e specially s o where the s imila r lithol ogies of the underlying Frontier rmat on are al o exposed. Ea st end southe ast of Wanship, Ut ah, a marked angular uncon­formity is expo s ed between the Vianship end Frontier forma ti on s , whereas, in the ar ee east of Coalville , Utah the an gular discor­dance is noted gener al l y only over di st ances of more than a mile .. Tbe basal 'Nenshlp c onglomerate i s unit 7 described We ge­mann ( 1 915, p_ 163) from hi s s trat i gr aphic section at Coalville , Utah ( Williams, per s ona l commun ic ation ). Trexler ( 1957, p. 1874) described four units whi ch compr i s e the Fr ontier formati on in the Coalville a reB as f ollows (de s cend­ing order): ( 4) 2440 feet of mBrine sandstone and s h ales with a 635-foot nonmarine s equence in the lower h.sl f; an early Ni obr a ra ( Coni ec i an) Fauna. ( J) 800 f e et of nonmarine s and st one end cl a y stones with a 75-foot bed of conelomer ate 200 fe et from the base. ( 2) 795 f ee t of ma rine s ands t one and sha l e dat ed as e arly Carlile ( Tur oni an ) Bnd l a t e Greenhorn ( Tur onian) ages ; coal i s as s ocia ted with sandst one s near the base . ( 1) 400 f eet of domin antly n onma r ine sands and cl a ys ( Pr obably Cenoman i an). The u ppe rmos t of the s e units ( unit 4) consi sts of 2 , 240 feet of mar ine s andstone and sh ale c onta in ing an e arly Niobr ara f auna \ * 20 w i t h 6 3 5 f o o t n o n - m a r n e s e q u e n c e i n t h e l o w e r h a l f 0 Under­l y i n g u n i t i s f o o t h i c k n e s s n o n - m a r i n e s a n d s t o n e and c l a y s t o n e u n i t h a v i n g f o o t c o n g l o m e r a t e f e et a b o v e t h e b a s e 0 It i s v e r y p r o b a b l e t h a t t h e u p p e r p a r t of T r ex l e r ' s u n i t 3» t h a t p a r t w h i c h i n c l u d e s t h e 75 f o o t c o n g l o m e r a te b e d , and h i s u n i t 4 a r e i n r e a l i t y t h e l o w e r W a n s h i p f o r m a t i on i n c l u d i n g t h e b a s a l c o n g l o m e r a t e 0. A s s u m i n g t h T r e x l e r * u n i t i s p a r t t h e W a n s h i p f o r m ­a t i o n , t h e n a r l y N i o b r a a s s i g n m e n t c o r r e l a t e s w i t h a t e N i o b r a r a a s s i g n m e n t t h e b e d s d i r e c t l y o v e r l y i n g t he W a n s h i p f o r m a t i o n and, t o g e t h e r , t h e s e a g e d e t e r m i n a t i o n s e s t a b ­l i s h a N i o b r a r a n a g e f o r t h e W a n s h i p f o r m a t i o n .. F o s s i l l e a v e s P l a t e s and V I ) i n d i c a t i n g l a t e u p p er C r e t a c e o u s HoW0 Brown, p e s o n a l c o m m u n i c a t i o n ) c o l ­l e c t e d t h e w r i t e r n e a r t h e u p p e r c o n a c t h e W a n s h i p f o r m ­a t i o n i n a r o a d c u t on UQ S„ H i g h w a y and 3 0 - S i n S £ £ , S e c* 1 0 , Te 4 No-, R.. 6 E„ These i n c l u d e: Osmund a ? ? s p D F e r n , i n d e t e r m i n a te S e q u o i a r e i c h e n b a c h i G e i n i t z O T h u j a ? s p, D r y o p h y l l u m s u b f a l c a t u m L e s q u e r e a ux . F i c u s p l a n i c o s t a t a L e s q u e r e a ux M y r t o p h y l l u m o r r e y i L e s q u e r e a u x ) i b u r n u m 7 1 a r g i n a t u r n L e s q u e r e a ux Cr e d n e r i a ? ; F r a g m e n t s of d i c o t y l e d o n o u s l e a v e s , u n d e t e r m i n e d. G e n e r a l l y , the W a n s h i p f o r m a t i o n i s a c o r r e l a t i v e , at l e a st i n p a r t , of t h e M e s a v e r d e g r o u p t o t h e s o u t h e a s t and of p a r t of t h e H i l i i a r d f o r m a t i o n t o t h e n o r t h e a s t ( P l a t e I V ) 0 \ 20 with a 635 foot non- mar i ne sequence in the lower half . Under­lying unit 4 is a 800 foot t hickness of non-marine sandstone Bnd claystone ( unit 3) having a 75 foot bed of conglomerate 200 feet above the base . is y.probab ,tha he upper art Trex­ler's unit 3, tha p.art which inc udes the fo ot co ngl omerate bed, end his unit ere in re ality he ID\'Yer Vianship forma tion including the basal conglomerate •. Assuming th a t Trexler I s unit 4 1s part of the Wanship form­ation, then h i s e arly Niobr a r a age assignment correlBte~ with a l ate Niobrara age assignment of the beds directly overlying the WaDshlp formation and , together , these age determinations esteb- !ish Niobraran ag e r the Wanship for mation. Fossil lea ves ( Plates V end VI) indicating a late upper Cretaceous age (R .W. Br own, pe r sonal commun ication) were col ­lected by the writer ne ar the upper con t ac t of the Wanship form­ation in ro ad cut U. S. Highway 189 30-8 in SE~, Sec. 10, T. N •. , R •. E. include : Osmunda'r o Fern, indeterminate r9jOia .eichenbechi ( Geinit,,) Heer hu aT 3p~ r yophyllwn s ubfa l catum. Lesque r eaux Ficus planicost e t a Lesquereaux M1r toPhyllum t orr eyi ( Lesquereaux) Dorf V burnum ~a r ginatum Lesque re eux eredner ia?' sp Fragme nts of dicotyledonous le aves, unde termined . Generally, the Wan ship f orma tion is a co rrelative, at least in part, of the Mesaver de gr oup to t he southeast and of part of the Hilllard formation to the north. ast (PlateIV) . -- EVANSTON REGION Veatch (1907) ? .r~ ~~ Adaville fm. -<l~)- TENTATIVE UPPER CRETACEOUS CORRELATION of the ECHO CANYON-COALVILLE AREA ECHO CANYON­COALVILLE (This Paper) STRAWBERRY QUADRANGLE 8 isseI! (1952) RED CREEK Walton (1944) TERTIARY ·-----7 t---~? ? ~ marine ~ ~~o~_ ~ MONTANAN Hilliard fm. ~! _ COLORADOAN··· .. ······ -------- ~V· ........ · hi. aeal diseonformity s a e (may be diasteml 000000 Echo Canyon eg. 1 ___- ------- Wanship fm. strong, local, angula ~ uncon formity ?--? \~. ~,\e{ ~{o ? Mancos sh. Frontier fm. PRICE RIVER Plate 1\ Spieker (1946) ? North Horn fm. Pric e Ri ver fm. Blackhawk fm. Star Point fm. Mancos sh. tongue TOP of ------ NIOBRARA Iii IDAHO WYO. 5 3 9ol-+-_.:::.U_T~A~H-,--_ M y r t o p h y l l u m t o r r e yi ( L e s q u e r e a u x j Dorf , , \ , , \ , I " I V Ficus plani cos t a t a Lesquereaux '" i '---. ) " Myrtopbyllum torreyi (Lesquer·eaux) \. Osmunda? !tl2. ... Pl ata V , , / , I \. / ./ Sequoia r eichenbachi ( Geinitz) Heer P l a t e VI V i b u r n u m m a r g i n a t u m L e s q u e r e a ux Dryophyllwn 22 subf lcatum L e squereaux Viburnum !!m",a=rg~ina_tum . L esque re ~ ux Plate VI t h e b a s i s m i c r o p a l e o n t o l o g i c a l d a t a ( o s t r a c o d s ), L a n k f o r d 1 9 5 p p * 3 3 , h a s a s s i g n e d C r e t a c e o u s - P a l e o c e ne a g e t o t h e W a n s h i p o r m a t i o n , . s t a t e s , h o w e v e r , t h t oo l i t t l e i s known a b o u t t h e m i c r o f a u n a l e v i d e n c e t o e s t a b l i s h p r e c i s e age p r o b l e m p r e s e n t e d t h i s m i c r o f a u n a i s a p t l y u p H a y d e n , 1 8 7 1 , p•> 3 7 7 ) , i n r e f e r e n c e t o T e r ­t i a r y i n v e r t e b r a t e s , w r o t e: s e e r e a s o n t h e r e m i g h t n o t h a v e been l i v i n g i n t h e s t r e a m s e s t u a r i e s t