Economic geology of the sulphur deposits at Sulphurdale, Utah

I wish to express my appreciation to all those individuals and organizations that have contributed their efforts and have provided financial assistance for the completion this investigation. This investigation is part of the Survey of Mineral Resources of Utah sponsored by the University of Utah Engineering Experiment Station under the direction of M. P. Nackowski.

ECONOMIC GEOLOGY OF THE SULPHUR DEPOSITS AT SULPHURDALE, UTAH E n r i q u e R o d r i g u ez t h e s i s s u b m i t t e d t o t h e f a c u l t y t he U n i v e r s i t y U t a h i n p a r t i a l f u l f i l l m e nt o f t h e r e q u i r e m e n t s f o r t h e d e g r e e of M a s t e r S c i e n ce D e p a r t m e n t M i n i n g G e o l o g i c a l E n g i n e e r i ng U n i v e r s i t y Utah A u g u s t , 1960 SlJLPHPR DEPOSITS by Enrique Levy Rodriguez A thesis submitted to the faculty of the University of Utah in partial fulfillment of the requirements for the degree of Master of Science Department of Mining and Geological Engineering University of Utah August, 1960 T h i s T h e s i s f o r t h e M . S . d e g r ee b y E n r i q u e Levy R o d r i g u ez h a s b e e n a p p r o v ed A u g u s t , 1960 4 4 0 5 1 1 This Thesis for the MoS. degree by Enrique Levy Rodriguez has been approved August, 1960 .. ~ad, Major Derartment w i s h t o e x p r e s s a p p r e c i a t i o n t o a l l t h o se i n d i v i d u a l s o r g a n i z a t i o n s t h a t h a v e c o n t r i b u t e d t h e ir e f f o r t s h a v e p r o v i d e d f i n a n c i a l a s s i s t a n c e f o r t he c o m p l e t i o n of t h i s i n v e s t i g a t i o n. T h i s i n v e s t i g a t i o n i s p a r t t h e S u r v e y M i n e r al R e s o u r c e s U t a h s p o n s o r e d t h e U n i v e r s i t y U t ah E n g i n e e r i n g E x p e r i m e n t S t a t i o n u n d e r t h e d i r e c t i o n of Mo P» N a c k o w s k i. g o v e r n m e n t S a l v a d o r a w a r d e d t o t w o - y e ar s c h o l a r s h i p t o s t u d y E c o n o m i c G e o l o g y a t t h e U n i v e r s i t y of U t a h „ M. P . N a c k o w s k i h a s g u i d e d t h e s e s t u d i e s a l so s u g g e s t e d t h e t o p i c f o r t h i s t h e s i s . a s s i s t a n c e h a s b e en i n v a l u a b l e i n d i r e c t i n g t h e p r o j e c t p r e p a r i n g t he m a n u s c r i p t . A m e r i c a n S u l p h u r R e f i n i n g v e ry h e l p f u l i n p r o v i d i n g l o d g i n g d u r i n g t h e f i e l d w o r k p e r i o d. T h e i r s t a f f d i r e c t o r s c o n t r i b u t e d w i t h t h e i r p h y s i c al e f f o r t s , k n o w l e d g e of t h e p r o p e r t y , and r e c o r d s of i n f o r m a t i on n o t a v a i l a b l e i n p u b l i c a t i o n s. s t a f f s g r a d u a t e s t u d e n t s t h e M i n i n g and G e o l o g i c a l E n g i n e e r i n g D e p a r t m e n t G e o l o g y D e p a r t m e n t a l so c o n t r i b u t e d g r e a t l y t h e p r o j e c t. ACKNOWLEDGEMENTS I wish to express my appreciation to all those individuals and organizations that have contributed their efforts and have provided financial assistance for the completion this investigation. This investigation is part of the Survey of Mineral Resources of Utah sponsored by the University of Utah Engineering Experiment Station under the direction of P. Nackowski. The government of El Salvador awarded to me a two-year scholarship to study Economic Geology at the University of Utah o Dr. Mo P. Nackowski has guided these studies and also suggested the topic for this thesis. His assistance has been invaluable in directing the project and preparing the manuscript. The American Sulphur and Refining Company was very helpful in providing lodging during the field work period. Their staff and directors contributed with their physical efforts, knowledge the property, records information not available in pUblications. The staffs and graduate students of the Mining and Geological Engineering Department and Geology Department also contributed greatly to the project. CONTENTS . . . . „ . 0 . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . P u r p o s e S c o p e . . . . . . . . . . . . . . . P r e v i o u s Work . . . . . . . . . . . . . . . . . . 4 H i s t o r y and P r o d u c t i o n . . . . . . . . . . . . . 6 • L o c a t i o n and A c c e s s i b i l i t y . . . . . . . . . . . 8 P h y s i c a l F e a t u r e s and W a t e r R e s o u r c e s . . . . . . 11 GEOLOGY . . . . . ...... 13 S t r a t i g r a p h y . . . . . . . . . . . . . 14 R o c k s P e n n s y l v a n i a n . . . . . . . . 15 O q u i r r h f o r m a t i o n . . . . . . . . . 15 R o c k s P e r m i a n . . . . . . . . . . . . 17 P a k o o n l i m e s t o n e . . . . . . . . . 17 C o c o n i n o s a n d s t o n e . . . . . . . . . . 18 K a i b a b l i m e s t o n e . . . . . 19 R o c k s C r e t a c e o u s 20 P r i c e R i v e r c o n g l o m e r a t e . . . . . . . 20 R o c k s T e r t i a r y . . . . . . . . . . . . 21 V o l c a n i c f l o w s p y r o c l a s t i c s . . . . 21 R o c k s P l e i s t o c e n e t o R e c e n t 25 B a s a l t f l o w s c i n d e r c o n e s . . . . . 25 W a t e r - l a i d t u f f s . . . . . . . . . 25 A l l u v i u m . . . . . . . . 26 S t r u c t u r e 27 F r o n t F a u l t s 27 P r i n c e A l b e r t F a u l t . . . . . . . . . . . . 29 E x c e l s i o r F a u l t 29 31 D e s c r i p t i o n S u l p h u r D e p o s i t s . . . . . . . . . 31 S u l p h u r d a l e V i c t o r C o n q u e r o r O r e b o d i e s . 31 P r i n c e A l b e r t O r e b o d y , M a r i p o s a , and Q u e e n V i c t o r i a P r o s p e c t s . . . . . . . . . 35 E x c e l s i o r O r e b o d y Y o r k P r o s p e c t . . 36 S u l p h u r O r e b o d y P h i l a d e l p h ia P r o s p e c t . . . . . 38 B l a c k P r o s p e c t . . . . . . . . . . . M i n e r a l o g y . 39 TABLE OF CDNTENTS PAGE ABSTRACT 0 0 0 1 INTRODUCTION . 3 Purpose and Scope . 0 • 0 • 0 0 •• 0 3 Previous Work . 0 • 0 • • • o. 0 • • 4 History and Production . . . 0 0 • • 6 "Location and Accessibility 0 0 • ." 0 • 8 Physical Features and Water Resources . . .. 11 GEOWGY • • 0 • u 0 G • 0 • • • 13 Stratigraphy ..•.. . . . 14 15 15 17 17 18 19 20 20 21 21 25 25 25 26 27 27 29 29 Rocks of Pennsylvanian Age . 0 • • • • • Oquirrh formation . • . . 0 0 • • 0 • • Rocks of Permian Age • • 0 0 • • • • Pakoon limestone . . •. .. 0 0 0 Coconino sandstone . 0 • • • • Kaibab limestone • 0 • • • • • • • • • Rocks of Cretaceous Age .• 0 • Price River conglomerate .•. Rocks of Tertiary Age • 0 • • • • • Volcanic flows and pyroclastics Rocks of Pleistocene to Recent Age . Basalt flows and cinder cones. Water-laid tuffs . . . • • • • . . . • Alluvium . • . . 0 • Structure . . . . . . . . • . . . . Front Range Faults •..... Prince Albert Fault .•. Excelsior Fault ... GEOLOGY OF ORE DEPOSITS 31 Description of Sulphur Deposits • 31 Su1phurda1e and Victor Conqueror Orebodies. 31 Prince Albert Orebody, Mariposa, and Queen Victoria Prospects . • • . • • . . 35 Excelsior Orebody and New York Prospect 36 Sulphur King Orebody and Philadelphia Prospect . . 0 • • • • • • • • • •• 38 Black Mine Prospect . 0 • • • • • • o. 39 Mineralogy . . . o. • • • • • • • • •• 39 O r e M i n e r a l s . . . . . . . . . « . . . . . . 40 S u l p h u r . . . . . . . . . . . . . . . . 40 I r o n s u l p h i d e s . . . . . . . . . . . . 40 G a n g u e M i n e r a l s . . . . . . . . . . . . . . 41 S i l i c e o u s S i n t e r , S i C ^ . n ^ O . . . . . 41 C a S 0 4 . 2 H 2 0 . . . . . . . . . . 43 Q u a r t z , S i 0 2 44 Z o n a t i o n M i n e r a l D e p o s i t s . . . . . . . . 44 P a r a g e n e s i s O r e G a n g u e M i n e r a l s . . . 46 G e n e s i s D e p o s i t s . . . . . . . . . . 47 O r e R e s e r v e s . . . . . . . . . . . . . . . . . . 51 S u g g e s t i o n s f o r E x p l o r a t i o n P r o s p e c t i n g . . . 61 . . . . . . . . . . . . . 63 M i n i n g M e t h o d s . . . . . . . . . . 63 M i n i n g C o s t s . . . . . . . . 64 M a r k e t P o t e n t i a l . . . . . . . . . . 65 67 . . . . . . . . . . . . . . . 69 . . . . . . . . . . . . . . 71 -v- PAGE Ore Minerals 0 0 0 0 0 • • • Q 40 Sulphur 0 • • • • • • • • • • • • • 40 Iron sulphides .•. Q • _ • • • • 40 Gangue Miner als . • . . 0 • • • 41 Siliceous Sinter, Si02 0 nH20 . ..• 41 Gypsum, CaS04.2H20 43 Quartz, Si02 •••• . • . . • . . •• 44 Zonation of Mineral Deposits 0 • • • • • 44 Paragenesis of Ore and Gangue Minerals • 46 Genesis of Ore Deposits Q D • • • • Q • •• 47 Ore Reserves .•••• o. • 0 • • 0 0 • 51 Suggestions for Exploration and Pz'ospecting • 61 ECONOMIC ASPECTS Mining Methods Mining Costs • • Market Potential CONCLUSIONS BIBLIOGRAPHY • APPENDIX . 0 63 63 64 65 67 69 71 L I S T ILLUSTRATIONS 1 0 I n d e x t h e S u l p h u r D e p o s i t s , S u l p h u r . . . a l e, B e a v e r , M i l l a r d C o u n t i e s , U t a h . . . . . . 2 . P r i n c i p a l S u l p h u r D e p o s i t s , S u l p h u r d a l e, B e a v e r , and M i l l a r d C o u n t i e s , U t a h . . . . . . 10 3 . C o m p o s i t e S t r a t i g r a p h i c S e c t i o n , S o u t h P a v a nt R a n g e , M i l l a r d C o u n t y , . . . . . . . . . . 16 4 . F o r t C i n d e r B a s a l t F l o w s . View L o o k i n g S o u t h w e s t . . . . . . . . . . . . . . . 33 5 . S u l p h u r d a l e Open P i t . L o o k i n g S o u h w e s t . 33 6 . E x c e l s i o r P i t . L o o k i n g . . . . . . . 37 7 . F a c e E x c e l s i o r P i t . G r a d e S u l p h ur O r e S h o w i n g R e l i c B e d d i n g t h e R e p l a c ed P r i c e R i v e r C o n g l o m e r a t e . . . . . . . . . . . 37 8 . P h o t o m i c r o g r a p h T h i n S e c t i o n S h o w i n g t he C o l l o f o r m T e x t u r e t h e I r o n S u l p h i d e s ( F e) E n c l o s i n g E l e m e n t a l S u l p h u r . . . . . . . . 42 9 . P h o t o m i c r o g r a p h T h i n S e c t i o n Showing S u l p h u r w i t h D i s s e m i n a t e d I r o n S u l p h i d e s ( F e - S) i n G r o u n d m a s s M i c r o c r y s t a l l i n e S u l p h ur a n d I r o n S u l p h i d e s . C o l l o f o r m (O) E n c l o se S u l p h u r . . . . . . . . . . 42 1 0 . P h o t o m i c r o g r a p h T h i n S e c t i o n Showing P l a g i o c l a s e P h e n o c r y s t s C o m p l e t e l y R e p l a c ed b y S i l i c a i n G r o u n d m a s s Amorphous S i l i c a I r o n S u l p h i d e s . . . . . . . . . . 45 1 1 . P h o t o m i c r o g r a p h T h i n S e c t i o n S h o w i n g t he F i b r o u s T e x t u r e A n g u l ar F r a g m e n t s Q u a r t z q ) . A r e a s a r e V o i d s . 45 1 2 . L o c a t i o n t h e D r i l l H o l e s a t t he V i c t o r C o n q u e r o r O r e b o d y , M i l l a r d C o u n t y, U t a h . . . . . . . . . . . . . . . 53 LIST OF ILLUSTRATIONS FIGURE PAGE 1. Index Map of the Sulphur Deposi ts, Su1phurd a1e, Beaver, and Millard Counties, Utah 0 0 0 • • • 9 Principal Sulphur Deposits, Su1phuTda1e, Beaver, and Millard Counties, Utah . 0 0 3. Composite Stratigraphic Sectio n , South Pavant 10 Range, Millard County, Utah 0 0 0 • 0 • 0 • •• 16 4. Cove Fort Cinder Cone and Basalt Flows. View Looking Southwest .• 0 0 • • • 33 5. Su1phurda1e Ope,n Pit. View Looking Sou t hwest. 33 6. Excelsior Pit. View Looking West 0 7. West Face of Excelsior Pit. High Gr ade Sulphur Ore Showing Relic Bedding of the Replaced 37 Price River Conglomerate •. 0 0 • • • • • •• 37 8. Photomicrograph of a Thin Section Showing the Co11oform Texture of the Iron Sulphides (Fe ) Enclosing Elemental Sulphur (S) 0 • • • 0 0 •• 42 9. Photomicrograph of a Thin Section Showing Sulphur with Disseminated Iron Sulphides (Fe-S) in a -Groundmass of Opaque Microcrystalline Sulphur and Iron Sulphides. Co11oform Opal 0) Enclose Sulphur ......... 0 • • • • O". • •• 42 10. Photomicrograph of a Thin Section Showing Plagioclase Phenocrysts (P) Completely Replaced by Amorphous Silica in a Groundmass of Amorphous Silica and Iron Sulphides • . • . • . • . . •• 45 11. Photomicrograph of a Thin Section Showing the Fibrous Texture of Gypsum (G) and Angular Fragments of Quartz ( q). Dark Areas are Voids. 45 12. Location Map of the Diamond Drill Holes at the Victor Conqueror Orebody, Millard County, Utah O'.O' • • • • co 0 • • • • • • • Ct 0 • O'O' 53 v i i S T ( C o n t i n u e d) 13o V e r t i c a l C r o s S e c t i o n s h e V i c o r C o n q u e r or O r e b o d y , M i l l a r d C o u n t y , U t a h « . 54 L o c t i o n h e Diamond D r i l H o and V e r c a l C r o s s S e c t i o n s h e S u l p h u r King O r o d y , M i l l a r d C o u n t y , U t a h . . . . . . . . 55 I G e o l g i c V e r t i c C r o s s S e t i o n s t he S u l p h u r a l e S u l p h u r D e p o s i t s , B e a v e r M i l l a rd C o u n t i e s , U t a h • p o c k et I I . D e t a i l e d G e o l o g i c V e r t c a l C r o ss S e c t i o n s t h e E x c e l s i o r O r e b o d y and Y o r k P r o s p e c t P i t , M i l l a r d C o u n t y, U t a h p o c k et I I I . D e t a i l e d G e o l o g i c and V e r t i c a l C r o s S e c t i h e P r i n c e A l b e O r e b o d y , Queen V i c t o r i a M a r i p o s a P r o s p e c t P i t s, M i l l a r d C o u n t y , U t a h . . . . . . . . . p o c k et V . D e t a i l e d S h o w i n g D r i l l H o le L o c a t i o n s V e r t i c a . 1 C r o s s S e t i o n at h e S u l p h u d a l e D e p o s i t , B e a v e r C o u n t y, U t a h . . . . . . . . . . . . . . . . . . in p o c k et - vii - L I ST OF ILLUSTRATIONS (Co ntinued ) FIGURE PAGE 1 3 . Ve r tical Cros s Secti ons of t he Vic t c£ Conquer or Oreb ody, Millard County , Utah . 0 0 • • 54 1 4 . Loc a tio n Map of t he Di amo nd Dril l Ho l e s and Ver t i cal Cross Sections at t he Sul phur King Or e b ody, Millard County , Utah •. .. •• 55 PLATE I. Geol o gic Map and Ve r tic a l Cr oss Se c tions of the Su1 phur d a1e Sulphur Deposits, Beaver and Mi l l ard Counties, Utah . • . . . . . . . . . . . . in poc ket II. Detailed Geologic and Vert i cal Cross Sec ti o ns Map of the Excelsior Or ebody and New York Prospect Pit, Millard County , Utah . . • . .. . . . . . . • . . o . in poc ket III . De tailed Geologic a nd Verti cal Cr os s Secti on Map of t he Prince Albe r t Or eb ody, Qu een Victoria and Mariposa Pros pect Pit s , Mi llard County, Utah . . . • . . . • . in pocket I V. Det ai led Map Showing Diamond Drill Hole Locations and Vertic a l Cross Se c ti on at t he Su1phu r da1e Deposit, Beaver Coun t y , Ut ah . •••. . •. •. . . . . . • . i n pocket L I S T OP Io M i n e r a l o g i c a l V e r t i c a l Z o n i n g . . . . . . . I I . A n a l y s i s W a t e r f r om S u l p h u r d a l e , . . I I I . 