The geology and ore deposits of the Cuprite mining district Item Type text; Thesis-Reproduction (electronic) Authors Lee, Charles Albert, 1908- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 01/10/2021 16:18:24 Link to Item http://hdl.handle.net/10150/551627 THU GKOICGY IdW OKK DliPOtilTS OF bhi coprits i m n m district by Charles A« Lee aM G erald C, Borland Subnit tod in partial fulfi linen t of tho recplremnts for the degree of L'-ostor of scienoo in tho Graduate College University of Arizona 1935 Approved: TABLti OF CvSlBHIb lifi’HouUo'riuii .................................. Acknowledgemente ................. Scope of the Present ,/ork Previous Geologic ,Vork .. GSOLuGiU HiiLuAflOIIS ................................................... % Location and Means of Approach ....................... 2 Settlements and Means of Communication ••* 5 C lim ate and V e g e ta tio n ...................................... • 3 Physiography ...................................... 5 R e l i e f ......... ........................... 5 D rainage ............................................. .............* • 6 HI of JAY OF imiiRG Hi TMii GLSERAL RLGIul ... 7 SIIUTIj GuAFHY........................................................... 9 Principal Rock Groups ......... ................. ... 9 Sedimentary Rocks .................................... ...11 P ale o z o ic ............................................. ... 11 Pennsylvanian ........................... ... 11 Post Pennsylvanian ................ ...12 Igneous Rooks ............................................. ... 19 P lu to n ic ...'-19 E x tru siv e ............................................. ... 21 Dike Rocks .......................................... ... 22 STRUCTURAL GEulvGY ............................................... 25 General Features ......................................................... 25 Early Folding ............................. 26 Over thrust Faults ....................................................2 7 Early Sormal Faults ................................. 28 Doming by I n t r u s i o n ................................................ 3u Post-Granodlorlte Pre-Dike Fracturing .... 3u Post Dike Transverse Faulting ........................ 51 Basin Range Faulting ................................................ 51 Age o f F o ld in g .......................... 32 Age of F a u ltin g ............... 32 GEOouGIC RISTjaY ............................................................... 32 MittERAjj RESOURCES ............................................................. 35 uRE DEPOSITS ......................................................................... 35 History of production .......................................* * 55 Geographic and. Geologic Distribution ..... 36 General Character of the Deposits ................... 37 Pyromet a somatic Deposits ............. 58 General Features ........................................ 38 M ineralogy .................. .cQ Replacement Deposits ......................................... *. 35 G eologic F e a tu re s .................................... 5v C ontents ./ Description of Bustervilic nine ......... 3y Vein D escription ................... ................... 39 Wall Rook A l t e r a t i o n .................................... .. 41 Mineralogy ............................... 42 G eneral Summary ............................... 42 Detailed Description of Minerals .. 42 Mineral Parage no sis ...................................45 Genetic Classification ............ 46 Age and Genes! s .......................................................... 46 EXiX...HATlv>a OP SYMBOLS .......................................................48 LIST OP ILLUSTRATIONS PLaTL I P ig . 1 , P hotograph lo o k in g so u th e a st from Buehman H i l l . 2. Photograph looking south from Buehman H ill. 3# Photograph looking so it invest from Duehmam H i l l . PL.Vi’B I I , Fig. 4. Photograph of the northeastern part of the area, looking southwest• . 5* Photograph looking south from Buehman H ill. 6. Photograph of the B usterrille Mine. PLATE I I I A. Photomicrograph showing treeclated pyrite surrounded fcy sphalerite and chaloopjrite veining sphalerite. B. Photomicrograph showing the minerA1 relation­ ships between pyrrhotitc, sphalerite, ohal- copyrite, galena, and calcitc• PLATE IV ' A. Photomicrograph showing tetrahedrite vein­ ing sphalerite. B. xhotomicrograph showing bournonite replacing tetrahedrite. PLATE V A. Photomicrograph showing ouloite replacing ehalcopyrlte in bournonite. B. Photomicrograph showing galena replacing chal oopyrite and bournonite and being replaced by culeite. PLATE VI Geologic Map. (In Pocket) C ontente PjjATii VI1 Structure Sections, (In Socket) PLATS V III ! . Bueterville iline, (In Pocket) Page 10, Strutiographic Column 13, Photograph of breeda overlying Maco linestone, 15. Photograph showing contact between rhyolite porphyry and quartzite# 17. Photograph of limy shale in Upper Cretaceous s e r i e s , 18. Photograph of boulder conglomerate, 2S, Photograph of andesite breccia. 