h e c l o s i n g p e r ­i o d of t h e C r e t a c e o u s a g e , end w h i l e C r e t a c e o u s t y p es w e r e s t i l l e x i s t i n g i n t h e s e a s , a f e w f r e s h b r a c k ­i s h w a t e r s p e c i e s t h a t c o n t i n u e d t o l i v e m u l t i p ly d u r i n g t h e e a r l i e r p a r t t h e T e r t i a r y a g e ". I n a s m u c h t h e m a c r o f o s s i l e v i d e n c e a t i s p r e d o m ­i n a n t l y i n f a v o r l a t e C r e t a c e o u s a g e , t h e q u o t a t i o n from i s a p p l i c a b l e t o , and t e n d s o a n s w e r t h e q u e s t i o n p o s e d b y, t h e p r e s e n c e e a r l y T e r t i a r y ( ? ) m i c r o f o s s i l s c o l l e c t e d L a n k - f o r d w h i c h l e d t o a C r e t a c e o u s - T e r t i a r y d e t e r m i n a t i o n f o r t he W a n s h i p f o r m a t i o n. C a n y o n c o n g l o m e r a t e * q u e s t i o n i n v o l v i n g t he a g e t h e f o r m a t i o n , h e r e i n r e f e r r e d t o t h e C a n y o n c o n ­g l o m e r a t e , h a s e x i s t e d f o r y e a r s i n r e l a t i o n t o t h e g e n e r al a r e a L o s t C r e e k , C a n y o n , C o a l v i l l e. T h i s w i l l f o r m a l l y p r o p o s e d i n p a p e r i n p r e p a r a ­t i o n f o r p u b l i c a t i o n i n t h e B u l l e t i n t h e A m e r i c a n A s s o c i a t i on o f P e t r o l e u m G e o l o g i s t s u n d e r j o i n t a u t h o r s h i p w i t h N . C . . W i l l i a m s. 23 On the basis of micro paleontological data (ostracods), Lankford ( 195 2 , pp. 33, 35) has assigned a Cretaceous-Paleocene age to the Wanship f orma tion. He states, however, th a t too little is kncmn about the microfaunal evidence to establish a precise age .. The problem presep.ted by this microfauna 1s aptly summed up by Meek ( Hayden, 1871, p. 377), who in reference to some Te r ­tiary invertebr ates, wrote : " I can see no good reason why there might not have been living in the streams and 'estuaries of the closing per­iod Of the Cretaceous age, and whi Ie Cretaceous types were still existing in the seas, B few fresh and brack­ish water species that continued to live and multiply during the earlier part of the Tertiary age". Inasmuch as the macrofossil evidence at hand 1s predom­inantly in favor of a late Cretaceous age, the quotation from Meek 1s appli cable to , Bnd tends t o answer the question posed by, the presence of early Terti ary (?) microfossils collected by LanK­ford which led to B Cretaceous-Tertiary age de termination for the Wan ship formation. Echo Canyon conglome rate· (New name) A question involving the age of the formation, herein referred to as the Echo Cenyon con­glomerate, has existed for many years in relation to the general area of Lost CreeK, Echo Canyon, and Coalville . * This name will be formal l y pr oposed in a paper now in preparB­tkn for publication in the Bulletin of the American Association of Petroleum GeolOjists under jOint authorship with N.C.Williams. 24 H a y d e n 8 6 9 , p.- 9 0 ) f i s t d e s c i b e d t h e s e q u e n c e r o c ks w h i c h i n c l u d e s t h e c o n g l o m e r a t e as t h e W a s a c h g r o u p. H i s t y p e s e c t i o n e x t e n d e d f r o m C a r t e r , s o u t h w e s t t o t he n a r r o w s w e s t C r o y d e n , U t a h ; d i s t a n c e a b o u m i l e s . S u b s e q u e n t l y , V e a t c h 1 9 0 7 , p p . 8 8 - 9 6 ) s u b d i v ­i d e d t h e W a s a t c h g r o u p i n t o t h e F o w k e s , K n i g h t f o r m ­a t i o n c o n c u r r e d w i t h t h e a r l i e r g r o u p d e s i g n a t i o n H a y d e n. E a r d l e y 1 9 4 , p . e f i n e d m e m b e r s e p a r a t e d an a n g u l a r u n c o n f o r m i t y , t h e f o r m a t i o n , w h e r e i t c r o p s out i n ^ c h o C a n y o n * He h e o w e r t h e P u l p i t c o n g l o m e r ­a t e t h e u p p e r t h e M i l l c o n g l o m e r a t e I n a e s t u d y t h e y p e W a s a c h i n d e s c r i p t i o n t h e W a s a t c h h i n t e r l a n d , E a r d l e y 1 9 5 1 , p . 4 3 5 ; 1 9 5 2 , 5 4 - 5 5 ) e d e f i n e d t h e two c o n g l o m e r a t e s s e p a r a t e d by an u n c o n ­f o r m i t y i n r e f e r r e d o h e m t h e Almy f o r m ­a t i o n u n c o n f o r m a b l y o v e r l i n h e K n i g h t f o m a t i o n ; t h u s a c o r r e l a t i o n w i h u n i t s d e f i n e d V e a t c h .. I t s a s s u m e d t h a t h e e d e f i n i t i o n t h e c o n g l o m e r a t es i n o u e i o n E a r d l e y e r m i n a e s t h e n a m e s , P u l p i t " and M i l l " members h e f o r m t i o n , i n a v o r , r e s p e c t i v e l y , t h e Almy and K n i g h t f o r m a t i o n s . If t h i s i s t r u e , and i n v i ew f o s s i l e v i d e n c e w h i c h e s t a b l i s h e s C r a c e o u s f t h e l o w e r o n g l o m e a t e s e q u e n c e , t h e n i s w a r r a n t e d. C o n g l o m e r a t e i s t h e r e f o r e p r o p o s e d. P r e v i o u s w o r k e r s s i n c l u d i n g S t a n t o n 8 9 1 , PP~ 3 8 - 4 4 ), 2~ Hayden ( 1 869, p •. 90) fi r st desc r ibed the se quance of rocks which includ es the Echo Canyon conglomer ate a s the Was a t ch group . His type section extended from Carter, Wyoming sou thwest to the narrows of Weber Canyon we st of Cro yden , Utah; a distance of ab ou t 65 miles . Subsequently, Veatch ( 1907, pp. 88- 96) subd iv ­ided the Wasatch group into the Almy, Fowkes, and Knight f orm­a tion and concurred with the e arlier group designation of Hayden .. Eardley ( 194 4 , p. 842) d ef ined two member s , separ ated by an angular unconformity, in the Almy forma ti on , where it crops out in Echo ny n~ Be named t he l ower member the Pulpit congl omer­ate and the upper member the Saw Mill conglomer a te .. In e r estudy of the t ype Wasa t ch and in a de scription of the Wasatch hinterl and, Eardley ( 1951, p. 1 435; and 1952, p. 54- 55) r edefined the t wo conglome r ates separ ated ao uncon­formity 1n Echo Canyon and referred t o t hem a s the Al my fo rm­ati on unconfor mably overl a in by t he Knight fo r mationj thus he made e correle tion wi t h unit s defined by Ve atch .. It i s assumed tha t the r edefini ti on of the two conglomer a tes in Que s t ion by Ea rdley t e r mina t es the names, " Pulpit " end "Saw Mill" membe r s of t he Almy form a t i on, in f avor, respective l y, of the Alroy Bnd Knight forme tions. I f this is true, Bnd in vi aw of new fossil evidence which establishes a Cr e t a ceou s age f or the lower c onglome r ate sequ ence, then a new name 1s wa rr anted. The name Echo Canyon Conglomerate is therefore propos ed. Previous wor ker s, inc l uding St anton ( 1 891, DD .. 38-44), V e a t c h 1 9 0 7 , p . 8 9 ) Wegemann 1 9 1 5 p . 