5 8 I V O r e R e s e r v e s . . . . . . . . . . V. R e s e r v e s . . . . . . . . . . V I . R e s u l t s t h e D r i l l i n g P r o g r a m . . . . . . V I I . E s t i m a t e M i n i n g . . . . . . . . . . LIST OF TABLES TABLE PAGE I. Miner alogical Vertical Zoning · · · . . · · · 46 II. Analysis of Water from Sulphurdale 9 Utah · 50 III . Tabulation of Ore Reserves 58 IV . Summary of Ore Reserves · · 0 · · · · · · 58 Vo Summary of Ore Reserves · · . · · 0 · · · 60 VI. Results of the Drilling Program · · . . · 60 VII. Estimate of Mining Cost · · . · 0 64 p u r p o s e t h i s t u d y i s d e s c r i b e t h e g e o l o gy o f t h e S u l p h u r d a l e a r e a and of t h e s u l p h u r o c c u r r e n c e s . The d i s t r i b u t i o n , s i z e , and g r a d e of t h e s u l p h u r d e p o s i t s were d e t e r m i n e d . The m i n e r a l o g y was s t u d i e d and h y p o t h e s e s c o n ­c e r n i n g mode of o r i g i n and d e p o s i t i o n a l c o n t r o l s p r o p o s e d. The u l p h u r d e p o s i t s h e S u l p h u r d a l e a r e a a re l o c a t e d M i l l a r d B e a v e C o u n t i s , U t a h i n T. * , R. 6 W. and T. 26 S . , R« 6 W. S . L . B . M . The a r e a s t u d i ed i n c l u d e s 18 s q u a r e m i l e s. a r e a g e o l o g i c a l l y a t t h e e a s t e r n b o r d er o f t h e B a s i n P r o v i n c e . Normal a u l t s t r e n d i ng N. 1 5 ° t o 7 5 ° E . d i p p i n g t o t h e w e s t , e a s t , and s o u t h a r e t h e most i m p o r t a n t s t r u c t u r a l f e a t u r e s i n t h e a r e a. The f a u l t t h a t d e m a r c a t e s t h e w e s t e r n b o r d e r of t h e T u s h ar R a n g e and S o u t h P a v a n t Range h a s b e e n a c t i v e up t o P l e i s t o ­c e n e and R e c e n t t i m e s . A b l o c k of P a l e o z o i c s e d i m e n t a ry r o c k s on t h e w e s t s i d e of t h e mapped a r e a f o r m s a h o r st b o u n d e d by T e r t i a r y f a u l t s . The h o r s t b l o c k h a s a t o t al e x p o s e d s t r a t i g r a p h i c t h i c k n e s s of 2 , 6 0 0 f e e t . The s t r a t i - g r a p h i c s e q u e n c e i s as f o l l o w s : P e n n s y l v a n i a n O q u i r rh l i m e s t o n e , P e r m i a n P a k o o n l i m e s t o n e , P e r m i a n C o c o n i no q u a r t z i t i c s a n d s t o n e , and t h e P e r m i a n K a i b a b l i m e s t o n e . The g r a b e n t o t h e e a s t i s c o m p o s e d m a i n l y of T e r t i a r y v o l c a n ic f l o w s and C r e t a c e o u s P r i c e R i v e r c o n g l o m e r a t e . The s t r a ta g e n e r a l l y s t r i k e N. 2 0 ° t o 30° E . and d i p 3 0 ° t o 4 0 ° E. T e r t i a r y v o l c a n i c f l o w s a r e p o r p h y r n i c q u a r tz l a t i t e s , l a t i t e s , a n d e s i t e s . p y c l a s t i c s a re m a i n l y a n d e s i t i c l a p i l l i t u f f s . B a s a l t f l o w s w e r e e x t r u d ed a n d c i n d e r c o n e s r o s e from t h e v a l l e y f l o o r as a r e s u l t of r e n e w e d v o l c a n i s m d u r i n g P l e i s t o c e n e and R e c e n t t i m e s. Damming of t h e s t r e a m s by t h e b a s a l t f l o w s c r e a t e d s h a l l o w - w a t e r l a k e s w h e r e s t r a t i f i e d b e d s of t u f f d e p o s i t e d. c l a s s i f i c a t i o n t h e s u l p h u r d e p o s i t s i s p r o p o s e d, e m p h a s i z i n g t h e t y p e r o c k h a t s e r v e s h o s t . main t y p e s a r e f o u n d . S u l p h u r d e p o s i t s i n w a t e r l a i d t u f f s. 2 ) S u l p h u r d e p o s i t s i n c o n g l o m e r a t e . S u l p h u r d e p o s i t s in r e c e n t b r e c c i a t a l u s s l o p e s. m i n e a l s p r e s e n t i n t h e s u l p h u r d e p o s i t s a re c l s s i f i e d o r e g a n g u e . m i n e r a l s a r e s u l p h ur i r o n s u l p h i d e s . m i n e r a l s a r e s i l i c e o u s s i n t e r, a nd ABSTRACT The pur pose of this s tudy is t o d ~ s crib e the geology of the Su1phurda1e area the su lphur occur ences The distribution, size, grade he sul phur deposits were determi ned . mineral ogy tudied a nd hypotheses con­cerning origin deposi ional ont ols proposed~ Th e s ulphur deposits of t he Su1phurda1e area a r e located i n Mill ard and Beave r Count i e s, Utah in T o 25 S o, Ro So , R. oB aM. studied includes 1 8 squar miles. -The ~rea geologically mapped i s at the eastern border of the Basin and Range Provi nce o Norm a l f ault s trending No 150 E . to N. 750 E. and dipping to the we s t, east , and sout are the mportant structural featur s in the area. aul that demarcates the western borde the Tushar Range Sout Pavant has been ac tive to Pleisto­cene Re ent times block Pal oz oic sedimentary rocks the west side the area rms horst bounded Tertiary faults . horst blo ck has total exposed strat igraphic thickness ,600 feet. strati­graphic sequence is follows : Pennsylvanian Oqu ir r h limestone, Pe mian Pakoon limestone, Permian Coconino quartzitic sandstone, the Permian Kaibab lime stone . The graben to the east is composed mai nly Terti ary volc anic flows Cretaceous Price River co ngl omerat . strata generally st r ike No 200 to 30° E . and d ip 300 to 400 E. The Tertiary volcanic flows are porphyr i ( ic 'qu artz 1atites, latites, and andesites. The py r o clastics are mainly andesitic ~api11i tuffs. Basalt ows were extruded and cinder cones rose the valley floor result of renewed volcanism during Pleistocene Recent times. the streams the basalt flows crea ed sha110w­water lakes where stratified beds tuff deposi ted. A classification of the sulphur deposits is proposed, emphasizing the type of rock t hat serves as ~ost. Three main types are found . 1) Sulphur deposits in water - laid tuffs. 2) Sulphur deposits in conglomerate. 3) Sulphur deposits in recent breccia talus slopes. The mine r als present in the sulphur deposits are cl a ssified as ore and gangue. Ore minerals are sulphur and iron sulphides . Gangue minerals are si liceous sinter, I g y p s u m , q u a r t z „ c o m p o s i t e m i n e r a l o g i c a l z o n i n g t he s u l p h u r d e p o s i t s i s p r o p o s e d „ t o p t o b o t t o m t h e f o l l o w ­i n g m i n e r a l s p r e d o m i n a t e s gypsum; and s u l p h u r ; s u l ­p h u r ; s u l p h u r , p y r i t e , m a r c a s i t e ; p y r i t e m a r c a s i t e; p y r i t e „ s u l p h u r d e p o s i t s a r e u n d o u b t e d l y a s s o c i a t ed w i t h t h e r m a l s p r i n g s s o l f a t a r i c n a t u r . t e m p e r a t u r e, s i l i c a - b e a r i n g s o l u t i o n s r i c h i n h y d r o g e n s u l p h i d e h a ve p e r m e a t e d f a v o r a b l e b e d s d e p o s i t i n g s u l p h u r n e a r t h e w a t er t a b l e . p r e c i p i t a t i o n t h e u l p h u r i s a c c o m p l i s h e d by t h e p a r t i a l o x i d a t i o n of t h e h y d r o g e n s u l p h i d e g a s „ The i r o n s u l p h i d e s p r e c i p i t a t e d b e l o w tl e w a t e r t a b l e f r om t he m i x i n g of a c i d s u r f a c e w a t e r s and a s c e n d i n g h y d r o t h e r m al s o l u t i o n s c h a r g e d w i t h h y d r o g e n s u l p h i d e g a s and f e r r o u s i o ns O r e r e s e r v e s t o t a l 4 , 8 4 5 , 0 0 0 s h o r t o n s w i t h s u l p h u r c o n t e n t a p p r o x i m a t e l y 8 5 0 , 5 2 1 l o n g t o n s . F u t u re e x p l o r a t i o n f o r e x t e n s i o n s s u l p h u r o r e b o d i e s new o n e s s h o u l d c o n c e n t r a t e d a l o n g t h e same s t r u c t u r e s t h at h a v e o c a l i z e d t h e e x i s t i n g d e p o s i t s. s u l p h u r o r e h a s e e n m i n e d p i t m e t h o d s .' h a s b e e n p r o c e s s e d t h e f o l l o w i n g m e t h o d s - a ) t h e r m a l , f l o t a t i o n , c) s o l v e n t e x t r a c t i o n . The l o c a t i o n e l a t i v e l y l o w g r a d e t h e s u l p h u r d e p o s i ts m a k e s f u t u r e v e n t u r e l a r g e l y d e p e n d e n t o c a l m a r k et f o r s u c c e s s f u l o p e r a t i o n . , S u l p h u r d a l e p r o p e r t y e n j o ys a f r e i g h t a d v a n t a g e t o some c o n s u m e r s o v e r o t h e r d i s t r i b u t o rs o f s u l p h u r and s u l p h u r i c a c i d i n t h e I n t e r m o u n t a i n a r e a. gypsum ~ and quar tz o A composite mineralogical zoning of the sulphur deposits is proposed o From top to bottom the follow­ing minerals pr edominate ~ gypsum ; gypsum a nd sulphur, sul= phur, sulphur, pyrite, and marcasite, pyyite and marc asite; pyrite o The sulphur deposits are undoub edly associated with thermal spr ings of sol fataric natur e . Low t emper ature 1 silica- bearing solutions ri ch in hydrogen sulphide gas have permeated fav or able beds depositi ng sulphur near the water tab1eo The precipitat ion of the s ul phur is accomplished by the partial oxidation the hydrogen sulphide gas o The n sulphides precipitated below t he water table ftom the mixing acid surface waters ce nding hydr othermal solutions char ged wi th hydrogen sulphide gas ferrous ions o Ore reserves total 4, 845,000 shor t tons with a sulphur content of approximately 850,521 long tons o Future exploration for extensions of known sulphur or ebodies or new ones should be concentr ated al ong the s ame structur es that have l ocalized the existing depositso The sulphur ore has b een mined by open pit methods~ The o r e has been processed by the following methods ~ a) thermal, b) flotation, and solvent ex tr actio n o The location and r elatively low grade of the sulphur deposits makes a future venture largely dependent on a l ocal market for a succe ssful operationa The Su1phurd ale property enjoys freight adva age to consumers over other distributors of sulphur sulphuric acid in the Intermountain area o INTRODUCTION L SCOPE T h e p u r p o s e t h i s s t u d y i s t o d e i b e t h e g e o l o gy o f h e S u l p h u r d a l e a r e a h e s u l o c c u r r e n c e s . The d i s t r i b u t i o n , s i z e , g r a d e t h e s u l p h u r d e p o s i t s and p r o s p e c t s w e r e d e t e r m i n e d . m i n e r a l o g y s t u d i e d and h y p o t h e s e s c o n c e r n i n g mode o f o r i g i n and d e p o s i t i o n al c o n t r o l s p r o p o s e d. s t u d y i n c l u d e d f i e l d l a b o r o r y i n v e s t i g a t i o n s. s t r a t i g r a p h i c s e c t i o n s w e r e m e a s u r e d w i t h c l o t h t a pe a n d B r u n t o n c o m p a s s . d e t a i l e d t h e i n d i v i d u al s u l p h u r d e p o s i t s w e r e s u r v e y e d w i t h s t e e l t a p e B r u n t o n c o m p a s s . t r a v e r s e s w e r e c l o s e d t i e d to c l a i m c o r n e r s o r s e c t i o n c o r n e r s . E r r o r s in e l e v a t i o n were c o r r e c t e d d i s t r i b u t i n g e q u a l l y t h e t o t a l e r r o r t he s t a t i o n s , b u t o n l y i f t h i s i n d i v i d u a l c o r r e c t i o n d i d n ot e x c e e d 0 . 5 f o o t p e r s t a t i o n . Geology of t h e d e p o s i t s was p l o t t e d on t h e s e m a p s . At t h e S u l p h u r d a l e o r e b o d y t he e l e v a t i o n of t h e t o p of t h e s u l p h u r b e d s was e s t a b l i s h e d at a l l p o i n t s p o s s i b l e by u s i n g a B r u n t o n c o m p a s s a n d a c l o th t a p e . R o c k s a m p l e s w e r e c o l l e c t e d t h e f i e l d s t u d i ed p e t r o g r a p h i c a l l y . T h e i r l i t h o l o g y , m i n e r a l o g y , o r e m i n e r al t e x t u r e s p a r a g e n e s i s , t y p e s a l t e r a t i o n were I NTRODUCTION I . PURPOSE AND SCOPE The purpose of thip study is to de s c r ibe the geology of t he Sulphurdal~ ar~and of t he sul p h u r occurrences . The distribution, size, and grade of the sul phur deposits and prospects were determined. The minera lo gy was studied and hypotheses concerning of origin depositional controls proposed. The study included field and labor a t ory investigations. The stratigraphic sections were measured with a cloth tape and Brunton compass. The detailed maps of the individual sulphur deposits we~e surveyed with a steel tape and a Brunton compass. All traverses were closed and tied to claim corners or sect~on corners. Errors elevation were corrected by distributing equally the total error among the stations, but only if this individual correction did not exceed O ~ 5 foot per station. the deposits was plotted th~se maps. the Sulphurdale orebody the elevation the top the sulphur beds established at all points possible using Brunton compass and cloth tape. Rock samples wer~ collected in the field and studied petrographically. Their lithology, mineralogy, o~mineral textures and paragenesis, and types of alteration were 4 - r e c o r d e d o d i a m o n d d r i l l c o r e a v a i l a b l e r om K i n g ' s e x p l o r a ­t i o n p r o g r a m e x a m i n e d . w e r e s e l e c t e d f or p e t r o g r a p h i c e x a m i n a t i o n. L a b o r a t o r y i n v e s t i g a t i o n s i n c l u d e d p o l i s h e d s e c t i on a n d t h i n s e c t i o n e x a m i n a t i o n , X - r a y d i f f r a c t i o n a n a l y s e s, a n d d i f f e r e n t i a l t h e r m a l a n a l y s e s. g e o l o g y t h e S u l p h u r d a l e a r e a p l o t t e d p l a n i m e t r i c d r a w n w i t h t h e r a d i a l l i n e p l o t t e r f r om c o n t r o l l e d a e r i a l p h o t o g r a p h s . s c a l e t h i s is o n e i n c h e q u a l 1 , 5 0 0 f e e t. F i e l d w o r k i n i t i a t e d t h e 2 6 t h J u l y , 1959 a n d c o m p l e t e d on t h e 2 6 t h of S e p t e m b e r , 1959. L a b o r a t o ry c o n d u c t e d t h e p e r i o d f r om O c t o b e r , t o May, 1 9 6 0 . I I . G e o l o g i c i n v e s t i g a t i o n s t h e d i s t r i c t h a v e b e en i n t e r m i t t e n t l y c o n d u c t e d f r o m t o 1 9 5 9 . R u s s e l l ( 1 8) v i s i t e d d e s c r i b e d t h e C r e e k s u l p h u r e p o s i t s in 1 8 8 3 . 1 6 ) d e s c r i b e d t h e s u l p h u r d e p o s i t s and p r o p o s e d h y p o t h e s i s f o r t h e i r o r i g i n . r e c o g n i z e d t he a s s o c i a t i o n t h e d e p o s i t s w i t h f a u l t s . a l s o s t a t ed t h a t t h e s u l p h u r was d e p o s i t e d by t h e p a r t i a l o x i d a t i o n of t h e H2 S g a s . S u l p h u r i c a c i d f o r m e d by f u r t h e r o x i d a t i o n of H2S t o SO3 i n w a t e r. - 4- recordedo The diamond drill core available f r om King's explora­tion program was examined. Samples were selected for petrographic examination. Laboratory investigatio~included polished section and thin section ~xamination, X-ray diff raction analyses, and differential thermal analyses. The geology of the Sulphurdale area was plotted on a planimetric map drawn with the radial line plotter from controlled aerial photographs. The scale of this map is one inch equal 1,500 feet. Field work was initiated on the 26th of July, 1959 and completed the 26th September, Laboratory work was conducted in the period from October, 1959 to May, 1960. II. PREVIOUS WORK Geologic investigations of the district have been intermittently conducted from 1883 to 1959. Russell (18) visited and described the Cove Creek sulphur d eposits in 1883. In 1907 Lee ( 16) described the sulphur deposits and proposed a hypothesis for the ir ori gin. Lee recognized the association of the deposits with faults. Lee also stated that the sulphur deposited the partial oxidation of the H2S gas. Sulphuric acid formed further oxidation of to S03 in water. 5 - e x t e n s i v e c o m p r e h e n s i v e work d o n e by C l a r e n c e R, 1 2 ) 1 9 5 1 d u r i n g e x p l o r a t i on p r o g r a m f o r t h e C h e m i c a l C o r p o r a t i o n A m e r i c a a t t h e ir p r o p e r t y . S u l p h u r r e s e r v e s w e r e t i m a t e d d i a m o nd d r i l l i n g . r e c o v e r y p o o r due t o t h e f r i a b i l i t y of s u l p h u r o r e . D r i l l h o l e s w e r e b o t t o m e d e l e m e n t al s u l p h u r c o n t e n t d e c r e a s e d s u l p h e u l p h u r c o n t e nt i n c r e a s e d . P a r t i a l s p e c t r o g r a p h i c n a l y s i s t h e i r on s u l p h i d e s showed u n u s u a l a m o u n t s of n i c k e l ( 0 . 0 3 t o 0 . 3 p er c e n t ) and c o b a l t ( 0 . 0 5 t o 0 . 