DEPARTMENT OF THE INTERIOR Hubert Work, Secretary U. S. GEOLOGICAL SURVEY George Otis Smith, Director Bulletin 771 ORE DEPOSITS OF THE SADDLE MOUNTAIN AND BANNER MINING DISTRICTS, ARIZONA BY CLYDE P. ROSS WASHINGTON GOVERNMENT PRINTING OFFICE 1925 - ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 25 CENTS PER COPY CONTENTS Page Summary ___,_________ , _ __ _ vn Introduction 1 Scope of the report 1 Location and extent of the area_ _ 2 Acknowledgments ______ ___ ___ _ -- 2 Topography 4 Stratigraphy and petrology 6 General features _ . _i 6 Paleozoic section__ _ 6 Cretaceous stratified rocks _ - 11 / Older Tertiary stratified rocks_________________ __ 15 Gila conglomerate________-_ _ _ __ 17 Quaternary alluvium____ __ __ ____ _____ 18 Cretaceous intrusive rocks __ 19 Quartz-hornblende diorite _ _ ____ __ 20 Quartz-mica diorite _____ _ _ __ 20 Structure____i________________ _ ______ _ _.._ 21 Geologic history__________________________________ 23 Ore deposits____ ___ __ __ _______^____ 29 History and production___ ____ __________________ 29 Claim boundaries _____________________________ 30 Lead-silver veins_______________________________ 30 Pyritic gold deposits.____________________________ 32 Disseminated pyrite deposits _______________________ 33 Contact-metamorphic deposits_______________________ 34 Generalizations and inferences________________________ 39 Mines and prospects. _ __ _ _ ______ 41 Adjust mine.__ ___ ___ ______!____________ 41 Saddle Mountain group______________!____________________ 43 Little Treasure mine.__ _______________________ 46 Lee group_____ ____________________________ 47 Carmichael group_______________________________ 48 Two Queens mine________________________________ 48 Pool's mine___________________________________ 49 Hoosier group ___________________1____________ 50 Rieder & Bailey group__ ______ ____________ 51 Faull group___________________________:______ 52 Christmas mine__ ___ ____ ___________________ 52 Mellor prospect__ ___________________________ 60 London-Arizona mine ____________________________ 61 Schneider group _____________________________ 63 Apex mine _ _ ______ 63 Gold-Copper Mines Co _ __ _ _ ._ 64 Hogvall prospect_____________________________:_ 65 nt IV CONTENTS Mines and prospects Continued. " Page Seventy-nine mine ____________ ___ ________ 66 Columbia mine_______ ________________________ 67 McHur prospect ______________________________ 68 Premier group _ __ 69 C. & B. group__________________________________ 69 Index___ ___ 71 ILLUSTRATIONS Page PLATE I. Geologic map and section of the Christmas area________ 2 II. A, The upper part of the valley of Rock Creek; B, Lee Moun­ tain and surrounding hills-____________________ 8 III. Generalized columnar sections of Paleozoic rocks in regions near the Christmas area______________________ 8 IV. A, Cambrian quartzite on upper Ash Creek; B, Ripple-marked Cambrian quartzite on upper Ash Creek _ ___ ___ 8 V. A, Mottled Cambrian quartzite on upper Ash Creek; B, Tornado limestone in the box canyon on upper Ash Creek-______ 8 VI. A, Coarse Cretaceous conglomerate on upper Ash Creek; B, Coarse Cretaceous conglomerate on Gila River above Apache i Spring _ 16 '^ VII. A, General view of older Tertiary conglomerate north of Saddle Mountain; B, Close view of older Tertiary conglomerate on west side of the Tablelands _______ _______ 16 VIII. A, Tuffaceous conglomerate of Tertiary age on the Tablelands; B, Dike of quartz-mica diorite cutting Cretaceous volcanic 4 rock on south side of Deer Creek east of Adjust mine___ 16 I.. A, Contorted Tornado limestone on Gila Eiver near southwest' ^ corner of the Christmas area ; B, Fault block of Tornado lime­ stone on east side of Gila River near Apache Spring____ 16 X. Property map of the Saddle Mountain and Banner mining dis­ tricts ______ ___ ____________________ 32 { XI. A, Outcrop of Big Rock vein on Saddle Mountain group; B, Sill ,^ of altered trap in Tornado limestone on Gila River just south of the southern border of the Christmas area_________ 32 XII. A, Outcrop of gypsum on Little Gold Gulch; B, The old Christ­ mas workings-1_______-___________________ 56 XIII. Map showing relations of the stoped-out ore bodies of the Christmas mine to the surface geology____________ 56 XIV. A, Contact-metamorphosed limestone north of No. 3 shaft, 4 Christmas mine; B, Tunnels constituting the principal work­ ings of the London-Arizona mine________________ 56 XV. Geologic section through No. 3 shaft, Christmas mine_____ 56 \ XVI. Geologic map of the part of the Banner mining district in the Ray quadrangle __________________________ 64 XVII. A, Curtin shaft; B, Workings on the Schneider group of the Gila Canyon Copper Co_______________________ 64 ILLUSTRATIONS V Page FIGUBE 1. Index map showing location of the Saddle Mountain and Ban­ ner mining districts_______________________ 3 2. Columnar section of Paleozoic rocks on upper Ash Creek___ 7 3. Section through the west end of the Tablelands, on line B-B', Plate I, showing relations of the Tertiary stratified rocks_ 15 4. Blue