1 7 1 ) , E a r d l e y ( 1 9 5 2, ppo. 5 4 , h a v e p l c e d t h e C r e t a c e o u s - T e r t a y b o u n d a r y h i g h ­e r t h a n t h e a s e t h e f i r s t s i g n i f i c a n t c o n g l o m e a t e w h i c h c r o ps o u t i n t h e C a n y o n - G o a l v i l l e a r e a* t h i c k n e s s t h e c o n g l o m e r a t e s c a l e d from a e r i a l p h o t o s 3 , 1 0 0 f e e t o b a s a l c o n t a c t i s d r a w n t he b o t t o m h e f i r s t i g n i f i c a n t c o n g l o m e r a t e a b o v e t h e u n d e r ­l y i n g W a n s h i p f o r m a t i o n c L o c a l l y , t h e r e i s a d i s c o n f o r m i t y a t or n e a r t h e b a s e t h e c o n g l o m e r a t e w h i c h r e p r e s e nt a d i a s t e m ( W i l l i a m s , p e r s o n a l c o m m u n i c a t i o n ) 0 This d i s c o n f o r m a b le r e l a t i o n s h i o i s l o c y e v i d e n t e a s t e s e r v o i r « b a s al c o n t a c t i s a l s o e m p h a s i z e d by a m a r k e d c h a n g e i n l i t h o l o g y from t h e g r a y , p e a - s i z e d c o n g l o m e r a t e s and s e n d s of t h e u p p e r W a n s h ip f o r m a t i o n , to t h e c o a r s e c o n g l o m e r a t e s of t h e Echo Canyon c o n ­g l o m e r a t e o The l o w e r Echo Canyon c o n g l o m e r a t e c o n t a i n s some v a r i e g a t e d r e d s a n d s t o n e s , s i l t s t o n e s , s h a l e s , and c o n g l o m e r ­a t e s , . The c o n t a c t w i t h t h e u n d e r l y i n g W a n s h i p f o r m a t i o n is a p p a r e n t e a s t of Echo r e s e r v o i r a b o u t o n e - h a l f m i l e s o u t h of t h e d a m s i t e. u p p e r l i m i t t h e c o n g l o m e r a t e i s d e f i n ed h e u n c o n f o r m i t y i n P l a t e V I I ) w h e r e t h e b e ds a r e t r u n c a t e d by t h e n e r l y h o r i z o n t a l o n g l o m e r a t e s T e r t i a ry g e o C o n g l o m e r a t e s a r i e g a t e d e d , g r a y , end b u f s h a l e s, s i l t s t o n e s , s a n d t o n c h a r a c t i s t i c t h e l o w e r h a lf 25 Veatch ( 1907. p. 89) , We gemann ( 1915 , p. 171), and Eardley (1952, pp. 54, 55) have pl a ced the Cretaceous-Tert i a r y boundary no high­er than the b ase of th e first signif icant conglome r ate which crops out in the Echo Canyon-Coal ville a r eB ... The thickness of the Echo Canyon conglome r ate was scal ed from aerial photos as 3, 100 feet ~ The basal contact is drawn a t the bottom of t he first s ign ificant conglomer ate bed above the under­lying Wanship forma tion. Locally , there is disconformlty or near the base of the Echo Canyon congl omerate which may represent B di es tem Williams per onal communicat ion) . disconformable rel atio nshio is loc a l l y evident east of Echo r eserv oir . The basal contact is o mphasized ma rked change in lithology from he gray , pe iz ed onglomera te s ands the upper Wanshlp forma tion, the oa e conglomer es CBllyon con­glome r te . lower con gl ome rate contains some varie gated red and on es , siltstones , ales, con glomer-ates ontact wi he underl ying Wansh formation is apparent e a st of' Echo re s ervoir abrut one- h a l f mile s outh of the damsite . The upper limit of the Echo Canyon conglomer ate is defined by t he unconf:ormi .ty in Echo Canyon ( Pl. ate VII) , whe re the beds are truncated the ne a rly horizontal c ongl omer ates of Tertiary a ge. Con glomerates and v arie ga ted r ed , gr ay, End buf f sha l es, sil tst ones, and sand s ton e s a r e cha r ac t e r istic of the lower half , , I '~------------------------=-----~---- Plate VII Panoramic view looking north up Saw Mill Creek. Shows the Knight formotion lying un­conformably upon the Echo Canyon conglomerate. 27 t h e c o n g l o m e a t e o u p p e r h a l f t h e s e q u e n ce i s p r e d o m i n a n t l y m a s s i v e , e d d i s h c o n g l o m e a t e c o n t a i n i n g some r e l a t i v e l y t h i n b e d g r a y t o r e d i l t s t o n e s h a l e 0 T h e a n d s t o n e s w h i c h o n t a i n t h e m a r i n e o s s i s C r e t a ­ceous a g e r e i n t e r b e d d e d w i t h c o n g l o m e r e s c o n t i n e n t a l o r i g in h e y o b a b l y e p r e s e n f i n l , l o c a a d a n c e t h e C r e t a ­ceous e a w h i c h e a c h e d w e s t w a r d b e f o r e b e i n g i v e n out by e x t e n s i v e f l o o d of g r a v e l d e r i v e d f r o m a w e s t e r n h i g h l a n d 0 d e s i g n a e d y p e s e c t i o n t h e c o n g l o m e r a te a t t h e b a s a l c o n t c t , e a s t e s e r v o i r , c o n t i n u es i n n o r t h e r l y d i e c t i o n t o w a r d s P u l p i t Hock, h e n o t u p p e r m o s t s e d i m e n t i n t h e t r o u g h t h e S t e v e n s o n Canyon s y n - c l i n e a t w h i c h p o i n t t h e o l d e r r o c k s r e c o v e r e d t h e e s s e n - t i a l l y h o r i z o n t a l T e r t i a r y c o n g l o m e r a t e s ,, H e r e t o f o r e d e c r i b e d u n f o s s i l i f e r o u s T e r t i a r y e q u e n c t h e c o n g l o m e r a t e h a s y i e l d e d a s s e m b l a g e m a r i ne n v e r t e b r a t e s f r om t h i n e n d s i n t e r b e d d e d w i t h c o n g l o m e r a t e s w i t h in 4 0 0 f e e t i t s base,, f o s s i l e v i d e n c e s u g g e s s l a te C o l o r a d o a n N i o b r a r e n ) a g e Q S p e c i m e n s w e r e i d e n t i f i e d Ae C o b b a n P e r s o n a l c o m m u n i c a t i o n ) end i n c l u d e: I n o c e r a m u s a b i a t u s ( S c h l o t h e i m) I n o c e r a m u s d e f o r m i s O s t r e a a n o m i o i d e s Meek O s t r e a c o n g e s t e / H" O s t r e a l u g u b r i s swere i d e n t i f i e d t h e a u h o r c h e c k ed T u r i t e l l a ? )by Wm„ L0 S t o k e s .. F o r h e p u r p o s e c o r e l a t i o n t h e o p h e C o l o r a d o 27 of the Echo Canyon conglome r ate . The upper half of the s e quence 1s predominantly a massive, r eddish conglome r ate containing some rel atively thin bed s of gr ay to red s iltstone and shale . The s an dstones ,":hieh c ont ain the marine f ossi l s of Cre t a-ceous age a re inte rbedd ed with conglome r a t es of cont inent el origin and t hey p r obabl y r epre s en t a fin a l, loca l ed v ance of the Cr eta ­ce ous s ee which r eached westv}ard before being d r iven ou t an extensive flo od gr avel der iv ed fr om west ern highland . The designa t ed t ype section of the Echo Canyon conglomer at e commences at the basal cont a ct, east of Echo r eser vo ir, continues in a northe rl y di r ec tion towards Pul pit Roc k, end t hen t o t he uppermost sediment s in the trough of the St evenson Ca nyon syn­cline at which point the older rock s a re covered by the essen­tially horiz on t al Tert iary cong lomer ates . Here tofore de s cr ibed as an unfos silife r ous Tertia ry s equenc e, the Echo Canyon conglomerate has yielded an assemblage of marine i nvertebr ate s fr om thin s ends interbedded wi th con gl omerat es within 400 feet of its ba se . This new fo ssil evid ence sugges t s a l ate Color ado an ( Niobraran)age. Specimens were identified by W. A. Cobba n ( Per sonal conununication) and include: Inoceramus l