5 p e r c e n t ) . No h y p o t h e s e s w e re p r o p o s e d by King t o e x p l a i n t h e p r e s e n c e of i r o n s u l p h i d es b e l o w t h e e l e m e n t a l s u l p h u r. v o l c a n i c s e q u e n c e t h e T u s h a r M o u n t a i n s was C a l l a g h a n 5 ) 1 9 3 9 . v o l c a n i c r o c k s t he M a r y s v a l e u r a n i u m d i s t r i c t w e r e d e s c r i b e d by K e r r 1 4 ) in 1 9 5 7 . T h e s e d i m e n t a r y r o c k s t h e S o u t h P a v a n t R a n g e have b e e n d e s c r i b e d c l a s s i f i e d G a r y C r o s b y 6 ) . His c l a s s i f i c a t i o n h a s b e e n f o l l o w e d t h i s t h e s i s. T h e o r i g i n s u l p h u r , p y r i t e , m a r c a s i t e h a s b e en s t u d i e d e x t e n s i v e l y . A l l e n , C r e n s h a w , J o h n s t o n 1 ) h a ve d o n e o u t s t a n d i n g w o r k i n t h e o c c u r r e n c e s t a b i l i t y f i e l ds o f m a r c a s i t e and p y r i t e . They p e r f o r m e d e x p e r i m e n t s a t t he G e o p h y s i c a l L a b o r a t o r y - - C a r n e g i e I n s t i t u t i o n of W a s h i n g t on a n d c o n c l u d e d t h a t m a r c a s i t e f o r m s u n d e r v e r y a c i d c o n d i t i o ns a n d p y r i t e u n d e r a l k a l i n e c o n d i t i o n s. - 5- The most extensive and comprehensive wo r k was done by Clarence R. King ( 12) in 1951 and 1952 ~ ng an exploration program for the Chemical Corporation of America at their property. Sulphur reserves were e s timated by diamond drilling. Core recovery was poor d ue to the friability of sulphur ore. Drill holes were bottomed when elemental sulphur content decreased and sulph i d e s ulphur content increased. Part ia1 spectrograph ic a nal ys is of the iron sulphides s~owed unusual amounts nickel 03 to 0.3 per cent) cobalt 0.05 to 0.5 per cent) . No hypotheses were proposed to explain the presence iron sulphides below the elemental sulphur. The volcanic sequen~in the Tushar Mountains was mapped by Callaghan ( 5) in 1939. The volcanic rocks of the Marysvale uranium district were described b y Kerr ( 14) in 1957. The sedimentary rocks of the South Pavant Range have been described and classified by Gary W. Crosby ( 6). His classification has been followed in this thesis. The origin of sulphur, pyrite, and marca site has been studied extensively. Allen, Crenshaw, and Johnston ( 1) have done outstanding work in the occurrence and stability fields of marcasite pyrite. performed experiments at the Geophysical Laboratory--Carnegie Institution Washington and concluded that marcasite forms under very acid conditions and pyrite under alkaline conditions. - 6 - I I I . A r o u n d s e t t l e r s s e n t t o p o p u l a t e a r e as s o u t h of S a l t Lake C i t y d i s c o v e r e d t h e s u l p h u r d e p o s i t s in t h e v i c i n i t y of Cove C r e e k and m i n e d s u l p h u r on a s m a ll s c a l e t o make g u n p o w d e r . A f o r t b u i l t by B r i g h a m Young at t h e s i t e of Cove P o r t t o p r o t e c t s e t t l e r s a g a i n s t I n d i a n r a i ds a n d t o s e r v e a s a s t a t i o n on t h e r o a d f r o m S a l t Lake C i t y to S t . G e o r g e was f i n i s h e d in 1 8 6 7. F a u r 9 ) s t a t e s t h a t F e r d i n a n d D i c k e r t f i r st d i s c o v e r e d t h e s u l p h u r d e p o s i t s in t h e v i c i n i t y of Cove F o rt i n 1 8 6 9 , b e t w e e n and d i s c o v e r e d o t h er p r o s p e c t s n o r t h of Cove F o r t . In Mr. D i c k e r t put up a p r o c e s s i n g p l a n t t h a t w o r k e d w i t h g r e a t s u c c e s s . T h i s p l a nt e x t r a c t e d t h e s u l p h u r f r om t h e o r e by t h e t h e r m a l p r o c e s s. I n t h e p r o p e r t y was t r a n s f e r r e d t o a s t o c k c o m p a n y . At t h i s t i m e , a c c o r d i n g to Du F a u r ( 9 ) P r o f e s s o r von R a th e s t i m a t e d t h e e x i s t e n c e of 1 , 3 0 0 , 0 0 0 t o n s of s u l p h u r a t t he S u l p h u r d a l e o r e b o d y. d e p o s i t s w e r e s o u r c e d o m e s t i c s u l p h u r from a b o u t t o 1 9 0 6 , d u r i n g w h c h p e r i o d p r o d u c t i o n a b o ut 1 , 0 0 0 t o n s of s u l p h u r p e r y e a r . D u r i n g a l l t h e U n i t ed S t a t e s d o m e s t i c p r o d u c t i o n of , 2 0 0 t o n s was mined f r o m t he Cove C r e e k d i s t r i c t ( 2 2 ). I n a b o u t 1918 M o r r i s e y q u i r e d h e p r o p e r t y and o r g a n i z e d Utah S u l p h u r I n d u s t r i e s . company and o t h er l e s s e e s x p l o i t e d t h e S u l p h u r d a l e o r e b o d y n d o t h e r d e p o s i ts 6- III. HISTORY AND PRODUCTION Around 1855 Mormon sett lers sent ~o popul ate areas sou Sal City discovered the phur dep si s in the vicinity Creek a nd min ed sulphur Oll smal l scale to ma ke gunpowder. ort built Brigham a t the te Fort to protect sett lers aga inst Indian raids and to serve as station the oad rom Sal City to St . G'eorge finished 1867. Du Faur ( 9) states that Mr. Ferdinand Dick ert first discovered the sulphur deposits the vicin t y Fort in 1869, and between 1872 a nd 1875 he dis covered other prospect s north Fort. I n 1883 Mr. Dickert processing plant that worked with eat success. Th is plant extracted the sUlphur from the ore the hermal process. In 1885 the property transferred to st o ck company_ At this time, according Faur 9) Professor Rath estimated the exi~tence 1,300,000 tons sulphur at the Sulphurdale orebody. The deposits were a source of domes t ic sulphur from about 1890 to 1906, during wh i ch period producti on was about 1,000 tons sulp~urper year. Dur ing 1893 all the Un ited States omestic production 1 ,200 ons min ed from the Creek district (22). In about 19f8 Mr. Morrisey a c quired t he pro pert y a nd or anize~ Utah Sulphur Industries . This c ompany a nd oth er lessees e xploited the Sulphurdale orebody a nd other depos i ts 7 - i n t h e a r e a i n t e r m i t t e n t l y f r o m t o a b o u t ( 1 2 ) 0 s y s t e m a t i c e x p l o r a t o r y e v e r u n d e r t a k e n to d e t e r m i n e t h e c h a r a c t e r , e x t e n t , g r a d t h e d i s c o v e r ed o r e b o d i e S o U n t i l r e c e n t o p e r a t i o n s o p e n p i m i n i n g o v e r ­b u r d e n s t r i p p i n g d o n e w i t h t e am h o r s e s s c r a p e r . h i g h g r a d e o r e m i n e d . p i l e s a v e r ­a g i n g f r om t o p e r c e n t s u l p h u r a r e s e e n a t t he S u l p h u r d a l e p i t . T h i s v e r y s e l e c t i v e m i n i n g h a s a l s o r e s u l t ed i n a h a p h a z a r d o u s p a t t e r n of c u t s and b e n c h e s . R e c e n t l y open p i t m i n i n g was d o n e w i t h a m o d e l 25 N o r t h w e s t s h o v e l and a D - 4 C a t e r p i l l a r b u l l d o z e r. I n F r e e p o r t S u l p h u r d i d s u f f i c i e n t d r i l ­l i n g t o d e t e r m i n e t h a t t h e s u l p h u r d e p o s i t s w e r e n o t s u i t a b le f o r F r a s c h p r o c e s s m i n i n g 1 3 ) . t h e C h e m i c a l C o r p o r a ­t i o n A m e r i c a u n d e r t o o k d i a m o n d d r i l l i n g p r o g r a m t o b l o ck o u t r e s e r v e s e l e m e n t a l s u l p h u r o r e a t t h e S u l p h u r d a l e, V i c t o r C o n q u e r o r , S u l p h u r o r e b o d i e s . Diamond d r i l l i n g c h o s e n i n o r d e r t o g a i n i n f o r m a t i o n t he s t r u c t u r e t e x t u r e t h e o r e 1 3 ) e x p l o r a t i on p r o g r a m was d e s i g n e d and d e v e l o p e d i n 1950 and 1951 b y King a n d K i n g , c o n s u l t i n g m i n i n g e n g i n e e r s . In 1953 p r o s p e c t i ng w a s done w i t h a c e s s p o o l d i g g e r a t t h e E x c e l s i o r and P r i n ce A l b e r t p i t s. S u l p h u r e x t r a c t e d f r o m t h e o r e t h e r m a l p r o c e ss u n t i l 1 9 5 1 , f l o t a t i o n m i l l c o n s t r u c t e d . p r o ­d u c t i o n w a s r e p o r t e d f r om t h e p r o p e r t y d u r i n g t h e s h o r t t i me - 7- in the area intermittently from 1918 to about 1949 (12) . No systematic exploratory work was ever undertaken to determine the character, extent, and gr a c e of the discovered orebodies . Until recent operations open pi t mining and over­burden stripping was done with a team of horses and a scraper. Only high grade ore was mined • . Waste piles aver­aging from 10 to 15 per cent sulphur are now seen at the Sulphurdale pit. This very selective mining has also resulted in haphazardous pattern cuts benches. Recently open pit mining done with model Noithwest shovel D-Caterpillar bulldozer. In 1937 Freeport Sulphur Company did sufficient dril­ling to determine that the sulphur deposits were not suitable for Frasch process mining ( 13). In 1950 the Chemical Corpora­tion of America undertook a diamond drilling program to block out r~serves of elemental sulphur ore at the Sulphurda1e, Victor Conqueror, and Sulphur King orebodies . Diamond drilling was chosen in order to gain information on the structure and texture of the ore ( 13) . The exploration program designed developed in by King and King, consulting mining engineers. prospecting was with cesspool digger at the Excelsior Prince Albert pits. Sulphur was extracted from the ore by thermal process until 1951, when a flotation mill was constructed. No pro­duction was reported from the property during the short time „ 8~ o f o p e r a t i o n t h e f l o t a t i o n m i l l „ 1 2 ) r e p o r t s t h at i n 1953 t h e i n t e r e s t now r e p r e s e n t e d by t h e U n i t e d S t a t es S u l p h u r C h e m i c a l C o r p o r a t i o n o b t a i n e d c o n t r o l t he p r o p e r t i e s w i t h o p t i o n t o b u y e p l a n t p r o d u c e s u l p h ur by a s o l v e n t e x t r a c t i o n p r o c e s s s t a r t e d p r o d u c t i o n i n 1 9 5 5. No p r o d u c t i o n f i g u r e s a r e a v a i l a b l e f r om t h i s l a s t p e r i o d of o p e r a t i o n„ p r o p e r t y i s Mr, N e a l f r om Los A n g e l e s , C a l i f o r n i a and t h e S u l p h u r d a l e M i n i n g Company, a N e v a d a c o r p o r a t i o n. I V . ACCESSIBILITY s u l p h u r d e p o s i t s t h e C r e e k d i s t r i c t a re l o c a t e d M i l l a r d B e a v e r C o u n t i e s , i n S ., S . , S a l t B a s e M e r i d i a n . The a r e a s t u d i e d i n c l u d e s a b o u t e i g h t e e n s q u a r e m i l e s ( F i g u r e s 1 a n d 2) . S u l p h u r d a l e d e p o s i t i s m i l e e a s t U„ S. h i g h w a y a t S u l p h u r d a l e w h i c h i s a b o u t m i l e s s o u t h Cove F o r t . All t h e o t h e r d e p o s i t s a r e l o c a t e d i n M i l l a rd C o u n t y n o r t h e a s t of Cove F o r t and n o r t h of U t a h h i g h w a y 1 3. The S u l p h u r King d e p o s i t , t h e B l a c k Mine p r o s p e c t , and t he f l u o r s p a r p r o s p e c t s a r e on a n o r t h s o u t h i m p r o v e d d i r t r o ad o n e - h a l f m i l e e a s t of Cove F o r t . A r o a d j u s t e a s t of F i s h l a ke N a t i o n a l F o r e s t b o u n d a r y l e a d s t o t h e E x c e l s i o r d e p o s i t and t h e New Y o r k and M a r i p o s a p r o s p e c t s . A r o a d t h r e e m i l e s e a st -8- of operation of the flotation mill. King ( 12) reports that in the interest represented the United States Sulphur and Chemical Corporation obtained control of the properties with an option to buy. A plant to produce sulphur solvent extraction process started production in 1955." production figures are available from this last period of operat ion .. The property is now owned by Mr. Thomas Neal from Los Angeles? California the Sulphurdale Mining Company? Nevada corporation. IV. LOCATION AND ACCESSIBILITY The sulphur deposits of the Cove Creek district are located in Millard and Beaver Counties, Utah in T. 25 5., R. 6 W. and T. 26 S., R. 6 W., Salt Lake Base Meridian. The area studied includes about eighteen square miles Figures and The Sulphurda1e deposit is one mile east of U. S. highway 91 at Sulphurdale which is about two miles south of Fort. the other deposits are located in Millard County northeast Fort north Utah highway 13. Sulphur deposit, the Black prospect, the fluorspar prospects are north south improved dirt road one-half mile east Fort. road just east Fishlake National Forest boundary leads to the Excelsior deposit the York Mariposa prospects. road three miles east - 9 - F I G . I I N D E X MAP OF T H E S U L P H U R D E P O S I TS S U L P H U R D A L E 1 BEAVER AMD M I L L A R D C O U N T I E S , UTAH Tff "'''--1 ' ""'. ~"J ,m CITY DSULPH UROALE _I. _ 1 9- I i ~ FIG. INDEX MAP OF THE SULPHUR DEPOSITS SULPHURDALE BEAVER AND MI LLARD COUNTIES, UTAH - 1 0 - F I G . 2 P R I N C I P A L S U L F U R D E P O S I T S, S U L P H U R D A L E B E A V E R AND M I L L A R D C O U N T I E S , UTAH (AFTER BULL. OF UNIV. OF UTAH, VOL. 50, NO. 18 ) R. 7 W. T. 25 S. -1 R. 6 W. LEG END. B­-@- ~ ... J ' SULFUR DEPOSIT U. S. HIGHWAY UTAH HIGHWAY GRAVEL ~ BLACK MINE ----- UNIMPROVED ~ PRIN CE A L B ERT \ , / . . , / \ . ' . ~'VICTOR CONQUEROR / / // / / ' \ .co V e For t . .-,r::::-...... -~ . / ., ~ M B E A V E R T. ,­I / ~~ 26 IO~· S. /~ / / TO BEAVER FIG. 2 PRINCIPAL SULFUR SULPHURDALE DEPOSITS, BEAVER AND MILLARD COUNTIES, UTAH ( AFTER BULL . OF UN I V. OF UTAH, V OL . 50, NO. 18 ) - 1 1 - o f F o r t l e a d s t o t h e V i c t o r C o n q u e r o r d e p o s i t , t h e P r i n ce A l b e r t d e p o s i t , and Queen V i c t o r i a p r o s p e c t . These d e p o s i ts a n d p r o s p e c t s a r e c o n n e c t e d by u n i m p r o v e d d i r t r o a d s t h a t a re p a s s a b l e e x c e p t when snow m e l t s in t h e W i n t e r and S p r i n g. F i l l m o r e , m i l e s n o r t h , B e a v e r , m i l e s s o u th S u l p h u r d a l e , s u p p l y f o o d a c c e s s o r i e s f o r m i n i ng o p e r a t i o n s . U n i o n P a c i f i c R a i l r o a d h a s s i d i n g at B l a c k R o c k , m i l e s w e s t F o r t . S e v i e r , s t a t i on o f t h e D e n v e r R i o G r a n d e R a i l r o a d , i s m i l e s e a s t of F o r t. WATER B e a v e r V a l l e y t o t h e w e s t t h e s u l p h u r d e p o s i t s is a t e l e v a t i o n 6 , 0 0 0 f e e t , t h e T u s h a r M o u n t a i n s and P a v a n t r i s e t o t h e e a s t t o e l e v a t i o n s 1 0 , 0 0 0 to 1 2 , 0 0 0 f e e t . T u s h a r M o u n t a i n s t h e P a v a n t R a n g e a re s e p a r a t e d by a low m o u n t a i n p a s s e a s t of Cove F o r t . The P a v a n t Range r i s e s g e n t l y t o h i g h e r e l e v a t i o n s t o t h e n o r th a n d e a s t of Cove F o r t , and t h e T u s h a r R a n g e r i s e s a b r u p t ly t o t h e e a s t of S u l p h u r d a l e . The m o n o t o n y of t h e v a l l e y is i n t e r r u p t e d by l o w - l y i n g h i l l s of b a s a l t i c f l o w s and c i n d er c o n e s w h i c h t e s t i f y t o t h e l a t e s t v o l c a n i c a c t i v i t y w i t h in t h e B a s i n and R a n g e P r o v i n c e. A l l t h e s u l p h u r d e p o s i t s a r e l o c a t e d in t o p o g r a p h ic d e p r e s s i o n s s u r r o u n d e d by low h i l l s or at t h e f l a n k s of n o r t h - t r e n d i n g r i d g e s. 11- of Cove Fort leads to the Victor Conqueror deposit, the Prince Albert deposit, Victoria prospect. deposits and prospects are connected unimproved dirt roads that are passable except melts the Winter Spring. Fillmore, 35 miles north, and Beaver, 23 miles south of Sulphurdale, supply food and minor accessories for mining operati'ons. The Union Pacific Railroad has a siding at Black Rock, 24 miles west of Cove Fort. Sevier, a station of the Denver and Rio Grande Railroad, is 20 miles east of Cove Fort. V. PHYSICAL FEATURES AND WAT~R RESOURCES Beaver Valley to the west of the sulphur deposits is at an eleva~ion of 6,000 feet, and the Tushar Mountains and Pavant Range rise to the east to elevations of 10,000 to 12,000 feet. The Tushar Mountains and the Pavant Range are separated mountain pass east Fort. The Pavant rises gently to higher elevations to the north and east Fort, the Tushar Range rises abruptly to the east Sulphurdale. monotony the valley is interrupted low-lying hills basaltic flows cinder cones which testify to the latest volcanic activity within the Basin Range Province. All the sulphur deposits are located i n topographic depressions surrounded hills the flanks north­trending ridges. 