Bird workings of Adjust Mining Co____-_-____ 42 5. Plan of principal workings at Little Treasure mine ____ 46 6. Geologic section through No. 1 shaft, Christmas mine____ 56 SUMMARY An area 7% miles square in the southwest corner of the Christmas quad­ rangle, in Final and Gila counties, Ariz., was mapped geologically in the spring of 1922, and the ore deposits in the Saddle Mountain and Banner min­ ing districts, which lie mainly in this area, were examined. The rocks of the two districts comprise pre-Cambrian Final schist; a considerable thick­ ness of Cambrian, Devonian, and Carboniferous beds of marine origin; Cre­ taceous lava, pyroclastic rocks, and sedimentary beds; dioritic intrusions of probable early Tertiary age; Tertiary formations of' volcanic and alluvial origin; and Quaternary alluvium of several ages. The Paleozoic succession just south of the Christmas area differs in a number of details from those both east and west. Some of the Cretaceous conglomerate is coarse and poorly sorted, and the possibility of a glacial origin is suggested. There is a strong unconformity at the top of the pre-Cambrian, but the Paleozoic formations, in spite of the great time gaps between them, are essentially con­ formable with one another. Erosion and some structural disturbance occurred after the deposition of .the Carboniferous limestone, and further folding and faulting after the Cretaceous volcanism, with recurrent periods of faulting up to comparatively recent time. Nearly 30 mines and prospects are described. Most of these were visited, but data for a few were gathered from other sources. All the ore deposits are believed" to be genetically related to the intrusion of dikes and similar masses of quartz-mica diorite near the beginning of Tertiary time. The de­ posits in the area include lead-silver veins, pyritic gold deposits on shear zones, disseminated pyrite deposits, and contact-metamorphic deposits. Ore bodies of the last type have in different places been mined for copper, lead, zinc, and gold, and vanadium prospects have been opened on deposits that may be related to this type. As all the different types of deposits were formed during the same period of mineralization and all are related to the intrusion of the quartz-mica diorite it is to be expected that gradations be­ tween them may be found, and the veins and- shear zones that are charac­ teristic of the Saddle Mountain district may grade in depth into contact-meta­ morphic deposits such as are characteristic of the Banner district. ORE DEPOSITS OF THE SADDLE MOUNTAIN AND ' BANNER MINING DISTRICTS, ARIZONA By CLYDE P. Eoss ' INTRODUCTION . Scope of the report. The field work for this report occupied about two months in the spring of 1922 and included the geologic mapping of about 56 square miles in the southwest corner of the Christmas quadrangle and the examination of most of the mines and prospects in the Saddle Mountain and Banner mining districts. The area mapped includes the Christmas mine and will, for convenience, be referred to as the Christmas area. The mines and most of the prospects in the Saddle Mountain district and the part of the Banner district included in the Christmas area were studied in some detail, and most of those in the part of the Banner district lying in the adjacent Eay quadrangle were examined more briefly. There was little mining activity in either district when they were visited, and most of the larger mines were either in charge of caretakers or de­ serted. In consequence many of the workings were inaccessible. The report is intended to give an idea of the character of the ore deposits in the two districts and the extent of their development. The general geology of the Christmas area is also discussed. Ean- some x has described that of the Eay quadrangle, and the part of his geologic map of that quadrangle which includes the Banner district is reproduced on Plate XVI. A number of the ore deposits in that district are described in the Eay folio. The Christmas area includes all the known ore deposits of any consequence in the Christmas quadrangle. In the southeastern part of the quadrangle there are coal deposits that have been known for 40 years and prospected in a number of places, but little coal has ever been shipped, and no min­ ing has been done since about 1907. The essential facts regarding the coal fields are contained in a report by Campbell,2 and the avail- 1 Ransome, F. L., Copper deposits of Ray and Miami, Ariz.: U. S. Geol. Survey Prof. Paper 115, 1919; U. S. Geol. Survey Geol. Atlas, Ray folio (No. 217), 1923. 2 Campbell, M. R., The Deer Creek coal fleld, Ariz.: U. S. Geol. Survey Bull. 225, pp. 240-258, 1904. 3146a 25 2 X 2 SADDLE MOUNTAIN AND BANNER DISTRICTS, ARIZ. able data are summarized and brought up to date in a -report on the Aravaipa and Stanley mining districts.3 The general geology of the Christmas quadrangle has been studied by Darton.4 Location and extent of the area. The Banner and Saddle Moun­ tain mining districts lie respectively in Gila and Final counties, Ariz.