abiatus ( Schlothe im) Inoc er amus def ormis Meek Ostrea s nom l ol des Me ek Os trea conges t e1) Os trea lu gubris :VJere identifi ed by the au t hor and checked TUrite lla? 11m. L. St okes . For t he purpose of cor r ela tion the t op of t heColor ado is d r a w n a b o v e t h e u p p e r m o s h o r i z o n f r o m w h i c h C r e t a c e o u s f o s s i ls w e r e c o l l e c t e d . I t p r o b a b l e , h o w e v e r , t h a t t h e C o l o r a d o - M o n t a n a t i m e p l a n e i s a c t u a l l y h i g h e r i n t h e t h i c k Canyon c o n g l o m e r a t e t h a t t h e u p p e r p a r t h e s e q u e n c e a t l e a s t, i s M o n t a n a n i n a g e 0 An e s t i m a t e t h e o r i g i n a l t h i c k n e s of t h e c o n g l o m e r a t e w o u l d v e r y d i f f i c u l t to make, f o r i t was d e e p l y e r o d e d p r i o r to d e p o s i t i o n of t h e K n i g h t f o r m ­a t i o n i n T e r t i a r y t i m e. L i k e l y c o r r e l a t i v e s P l a t e h e c o n g l o m ­e r a t e t o t h e s o u t h a r e t h e C u r r a n t C r e e k f o r m a t i o n ( W a l t o n, 1 9 4 4 , p.- 1 1 7 ; B i s s e l l , 1 9 5 2 , p . p o s s i b l y , t h e P r i ce R i v e r f o r m a t i o n of S p i e k e r ( 1 9 4 6 , p. 1 3 0 ) . To t h e n o r t h e a st n e a r E v a n s t o n , Wyoming V e a t c h 1*907, p . 72) d e s c r i b e s an u p p er N i o b r a r a a u n a f r o m t h e m i d d l e h e H i l l i a r d f o r m a t i o n t h at may be a c o r r e l a t i v e of t h e f o s s i l a s s e m b l a g e d e s c r i b e d f r o m t he l o w e r Echo Canyon c o n g l o m e r a t e. W a l t o n 1 9 4 4 , P. 1 0 9 , s t a t e s t h a h e M e s a v e r d e g r o up n e a r M o u n t a i n t h e s o u t h f l a n k t h e U i n t a s N i o - b r a r a n i n and s u g g e s t h a t t h e o v e r l y i n g C u r r a n t C r e e k f o r - matLon i s r o u g h l y q u i v a l e n t t o t h e P r i c e R i v e r N o r t h f o r m a t i o n s . L a e r , B i s s e l l 1 9 5 2 , p.. 6 1 4 ) c o u l d f i n d d d i ­t i o n a l i d e n c e f o r d i f f e r e n t o r r e l a t i o n t h e Cur­r a n t C r e e k f o r m t i o n , and c o n c u r r e d , a c c o r d i n g l y , w i t h t h e d e s ­i g n a t i o n of W a l t o n .. S p i e k e r 1 9 4 6 , p . s s i g n e d t h e P r i c e R i v e r f o r m a t i on 28 dl'B",on above the uppermos t horizon from whi ch Cretaceous fossils were collected.. It i s probeble, ha.vever, that the Colorado­Montana time pl ane is actually higher in the thick Echo Canyon congl omerate and that the upper par t of the sequence , at least , 1s Montanan in age. estimate of the original thicknes s of the Echo Canyon congl omerate would be very difficult t o make, for it deeply eroded prior depos ition the Knight form­ation in Tertiary time . Likely correla tives ( Plate IV) of t he Echo Canyon conglom­er ate to the south are the CUrrant Creek formation ( Walton, 1944, 117; and Bis sell, 1952, p. 613) and possibly, the Price River ormation Spieker 1946, p . 130). the north east ne ar Evanston, Wyomin~ Ve atch (l!907 , p. 7 2 ) describes en upper Niobrara f auna from the mi ddle of t he Hilliard format1 0n that l::e ecorrelative he fossil ssemblage described fr om the ower con glomerate. Walton ( 1944, p . 109 , 120) sta te s tha t t he Me saverde gr oup ne ar Tabby Mountain on the south flank of the Uints Arch i s Nio­brar an in age snd sugpe s t s th at the overlying Curr ant Creek for­mati. on is roughly e quiv el ent to the Price River and North Horn formations. La t er, Bissell ( 1952, p. 614) could find no a ddi­tional e v id enc e for a dl f f erent age and c orrel ati on of the Cur­rent Creek form a tion, end concurred, accordingly, with the des­i gnation \'Ialton. Spieker ( 1946, p. 131) a ssign ed the Price River formation t o a f i x e d age i n t h e M o n t a n a n , a t l e a s t t h e l o w e r p a r t , a nd s t a e s t h a i t i s p r o b a b l a t e M o n t a n a n . L a t e r > S p i e k e r ( 1 9 4 9, 2 4 ) , t h a t i n v e r t e b r a t e e v i d e n c e t h e P r i ce R i v e r f o r m a t i o n t o l a t e M o n t a n a n a t i t s t y p e l o c a l i t y. t h e b a s i s l i k e l i t h o l o g i e s and t h e f o s s i l e v i d e n ce a l r e a d y c i t e d , c o r r e l a t i o n t h e Canyon c o n g l o m e r a te w i t h p a r t s t h e C u r r a n t C r e e k and P r i c e R i v e r f o r m a t i o ns s e e m s r e a s o n a b l e P l a t e I V ). T e r t i a r y S y s t em K n i g h t f o r m a t i o n . . O v e r l y i n g a l l o l d e r o r m a t i o n s w i t h" m a r k e d a n g u l a r d i s c o r d a n c e s t h e K n i g h f o r m a t i o n w h i c h is p r e s e n t as a more l e s s c o n t i n u o u s b l a n k e t o v e r of t he L o s t C r e e k - E c h o a r e a , ^ o c k s o l d e r t h a n t h e K n i g h t f o r ­m a t i o n a r e e x p o s e d o n l y i n Weber V a l l e y , C a n y o n , L o st C r e e k and t h e i r d e e p e r t r i b u t a r i e s. minimum h i c k n e s s 1 , 5 0 0 e e t s e s t i m a t e d f o r t he K n i g h t f o r m a t i o n w i t h i n t h e a r e a , a l t h o u g h i t p r o b a b ly a t t a i n s g r e a t e r h i c k n e s s i n c o n t i g u o u s a r e a s. b a s a l c o n t a c t t h e K n i g h t f o r m a t i o n P l a t e V I I I) w i t h o l d e r r o c k s i s u s u a l l y r e c o g n i z a b l e w h e r e v e r i t i s e x ­p o s e d , i s e s p e c i a l l y t r i k i n g i n a r e a s s u c h Can­y o n w h e r e d i p p i n g b e d s J u r a s s i c age a r e t r u n c a t e d t he f l a t - l y i n g k n i g h t c o n g l o m e r a t e. A d e t a i l e d d e s c r i p t i o n of t h e K n i g h t f o r m a t i o n is beyond 29 t o 8 fixed age in the Montanan , at le ast the 10. ... er pe rt, s nd ste t es tha t it is probabl y l ate Montanan. Later, Spieker (1949, p . 24) f comments that invertebr ate ev idence shows the Price River forma tion to be lete Montanan at its type local ity. On the basia of li ke lithologi es end the fossil evidence alre ady cited, a correlation of the Echo Conyon conglomerate with parts of the Currant Creek Bnd Price River f ormations seems reasonable ( Pl e te IV). Tertiary System Kni.nt formation. Overlying all older f orma tions with ' marked angular discord ence i s the Knigh t formation which is present AS e mar.a or less continuous bl anket over most ot the Lo st Creek-Echo Canyon area . ~ ocks old er th an the Knight for­mation Bre exposed only 1n V/eber Valley, Echo 'Canyon , and Lost Creek end their deeper tributa rie s·. A mi nimum t hickness of 1,500 f e et i s estimated for the Knight for ma tion within the mapped area, el though it pr obably atta ins a much greeter t hickness in cont i guous areas. The basel contact of the KniFht for ma tion ( Pl ate VIII) with ol der rocks 1s usual l y re cognizable whe rever it is ex­poeed, and is especially s triking in ar e e s such as Toone Can­yon whe re dippine bed s of Juras sic a~e ere txunc nt ed by the fl a t-lyi ng Kn i ght conelomer ate. A detailed do scription of the Kni ht for ma tion is b eyond P l a t e VIII Plate VIII Nearly vartical Kelv in formation truncatad by the flat-lying Knight formation on tha south-facing slopa of Toone Canyon . View looking north. 