1 2 - T h e d r a i n a g e p a t t e r n i s l a r g e l y m o d i f i e d d e n d r i t ic The main s t r e a m s f l o w w e s t i n t o t h e v a l l e y . S m a l l e r t r i b u ­t a r i e s t r e n d n o r t h - s o u t h . The d r a i n a g e p a t t e r n i s c o n t r o l l ed b y s t r u c t u r a l l y e l e v a t e d b l o c k s and n o r t h - s o u t h f a u l t s. M o i s t u r e f r om a n d r a i n t o t o i n c h es p e r y e a r . t h e s t r e a m s , i n c l u d i n g C r e e k , a r e f ed m a i n l y p r e c i p i t a t i o n a r e i n t e r m i t t e n t s i n c e p r e c i p i ­t a t i o n d u r i n g t h e m o n t h s a m o u n t s t o b u t f e w c l o u d ­b u r s t s . S e v e r a l s p r i n g s a r e l o c a t e d t h e m o u n t a i n s d i r e c t ly e a s t S u l p h u r d a l e ; t h em o c c u r a l o n g t h e t r a c e of t h e F r o n t f a u l t . s p r i n g s h a v e p r o v i d e d w a t e r f or p l a n t c u l i n a r y u s e a t S u l p h u r d a l e . s m a l l r e s e r v o i r h as b e e n b u i l t a t t h e s i t e t h e p l a n t t o r e c e i v e t h e w a t e rs f r om t h e s e s p r i n g s . s h o r t a d i t i n t h e h i l l s i d e j u s t e a st o f t h e S u l p h u r d a l e p i t h a s c u t i n t o f r a c t u r e d p o r o us p o r p h y r i t i c v o l c a n i c f l o w s . w a l l s t h i s a d i t a r e wet a n d x y a t e r f l o w s o u t t h e f l o o r t h e a d i t. - 12- The drainage pattern is largely modified dendritic. streams flow west into the valley. Smaller tribu­taries trend north-south. drainage pattern is controlled by structurally elevated blocks north-south faults. Moisture from snow and rain amount to 14 to 15 inches per year. All the streams, including Cove Creek, are fed mainly by precipitation and are intermittent since precipi­tation during the summer months amounts to but a few cloud­bursts. Several springs are located in the mountains directly east of Sulphurdale; some of them occur along the trace of the Front Range fault. These spring~ have provided water for plant and cUlinary use at Sulphurdale. A small reservoir has been built at the site of the plant ~receive the waters from these springs. A short adit in the hillside just east of the Sulphurdale pit has cut into fractured and porous porphyritic volcanic flows. The walls of this adit are wet and some water flows out on the floor of the adit. -13- s o u t h e r n t h e P a v a n t t h e n o r t h e rn e x t r e m e of t h e T u s h a r M o u n t a i n s a r e a t t h e e a s t e r n m a r g i n of t h e G r e a t B a s i n. P a l e o z o i c C r e t a c e o u s s e d i m e n t a r y r o c k s c r o p o u t in t h e n o r t h e a s t e r n n o r t h p a r t s t h e a r e a m a p p e d . The o l d e s t f o r m a t i o n i s t h e l i m e s t o n e s e q u e c e t h e P e n n s y l v a n - i a n O q u i r r h f o r m a t i o n w h i c h i s o v e r l a i n u n c o n f o r m a b l y t he P e r m i a n P a k o o n l i m e s t o n e . h i g h e r t h e s t r a t i - g r a p h i c s e c t i o n i s t h e P e r m i a n C o c o n i n o q u a r t z i t i c s a n d s t o n e. The P e r m i a n K a i b a b l i m e s t o n e o v e r l i e s c o n f o r m a b l y t he C o c o n i n o s a n d s t o n e . The y o u n g e s t s e d i m e n t a r y f o r m a t i o n is t h e C r e t a c e o u s P r i c e R i v e r c o b b l e - b o u l d e r c o n g l o m e r a t e t h at u n c o n f o r m a b l y o v e r l i e s t h e O q u i r r h f o r m a t i o n . The P r i ce R i v e r c o n g l o m e r a t e i s o v e r l a i n by t h e T e r t i a r y v o l c a n i c r o c k s. The s e d i m e n t a r y r o c k s g e n e r a l l y s t r i k e N. 10° W. t o N. 4 5 ° E. a n d d i p 2 0 ° t o 34° E. and SE. t h e a r e a i s c o v e r e d T e r t i a r y v o l c a n i c s. v o l c a n i c f l o w s r a n g e c o m p o s i t i o n f r om q u a r t z l a t i te t o a n d e s i t e . p y r o c l a s t i c s a r e p r e d o m i n a n t l y a n d e s i t ic l a p i l l i t u f f. K e r r ( 1 4 ) c o n t e n d s t h a t t h e v o l c a n i c r o c k s w h i c h o v e r ­l i e t h e c o n g l o m e r a t e t h e S o u t h P a v a n t a r e e a r ly T e r t i a r y t h u s b e l o n g t o t h e B u l l i o n S e r i e s. GEOLOGY The -southern end of the Pavant Range and the northern extreme the Tushar Mountains are at the eastern margin of the Great Basin. Paleozoic and Cretaceous sedimentary rocks crop out 1n the northeastern and north parts of the area mapped. The oldest formation is the limestone seque n ce of the Pennsylvan­ian Oquirrh formation which is overlain unconformably by the Permian Pakoon limestone. Next and higher in the strati­graphic section is the Permian Coconino quartzitic sandstone. Permian Kaibab limestone overlies conformably the Coconino sandstone. youngest sedimentary formation is the Cretaceous Price River c~bble-boulder conglomerate that unconformably overlies the Oquirrh formation. Price River conglomerate is overlain the Tertiary volcanic rocks. sedimentary rocks generally strike 100 to 450 E. and dip 200 to 340 SED Most of the area is covered by Tertiary volcanics. The volcanic flows range in composition from quartz latite to andesite. The pyroclastics are predominantly andesitic lapilli tuff. Kerr 14) contends that the volcanic rocks which over­lie the conglomerate in the South Pavant Range are early Tertiary and thus belong to the Bullion Canyon Series. - 1 4 - C r o s b y 6 ) h a s d e s i g n a t e d t h e s e r o c k s a s B e l k n ap S e r i e s t h a t w e r e e x t r u d e d d u r i n g P l i o c e n e t i m e . t he B u l l i o n v o l c a n i c s e x t e n d e d a s f a r n o r t h a s t h e B e l k n a p v o l c a n i c s , t h e f i r s t d e s i g n a t i o n w o u l d a p p r o p r i a t e . D a t i n g t h e v o l c a n i c r o c k s n o t a t t e m p t e d s i n ce e x t e n s i v e f a u l t i n g s e p a r a t e s t h i s a r e a f r o m t h e a r e a mapped C a l l a g h a n ( 5 ). C i n d e r c o n e s b a s a l t f l o w s c o v e r t h e w e s t e r n p a rt o f t h e a r e a . a r e p a r t w i d e z o n e r e c e n t v o l c a n ic r o c k s t h a t e x t e n d s f r om F i l l m o r e t o t h e U t a h - A r i z o n a b o r d e r. b a s a l t f l o w s p r o b a b l y m o d i f i e d t h e d r a i n a g e a l o ng t h e f r o n t t h e T u s h a r M o u n t a i n s and s o u t h e r n P a v a n t R a n ge b y w e s t - f l o w i n g s t r e a m s c r e a t i n g s h a l l o w - w a t er l a k e s . W a t e r - l a i d t u f f a c c u m u l a t e d in t h e s e l a k e s f r o m t he i n t e r m i t t e n t e x p l o s i v e a c t i v i t y of t h e n e a r b y v o l c a n o e s . The a r e a l e x t e n t t h e s e Q u a t e r n a r y l a k e b e d s i s n o t s i n ce t h e y n o t o n l y h a v e b e e n c o v e r e d by a l l u v i u m b u t a l s o h a ve b e e n e r o d e d by s t r e a m s . S i l i c i f i e d , more r e s i s t a n t p a t c h es o f t h e s e l a k e b e d s r e m a i n . The s u l p h u r d e p o s i t s a r e p r o b a b ly of l a t e P l e i s t o c e n e and more l i k e l y of R e c e n t a g e . The v a l l e y s and s t r e a m c o u r s e s a r e c o v e r e d w i t h s i l t , s a n d , and g r a v e l . I . STRATIGRAPHY T h e s e d i m e n t a r y s e q u e n c e r a n g e s i n a g e f r om 14- Crosby ( 6) has designated these same rocks as Mount Belknap Series that were extruded during Pliocene time. If the Bullion Canyon volcanics extended as far north as the Mount Belknap volcanics, the first designation would be more appropriate. Dating of the volcanic rocks was not attempted since extensive faulting separates this area from the area mapped by Callaghan (5). Cinder cones and basalt flows cover the western part I of the area. They are part of a wide zone of recent volcanic rocks that extends from Fillmore to the Utah-Arizona border. The basalt flows probably modified the drainage along the front of the Tushar Mountains a nd southern Pavant Range by damming west-flowing streams and creating sh~llow-water lakes. Water~laid t~ff accumulat~these lakes from the intermittent explosive p.ctivity of. the nearby volcanoes. The areal extent of these Quaternary lake beds is not known since they not only have been covered alluvium but also have been eroded streams. Silicified, resistant patches of these lake beds remain. sulphur deposits are probably late Pleistocene likely Recent age. The valleys stream courses are covered with silt, sand, and gravel. I. STRATIGRAPHY The sedimentary sequence ranges in age from 1 5 - P e n n s y l v a n i a n t o R e c e n t . D e t a i l e d s e c t i o n s w e r e m e a s u r e d at t h r e e d i f f e r e n t p l a c e s . K a i b a b l i m e s t o n e t h e C o c o n i no s a n d s t o n e w e r e m e a s u r e d t h e w e s t s l o p e V a l l e y P e a k. P a k o o n l i m e s t o n e t h e O q u i r r h o r m a t i o n w e r e m e a s u r ed r i d g e n o r t h t h e S a l t g u l l y t h e r i d g e e a st o f t h e S u l p h u r o r e b o d y . P r i c e R i v e r c o n g l o m e r a te was n o t m e a s u r e d s i n c e i t i s f a u l t e d and o n l y p a r t l y e x p o s ed d u e t o t h e c o v e r of T e r t i a r y v o l c a n i c r o c k s and Q u a t e r n a ry a l l u v i u m e The v o l c a n i c r o c k s w e r e n e i t h e r m e a s u r e d n or d a t e d o F o l l o w i n g i s a d i s c u s s i o n of t h e s e v e r a l s t r a t i g r a p h ic u n i t s e x p o s e d in t h e a r e a. R o c k s P e n n s y l v a n i a n O q u i r r h f o r m a t i o n . O q u i r r h f o r m a t i o n i s t h e o l d e st s e d i m e n t a r y s e q u e n c e i n t h e a r e a . O q u i r r h f o r m s t he s t e e p e s c a r p m e n t n o r t h e a s t F o r t . r i d g e c u r v es n o r t h e a s t t o w a r d V a l l e y r e p r e s e n t s f a u l t l i ne e s c a r p m e n t . s t r i k e t h e b e d s c h a n g e s f r om 15° to N„ 30° d i p a l s o v a r i e s f r om 2 0 ° 3 2 ° E. N e a r t h e e s c a r p m e n t t h e l i m e s t o n e h a s b e e n s t r o n g ly b r e c c i a t e d s i l i c i f i e d . F a u l t s i n t h e v i c i n i t y t he S u l p h u r p a r a l l e l t o t h e e s c a r p m e n t h a v e p r o d u c e d s t r a t i - g r a p h i c t h r o w s f e e t f e e t. S o u t h t h e S a l t g u l l y t h e O q u i r r h i s o v e r l a in u n c o n f o r m a b l y t h e P r i c e R i v e r c o n g l o m e r a t e , n o r t h of t h i s g u l l y i t o v e r l a i n u n c o n f o r m a b l y t h e P a k o on - 15- Pennsylvanian to Recent. Detailed section s were measured at three different places. The Kaibab limestone and the Coconino sandstone were measured on the west slope of Dog Valley Peak. The Pakoon limestone and the Oquirrh f ormation were measured on a ridge north of the Salt Lake gully and on the ridge east of the Sulphur King orebody. The Price River conglomerate not measured since it is faulted only partly exposed due to the cover Tertiary volcanic rocks Quaternary alluvium o volcanic rocks were neither measured nor dated o Following is discussion the several stratigraphic " units exposed the area. Rocks of Pennsylvanian Age Oquirrh formation. The Oquirth formation is the oldest sedimentary sequence in the area. The Oquirrh forms the steep escarpment northeast of Cove Fort. This ridge curves northeast toward Dog Valley and represents a fault line escarpment. The strike of the beds changes from N. 150 W. to No 300 E. The dip also varies from 200 E. to 320 E. Near the escarpment the limestone has been strongly brecciated and silicified. Faults in the vicinity of the Sulphur King parallel to the escarpment have produced strati­graphic throws of 400 feet and 250 feet . South of the Salt Lake gully the Oquirrh is overlain unconformably by the Price River con glomerate, and north of this gully it is overlain unconformably by the Pakoon - 1 6 - O O UJ o O CO UJ o o o N o Ixl _J < GL >- or < or UJ l- I- UJ or o ALLUVIUM WATER-LAID TUFF SILT, SAND, AND GRAVEL PAVANT BASALT BLACK BASALT FLOWS AND CINDERS VOLCANIC FLOWS AND PYROCLASTICS 2 0 0 0 ' + PRICE RIVER CONGLOMERATE 4 5 0 ' + PINKISH LATITE PORPHYRY, LATITE PORPHYRY, ANDESITE PORPHYRY, AND ANDESITE VITROPHYRE. GREEN. ANDESITE LAPILLI TUFF SUB-ROUNDED COBBLES AND BOULDERS OF DARK GRAY LIMESTONE AND WHITE TO PINK QUARTZITE. INTERBEDDED SANDY HORIZONS oO-.O KAIBAB LIMESTONE I I I 9 0 5 ' W D , 1 MASSIVE, LIGHT GRAY, COARSELY CRYSTALLINE LIMESTONE. SANDY DOLOMITE, RECRYSTALLIZED CRINOIDAL LIMESTONE. CHERT NODULES. WHITE QUARTZITE AND SANDSTONE INTERBEDDED WITH DARK GRAY, MEDIUM GRAINED LIMESTONE. DARK GRAY, COARSELY CRYSTALLINE, FOSSILIFEROUS. LIMESTONE. m m or UJ COCONINO SANDSTONE 594 WELL-BEDDED, STRONGLY FRACTURED, PURPLE- TO BUFF- COLORED QUARTZITIC SANDSTONE. RED SANDSTONE, SANDY LIMESTONE, AND DARK RED MUDSTONES. PAKOON LIMESTONE LIGHT GRAY LIMESTONE, CHERT NODULES SANDY LIMESTONE,CHERT FRAGMENTS. < > _J UJ CL OQUIRRH LIMESTONE MASSIVE, WHITE CHERT BEDS AND LIGHT GRAY, SANDY LIMESTONES. BLUE GRAY, FOSSILIFEROUS LIMESTONES INTERBEDDED WITH SHALES, SANDSTONES, AND DOLOMITES 8 7 6 ' +- F I G . 3 C O M P O S I T E S T R A T I G R A P H I C S E C T I ON S O U T H P A V A N T R A N G E , M I L L A R D UTAH (,) -0 N 0 Z lIJ () N 0 CJ) lIJ 16- :.;,:'~'~';;c.:~.: WATER-LAID TUFF ALLUVIUM ~.~.~:Q:~Q~~t.Q;~~~~:~_ _ ~S~I~L~T2, _S~A~N~D ~, _A_N_D_ __G_ R_A_V_E_L ________- -j ...L.MJ.1J.!J: IJ.'I ' I/'/ BLACK BASALT FLOWS AND CI NDERS ~ < t ::> a \/'1.l '.i':Z''- _______________________________ _ I--+------------------~' ,,"~/\.:,~ J DARK GRAY TO PINK ISH BROWN QUARTZ ~ ~ \~/~. . a:: -<t ~ a:: lLJ ~ ~ lLJ a:: u VOLCANIC FLOWS ~~~;~~ LATITE PORPHYRY, LATITE PORPHYRY, ~':?'~~~ .. _ :~~ VITROPHYRE. , ,'IT~,~" ~~/J; ) GREEN. ANDESITE LAPILLI TUFF 2000 + .~~:~o~~!j o~o 0 ' 0 ' 0 ' 0 . PRICE RIVER .''o0.g;,o .'oo .0 .0 . 0 . CONGLOM E RATE .o'o~ .• ;'~c;, 00 . . : 0 . . 0 SUB-ROUNDED COBBLES AND BOULDERS OF DARK GRAY LIMESTONE AND WHITE TO INTERBEDDED SANDY HORIZONS 450' + Pcio'·O.0:.2.0,;,' ~~= +---4-------- 1 T I LIMESTONE . KA I BAB LIMESTONE 905' ~ = 1. . '"." 1. . ". .1.0..".J .. J.. . . ' ' . . .,..,.} WHITE QUARTZITE AND SANDSTONE INTERBEDDED WITH DARK GRAY, LIMESTONE . DARK GRAY, COARSELY CRYSTALLINE, FOSS ILIFEROUS . LIMESTONE . = = <=> ~------------3· ·~···~· =··~· ¢".1-----~----------------~ / " . STRONG LY FRACTURE D, COCONINO SANDSTONE .... . '. " . . ' :":' ·· :·:\··: ·.t:/' .. . . : . J; .. ' . ' .,. ' .. ,./. .. ~ .. ; . '. ,' . ~ ' ... . '. , .. . . 