24. Photograph of andesite porphyry, rhyolite porphyry dike, and boulder conglomerate. I'Miiob'MivM A ^ o wlfidfiaent s. The authors \^Lsh to express their appreciation to Dr. B. S. Butler, Dr. It. N* Short, and Dr. A. A. Stoyenoo, all of the Unireralty of Arizona. Their helpful suggestions and aid in the field were extremely valuable. The writers are also indebted to Mr. Frank Estrada for permission to work on his lend; also to Hr. Foster of the Bustorville Mine, who permitted the vriters to go to the mine and to collect samples. Scope of the Present Work This report discusses the stratigraphy, petrography, structure , ore deposits, end general geologic history, Inter­ pretations and conclusions are made where the facts seem to justify them. Field work was begun the middle of October, 1994, and continued on weekends and vacations through tie winter and spring of the following year. Aq no satisfactory topograph­ ic map was available much of the time available for field work was used in the preparation of a base map, and hence the geolo­ gical study was not as complete as desired. The writers fool that there is yet much that needs to be more fully investigated. P re' M G eologic iTork Previous information on the region is confined to -8 - 9. S, Geologicnl Survey Bulletin 582, “Mineral Deposits of the Santa Hi to md Patagonia Mountains," by Prank C. Schrader and Janes M*. H ill, published in 1915. Tho work was of n re- eonnaiseance nature and the map was on such a snail scale that no details of geology were shown. However, the report contains much valuable and pertinent information, which has 1m part bom incorporated in this manuscript. 2tore recent work has been done in the general region by candidates for advanced degrees end by classes in field geology at the University of A rizona. GEOGRAPHIC RELATIONS Location and Means of Approach The Cuprite district is in southeastern Arizona in the southeastern part o f Pima County, approximately 28 miles southeast of Tucson, Arizona. It is in the northern pert of the Santa Rita Mountains at a general elevation of 4,000 foot. The portion of the district mapped by the authors extends for two miles in a north-south direction, about two and a half miles in an cast-west direction anl, comprises about four and a half square miles. It may be reached by turning south from U. S. High­ way 80 one mile east of Vail Junction and traveling 8 miles on a fair desert road. The main line of the Southern Pacific Railroad goes through Vail one mile north of Iho highway and -5 over thio line several passenger and freight trains pans in each direction daily# S e ttle m e n ts and Means o f Corsaun lo o t ion The only settlement is Bustervllle, in the eastern part of the area, consisting of four houses in vdiich live the non who operate the Bus tervllle Hino. The only other habitation within the area is the hone of Mr# Frank Estrada located in the western port, about two and one-half miles from the Bustcr- ville Mine, There is no telephono, electric, or moil service in Bus tervllle. The residents obtain their mail at Vail Station, eight miles to the north# Siator also must be hauled-but at the time of writing H ft woll is being drilled just off the northern edge of the nap. from which it is hoped that sufficient water w ill be developed to supply the needs of Bustervllle. Bie climate is arid with hot days end cool nights# Summers are extremely hot,but due to the mild winters it is possible to continue field work throughout the year. Rain in the summer is likely to fall in cloudbursts which cause floods of short duration but extreme violence. These summer rains may be expected frem July to September. The winter rains come from from December to March and enow fa lls occasionally. On the higher peaks In the Santa Hita Mountains to the south of this area mow may remain till the latter part of March or the middle of April* Mo official weather records ware consulted, but by reference to Mr. Schrader’s report one finds the following: \ According to the records of the weather Bureau kept at Tuoscn, which may bo regarded as approxi­ mately representing the valley portion of the area, the average maximum temperature for the 13 years