31 t h e s c o p e h i s p a p e r and i s u n w a r r a n t e d i n a s m u c h a s r a p id a c i e s c h a n g e s l e n s - o u t s a l m o s i m p o s s i b l e f o l l ow a n y one l i t h o l o g i c u n i t f o r v e r y g r e a t d i s t a n c e m a j or l i t h o l o g i c c o n s t i t u e n t t h e K n i g h t f o r m a t i o n i s c o n g l o m e r a t e. M i n o r u n i t s s a n d s s h a l e s o c c u r i n t e r v a l t h r o u g h t he s e c t i o n and n e a h e b a s e t h e o r m a t i o n c o a l b e d s o c c u r and h a v e b e e n m i n e d L o s t Greek s e v e a l t r i b u t a r i e s. I n g e n e r a l p p e n c e , c o l o r , l i t h o l o g y , t h e K n i g h t f o r m ­a t i o n c o n s i s t i n g m a s s i v e c o n g l o m e r a t e s , a n d s t o n e s , and t h i n s h a l e s , a l l w i t h c h a r a c t e r i s t i c r e d d i s h c a s t ) i s v e ry s i m i l a r t o h e u n d e r l y i n g c o n g l o m e r a t e. V e a t c h 1 9 0 7 , p.. 2 ) t h e t y p e s e c t i o n t h e K n i g ht f o r m a t i o n w h e e i t e x p o s e d n e a K n i g h S t a i o n t h e U n i on * P a c i f i c R a i l r o a d i n s o u t h w e s t e r n Wyoming. . A l t h o u g h i t i s f o s s i l i f e r o u s in t h e E v a n s t o n a r e a of s o u t h ­w e s t e r n Wyoming ( V e a t c h , 1 9 0 7 , p . 9 3 ) , t h e K n i g h t f o r m a t i o n , as e x p o s e d i n t h e L o s t C r e e k - E c h o Canyon a r e a , h a s y i e l d e d no d i a g ­n o s t i c f o s s i l s .. Q u a t e r n a r y D e p o s i ts R e c e n t a c c u m u l a t i o n s s e d i m e n t a r y e b r i s i n c l u d e : a l l u v i u m, c o l l u v i u m , r i v e r t e r r a c e g r a v e l s , a n d l i d e s , p e d i m e n t g r a v e l s. e x t e n s i v e e c e n t d e p o s i t s a r e t h e a l l u v i a l f l o od p l a i n s i n t h e V a l l e y , L o s t C r e e k , , C a n y o n , t h e ir d e e p e r t r i b u t a r i e s , w h i c h a r e u t i l i z e d r g e l y f o r a g r i c u l t u r al p u r p o s e s . 31 the scope of t his paper end is unwarranted inasmuch as r ep i ,d f acies chan ges and lens-outs make i t al mos t impossible t o follow anyone 11tholo[ ic unit for a very exeat distance . The major I1tholo eic constituent of the Knight formati on is conglome r a te . Mi nor units of sa nd 5 and sha les occur a t inter val s through the section end ne e r t he ba se of the f or mation coel beds occur and have been mined in Lost Creek and seve r al of i t s tributa r ies. In gener al a ppe a r a nce , col or, and lithol ogy , the Knight f orm-e ti an ( consistinr of massive conglomerates, s andstones, and thin shales , all with a char acteristic reddi sh cast) is very simil ar to t he underlying Echo Canyon congl ome r ate . Veetch ( 1907, p . 9 21 named the type section of the Knight formation whe r e it i s exposed nea r Kni gh t Sta t i on on the Union • Pac ific Railroad in southwestern Wyoming. Although it is fo s sil ifer ous in the Ev anston Brea of south­western Wyoming (Veetch, 1907 , p . 931 , the Knight formation , as exposed in t he Lost Creek-Echo Cany on area , ba s yielded no dl ag­no st1c fossils .. Quaternary De posits Recent accumul ations of sedimentary d ebris include: alluvium, colluvium, river terrace gravels, l a nd s lid es, and pediment gr a vel s . The most extensive r ecent de posits are the alluvial flood pla ins in the Weber Valley , Lost Cr eek " Echo Cany on , and the i r deeper tributaries, whi ch are utilized l a r gely for agricultural purpo ses. W e a t h e r e d o p e s a r e a l m o s e v e r y w h e r e p a r t i a l l y c o v e r b y c o l l u v i u m c o n s i s t i n g p o o r l y s o r t e d s a n d s , g r a v e l s , c o b ­b l e s , and b o u l d e r s w h i c h h a v e r e m a i n e d e s s e n t i a l l y n e a r t h e ir s o u r c e , t h e s o u r c e f o r m a t o n ( K n i g h t ) h a s b e e n e r o d e d away 0 32 We ather ed s l opes are almos t everywhere pa rti ally cover ed by colluvium con siating of poorly sorted sand s, gr avels, cob­bles, end boulders which have remained essentially ne ar their source, as the source format i on Knight) has been eroded away. R e g i o n a l S t r u c t u re A d e f i n i t e n o r t h e a t e r l y o r i e n t a t i o n t h e m a j o r s t r u c t u re e l e m e n t s i s n o t e d i n t h e L o s t C r e e k - E c h o a r e a. s t r u c t u r e t h e L o s C r e e k - E c h o v i c i n i t y i s r e ­l a t e d b o t h t o t h e s t r u c t u r e s t h e W a s a t c h M o u n t a i n s t h e w e st a n d o t h e U i n t a M o u n t a i n s t h e s o u t h e a s t , end i s or l e ss a t r a n s i t i o n a l f e a t u r e b e t w e e n t h e m o u n t a i n r a n g e s. I n t e r s e c t i o n t h e W a s a t p U i n t a M o u n t a i n s r e s u l t s in a r e a t r a n s i t i o n n v o l v i n g c o m p l e x g e o l o g i c t i m e r e l t i o n ­s h i p s . S t u d y t h e s e r e l a t i o n s h i p s w i t h i n t h e a r e a t r a n s i ­t i o n l e a d s t o p r e c i s e c h r o n o l o g y t h e s t r u c t u r a l h i s t o ry of t h e a r e a t h a n s t u d i e s i n a d j a c e n t a r e a s W i l l i a m s, 1 9 5 5 , P. 2 7 W a s a t c h M o u n t a i n s t r e n d e s s e n t i a l l y o r t h c o n s i st s e r i e s c o m p l e x t r a n s v e r s e f o l d s , t h e a x e s w h i c h a re o r i e n t e d e a s t - w e s t E a r d l e y , 1 9 4 4 , p . 8 6 0 ) . . W a s a t c h a n ge e x t e n d s f r o m c e n t r a l U t a h i n t o d a h o. I n t e r s e c t i n g t h e W a s t c h M o u n t a i n s f r o m t h e e a s t i s t he b r o a d , w e s t w a r d p l u n g i n g U i n t a A r c h w h i c h i s f l a n k e d t he STRUCTURE Regional Structure definite northea s terly orientation of the maj or structure elements 1s noted in the Lost Creek-Echo Canyon areB. The structure of the Los t Creek-Echo Canyon vicinity 1s r e ­lated both to the structures of the Wasatch Mounta ins on the west and t o the Uints Mountains on the so utheast , e nd is more Or less B tr ansitional fe ature between the two mountain r anges . Intersection of the Wasatc:h and Uinta Mounta in s re su lts in an er ee of transiti on i nvolving complex geologic time rel a tion­ships. Study of the se rel a tionships within the area of transi­~ an leads to a more precise chronology of the structural history the e re a then do studies made in adjacent areas ( Wil l iams , 195 5, p . 