594' ; .... .. , f----------------- "". ,,'. ' PAKOON LIMESTONE OQUIRRH LIMESTONE 206' ~ ' . . ' .' . " .. B76' + l<T'cr"'!1'O'; --~----------------~ COLORED QUARTZ IJIC SANDSTONE . RED SANDSTONE, SANDY LIMESTONE, AND DARK RED MUDSTONES . • LIGHT GRAY LIMESTONE, CHERT NODULES . SANDY LIMESTONE ', CHERT FRAGMENTS . MASSIVE, WHITE CHERT BEDS AND LIGHT GRAY, SANDY LIMESTONES . BLUE GRAY, FOSSI LI FEROUS LI MESTONES INTERBEDDED WITH SHALES, SANDSTONES, AND DOLOM ITES FIG. :3 COMPOSITE STRATIGRAPHIC SECTION SOUTH PAVANT RANGE, MILLARD COUNTY, UTAH 1 7 - l i m e s t o n e . b a s e t h e f o r m a t i o n i s c o v e r e d a l l u v i u m. T h e O q u i r r h f o r m a t i o n c o n s i s t s m a i n l y g r a y t o b l u e - g r a y f o s s i l i f e r o u s l i m e s t o n e s i n t e r b e d d e d w i t h t h i n - b e d d ed s a n d s t o n e s , c a l c a r e o u s s a n d s t o n e b e d s , f e w d o l o m i te h o r i z o n s . t h e t o p t h e O q u i r r h i s l i g h t - g r a y , t h i c k - b e d d e d, f i n e - g r a i n e d , s a n d y l i m e s t o n e i n t e r b e d d e d w i t h m a s s i v e b e ds o f w h i t e c h e r t. t h e l i m e s t o n e b e d s n e a r t h e m i d d l e a r e p r o f u s e ly f o s s i l i f e r o u s . f o l l o w i n g f o s s i l s w e r e c o l l e c t e d i d e n t i f i e d. i d e n t i f i c a t i o n A l v a r o A c o s t a , g r a d u a t e s t u d e nt i n t h e G e o l o g y d e p a r t m e n t t h e U n i v e r s i t y U t a h: D i t o m o p y g e R h o m b o p o r a s p. P o l y p o r a s e v e r a l s p e c i es F e n e s t r e l l i n a S p i r i f e r o c c i d e n t a l i s ( ?) D i c t y o c l o s t u s ( ? ) b a s si P i c t y o c l o s t u s f e r n g l e n e n s i s ( ?) L i t h o s t r o t i o n w h i t n e yi N o r t h t h e S a l t g u l l y e a s t t h e S u l p h ur K i n g o r e b o d y w h e r e t h e O q u i r r h f o r m a t i o n m e a s u r e d , b e ds a r e d u p l i c a t e d f a u l t i n g . i n t e g r a t e d t h i c k n e s s 900 f e e t p l u s o b t a i n e d c o r r e l a t i n g s i m i l a r h o r i z o n s. C r o s b y 6 ) m e a s u r e d t h i c k n e s s f e e t s e c . 3 0 , S . , R o c k s P e r m i a n P a k o o n l i m e s t o n e . P a k o o n l i m e s t o n e i s o v e r l a i n by - 17- limestone. The base of the formation is covered by alluvium. The Oquirrh formation consists mainly of gray to blue­gray fossiliferous limestones interbedded with thin-bedded sandstones, calcareous sandstone beds, and a few dolomite horizons .. At the top the Oquirrh is a light-gray, thick-bedded, fine-grained, sandy limestone in terbedded with massive beds of white chert. Some of the limestone beds near the middle are profusely fossiliferous. The following fossils were collected and identified. The identification was made by Alvaro Acosta, graduate student in the Geology department of the University of Utah: Ditomopyge Rhombopora sp. Polypora several species Fenestrellina S~irifer occidentalis (7) D1ctyoclostus (7) bassi Dictyoclostus fernglenensis (7) Lithostrotion whitneyi North of the Salt Lake gully and east of the Sulphur King orebody where the Oquirrh formation was measured, beds are duplicated by faulting. An integrated thickness of 900 feet plus was obtained by correlating similar horizons. Crosby ( 6) measured a thickness of 949 feet in sec. 30, T. 24 S., R. 6 W. Rocks of Permian Age Pakoon limestone. The Pakoon limestone is overlain by 1 8 - t h e c o n s p i c u o u s r e d s a n d s t o n e q u a r t z i t i c s a n d s t o n e t he P e r m i a n C o c o n i n o f o r m a t i o n. t h e e a s t s l o p e t h e f r o n t r a n g e i m m e d i a t e ly s o u t h w e s t t h e S a l t g u l l y , t h e b a s e t h e P a k o on f o r m a t i o n i s o v e r l a i n u n c o n f o r m a b l y t h e P r i c e R i v e r c o n ­g l o m e r a t e . b e d s s t r i k e 3 0 ° E. d i p 2 0 ° E. P a k o o n f o r m a t i o n i s c o m p o s e d e s s e n t i a l l y l i g h t - g r a y , f i n e - g r a i n e d l i m e s t o n e s w i t h a b u n d a n t b l a c k c h e rt n o d u l e s l e n s e s v e r y d e n s e , r e s i s t a n t l i m e s t o n e . The b a s e c o n s i s t s of 40 f e e t of a s a n d y l i m e s t o n e w i t h b e d d e d, a n g u l a r c h e r t f r a g m e n t s . T h i s i s a c o n s p i c u o u s m a r k e r b e d. No f o s s i l s w e r e f o u n d i n t h e s e s t r a t a. N o r t h t h e S a l t g u l l y t h e P a k o o n m e a s u r e d 206 f e e t . s e c 2 1 , S . , C r o s b y 6 ) m e a s u r e d t h i c k n e s s f e e t. C o c o n i n o s a n d s t o n e . C o c o n i n o q u a r t z i t i c s a n d s t o ne f o r m s s t e e p s l o p e a l o n g t h e r i d g e t h a t d e s c e n d s e a s t w a rd f r om Dog V a l l e y P e a k . I t s r e d d i s h c o l o r i s somewhat masked t h e p r o f u s e v e g e t a t i o n of s c r u b o a k . O u t c r o p s w e r e a l so f o u n d t h e s o u t h w e s t s l o p e t h e h i g h r i d g e e a s t of t he t e r m i n a t i o n of t h e S a l t Lake g u l l y . The b e d s s t r i k e N. 40° E, and d i p 2 7 ° N o r t h of t h e P r i n c e A l b e r t d e p o s i t a s m a ll b l o c k of C o c o n i n o s a n d s t o n e h a s b e e n u p l i f t e d and i s i n f a u lt c o n t a c t w i t h t h e P r i c e R i v e r c o n g l o m e r a t e. T h e C o c o n i n o s a n d s t o n e c o n s i s t s s e r i e s w e l l - b e d d e d , s t r o n g l y f r a c t u r e d , p u r p l e - t o b u f f - c o l o r e d q u a r t z i t ic - 18- the conspicuous red sandstone and quartzit ic sandstone of the Permian Coconino formation. At the east slope of the front range immediately southwest of the Salt Lake gully, the base of the Pakoon formation is overlain unconformably by the Price River con­glomerate. The beds strike N. 300 E . and dip 2Do E. The Pakoon formation is composed essentially of light­gray, fine-grained limestones with abundant black chert nodules and lenses of very dense, resistant limestone. The base consists feet sandy limestone with bedded, angular chert fragments. This is conspicuous marker bed. fossils were found in these strata. North of the Salt Lake gully the Pakoon measured 206 feet. In sec. 21, T. 24 S., R. 6 W. Crosby ( 6) measured a thickness of 174 feet. Coconino sandstone. The Coconino quartzitic sandstone forms a steep slope along the .ridge that descends eastward from Valley Peak. Its reddish color is masked by the profuse vegetation scrub oak. Outcrops were also found on the southwest slope ·of the high ridge east the termination the Salt gully 0 beds strike 400 E. dip 270 E. North the Prince Albert deposit small block Coconino sandstone has been uplifted is in fault contact with the Price River conglomerate. The Coconino sandstone consists of a series of well­bedded, strongly fractured, purple-to buff-colored quartzitic 1 9 - s a n d s t o n e s . b o t t o m t h e s t r a t a w e l l d e f i n e d 100 f e e t r e d s a n d s t o n e s , s a n d y l i m e s t o n e s , d a r k r ed m u d s t o n e s . t h e w e s t s l o p e V a l l e y P e a k t h e t h i c k n e s s of t h e C o c o n i n o s a n d s t o n e i s f e e t . C r o s b y 6 ) m e a s u r e d 288 f e e t f o r t h i s f o r m a t i o n in s e c 3 1 , T. 24 S . , R, 6 W. K a i b a b l i m e s t o n e . K a i b a b l i m e s t o n e f o r m s t h e h i gh r i d g e t h e e a s t w a l l o f V a l l e y c t h e n o r t h e r n p a r t of t h e a r e a t h e K a i b a b l i m e s t o n e i s f a u l t c o n t a c t w i th t h e T e r t i a r y v o l c a n i c s P r i c e R i v e r c o n g l o m e r a t e . F u r t h er n o r t h t h e T r i a s s i c t h i n - b e d d e d , r e d s h a l e s , s a n d s t o n e s, a n d l i m e s t o n e s o v e r l i e t h e K a i b a b l i m e s t o n e t he n o r m a l s e q u e n c e . The K a i b a b w e d g e s o u t t o w a r d t h e s o u th a n d w e s t in t h e v i c i n i t y of t h e M a r i p o s a p r o s p e c t p i t. West of t h i s p i t t h e K a i b a b f o r m a t i o n o v e r l i e s c o n f o r m a b ly t h e C o c o n i n o q u a r t z i t i c s a n d s t o n e. b e d s i n t h e n o r t h e r n p a r t s t r i k e 10° d ip 34° t h e v i c i n i t y t h e S p r i n g s f a u l t t h e s t r i ke c h a n g e s t o N. 4 5 ° E. and t h e s t r a t a d i p 30° t o 4 5 ° E. Near t h e t o p of t h e s e c t i o n t h e b e d s a r e m a s s i v e , l i g h t - g r a y , and c o a r s e l y c r y s t a l l i n e l i m e s t o n e. R e c r y s t a l l i z e d c r i n o i d a l l i m e s t o n e s , s a n d y d o l o ­m i t e h o r i z o n s , w h i t e q u a r t z i t e b e d s a r e i n t e r b e d d e d w i th d a r k - g r a y , g r a i n e d l i m e s t o n e s . l i m e s t o n es n o t a b l y h a v e a b u n d a n t s t r e a k s n o d u l e s d e n s e , c h e m i c a l ly - 19- sandstones. The bottom of the strata i s well defined by 100 feet of red sandstones, sandy limestones, and dark red mudstones. On the west slope of Dog Valley Peak the thickness of the Coconino sandstone is 594 feet. Crosby ( 6) measured 288 feet for this formation sec. 31, S., R. Kaibab limestone. The Kaibab limestone forms the high ridge of the east wall of Dog Valley. In the northern part of the area mapped the Kaibab limestone is in fault contact with the Tertiary volcanics and Price River conglomerate. Further north the Triassic Moenkopi thin-bedded, red shales, sandstones, and limestones overlie the Kaibab limestone ' in the normal sequence. Kaibab wedges out toward the south and west the vicinity the Mariposa prospect pit. this pit the Kaibab formation overlies conformably the Coconino quartzitic sandstone. The beds in the northern part strike N. 100 E. and dip 340 E. In the vicinity of the Soap Springs f~u1t the strike changes to 450 the strata dip 300 to 450 Near the top the section the beds are massive, light-gray, and coarsely crystalline limestone. Recrystallized crinoidal limestones, some sandy dolo­mite horizons, and white quartzite beds are interbedded with dark-gray, medium grained limestones. These limestones notably have abundant streaks and nodules of dense, chemically - 2 0 - r e s i s t a n t l i m e s t o n e t h a t w e a t h e r s brown a n d s t a n d s o u t in r e l i e f . t h e b o t t o m t h e s e c t i o n t h e l i m e s t o n e i s d a rk g r a y , c o a r s e l y c r y s t a l l i n e , f o s s i l i f e r o u s . O n l y f e w c u p c o r a l s c r i n o i d s t e m s w e r e c o l l e c t ed n e a r t h e t o p t h e f o r m a t i o n . U n f o r t u n a t e l y i t n ot p o s s i b l e t o i d e n t i f y t h e s e f o s s i l s . T h e t h i c k n e s s t h e K a i b a b l i m e s t o n e t h e w e s t s l o pe V a l l e y P e a k i s f e e t . 6 ) m e a s u r e d t h i c k ­n e s s 1 , 1 9 3 f e e t s e c . 2 8 , T„ S . , R o c k s C r e t a c e o u s Age P r i c e R i v e r c o n g l o m e r a t e . P r i c e R i v e r c o n g l o m e r a te c a p s t h e r i d g e n o r t h e a s t F o r t . t h e S a l t Lake g u l l y o u t c r o p s t h e c o n g l o m e r a t e a b r u p t l y s w i n g e a s t w a rd f i n a l l y d i s a p p e a r i n g u n d e r c o v e r v o l c a n i c s . t h e e a st s i d e t h e S o a p S p r i n g s f a u l t , t h e c o n g l o m e r a t e r e a p p e a rs a g a i n i n n o r t h e a s t - t r e n d i n g r i d g e s n e a r t h e M a r i p o s a and P r i n c e A l b e r t p i t s. S o u t h t h e E x c e l s i o r o r e b o d y t h e P r i c e R i v e r c o n g l o m ­e r a t e i s i n f a u l t c o n t a c t w i t h t h e v o l c a n i c r o c k s . t he f a u l t t h e c o n g l o m e r a t e i s d i f f i c u l t r e c o g n i z e t o s t r o ng s i l i c i f i c a t i o n b r e c c i a t i o n. T h e c o n g l o m e r a t e b e d s g e n e r a l l y s t r i k e 30° and d i p 2 5 ° t o 30° SE. F a u l t i n g h a s d i s t u r b e d t h e b e d s n e a r t he E x c e l s i o r o r e b o d y w h e r e t h e y s t r i k e 6 5 ° d i p 2 0 ° P r i c e R i v e r c o n g l o m e r a t e c o n s i s t s s u b - r o u n d ed 20- resistant limestone that weathers bro \,ffi and .stands out in relief. At the bottom of the section the limestone is dark gray, coarsely crystalline, and fossiliferous. Only a few cup corals and crinoid stems were collected near the top of the formation. Unfortunately it was not possible to identify these fossils o The thickness of the Kaibab limestone on the west slope of Dog Valley Peak is 905 feet . Crosby ( 6) measured a thick­ness of 1,193 feet in sec. 28, T. 24 S., R. 6 W. Rocks of Cretaceous Age Price River conglomerate. The Price River conglomerate caps the ridge northeast of Cove Fort. South of the Salt Lake gully outcrops of the conglomerate abruptly swing eastward finally disappearing under a cover of volcanics. On the east side of the Soap Springs fault, the conglomerate reappears again in northeast-trending ridges near the Mariposa and Prince Albert pits. South of the Excelsior orebody the Price River conglom­erate is in fault contact with the volcanic rocks. Near the fault the conglomerate is difficult to recognize due to strong silicification and brecciation. The conglomerate beds generally strike N. 300 E. and dip 250 to 300 SED Faulting has disturbed the beds near the Excelsior orebody where they strike N. 650 W. and dip 200 SW. The Price River conglomerate consists of sub-rounded - 2 1 - c o b b l e s b o u l d e r s d a r k - g r a y l i m e s t o n e p u r p l e to w h i t e q u a r t z i t e . s a n d y h o r i z o n w i t h s u b - r o u n d e d l i m e s t o ne g r a n u l e s o u t c r o p s i n t h e h i l l s i d e a b o v e t h e V i c t o r ia p r o s p e c t d i g g i n g s . The v o i d s b e t w e e n t h e s a n d g r a i n s a re f i l l e d w i t h r e d , h e m a t i t i c c e m e n t . s a n d y h o r i z o n r e p r e s e n t c h a n n e l s w i t h i n t h e c o n g l o m e r a t e b l a n k e t . It o u t c r o p s c o n s i s t e n t l y a b o v e t h e s u l p h u r d e p o s i t s i n c o n g l o m e r ­a t e . t h e E x c e l s i o r o r e b o d y t h e P r i c e R i v er c o n g l o m e r a t e h a s an e s t i m a t e d t h i c k n e s s of 450 f e e t . This t h i c k n e s s was c a l c u l a t e d f r o m a e r i a l p h o t o g r a p h s. R o c k s of T e r t i a r y Age V o l c a n i c f l o w s p y r o c l a s t i c s . T e r t i a ry v o l c a n i c r o c k s c o v e r t h a n t w o - t h i r d s t h e a r e a . The h i g h m o u n t a i n f r o n t e a s t S u l p h u r d a l e i s c o m p o s e d e n t i r e ly v o l c a n i c r o c k s r i s e s a t l e a s t 3 , 0 0 0 f e e t a b o v e t he v a l l e y f l o o r . North of U t a h H i g h w a y 13 t h e v o l c a n i c s h a v e low r e l i e f and o c c u p y n o r t h - t r e n d i n g r i d g e s . In t h i s a r e a t he v o l c a n i c r o c k s c a p t h e c o n g l o m e r a t e . E a s t of t h e E x c e l s i or d e p o s i t t h e v o l c a n i c r o c k s o v e r l a p t h e P r i n c e A l b e r t f a u lt a d v a n c i n g n o r t h and e a s t i n t o t h e S o u t h P a v a n t R a n g e. T h e v o l c a n i c f l o w s s t u d i e d i n t h i n s e c t i o n i n c l u de q u a r t z l a t i t e p o r p h y r y , l a t i t e p o r p h y r y , a n d e s i t e p o r p h y r y, a n d a n d e s i t e v i t r o p h y r e . t h e f i e l d a l l t h e f l o w r o c k s a re p o r p h y r i t i c w i t h p h e n o c r y s t s of p l a g i o c l a s e f e l d s p a r in a 21- cobbles and boulders of dark-gray limestone and purple to white quartzite. A sandy horizon with sub-rounded limestone granules outcrops in the hillside above the Queen Victoria prospect diggings. voids between the sand grains are filled with a red, hematitic cement. This sandy horizon may represent channels within the conglomerate blanket. It outcrops consistently above the sulphur deposits in conglomer­ate. West of the Excelsior orebody the Price River conglomerate has estimated thickness feet. This thickness calculated from aerial photographs. Rocks Tertiary Age Volcanic flows and pyroclastics. The Tertiary volcanic rocks cover more than two-thirds of the area. The high mountain front east of Sulphurdale is composed entirely of volcanic rocks and rises at least 3,000 feet above the valley floor. Utah Highway the volcanics have relief occupy north-trending ridges. this area the volcanic rocks cap the conglomerate. East the Excelsior deposit the volcanic rocks overlap the Prince Albert fault advancing north east into the South Pavant Range. The volcanic flows studied in thin section include quartz latite porphyry, latite porphyry, andesite porphyry, and andesite vitrophyre. In the field all the flow rocks are porphyritic with phenocrysts plagioclase feldspar - 2 2 - g r o u n d m a s s t h a t v a r i e s in c o l o r f r o m d a r k g r a y t o p i n k i sh b r o w n . t h e m i c r o s c o p e , p h e n o c r y s t s a l i g n m e n t. The g r o u n d m a s s i s v e r y f i n e , l e s s t h a n 0 . 