1 27 ). The Wasatch Mountains trend essentially n orth and consist of a series of complex tr ansverse folds, the exes of which ere oriented east-west ( Eardley, 1944, p. 860 ). The Wasatch r ange extend s from central Utah into I daho. Inter secting the Was a tch Mountains fr om the east is the broed , we stward plunging Uinta Ar ch which is fl <:mked on the 33 34 n o r t h h e B r i d g e r b a s i n t h e s o u t h t h e U i n t a b a s i n. U i n t a i s a p p r o x i m a t e l y m i l e s l o n g m i l e s w i d e, and t r e n d i n e a s t e r l y d i r e c t i o n. F o l d s S t e v e n s o n C a n y o n s y n c l i n e . Almost c o i n c i d e n t w i t h S t e v e n ­s o n C a n y o n t h e a x i s a s y n c l i n e r e f e r r e d t o a s t h e S t e v e n ­s o n S y n c l i n e E a r d l e y , 1 9 4 4 , 855 ) . f o l d b r o a d , e s s e n t i a l l y s y m m e t r i c a l s t r u c t u r e i n w h i c h e v r a l t h o u s ­and f e e t t h e c o n g l o m e r a t e e t h e y o u n g e s t r o c ks i n v o l v e d . a x i s t h e f o l d can t r a c e d o r a p p r o x i m a t e ly m i l e s n o r t h e a s e r l y f r om t h e h e a d S t e v e n s o n C a n y o n c The w i d t h t h e s y n c l i n e i s a p p r o x i m a t e y m i l e s . p r o j e c t i on t h e s t r u c t u r e t h e n o r t h e a s t o b s c u r r e d b e n e a t h b l a n k et o f t h e T e r t i a r y K n i g h t f o r m a t i o n. S t e v e n s o n s y n c l i n e i s f l a n k e d t h e s o u t h e a st t h e C o a l v i l l e a n t i c l i n e t h e n o r t h w e s t t h e H e n e f er a n t i c l i n e E a r d l e y , 1 9 4 4 , p . 8 5 5 ). C o a l v i l l e a n t i c l i n e . . n o r t h e a s t h e C o a l v i l le a n t i c l i n e p r o j e c t s i n t o t h e s o u t h e r n b o u n d a r y t h e a r ea f o r d i s t a n c e a b o u t m i l e , t h e a s y m m e t r y t h e s t r u c ­t u r e , p r o n o u n c e d t o t h e s o u t h , s r e a d i l y r e c o g n i z e d , n o r t h w e s t l i m b t h e t r u c t u r e d i p s a t a n g l e s l e s s t h a n 4 0 °, b u t t h e s o u t h e a s t l i m b d i p s s t e e p l y i s l o c a l l y o v e r ­t u r n e d t o t h e s o u t h e a s t . T r e n d i n g n o r t h e a s t e r l y , t h e C o a l v i l a n t i c l i n e s a b o u t m i l e s w i d e and m i l e s l o n g. 34 north by t he Bridger basin and on the south by the Uinta basin. The Uinta Arch is approximately 160 miles long , 40 miles wide, end trend s in an easterl y direction. Folds Stevenson Canyon syncl ine . Almo s t coincident wi th Steven-son Canyon i s the axis of 8 syncline referred to 8 S the Steven­son Canyon Syncline ( Eardley, 1944, p . 855). This fold i s a broed , essenti ally symmetrical struc ture in which s ev e ral thou s ­Bnd feet of the Echo Canyon conglomer ate a r e the youngest rocks involved. The axis of the fold c an be tr aced f or appr oximat ely 15 miles northeas t erly from the he ed of Stevenson Canyon . The width of the syncline is ap proximate l y 6 miles . The pr ojection of the struc ture to the northeast i s obscurred beneath a bl anket of the Tertiary Kni ght for mation. The Stevenson Canyon syncline is fl anked on the southeast by the Coalville an ticline and on the northwest by the Henefer anticline ( Eardley, 1944, p. 855) . - Coalville an ticline .. The northeas t end of the Coalville anticline pr ojects into the southern bound ary of the mapped Bre s for a distance of about one mile, and the esymoe try of the struc­tur e, more pronounced to the south , i s readily recognized . The northwest limb of the s tr uc t ure dips at angles less than 40°, but the southeast limb dips more steeply and is loc ally ov er ­turned to the southeast. Trending northeas terly, the Coalvil le anticline i s about 4 miles ~ i de Bod 9 miles long. 35 The o l d e s t b e d s e x p o s e d i n t h e C o a l v i l l e s t r u c t u r e a r e t h o se Of t h e K e l v i n f o r m a t i o n e a r l y C r e t a c e o u s a g e T e r t i a ry K n i g h t f o r m a t i o n c o v e r s t h e s t r u c t u r e , b u t n o i n v o l ­v e d i n t h e f o l d i n g w h i c h a f f e c t e d t h e o l d e r f o r m a t i o n s. T o o n e a n t i c l i n e . . C r e e k i t s t r i b u t a r i e s c u t t h r o u g h K n i g h t c o n g l o m e r a t e t o e x p o s e a n t i c l i n a l s t r u c ­t u r e w h i c h p l u n g e s t o h e s o u t h w e s t n e a r m o u t h T0 o n e Can­y o n T h i s t r u c t u r e i s h e r e i n r e f e r r e d t o a s t h e Canyon a n t i c l i n e . S i m i l a r i n e s p e c t s o t h e C o a l v i l l e o l d , C a n y o n a n t i c l i n e i s a s y m m e t r i c a l , h a v i n g t e e p l y d i p p i n g s o u t h ­e a s t l i m b w h i c h i s o v e r t u r n e d i n C a n y o n . t he n o r t h w e s t l i m b d i p f r o m 30° t o 50° n o r t h w e s t e r l y. O u t c r o p s t h e P r e u s s , Stump, M o r r i s o n f o r m a t i o n s c u r ve a r o u n d t h e o s e t h e s t r u c t u r e i n t h e m o u t h s e r v e b e s t t o d e f i n e i t s c o n f i g u r a t i o n . c o r e C r e ek l i m e s t o n e p r e e n t i n t h e f o l d n o r t h w a r d , w h e r e u p p e r L o st C r e e k t r a v e r s e s t h e f o l d , t h e o l d e r N u g g e t a n d s t o n e c r o p s out i n t h e a n k s . P e r h a p s t h e e d b e d s u n d e r l y i n g t h e N u g g e t a l so a r e b r e a c h e d , t h i s c a n n o t p r o v e n b e c a u s e h e a v y o v e r ­b u r d e n . a n t i c l i n e m i l e s l o n g and l j m i l es w i d e i n t h e o b s e r v a b l e a r e a , b u t t o t h e n o r t h e a s t i t i s l a r g e ly o b s c u r e d t h e T e r t i a r y s e d i m e n t s c o n s i d e r a b l y l o n g e r. i n c o m p e t e n c y t h e C r e e k l i m e s t o n e i s w e l l d i s ­p l a y e d i n t h e Toone Canyon a n t i c l i n e . E r r a t i c d i p s a r e common J5 The oldest beds exposed in t he Coalville structure a1'e those of the Kelvin formation of early Cretaceous age . The Tertiary Knight formation covers much of the structure, but i s no t invol­ved in the folding which af fec ted the older formations . Toone Canyon an ticlin e~ Lost Creek and its tri but aries have cut through the Knight congl ome r ate to expose an ant iclinal struc­ture which plunges to t he southwest neBr the mouth of Toone Can­yon . Thi s structure 1s herein referr ed to as the Toone Canyon enticline. Similar in some r espects t o the Coalville f old , the Toone Canyon anticline is asymmetrical, hav ing a s te epl y dipping south­east 11mb which is overturned 1n Toone Caoyon. Rocks of the • nort hwes t limb dip from 300 to 500 northwesterly. Outcrops of the Preuss , Stump , and Morri son formations curve around the n ose of the structure in the mouth of Toone Canyon and serve best to defln,e its configuration. .A core of Twin Creek lime'stone i s pre s ent in the fold and northward, where upper Lost Creek traverses the fold, the older Nugget s andstone crops out in the f l anks . Perheps the r ed beds unde rlying the Nu gget also ere breached, but this cannot be proven because of heavy ov er­burden. The Toone Canyon anticline i s 5 miles long end ~ miles wide in the observable area, but to the northeast it is largely obscured by the Tertiar y sed~ments and may be considerably l onger. The incompe tency of the Twin Creek limest one is Ylell dis­pl ayed in the Toone Canyon anticline. Erratic dips are common and " Z " f o l d s a r e w e l l shown a t t h e m o u t h of H e l l Canyon ( P l a te I X ) . The e r r a t i c d i p s i n t h e Twin C r e e k l i m e s t o n e s e r v e t o com­p l i c a t e somewhat c o n f u s e t h e n t e r p r e t a t i o n e g e n e r al a n t i c l i n a l s t r u c t u r e . The p o s i t i o n and l i n e a t i o n of t h e Toone C a n y o n a n t i c l i n e s u g g e s t t h a t i t i s a c o n t i n u a t i o n of t h e H e n e f er a n t i c l i n e t o h e s o u t h w e s t E a r d l e y , p.. 855 ) . i s c o n ­j e c t u r a l , h o w e v e r , n a s m u c h a s t h e s t r u c t u r e p l u n g es b e n e a t h t h e f l a t - l y i n g K n i g h t f o r m a t i o n and o n l y d i p s , c o r r e s p o n d ­i n g t o t h e s o u t h e a s t f l a n k , a p p e a r b e y o n d t h e K n i g h t f o r m a t i o n in t h e a r e a t h e H e n e f e r a n t i c l i n e. F a u l t i n g O n l y f a u l t g n i f i p a n t m a g n i t u d e r e c o g n i z e d in t h e a r e a P l a t e X ) , T h i s s t r u c t u r e t r a c e d a p p r o x i m a t e ly m i l e s i s e s s e n t i a l l y p a r l l e l t o L o s C r e e k f r o m Cedar C a n y o n t o t h e j u n c t i o n T r a i l F r a n c i s C r e e k s . of t h e f a u l t s c i s s o r - l i k e a c t i o n w i t h t h e p i v o t t h e s o u t h ­e r n d i s p l a c e m e n t a p p r o a c h i n g f e t n o r t h e r n e n d . The e a s t s i d e of t h e f a u l t i s d o w n t h r o w n ; t h e u p - t h r o w n s i d e h a s b e e n s t r i p p e d of i t s T e r t i a r y c o v e r e x p o s i n g t he f o l d e d J u r a s s i c and Lower C r e t a c e o u s r o c k s in t h e Toone Canyon a n t i c l i n e . U n c o n f o r m i t i e s B a s a W a n s h i p u n c o n f o r m i t y . I n h e v i c i n i t y C r e ek t h e W a n s h i p f o r m a t i o n l i e s t h e F r o n t i e r f o r m a t i o n w i t h o n l y 36 and "Z" folds ere well shown at the mouth of Hell Canyon (Plate IX). The erratic dips in t he Twin Creek l imes t one s erve t o com­plicate and somewha t confuse the i nterpretation of t h e gener al anticlinal s tructure. The position and lineation of t he Toone Canyon anticline sugpest t ha t it i s e continuation of the Henefer anticline to t he southwest ( Eardley, 1944, p_ 855). This is con­jectur al, however, i nasmuch as the Toone Canyon sttucture plunges beneath the fl a t-lying Knight for ma tion Bnd only dips , cor respond­ing to the southeast fl ank, appear beyond the Kni ght formation i n the area of the Henefer an ti c line. Faulting Only one fault of s i gnifipant magnitude was recognized in the area ( Pl ete X). This structure can be traced approximately 8 miles and 1s essentially pa r a llel to Los t Creek from Cedar ee'ny,on to the junction of Trail and Fr ancis Creeks. Movement of the fault was a scissor-like action with th e pivot a t the south­ern end and a maximum displ ac ement appr oaching 1000 fe e t a t t he northern end. eas side the ault 1s down thrown; he up­thrown id e ha been stripped its Tertiary cover exposing the folded Jurassic Lowe r Cretaceous rocks the Canyon anticline. Unconfor mitie s Baaa l Wenahip unconformity. In t he vicinity of Meadow Creek the Waos hip formation lies on the Fr ontier for ma tion with only a P l a t e IX -<1 Plat. IX II ZI! fold in the incompetent Twin Creek limestone on the northeast facing slope of Hell Canyon ot the mouth. View looking southwest. P l a t e X D r a g - f o l d i n g in a t h e e a s t side of c o n g l o m e r a t e bed in the Knight f o r m a t i o n in Toone t h e Toone Canyon fault. View looking n o r t h e a s t. Canyon on Drag-folding in a the east side of co ng lo merate bed in the Knight formation in Toone the Toone Cany on fault. Vi ew looki ng no r th east. Plate X Canyon o n w OQ s l i g h t d i s c o r d a n c e ( l e s s t h a n 5 ° ) ; h o w e v e r , n e a r t h e town of W a n s h i p , U t a h , t o t h e s o u t h , F r o n t i e r K e l v i n b e d s d i p a l ­m o s t 9 0 ° a r e t r u n c a t e d t h e g e n t l y t i l t e d b a s a l W a n s h ip c o n g l o m e r a t e M o r r i s , 1953% Po- 4 6 ) 0 h i g h a n g u l a r d i s c o r d ­a n c e i s p r o n o u n c e d o n l y l o c a l l y , . t h e C o a l v i l l e a n t i c l i ne t h e a n g u a r d i s c o r d a n c e i s s m a l l , can d e t e c t e d o n l y c a r e f u l m e a s u r e m e n t o v e r d i s t a n c e of s e v e r a l m i e s • b a s ­a l Wanship c o n g l o m e r a t e , h o w e v e r , s e r v e s e x c e l l e n t mark­e r t h e u n c o n f o r m i t y t h r o u g h o u t t h e a r e a. B a s a l K n i g h t u n c o n f o r m i t y . e s s e n t i a l l y f l a t - l y i ng K n i g h f o r m a t i o n , w h e r e p r e s e n t , l i e s u n c o n f o r m a b l y t he t i l t e d e d g e s a l l o l d e r f o r m a t i o n s . a s s i c e x a m p l e t a n g u a r u n c o n f o r m i t y i s i n C a n y o n , q u a r t e r m i l e n o r t h ­e a s t t h e m o u t h M i l l PI a t e X I ) * T h e r e t h e n e a r ­l h o r i z o n t a l K n i g h t f o r m a t i o n l i e s u n c o n f o r m a b l y upon t h e b e ds o f t h e Echo Canyon c o n g l o m e r a t e w h i c h d i p up t o . 2 5 ° n o r t h w e s t. R i c h a r d s o n 1 9 4 1 , p . 33) r e c o g n i z e d t h e u n c o n f o r m i t y c o n c e r n i ng w h i c h he s t a t e d , "The s i g n i f i c a n c e of t h e u n c o n f o r m i t y i n t he r e d b e d s , w h i c h may be o n l y l o c a l , r e m a i n s t o be d e t e r m i n e d ". S u b s e q u e n t l y , E a r d l e y ( 1 9 4 4 , p . 