0 1 a n d is p r o b a b l y c o m p o s e d of f e l d s p a r l a t h s . Some of t h e a n d e s i ne p h e n o c r y s t s a r e z o n e d w i t h o r t h o c l a s e r i m s . B i o t i t e p h e n o ­c r y s t s h a v e p o i k i l i t i c p l a g i o c l a s e and z i r c o n. T h e q u a r t z l a t i t e r o c k s w e r e f o u n d e a s t S u l p h u r d a le a t p l a c e c a l l e d P o i n t . M e g a s c o p i c a l l y , t h e s e r o c ks a r e g r e e n i s h brown and h a v e p l a g i o c l a s e and p o t a s h p h e n o c y s ts i n a v e r y f i n e , d e n s e g r o u n d m a s s . C r a c k s and v u g s a r e f i l l ed o r l i n e d w i t h o p a l and q u a r t z c r y s t a l s . M i c r o s c o p i c a l l y, t h e e s s e n t i a l m i n e r a l s i d e n t i f i e d and t h e i r r e l a t i v e p r o p o r ­t i o n s a r e as f o l l o w s : a n d e s i n e , 45 p e r c e n t ; o r t h o c l a s e , 40 p e r c e n t ; and q u a r t z , 10 p e r c e n t . A c c e s s o r y m i n e r a l s a re b i o t i t e and m a g n e t i t e . A l t e r a t i o n h a s p r o d u c e d i n c i p i e nt c a r b o n a t e . N o r t h o f t h e P r i n c e A l b e r t p i t e a s t t h e Soap S p r i n g s f a u l t t h e v o l c a n i c r o c k s a r e m a i n l y l a t i t e p o r p h y r y. H e r e t h e y a l s o o v e r l i e t h e c o n g l o m e r a t e . M e g a s c o p i c a l l y, t h e p l a g i o c l a s e and p o t a s h f e l d s p a r p h e n o c r y s t s show c o n s p i c ­u o u s f l o w s t r u c t u r e . The g r o u n d m a s s i s p i n k i s h brown and f i n e - t e x t u r e d . M i c r o s c o p i c a l l y , t h e e s s e n t i a l m i n e r a ls o b s e r v e d and t h e i r r e l a t i v e p r o p o r t i o n s a r e a s f o l l o w s: a n d e s i n e up t o 4 mm., 35 p e r c e n t ; o r t h o c l a s e up t o 2 mm., 30 p e r c e n t ; q u a r t z , l e s s t h a n 5 p e r c e n t . M a g n e t i t e i s t he more i m p o r t a n t a c c e s s o r y m i n e r a l . The f e l d s p a r p h e n o c r y s ts 22- groundmass that varies In color from dark gray to pinkish brown. Under the microscope, phenocrysts show alignment. groundmass is very fine, less than 0.01 mm., and is probably composed feldspar laths. the andesine phenocrysts are zoned with orthoclase rims. Biotite pheno­crysts have poiki1itic plagioclase zircon. The quartz 1atite rocks were found east of Su1phurda1e at a place called Rocky Point. Megascopica11y, these rocks are greenish have plagioclase potash phenocysts in very fine, dense groundmass. Cracks vugs are filled or lined with opal quartz crystals. Microscopically, the essential minerals identified th~ir relative propor­tions are follows: andesine, per cent; orthoclase, 40 per cent; quartz, per cent. Accessory minerals are biotite magnetite. Alteration has produced incipient carbonate. North of the Prince Albert pit and east of the Soap Springs fault the volcanic rocks are mainly latite porphyry. Here they also overlie the conglomerate. Megascopica11y, the plagioclase potash feldspar phenocrysts conspic­uous flow structure. groundmass is pinkish and fine-textured. Microscopically, the essential minerals observed their relative proportions are as follows: andesine to per cent; orthoclase to per cent; quartz, less than per cent. Magnetite is the more import~nt accessory mineral. The feldspar phenocrysts 2 3 - a r e s p e c k l e d w i t h c l a y m i n e r a l s . C a l c i i s v e r y p r o m i n e n t. Some c h l o r i t e was a l s o o b s e r v e d . The g r o u n d m a s s i s m i c r o - c r y s t a l l i n e , 0 . 1 0 . 0 1 p o s s i b l y c o n t a i n s l a t h s of p l a g i o c l a s e c r y s t a l l i t e s. T h e a n d e s i t e p o r p h y r y o b s e r v e d o v e r l y i n g t he c o n g l o m e r a t e w e s t t h e M a r i p o s a p r o s p e c t p i t . t h i s a r ea t h e v o l c a n i c r o c k s a r e o n l y a b o u t 100 f e e t t h i c k . M e g a s c o p ic a l l y , t h e s e r o c k s a r e d a r k g r a y , d e n s e w i t h p l a g i o c l a se f e l d s p a r and h o r n b l e n d e p h e n o c r y s t s i n a v e r y f i n e g r o u n d m a ss The p h e n o c r y s t s show m a r k e d f l o w s t r u c t u r e . M i c r o s c o p i c a l l y, t h e e s s e n t i a l m i n e r a l s a n d t h e i r r e l a t i v e p r o p o r t i o n s a re a n d e s i n e p h e n o c r y s t s 2 t o 3 mm., 15 p e r c e n t ; q u a r t z , l e ss t h a n 5 p e r c e n t ; and h o r n b l e n d e , a b o u t 4 p e r c e n t . B i o t i te i s an a c c e s s o r y m i n e r a l . The g r o u n d m a s s i s m i c r o c r y s t a l l i n e, l e s s t h a n 0 . 0 1 mm., and p o s s i b l y c o n s i s t s of p l a g i o c l a se f e l d s p a r . The i n d e x o f r e f r a c t i o n of t h e g r o u n d m a s s is g r e a t e r t h a n t h a t of b a l s a m . A l t e r a t i o n of t h e f e r r o m a g - n e s i u m m i n e r a l s h a s p r o d u c e d m i n o r b i o t i t e and p y r i t e. T h e a n d e s i t e v i t r o p h y r e o u t c r o p s t h e h i l l s n o r t h t h e s u l p h u r d a l e p i t . M e g a s c o p i c a l l y , t h e s e r o c ks a r e g r e e n w i t h p i n k b a n d s . P l a g i o c l a s e p h e n o c r y s t s p r o n o u n c e d f l o w s t r u c t u r e . M i c r o s c o p i c a l l y , t h e e s s e n t i al m i n e r a l s t h e i r r e l a t i v e p r o p o r t i o n s a r e a n d e s i n e p h e n o ­c r y s t s g r e a t e r t h a n 2 mm., 24 p e r c e n t ; q u a r t z , l e s s t h a n 5 p e r c e n t . M a g n e t i t e i s an i m p o r t a n t a c c e s s o r y m i n e r a l . The g r o u n d m a s s i s m i c r o c r y s t a l l i n e , l e s s t h a n 0 . 0 1 mm., and - 23 ... are speckled with clay minerals. Calci t e is very prominent. chlorite also observed. groundmass is micro­crystalline, 0.1 to 0.01 mm., and possibly contains laths of plagioclase crystallites. The andesite porphyry was observed overlying the conglomerate west of the Mariposa prospect pit. In this area the volcanic rocks are only about feet thick. Megascopic­ally, these rocks are dark gray, dense with plagioclase feldspar hornblende phenocrysts in very fine groundmass. phenocrysts marked flow structure. Microscopically, the essential minerals and their relative proportions are andesine phenocrysts to per cent; quartz, less than per cent; hornblende, about per cent. Biotite is accessory mineral. groundmass is microcrystalline, less than 0.01 possibly consists plagioclase feldspar. index of refraction the groundmass is greater than that balsam. Alteration the ferromag­nesium minerals has produced minor biotite pyrite. The andesite vitrophyre outcrops in the low hills north of the sulphurdale pit. Megascopically, these rocks are green with pink bands. Plagioclase phenocrysts show pronounced flow structure. Microscopically, the essential minerals and their relative proportions are andesine pheno­crysts greater than per cent; quartz, less than per cent. Magnetite is important accessory mineral. groundmass is mic.1:rocrystalline, less than 0.01 2 4 - h y a l i n e . g l a s s y g r o u n d m a s s s h o w s p r o n o u n c e d f l ow s t r u c t u r e . g l a s s y b a n d s a l t e r n a t e w i t h b a n d s an a p h a n i t i c m i c r o c r y s t a l l i n e g r o u n d m a s s . b a n d s h a ve a b u n d a n t , i n c i p i e n t , a c i c u l a r m a g n e t i t e c r y s t a l s. p y r o c l a s t i c r o c k s s t u d i e d t h i n s e c t i o n i n c l u de w e l d e d t u f f s l i t h i c l a p i l l i t u f f s . t h e Soap S p r i n g s f a u l t t h e p y r o c l a s t i c s g e n e r a l o v e r l i e t h e v o l c a n ic f l o w s . h i l l f e e t n o r t h S u l p h u r d a l e o u t c r o p s r e d , v e s i c u l a r , w e l d e d t u f f . M e g a s c o p i c a l l y , t h e w e l d e d t u ff c o n t a i n s d a r k r e d , a n g u l a r , p o r o u s f r a g m e n t s . Some s a n i d i ne p h e n o c r y s t s a r e a l s o i d e n t i f i a b l e . M i c r o s c o p i c a l l y , t he e s s e n t i a l m i n e r a l s and t h e i r r e l a t i v e p r o p o r t i o n s a r e g l a ss s h a r d s , 80 p e r c e n t ; s a n i d i n e p h e n o c r y s t s , 5 p e r c e n t ; and q u a r t z f r a g m e n t s , 5 p e r c e n t . A l s o , h e m a t i t e w h i c h f i l ls t h e p o r e s and c r a c k s , and p y r i t e w e r e o b s e r v e d. l i t h i c l a p i l l i t u f f s a m p l e c o l l e c t e d t o p of t h e r i d g e e a s t t h e P h i l a d e l p h i a p r o s p e c t p i t . h a nd s p e c i m e n t h i s r o c k c o n t a i n s g r e e n , a n g u l a r , l i t h i c f r a g m e n ts l e s s t h a n 32 mm, i n a r e d , a p h a n i t i c g r o u n d m a s s . Under t he m i c r o s c o p e t h e g r e e n f r a g m e n t s h a v e p e r c e n t a n d e s i ne p h e n o c r y s t s in a v e r y f i n e , l e s s t h a n 0.1 mm., g r o u n d m a s s of p l a g i o c l a s e l a t h s . The r e d g r o u n d m a s s a l s o shows a n d e s i ne p h e n o c r y s t s , 15 p e r c e n t , and a n g u l a r f r a g m e n t s of q u a r t z. H e m a t i t e v e i n l e t s and c l a y a l t e r a t i o n of t h e f e l d s p a r s a re p r o m i n e n t . - 24- hyaline. The glassy groundmass shows pro nounced flow structure. The glassy bands alternate with bands of an aphanitic microcrystalline groundmass. These bands have abundant, incipient, acicular magnetite crystals. The pyrocl~stic rocks studied in thin section include welded tuffs and l~thic 1apilli tuffs. West of the Soap Springs fault the pyroclastics in general overlie the volcanic flows. On a hill 300 feet north of Su1phurda1e outcrops a red, vesicular, welded tuff. Megascopical1y, the welded tuff contains dark red, angular, porous fragments. sanidine phenocrysts are also identifiable. Microscopically, the essential minerals their relative proportions are glass shards, per cent; sanidine phenocrysts, per cent; and quartz fragments, per cent. Also, hematite which fills the pores cracks, pyrite were observed. A lithic 1api11i tuff sample was collected on top of the ridge east of the Philadelphia prospect pit. In hand specimen this rock contains green, angular, lithic fragments less than mm. in red, aphanitic groundmass. the microscope the green fragments have 20 per cent andesine phenocrysts very fine~ less than groundmass of plagioclase laths. red groundmass so andesine phenocrysts, per cent, angular fragments quartz. Hematite vein1etsand clay alteration the feldspars are prominent. 2 5 - Q u a r t z v e i n s w i t h m i n o r a m o u n t s g o l d s i l v e r a re f o u n d i n w i d e e a s t - t r e n d i n g s o u t h t h e P r i n c e A l b e rt f a u l t . v o l c a n i c r o c k s w i t h i n t h i s a r e s t r o n g ly k a o l i n i z e d . P r o p y l i t i z a t i o n i s a l s o p r o n o u n c e d w i t h i n t h is z o n e . R o c k s P l e i s t o c e n e t o R e c e n t Age B a s a l t f l o w s c i n d e r c o n e s . b a s a l t f l o w s and c i n d e r c o n e s a r e o u t s i d e t h e a r e a b a s a l t f l o ws o u t c r o p i n t h e v a l l e y d i r e c t l y w e s t S u l p h u r d a l e . Wells d r i l l e d a t Cove F o r t and Dog V a l l e y h a v e i n t e r s e c t e d t he b a s a l t a t s h a l l o w d e p t h and c o n t i n u e d down t o 200 f e e t. T h e c i n d e r c o n e i n t h e v i c i n i t y of S u l p h u r d a l e r i s es o v e r 1 , 0 0 0 f e e t a b o v e t h e l e v e l t h e v a l l e y . f a ct t h a t t h e c r a t e r i s o n l y s l i g h t d e p r e s s i o n i n d i c a te p e r h a p s t h a t t h e c i n d e r a t t a i n e d h i g h e r e l e v a t i o n in t h e p a s t s e e F i g u r e p a g e 3 3 ). b a s a l t i s b l a c k v e s i c u l a r . c i n d e r s a re r e d b l a c k w i t h n u m e r o u s g a s v e s i c l e s . W a t e r - l a i d t u f f s . r o c k f o r m a t i o n i s b e s t e x p o s ed i n t h e S u l p h u r d a l e p i t . i s o l a t e d o u t c r o p s h a v e b e en f o u n d t o w a r d t h e n o r t h . S i m i l a r r o c k s w e r e f o u n d i n s h a l l ow p i t s a t t h e V i c t o r C o n q u e r o r o r e b o d y. w a t e r - l a i d t u f f s a r e w e l l - s t r a t i f i e d i n t e r ­b e d d e d w i t h t h i n l a y e r s o r l e n s e s b l a c k s i l t y b e d s. - 25- Quartz veins with minor amounts of gold and silver are found in a wide east-trehding zone south of the Prince Albert fault. The volcanic rocks within this zone are strongly kaolinized. Propylitization is also pronounced within this zone. Rocks of Plei~tocene to Recent Age Basalt flows· and cinder cones. The basalt flows and cinder cones are outside of the area mapped. The basalt flows outcrop in the valley directly west of Sulphurdale. Wells drilled at Fort Valley have intersected the basalt at shallow depth ~ontinued to feet. The cinder cone in the vicinity 6f Sulphurdale rises over 1,000 feet above the level of the valley. The fact that the crater is now only a slight depression may indicate perhaps that the cinder cone attained a higher elevation in the past ( see Figure 4, page 33). The basalt is black and vesicular. The cinders are red and black with numerous gas vesicles. Water-laid tuffs. This rock formation is best exposed in the Sulphurdale pit. Other isolated outcrops have been found toward the north. Similar rocks were found in shallow pits at the ' Victor Conqueror orebody. The water-laid tuffs are well- stratified and inter­bedded with thin layers or lenses of black mud and silty beds. - 2 6 - W h i t e , s u l p h u r - b a r r e n , s i l i c e o u s s i n t e r l a y e r s a r e a l so i n t e r s t r a t i f i e d w i t h t h e t u f f„ w a t e r - l a i d t u f f i s c o m p o s e d p o o r l y s o r t e d, w h i t e , v e r y p o r o u s f r a g m e n t s t u f f s a n d c e m e n t e d w i th e l e m e n t a l s u l p h u r . t h e l a y e r s a r e t h i n - b e d d e d and f r e e of p e b b l e s . The t h i c k e r l a y e r s h a v e a b u n d a n t s u b - r o u n d ed p e b b l e s c o b b l e s p o r p h y r i t i c v o l c a n i c r o c k s . These p e b b l e s a r e c o l o r e d w h i t e , g r e e n , and r e d . The p e b b l e s a re h i g h l y s i l i c i f i e d w h e r e s u l p h u r i s a b u n d a n t . The s i l t c o n t e nt o f t h e b e d s seems t o i n c r e a s e away f r om t h e m o u n t a i n f r o n t. T h e t u f f b e d s h a v e t h i c k n e s s t o f e e t . This i s an e s t i m a t e d t h i c k n e s s o b t a i n e d f r o m o u t c r o p s a n d c o re d r i l l i n g s a m p l e s. A l l u v i u m . A l l u v i u m n c l u d e s v a l l e y f i l l , s t r e am g r a v e l s , b e n c h g r a v e l s , a l l u v i a l f a n r e m n a n t s , l a n d s l i de m a s s e s . G e n t l e s l o p e s of s a n d , s i l t , and g r a v e l c o v e r t he b e d r o c k a l o n g t h e m o u n t a i n f r o n t and main s t r e a m c o u r s e s. N o r t h t h e P r i n c e A l b e r t d e p o s i t b l a n k e t s i lt a n d v o l c a n i c r o c k f r a g m e n t s c a p t h e low r i d g e s o b s c u r i n g t he a c t u a l e x t e n t of t h e s e d i m e n t a r y r o c k s . On t o p of t h e r i d ge s o u t h and w e s t of t h e M a r i p o s a p r o s p e c t p i t q u a r t z i t i c s a n d ­s t o n e b l o c k y f r a g m e n t s a r e s p r e a d p r o f u s e l y o v e r t h e P r i ce R i v e r c o n g l o m e r a t e. A n g u l a r f r a g m e n t s l i m e s t o n e p r e s e r v e d a t t h e S u l p h ur K i n g d e p o s i t a n d B l a c k h a v e p r o b a b l y r e s u l t e d f r om t he 26- '~ite, sulphur-barren, siliceous sinte layers are also interstratified with the tuff. The water-laid tuff is composed of poorly sorted, white, very porous fragments of tuff and sand cemented with elemental sulphur. Some of the layers are thin-bedded and free pebbles. thicker layers have abundant sub-rounded pebbles and cobbles of porphyritic volcan ic rocks. These pebbles are colored white, green, red. pebbles are highly silicified where sulphur is abunaant. silt content of the beds to increase from the mountain front. The tuff beds have a thickness of 60 to 100 feet. This 1S estimated thickness obtained from · outcrops and core drilling samples. Alluvium. Alluvium i ncludes valley fill, stream gravels, bench gravels, alluvial fan remnants, and landslide masses. Gentle slopes sand, silt, gravel cover the bedrock along the mountain front stream courses. North of the Prince Albert deposit a blanket of silt and volcanic rock fragments cap the ridges obscuring the actual extent the sedimentary rocks. top the ridge south west the Mariposa prospect pit quartzitic sand­stone blocky fragments are spread profusely over the Price River conglomerate. Angular fragments of limestone preserved at the Sulphur King deposit and Black Mine have probably resulted from the - 2 7 - a c c u m u l a t i o n of b r e c c i a a t t h e f o o t of a f a u l t . One m i le s o u t h of S u l p h u r d a l e r e c e n t movement of t h e f a u l t b l o c k s h as p r o d u c e d l a r g e l a n d s l i d e m a s s e s. I I . STRUCTURE F a u l t s s t r i k e 15° t o 75° d i p s t e e p ly t o t h e e a s t , w e s t , and s o u t h . They h a v e f o r m e d a s e r i e s of u p l i f t e d s t e p - f a u l t e d b l o c k s and a g r a b e n. T h e n o r m a l f a u l t s o f f s e t T e r t i a r y - Q u a t e r n a r y S e v i er R i v e r s e d i m e n t s a l o n g t h e e a s t e r n e d g e V a l l e y ( 6 ). A l o n g t h em s o u t h S u l p h u r d a l e , c a n y o n s h a v e d e e p T TVn s h a p e t h e i r o u t l e t s a r e c o n s t r i c t e d . t h e s e f a u lt z o n e s l a n d s l i d e s t h e r m a l s p r i n g s p o i n t c o n t i n u o u s or r e c u r r e n t u n r e s t f r o m t h e T e r t i a r y to t h e p r e s e n t t i m e. C o n j u g a t e j o i n t s w e r e o b s e r v e d i n t h e v o l c a n i c r o c ks e a s t S u l p h u r d a l e . s e t h a s s t r i k e 3 5 ° and v e r t i c a l d i p ; t h e o t h e r s e t s t r i k e s d i p s 85° S u l p h u r d e p o s i t s a r e s p a t i a l l y r e l a t e d t o t h e f a u l t s. T h e s e f a u l t s s e r v e d c h a n n e l s f o r t h e t h e r m a l s p r i n g s t h at w e r e a c t i v e d u r i n g a f t e r t h e l a t e v o l c a n i s r a . t h e r m al s p r i n g w a t e r s c a r r i e d t h e s u l p h u r t h a t d e p o s i t e d t he p o r o u s b e d s t h e w a t e r - l a i d t u f f , t h e q u a r t z i t e - l i m e s t o ne c o n g l o m e r a t e , t h e r e c e n t b r e c c i a t a l u s s l o p e s . F o l l o w i ng i s a d i s c u s s i o n of t h e more i m p o r t a n t f a u l t s in t h e a r e a. F r o n t R.ange F a u l ts T h e w e s t e r n b o r d e r t h e T u s h a r M o u n t a i n s S o u th -27- accumulation breccia at the foot ault. mile south Sulphurdale recent the fault blocks has produced large landslide masses. II. STRUCTURE Faults strike N. 150 E. to N. 750 E. and dip steeply to the east, west, south. have formed series of uplifted step-faulted blocks graben. The normal faults offset Tertiary-Quaternary Sevier River sediments along the eastern edge of Dog Valley (6). Along them and south of Sulphu rdale, canyons have a deep ltV" shape and their outlets are constricted. Near these fault zones landslides and thermal springs point to continuous or recurrent unrest from the Tertiary the present time. Conjugate joints were observed in the volcanic rocks east of Sulphurdale. One set has a strike of N. 350 E. and a vertical dip; the other set strikes N. 55° W. and dips 850 S. Sulphur deposits are spatially related to the faults. These faults served as channels for the thermal springs that were active during and after the late volcanism. The thermal spring waters carried the sulphur that was deposited in the porous beds of the water-laid tuff, the quartzite-limestone conglomerate, and the recent breccia talus slopes. Following is discussion the important faults the area. Front Range Faults The western border of the Tushar Mountains and South 2 8 - P a v a n t a r e d e f i n e d l a r g e a u l t s c t h e se f a u l t s s t r i k e s 25° d i p s 55° E. a t t h e s i t e t he S o a p S p r i n g s . l e d g e c o m p l e t e l y s i l i c i f i e d and b r e c c i a t ed v o l c a n i c r o c k c o n s p i c u o u s s i i c k e n s i d e s . T h i s f a u l t has b e e n t r a c e d t h e a e r i a l p h o t o g r a p h s n o r t h U t a h h i g h w a y 13 a n d t h e n r e c o g n i z e d a g a i n d e e p g u l l y n o r t h e a s t t he M a r i p o s a p r o s p e c t . At t h i s p o i n t t h e K a i b a b l i m e s t o n e h as b e e n s t r o n g l y s i l i c i f i e d and f r a c t u r e d . The t o p o g r a p h ic s a d d l e a t t h e b o t t o m of t h e e a s t s l o p e of Dog V a l l e y P e a k is p r o b a b l y on t h i s f a u l t . An u p l i f t e d b l o c k of K a i b a b l i m e s t o ne o u t c r o p s w e s t of t h e f a u l t . On t h e e a s t s i d e , C r e t a c e o us P r i c e R i v e r c o n g l o m e r a t e o v e r l a i n by T e r t i a r y v o l c a n i cs f o r m s t h e d o w n d r o p p e d b l o c k. e a s t s i d e t h e S u l p h u r d a l e o r e b o d y i s b o u n d by f a u l t t h a t p a r a l l e l s t h e m a o r f a u l t d e s c r i b e d a b o v e . The f a u l t t r a c e i s v i s i b l e s o u t h w a r d a l o n g t h e f r o n t t he T u s h a r M o u n t a i n s ; b u t n o r t h w a r d i t s t r a c e h a s b e e n o b l i t e r ­a t e d by t h e e r o s i o n of t h e r e l a t i v e l y s o f t v o l c a n i c r o c k s. N o r t h e a s t of Cove F o r t t h i s f a u l t c o n t i n u e s a t t h e f o o t of t h e e s c a r p m e n t f o r m e d u p l i f t e d b l o c k P a l e o z o ic s e d i m e n t s . Two s u l p h u r d e p o s i t s and t h e f l u o r s p a r p r o s p e c ts a r e l o c a t e d on t h i s f a u l t z o n e . It a l s o i s m a r k e d by o u t ­c r o p s of s i l i c i f i e d and b r e c c i a t e d r o c k f o u n d at t h e b a s e of t h e e s c a r p m e n t . North of t h e B l a c k M i n e , C r o s b y ( 6 ) has mapped t h i s f a u l t or a b r a n c h of i t w h i c h o f f s e t s T e r t i a r y - Q u a t e r n a r y h i g h l e v e l g r a v e l s. - 28- Pavant Range are defined by large f ault s . One of these faults strikes N. 250 E. and dips ~5° E . at the site of the Soap Springs. A ledge of completely silicified a nd brecciated volcanic rock shows conspicuous slickensides. This fault has been traced in the aerial photographs north of Utah highway 13 and then recognized again in a deep gully northeast of the Mariposa prospect. this point the Kaibab limestone has been strongly silicified fractured . topographic saddle at the bottom the east slope Valley Peak is probably this fault. uplifted block Kaibab limestone outcrops west the fault . the east side 9 Cretaceous Price River conglomerate overlain Tertiary vOlcanics forms the downdropped block. The east side of the Su lphurdale orebody is bound by a fault that parallels the ma j or fault described above. The fault trace is visible southward along the front of the Tushar Mountains; but northward its trace has been obliter­ated the erosion the relatively soft volcanic rocks. Northeast Fort this fault continues at the foot of the escarpment formed by an uplifted block of Paleozoic sediments. sulphur deposits the fluorspar prospects are located this fault zone. lso is marked out­crops silicified brecciated rock found the base of the escarpment . the Black Mine, Crosby 6) has this fault o r branch it which offsets Tertiary­Quaternary high level gravels. 2 9 - E a s t t h e S u l p h u r d e p o s i t b r a n c h f a u l ts w e r e l o c a t e d r e c o g n i z i n g r e p e t i t i o n t h e s t r a t a t he O q u i r r h f o r m a t i o n . f a u l t s s t r i k e a p p r o x i m a t e l y n o r th a n d j o i n t h e f a u l t t h e v i c i n i t y t h e F l u o r s p ar p r o s p e c t . P r i n c e A l b e r t F a u lt A b o u t f e e t s o u t h t h e E x c e l s i o r d e p o s i t , f a u lt t r e n d i n g 75° p r o b a b y d i p p i n g s t e e p l y t o t h e s o u th s h a r p c o n t a c t P r i c e R i v e r c o n g l o m e r a t e t he n o r t h T e r t i a r y v o l c a n i c s t h e s o u t h. H y d r o t h e r m a l s o l u t i o n s f l o w i n g o n g t h i s f a u l t have p r o d u c e d w i d e z o n e t e n s e s i l i c i f i c a t i o n t h e c o n g l o m ­e r a t e p r o p y l l i t i z a t i o n t h e v o l c a n i c s. P h i l a d e l p h i a p r o s p e c t p i t i s t h e w e s t of t h e P r i n c e A l b e r t f a u l t . P r i n c e A l b e r t f a u l t t he S o a p S p r i n g s f a u l t i n t e r s e c t w i t h n o t i c e a b l e d i s p l a c e m e nt o b s e r v e d e i t h e r t h e f i e l d t h e a e r i a l p h o t o g r a p h s. I n t e n s e s i l i c i f i c a t i o n f r a c t u r i n g t h e r o c k s was o b s e r v e d a l o n g an e a s t - t r e n d i n g f a u l t n o r t h w e s t of t h e P r i n ce A l b e r t p i t . This f a u l t h a s u p l i f t e d a s m a l l b l o c k of P e r m i an C o c o n i n o s a n d s t o n e. E x c e l s i o r F a u lt A n o t h e r l a r g e f a u l t l o c a t e d b o u t 2 , 0 0 0 f e e t e a st o f t h e B l a c k M i n e t h i s p o i n t , t h e O q u i r r h f o r m a t i o n is s t r o n g l y s i l i c i f i e d b r e c c i a t e d . f a u l t a p p e a r s t o d ip ,', - 29- East of the Sulphur King depo sit two branch faults were located by recognizing repetition of the strata in the Oquirrh formation. These faults strike approximately north and join the main fault in the vicinity of the West Fluorspar prospect. Prince Albert Fault About 400 feet south of the Excelsior deposit, a fault trending N. 750 E. and probab l y dippi ng steeply to the south makes a sharp contact of Price River cong lomerate to the north and Tertiary volcanics to the south. Hydrothermal solutions flowi ng a l on g this fault have produced a wide zone of i n tense silicification of the con glom­erate and propyllitization of the vo lca n ics. The Philadelphia prospect pit is at the west end of the Prince Albert fault. The Prince Albert fault and the Soap Springs fault intersect with no noticeable displacement observed either in the field or on the aerial photographs. Intense silicification and fracturing of the rocks was observed along east-trending fault northwest the Prince Albert pit. fault has uplifted small block Permian Coconino sand stone. Excelsior Fault Another large fault was located a bout 2,000 feet east of the Black Mine . At this poi nt, the Oquirrh formation is strong ly silicified and brecciated. The fault appears to dip - 3 0 - t o t h e e a s t and c l e a r l y o f f s e t s t h e P a k o o n l i m e s t o n e in t he v i c i n i t y of t h e S a l t Lake g u l l y ( s e e P l a t e I ). E x c e l s i o r o r e b o d y p r o b a b l y l o c a l i z e d t h e r m al s p r i n g s o l u t i o n s a s c e n d i n g t h e p l a n e t h e E x c e l s i or f a u l t b r a n c h i n g f r a c t u r e s. 30- to the east clearly offsets the Pakoon limestone the vicinity the Salt gully see Plate I). The Excelsior orebody was probably localized by thermal spring solutions ascending on the plane of the Excelsior fault and branching fractures. DEPOSITS I . DEPOSITS s u l p h u r d e p o s i t s a r e d i s s e m i n a t e d b e d d i ng r e p l a c e m e n t . c l a s s i f i c a t i o n t h e s u l p h u r d e p o s i t s is p r o p o s e d e m p h a s i z i n g t h e t y p e of r o c k t h a t s e r v e s a s a h o s t. T h r e e m a i n t y p e s a r e f o u n d: 1 . S u l p h u r d e p o s i t s w h i t e , v e r p o r o u s w a t e r - l a id t u f f w h i c h i s i n t e r b e d d e d w i t h s i l i c e o u s s i n t e r d e p o s i t ed f r om t h e r m a l s p r i n g a c t i v i t y . E x a m p l e s t h i s t y p e a r e t he S u l p h u r d a l e V i c t o r C o n q u e r o r o r e b o d i e s. S u l p h u r d e p o s i t s i n C r e t a c e o u s q u a r t z i t e - l i m e s t o ne c o n g l o m e r a t e w h i c h t h e l i m e s t o n e i s e i t h e r a l t e r e d to g y p s um r e p l a c e d v e r y p o r o u s , w h i t e s i l i c e o u s s i n t e r. E x a m p l e s t h i s t y p e a r e t h e E x c e l s i o r , P r i n c e A l b e r t, M a r i p o s a , V i c t o r i a , Y o r k. 3 . S u l p h u r d e p o s i t s r e c e n t t a l u s s l o p e s P a l e o ­z o i c l i m e s t o n e s a t t h e b a s e T e r t i a r y f a u l t s . S i l i c e o us s i n t e r f i l l s t h e s p a c e s b e t w e e n t h e l i m e s t o n e f r a g m e n t s and a l s o r e p l a c e s t h e l i m e s t o n e . i s a b u n d a n t . S u l p h ur K i n g t h e B l a c k a r e e x a m p l e s t h i s t y p e. S u l p h u r d a l e V i c t o r C o n q u e r o r O r e b o d i es The S u l p h u r d a l e and V i c t o r C o n u e r o r o r e b o d i e s h a ve v e r y s i m i l a r s t r u c t u r a l m i n e r a l o g i c a 1 c h a r a c t e r i s t i c s. a r e i n t o p o g r a p h i c d e p r e s s i o n s a r e s u r r o u n d e d GEOLOGY OF ORE DEPOSITS I. DESCRIPTION OF SULPHUR DEPOSITS The sulphur deposits are disseminated and bedding replacement. A classification of the sulphur deposits is proposed emphasizing the type rock that serves as host. Three main types are found: 1. Sulphur deposits in white, ver y porous water-laid tuff which is interbedded with siliceous sinter deposited from thermal spring activity . . Examp1es of this type are the Su1phurda1e and Victor Conqueror orebodies. 