843) d e s c r i b e d t h e u n c o n f o r m i ty a s a d i v i s i o n b e t w e e n t h e two members of t h e Almy c o n g l o m e r a t e. G e n e r a l l y , t h e b a s a l K n i g h t u n c o n f o r m i t y i s e a s i l y r e c o g ­n i z e d e s p e c i a l l y w h e t h e K n i g h t o r m a t i o n r u n c a t e s r o c k s of d i s s i m i l a r l i t h o l o g y s t r u c t u r a l a t t i t u d e . o t h e r a r e as s u c h a s a l o n g t h e a x i s h e S t e v e n s o n s y n c l i n e , where 39 slight discord ance (l e ss than 50); howev er , ne ar the town of Wanship, Utah, to the south, Frontier and Kelvin beds dip al­most 900 and are trunca t ed by the ge ntly til ted basal Vlanship con glomer ate ( Morris, 1953, p_ 46). This hi gh angular discord­ance is pronounced only locally . In the Coalville anticline the angu l ar discordance is small , and CBn be dete ct ed only by careful measurement over a distance ot several mi l es . The bas­el V/anship conglomer ate, however, serves a s an excellent ma rk­er above the unconrormity throughout the ares. Basel Knight unc onformity . The essentially fla t-lying Kni gh t formation, whe ll e pre sent, lies unconfoI'mably upon the til ted ed ges of all ol der forme tioI\s. A c l ass ic example of t he angu l ar unconformity is in Echo Canyon, one quarter mile north­east of the mouth of Saw Mill Canyon (Pl ate XI). There the near ­l y horizontal Knight for ma tion lie s unconfor mabl y the beds of the onglomerate which dip to 25 0 northwest .. Richardson ( 1941, p. 33 ) r,cognized the unconfor mity concer ning which stated, s i €~ ific an c e the unc o n~ormity in the red beds, wh ch only local, rema ins to determined". Subs equently, Eardley 1944 p. 843 ) described the unconformity as division between the t wo the Al my conglomer ate .. Gener ally, the basal Knight unconformity i s easily recog­nized especially whe r e the Knight f ormation t runcate s rocks of dissimilar lithology or structural attitude .. In other are as such as along the axis of t he St evenson Canyon sync line , wher e Plate XI Classic angular unconformity looking northeast up Echo Conyon . The Knight formation above and the Echo Canyon formation below the plane of the unconformity. h e K n i g h t o v e l i e s t h e c o n g l o m e r a t e and h a s t h e same a t t i t u d e , i f f i c u l t y i s e n c o u n t e r e d i n d i s i n g u i s h i n g b e w e e n t he w o f o r m a t i o n s i n d e f i n i n g t h e u n c o n f o r m i t y* p l a n e t h e u n c o n f o r m i t y i s e s s e n t i a l l y smootho Only o c a l l y a r e t h e r e s m a l l v a l l e y s and h i l l s a t t e s t i n g t o p r e - K n i g h t o p o g r a p h y , c o n s e q u e n t l y , t h e u n c o n f o r m i t y o n l y a p p r o x i m a t e d a r e a s w h e r e b e d s a b o v e b e l o w t h e u n c o n f o r m ­i t y e l i t h o l o g i c a l y a l i k e f l a t - l y i n g . This a p p r o x i m a t i on i s s o c o n f i r m e d t h e f a c t t h a t t h e o v e r l y i n g K n i g h f o r m a ­t i o n i s u s u a l l y l e s s r e s i s t a n t t h a n t h e u n d e r l y i n g c o n g l o m e r a te and a b e n c h or t e r r a c e - l i k e t o p o g r a p h i c e x p r e s s i o n of t h e con­t a c t d e v e l o p e d P l a t e X I I ), P o s t K n i g h t D e f o r m a t i R e g i o n a l w a r p i n g t h e K n i g h t o r m a t i o n n o t c r i t i ­c a l l y t u d e d , h o w e v e r , l o c a l l y , d i p s o 20° e n o t e d t he o r m a t i o n n d c a i n g t h a t a s b e e n d e f o r m e d i n t o b r o a d f o l d s. T h i s P o s - E o c e n e o l d i n g a s s o c i a t e d w i t h t h e B a s i n and R a n g e d i s t u r b a n c e i n h e n o r t h e n W a s a c h M o u n t a i s w h i c h E a r d ­l e y 1 9 4 4 , P» s u g g e s t s a s p r o b a b l y b e g i n n i n g o w a r d t h e t h e P l o c e n eo 41 t he Kni ght ov e r lies the Echo Canyon conglomerate end has the same at tit ude , d if ficulty is encount er ed in dis t inguishing be t ween the t wo for mati ons or in defining the unconformi t y~ The pl ene of the unconfor mity is essential l y smoothG Only l ocal ly ar e there small valleys end hills atte s ting to a pre­Kni ght t opography, consequently, the unconformity can only be approximated i n areas where beds above and below the unconf or m­i ty a r e lithol ogica l ly alike and l a ~lyin g. Thi s approximation is a l so conf irmed by the fact that the ov erlying Kni gh t forma ­tiDn i s usually less resistant than the underlying conglomer ate and 8 bench or ter r ace -like t opo gra phic expression of the con-t act i s dev eloped ( Pla te XII). • Post Knight Deformati on Regi onal war ping of the Knight f or ma tion was not criti­cally s tud i ed , however , locally, dips up t o 200 a r e noted in the f ormati on i nd i ca t ing that i t h as been deformed into broad folds" This Pos t - Eocene f olding may be ass ocia t ed with the Basin and Ran ge dis t u r bance in t he northe r n Wasa t ch Mountai n s vlhich Eard­l ey ( 1944 , p. 865) sugrests as probably be ginning t oward th e end of the PI i ocene . Plate XII Terrace-like top ographic expressi on of the ba slll Knight unconformity on the west side of Saw Mill Creek. ~1 D r a i n a g e m e a n d e i n g R i v e r P l a t e X I I I ) i s t h e m a s t e r s t r e am o f t h e r e g i o n and L o s Creek: C r e e k a r e i t s main t r i b u t a r i e s i n t h e s t u d i e d a r e a . , ^he n e a r l y h o r i z o n t a l c o n g l o m ­e r a t e h a s i n f l u e n c e d t h e d e v e l o p m e n t d e n d r i t i c d r a i n a g e s y s ­t em o v e r m o s t t h e a r e a . L i t t l e t r u c t u r a l c o n t r o l is s u g g e s t e d by t h e t r i b u t a r y d r a i n a g e s , t h o u g h t h e b a r b e d n a t u re o f A s p e n C r e e k n e a r Emory h i n t s of a s l i g h t d e f o r m a t i o n w h i ch p r o b a b l y o r i g i n a t e d d u r i n g t h e e s t a b l i s h m e n t of t h e p r e s e n t d r a i n ­a g e p a t t e r n o The a r e a as a w h o l e i s i n t h e e a r l y m a t u r e s t a g e of t h e i d e a l i z e d f l u v i a l c y c l e„ L a n d f o r m s F o r t h e most p a r t , m o d i f i e d b a d l a n d o p o g r a p h y t y p i f i es t h e L o s C r e e k - E c h o a r e a 0 R e s i s t a n t u n i t s of t h e K n i g ht f o r m a t i o n d e f e n d h a r p c l i f f s l e d g e s a n d , l o c a l l y , C h i n a t o w n , a p i d r o s i o n h a s p r o d u c e d s t e e p c l i f f s n u m e r o us s t a t u e - l i k e p i n n a c l e s 0 I n t e n s e r e d c o l o r a t i o n t h e K n i g h t s i l t - s t o n e s , s a n d s t o n e s , c o n g l o m e r a t e s t o g e t h e r w i t h t h e e f f e c t s m a s s - w a s t i n g h a v e p r o d u c e d B r y c e i n m i n i a t u r e» GEOMORPHOLOGY Drainage The meande r ing Weber River ( Pl ate XIII) is the master stream of the re gion Bnd Los t Creek and Echo Canyon Creek are its main tributaries in th e studied areB .. The nearly horizontal conglom­erate has influenced the dev elopment of a dendritic drainage sys­tem over most of th e area . Little or no s tructur al control is suggested the tributary drainages, though 'the barbed natur'B • otAspen Creek. ne ar hints slight deformation which probably originated during the establishment the present drain­age pattern. area whole is in the early mature stage the idealized rluvi el cycle. Landforms For the mos t pa rt. a mod ified badland t opography typiries the Los t Creek-Echo Canyon area . Resistant unit s or the Knight formation defend s har p cliffs and led ges and, locally, as in Chinat own, r apid e ro sion has produced steep cliffs and numer ous statue-like pinn acles . lntense red col or e