2 . Sulphur deposits in Cretaceous quartzite-limestone conglomerate in which the limestone is either altered to gypsum or replaced by very porous, white siliceous sinter. Examples of this type are the Excelsior , Prince Albert, Mariposa, Queen Victoria, and New York . 3. Sulphur deposits in recent talus slopes of Paleo­zoic limestones at the base of Tertiary faults. Siliceous sinter fills the spaces between the limestone fragments and also replaces the limestone. Gypsum 1S abundant. The Sulphur King and the Black Mine are examples of this type. Su1phurda1e and Victor Conqueror Orebodies TheSu1phurda1e a nd Victor Con q ueror orebodies have very similar structural and mineralogical characteristics. They are in topographic depressions and are surrounded by 3 2 - T e r t i a r y v o l c a n i c r o c k s s e e F i g u r e 5 ) . s u l p h u r o c c u rs a s s m a l l , b r i g h t - y e l l o w g r a i n s c r y s t a l s f i l l i n g p o r e s and l i n i n g c a v i t i e s w h i t e , v e r y p o r o u s , w e l l - b e d d e d w a t e r - l a i d t u f f w i t h i n t e r s t r a t i f i e d s i l i c e o u s s i n t e r. a t t h e S u l p h u r d a l e o r e b o d y h y d r o g e n s u l p h i d e gas e m a n a t i o n s a r e v e r y p r o f u s e i s s u e t h r o u g h s m a l l v e n t s or f r a c t u r e s . t h e s u l p h u r i s d i s s e m i n a t e d t h e p o r o us b e d s t h e w a t e r - l a i d t u f f . The l p h u r s o c o m b i n ed w i t h f i n e l y d i v i d e d , b l a c k i r o n l p h d e s n c l u d i n g p y r i te a n d m a r c a s i t e . p l a c e s t h e i r o n s u l p h i d e s o u t c r o p a l o ng f r a c t u r e s v e n t s c o n t i n u e d s o l f a t a r i c a c t i v i t y . z o ne i r o n s u l p h i d e s e l e m e n t a l s u l p h u r e x t e n d s to 172 f e e t b e l o w t h e s u r f a c e at t h e l o c a t i o n of d r i l l h o le No. 23 ( s e e P l a t e I V ). t h e S u l p h u r d a l e p i t some t h e b e d s o f w a t e r - l a id t u f f a r e p o o r l y s o r t e d c o n t a i n w e l l - r o u n d e d p e b b l e s of v o l c a n i c r o c k s . p e b b l e s v a r y c o l o r f r o m l i g h t - g r ay t o g r e e n p i n k . p e b b l e s a r e c o m p l e t e l y s i l i c i f i ed b u t s t i l l show g h o s t s of t h e i r p h e n o c r y s t s . Most of t h e se b e d s a r e m i n e r a l i z e d . Other b e d s , 2 o r 3 f e e t t h i c k , a re s i l t y and b a r r e n of s u l p h u r . They e x t e n d l a t e r a l l y o n l y a f ew f e e t. I n s u r f a c e o u t c r o p s e x p o s e d a t m o s p h e r i c c o n d i t i o ns t h e s u l p h u r i s b l e a c h e d . c o l o r r e a p p e a r s t h e s u r f a ce i s s c r a t c h e d l i g h t l y w i t h p i k. S u l p h u r d a l e o r e b o d y h a s b e e n w e l l o u t l i n e d - 32- Tertiary volcanic rocks ( see Fig ure 5) 0 The sulphur occurs as small, bright-yellow grains or crystals filling pores and lining cavities of a white, very porous, well-bedded water­laid tuff with interstratified siliceous sinter. Now at the Sulphurdale orebody hydrogen sulphide gas emanations are very profuse and issue through small vents or fractures o Most of the sulphur is disseminated in the porous beds of the water-laid tuff. Th e s u lphur i s a l so combined with finely divided, black iron s u lph i des i ncluding pyrite and marcasite. In places the iron sulphides outcrop along fractures or vents of continued solfatar i c activit y . A zone of mixed iron sulphides and elemental sulphur extends down to feet below the surface the location drill hole No . see Plate IV). At the Sulphurdale pit so me of the beds of water-laid tuff are poorly sorted and contain well- rounded pebbles of volcanic rocks . These pebbles vary in color from light-gray to green and pink. The pebbles are completely silicified but still ghosts their phenocrysts . these beds are mineralized. beds, or feet thick, are silty barren sulphur. ex end terally only few feet. In surface outcrops exposed to atmospheric conditions the sulphur is bleached. The color reappears if the surface is scratched lightl y with a p i c k o The Sulphurdale orebody has been well outlined by F i g u r e 5. S u l p h u r d a l e o p e n p i t . V i ew l o o k i n g s o u t h w e st - 33 - -Figure 4. Cove Fort cinder cone and basalt fl ows. View looking southwest . Figure 50 Sulphurdale open pit. - View looking southwest J d r i l l i n g on a l l s i d e s e x c e p t to t h e n o r t h and n o r t h e a st d i r e c t i o n s . The maximum d i m e n s i o n s a r e 1 , 5 0 0 f e e t in a n o r th s o u t h d i r e c t i o n f e e t i n e a s t w e s t d i r e c t i o n . Over­b u r d e n r a n g e s t o f e e t . e a s t s i d e t h e o r e b o dy r e s t s o v e r a p o r p h y r i t i c l a t i t e f l o w and i s b o u n d by a f a u lt t h a t t h e w a t e r - l a i d t u f f o v e r l a p s . These f l o w s a r e s t r o n g ly j o i n t e d and c o a t e d w i t h c l a y and l i m o n i t e s t a i n a l o n g p l a n es p a r a l l e l t o t h e f a u l t . At t h e b o t t o m of t h e t r e n c h ( s ee P l a t e IV) w h e r e t h e f a u l t is e x p o s e d h y d r o g e n s u l p h i d e gas b u b b l e s t h r o u g h t h e wet mud. E p s o m i t e c o l l e c t s a t t h e b o t t om o f t h e t r e n c h . The c l a y a r o u n d t h e t r e n c h h a s a b l u i s h g r e en c o l o r p o s s i b l y o^ue t o t h e f o r m a t i o n of f e r r o u s s u l p h a t e . At t h i s t r e n c h and o n l y 10 f e e t f r o m t h e s u r f a c e , s e v e r a l m a s s es a b o u t 3 f e e t in d i a m e t e r of b l a c k s u l p h i d e s w e r e e x c a v a t e d. I n f o r m a t i o n a b o u t t h e V i c t o r C o n q u e r o r o r e b o d y h as b e e n o b t a i n e d f r o m d r i l l l o g s s e e F i g u r e s a n d 1 3 , p a g es a n d 5 4 ) . o u t l i n e d d r i l l i n g t h e V i c t o r C o n q u e r or o r e b o d y h a s a a s i n s h a p e . The d i m e n s i o n s of t h i s o r e b o dy a r e 600 f e e t in an e a s t e r l y d i r e c t i o n and 200 f e e t i n a n o r t h e r l y d i r e c t i o n . A f ew p r o s p e c t p i t s h a v e e n c o u n t e r ed o r e o n l y a f e w i n c h e s b e l o w t h e s u r f a c e . The s o i l o v e r t he o r e b o d y i s m i x e d w i t h w h i t e f r a g m e n t s of t u f f . T h i s d e p o s it h a s b e d s of w a t e r - l a i d t u f f i n t e r s t r a t i f i e d w i t h b a r r en b a n d s of s i l t y m a t e r i a l and v e r y h a r d s i l i c e o u s f r a g m e n t s. Most of t h e h o l e s t h a t c u t e l e m e n t a l s u l p h u r o r e h a v e a l so e n c o u n t e r e d h e a v y i r o n s u l p h i d e s n e a r t h e b o t t o m. -34- drilling all sides except the north northeast directions. dimensions are 1,500 feet north south direction and 800 feet in an east west direction. Over-burden ranges up to 20 feet. The east side of the orebody rests over porphyritic latite flow is bound fault that the water-laid tuff overlaps. flows are strongly jointed coated with clay limonite stain along planes parallel to the£ault~ the bottom the trench (see Plate where the fault exposed hydrogen sulphide gas bubbles . through the Epsomite collects at the bottom of the trench. clay around the trench has bluish green color possibly 4ue to the formation ferrous sulphate. At this trench only feet from the surface, several masses about feet diameter black sulphides were excavated. Information about the Victor Conqueror or~body has been obtained fr9m drill logs ( see Figures 12 and 13, pages 53 and 54). As outlined by drilling the Victor Conqueror orebody has b ·~sfn shape. dimensi9ns th is orebody are feet in easterly direction feet in northerly direction. A few prospect pits have encountered ore only a few i~~hes below the surface. soil over the orebody is mixed with white fragments tuff. This deposit has beds water-laid tuff interstratified with barren bands silty material very hard siliceous fragments. the holes that cut elemental sulphur ore have also encountered heavy iron sulphides near the bottoi. - 3 5 - Th e V i c t o r C o n q u e r o r o r e b o d y i s s t r u c t u r a l l y c o n t r o l l ed b y 15° m a j o r e a r l y T e r t i a r y f a u l t , t h e t r a c e w h i ch i s o n l y f e e t t h e w e s t t h e o r e b o d y. P r i n c e A l b e r t O r e b o d y , M a r i p o s a , V i c t o r i a P r o s p e c ts P r i n c e A l b e r t o r e b o d y s e e P l a t e s I I I ) is l o c a t e d t h e w e s t s i d e n o r t h e a s t - t r e n d i n g r i d g e n o r th o f t h e V i c t o r C o n q u e r o r o r e b o d y . V i c t o r i a is s i t u a t e d t h e e a s t s i d e t h e r i d g e d i r e c t l y e a st o f t h e P r i n c e A l b e r t . The M a r i p o s a p i t i s a b o u t 1 , 0 0 0 f e et w e s t of t h e P r i n c e A l b e r t . These t h r e e o c c u r r e n c e s of s u l p h u r a r e p r o b a b l y r e l a t e d t o a f a u l t w h i c h i s a l m o st e n t i r e l y c o n c e a l e d by a l l u v i u m . T h i s f a u l t s t r i k e s N. 5° E. and d i p s a b o u t 67° E. The p r o b a b l e d i m e n s i o n s of t h e P r i n ce A l b e r t o r e b o d y a r e 300 f e e t in a n o r t h e r l y d i r e c t i o n and 300 f e e t in an e a s t e r l y d i r e c t i o n. t h e P r i n c e A l b e r t p i t t h e s u l p h u r f i l l s t h e p o r es h i g h l y p o r o u s a p p a r e n t l y d e n s e s i l i c e o u s s i n t e r. Q u a r t z i t e p e b b l e s a r e f e w . The s u l p h u r a t t h e Queen V i c t o r ia a n d M a r i p o s a p r o s p e c t p i t s f i l l s t h e p o r e s l i n e s c a v i t i es o f a w h i t e , v e r y p o r o u s and l i g h t w e i g h t s i l i c e o u s s i n t e r. Q u a r t z i t e p e b b l e s a r e more a b u n d a n t in t h e s e two d e p o s i ts t h a n a t t h e P r i n c e A l b e r t o r e b o d y. D e e p r e d h e m a t i t i c s o i l c a p s t h e P r i n c e A l b e r t o r e b o dy a n d i s a l s o p r e s e n t a b o v e t h e M a r i p o s a V i c t o r ia p i t s . i s a b u n d a n t b e l o w t h i s r e d c a p p i n g r e p l a c es -35- The Victor Conqueror orebody 1.S structurally controlled by a No ISo E. major early Tertiary fault, the trace of which 1S only 800 feet to the west of the orebody. Prince Albert Orebody, Mariposa, and Queen Victoria Prospects The Prince Albert orebody ( see Plates I and III) is located on the west side of a northeast-trending ridge north of the Victor Conqueror orebodyo The Queen Victoria is situated on the east side of the same ridge and directly east of the Prince Albert. Mariposa pit is about 1,000 feet west the Prince Albert. three occurrences of sulphur are probably related to fault which is almost entirely concealed alluvium. This fault strikes 50 E. dips about 670 probable dimensions the Prince Albert orebody are feet northerly direction 300 feet easterly direction. At the Prince Albert pit the sulphur fills the pores of a highly porous but apparently dense siliceous sinter. Quartzite pebbles are few. sulphur at the Victoria and Mariposa prospect pits fills the pores and lines cavities of white, very porous light weight siliceous sinter. Quartzite pebbles are abundant these deposits than at the Prince Albert orebody. Deep red hematitic soil caps the Prince Albert orebody and is also present above the Mariposa and Queen Victoria pits. Gypsum is abundant below this red capping and replaces - 3 6 - t h e l i m e s t o n e p e b b l e s. V e r t i c a l c r o s s s e c t i o n AT s e e P l a t e I I I ) t h at t h e V i c t o r i a p r o s p e c t p i t i s a p p r o x i m a t e l y a t t h e same e l e v a t i o n as t h e t o p of t h e s u l p h u r a t t h e P r i n c e A l b e rt o r e b o d y . E x c e l s i o r O r e b o d y a n d New Y o r k P r o s p e ct E x c e l s i o r o r e b o d y s e e P l a t e s I I ) i s l o c a t ed a b o u t 4 , 5 0 0 f e e t n o r t h w e s t t h e V i c t o r C o n q u e r o r . Y o r k p r o s p e c t p i t i s s i t u a t e d 1,100 f e e t w e s t of t h e E x c e l s i or p i t . E x c e l s i o r d e p o s i t i s p e r h a p s t h e l a r g e s t t he s u l p h u r d e p o s i t s i n c o n g l o m e r a t e s e e F i g u r e 6 ) . p r o b a b le d i m e n s i o n s t h i s o r e b o d y a r e f e e t n o r t h e r ly d i r e c t i o n f e e t e a s t e r l y d i r e c t i o n . is p r o b a b l y r e l a t e d to b o t h t h e P r i n c e A l b e r t and E x c e l s i or f a u l t s ( s e e P l a t e I I ) . These two f a u l t s w o u l d a l s o l i m i t t he o r e b o d y t o t h e s o u t h and e a s t. s u l p h u r o c c u r s i n w h i t e , p o r o u s s i l i c e o us s i n t e r f i l l i n g p o r e s l i n i n g c a v i t i e s . T h i s p o r o u s mass s u r r o u n d s p i n k t o b l e a c h e d q u a r t z i t e p e b b l e s . is a b u n d a n t a r e a s t h e p i t , g e n e r a l l y o c c u r s in l e s s e r a m o u n t s w h e r e s u l p h u r i s r i c h e r . r o a d c u t a r o u nd t h e p i t w h e r e t h e c e s s p o o l h o l e s a r e l o c a t e d a b u n d a nt g y p s u m . The r e d h e m a t i t i c s o i l i s a g a i n p r e s e n t d i r e c t ly a b o v e t h e o r e b o d y . At t h e w e s t f a c e of t h e p i t ( s e e F i g u r e 7) t h e o r e b o d y shows r e l i c b e d d i n g of t h e P r i c e R i v er 36- the limestone pebbles. Vertical cross section A-At ( see Plate III) shows that the Queen Victoria prospect pit is approximately at the same elevation the top the sulphur at the Prince Albert orebody. Excelsior Orebody and York Prospect The Excelsior orebody ( see Plates I and II) is located about 4,500 feet northwest of the Victor Conqueror. The New York prospect pit is situated feet west the Excelsior pit. The Excelsior deposit is perhaps the largest of the sulphur deposits in conglomerate ( see Figure 6). The probable dimensions of this orebody are 400 feet in a northerly direction and 200 feet in an easterly direction. It is probably related both the Prince Albert Excelsior faults(see Plate II). faults would also limit the orebody to the south east. The sulphur occurs in a white, porous mass of siliceous sinter filling pores and lining cavities. This porous mass surrounds pink to bleached quartzite pebbles. Gypsum is abundant in some areas of the pit, but generally occurs in lesser amounts where sulphur is richer. A road cut around the pit where the cesspool holes are located shows abundant gypsum. red hematitic soil is again present directly above the orebody. the west face the pit see Figure the orebody relic bedding the Price River 3 7 - F i g u r e E x c e l s i o r p i t . l o o k i n g to . t h e w e s t. F i g u r e f a c e E x c e l s i o r p i t . High . g r a d e s u l p h u r o r e s h o w i n g r e l i c b e d d i n g of t h e r e p l a c e d P r i c e R i v e r c o n g l o m e r a t e. - 37- Figure 6. Excelsior pit. " the west. View looking to Figure 7. West face of Excelsior pit. High _ grade sulphur ore showing relic bedding of the replaced Price River conglomerate. 3 8 - c o n g l o m e r a t e . r e p l a c e d b e d s s t r i k e 60° d ip 2 0 ° t h e t o p t h e h i l l b e t w e e n t h e E x c e l s i o r Y o r k t h e c o n g l o m e r a t e i s s t r o n g l y s i l i c i f i e d . T h i s s i l i c i f i ed z o n e i s a b o u t f e e t w i d e e x t e n d s 2 , 0 0 0 f e e t n o r t h of t h e E x c e l s i o r p i t . c o n g l o m e r a t e w i t h i n t h i s i s v e ry h a r d s t r o n g l y b r e c c i a t e d . q u a r t z i t e p e b b l e s a r e s