DEPARTMF T OF THE INTERIOR TNITI·,D Sl A IS (1EOLOGICAL SURVEY MIN I EPO IT MAP OF THE SILVER CITY 1o x 2o QJA)R LE, NEW MEXICO AND ARIZONA By D. H. ichter and V. A. Lawrence tv til 0 0 0 0 MISCELLANEOUS INVESTIGATIONS SERIES Published by the U.S. Geological Survey, 1983 DEPARTMENT OF THE INTERIOR TO ACCOMPANY MAP 1-1310-B UNITED STATES GEOLOGICAL SURVEY MINERAL DEPOSIT MAP OF THE SILVER CITY l 0 X2° QUADRANGLE, NEW MEXICO-ARIZONA By D. H. Richter and V. A. Lawrence This pamphlet, which accompanies map 1-1310-B, Is a descriptive Ore minerals-List of ore minerals known to occur In deposit with Im­ compilation of more than 600 mineral deposits In the Sliver City 1° x portant ore minerals, If known or appropriate, underlined. Leaders 2° quadrangle. It Includes both metallic and nonmetallic deposits, but Indicate no Information available. excludes such commodities as sand and gravel, rock, and most other History and development-Brief history of deposit and description of low cost per unit volume construction materials. The compilation is physical workings. Tonnage and grade figures are given, If data are generally restricted to deposits that have been described In the lltei:c#ure, available. although data for a few deposits are from unpublished sources. Production-Where data are available the quantity of metal or commodity Individual descriptions of deposits are grouped under the 10 regional produced Is given. If only monetary values have been reported, areas shown on the accompanying map, plus an Intervening general basin they are shown in time-of-production dollars. area, and are numerically keyed to each area on the map. The follow­ References-Principal sources of Information for preceding data. Ing Information for each deposit, or group of deposits, Is provided: References are keyed numerically to the reference list in back of Name-Most commonly used name; other known names are shown In pamphlet. Where no references are shown, Information Is from un­ parentheses. No attempt Is made to categorize name; name may published data gathered by the authors. refer to a mine, prospect, claim, claim group, or specific mine work­ Ing, such as a shaft, adlt, or tunnel. Leaders Indicate deposits whose All weights and measures used In the descriptions are In the metric names are unknown. system. Conversion factors relating to gold and sliver quantities and grades are as follows: Location-All locations are given by section, township, and range, generally to within a quarter section. metric ton x 1.1 = short ton Geology-Brief description of deposit, Including Information on the age kilogram x 32.15 = troy ounce and nature of the host rocks, where known. Leaders Indicate no Information available. gram/metric ton (g/t) x 0.029 = troy ounce/short ton 1 GILA AND NORTHERN PELONCILLO MOUNTAINS AREA (includes Ash Peak and Lone Star mining districts) HYDROTHERMAL DEPOSITS Porphyry Cu (Mo) Deposits The porphyry copper and closely associated copper vein deposits in the Lone Star mining district are genetically related to a group of small, chiefly granodiorite plutons and silicic to intermediate hypabyssal rocks of Late Cretaceous to early--Tertiary age (67-52 m.y.) emplaced along wide ENE-trending shear zones in Late Cretaceous (70 m.y.) andesite flows and breccias. Copper minerals were discovered in the Lone Star district about 1886 and between then and the early 1940's exploration and mining activity was focused on the high grade copper vein deposits. With the exception of the San Juan mine (map no. 2), data on -mining activity and production are virtually non-existent for the many small mines that operated dut'ing that period. The porphyry copper potential of the district was recognized in the late 1940's. MAP NO. NAME LOCATION GEOLOGY ORE MINERALS HISTORY AND DEVELOPMENT PRODUCTION REFERENCES Dos Pobres Sec. 27 Sulfide veins and disseminations in Primary minerals--chalco­ Discovered in 1957 and being None 109, 131, 155, (Phelps Dodge-Safford) T. 5 S., fragmented quartz monzonite porphyry pyrite, bornite, niolyb­ developed in 1980 for modified 160, 190, 191, R. 26 E. dikes (52 m.y.) and host andesite denite. Oxide and super­ underground block caving. Deposit 209 volcanics at apex of granodiorite gene minerals--chryso­ contains 363 million metric tons of pluton localized at intersection of colla, cuprite, native 0.72% Cu with values in MoS 2 , Au, ENE shear zone and NE-trending drag copper, chalcocite, and Ag fold. Supergene enrichment minor covellite San Juan Sec. 35 Secondary copper minerals in veins Oxide and supergene miner­ Discovered about 1886 and worked as Minimum of 340 10, 35, LOO, (Peacock Mine) T. 5 S., and disseminations in quartz mon­ als--chrysocolla, broch­ underground mine probably between metric tons of Cu 160, 190, 191, R. 26 E. zonite porphyry pluton (58 m. y.) and antite, malachite, -azur::­ 1905 and 1920. Developed for sur­ produced prior to 193 its granodiorite porphyry border ite, cuprite, chalcocite face in situ leaching in 1960's. 1920. Estimated zone, breccia pipes, and host ande­ Present ( 1980) leaching operations 10,000 metric tons site volcanics. Pluton intrudes ENE producing about 7 metric tons of Cu Cu from leaching shear zone. Supergene enrichment daily. Deposit contains 18 million operations minor metric tons of 0. 5% Cu in oxide ore Safford Kennecott Sec. 5 Sulfide veins and disseminations in Primary minerals--chalco- Discovered in 1955 and subsequently None 2, 19, 33, 43, T. 6 S., swarm of silicic to in termed tate ~. bornite, molyb- d-eveloped for underground solution 130, 190 R. 27 E. dikes and andesite volcanics in ENE denite. Oxide and super- mining. Inactive in 1980. Deposit shear zone north of Lone Star grano- gene minerals--chryso- contains 1,800 million metric tons · diorite pluton (58 m.y.). Sericite colla, malachite, brochan- of 0.41% Cu in mixed oxide--sulfide from alteration halo dated at 53 tite, chalcocite, covel- ore with values in MoS 2, Au, and Ag m.y. Extensive oxidized zone but lite minor supergene enrichment. Ore body covered by as much as 240 m of middle Tertiary volcanic rocks Horseshoe NW1/4sec. 17 Secondary copper minerals in veins -Oxide minerals--chryso- Developed by 2 shafts and adit prior None T. 6 s., and disseminations in quartz mon- colla, malachite, brochan- to 1920 for high grade oxidized ore R. 27 E. zonite porphyry and host andesite tite in shear zones and along porphyry-- volcanics volcanic contact. Inactive in 1980. Deposit contains estimated 70,000 metric tons of 1.0% Cu to depth of 15m MAP NO. NAME LOCATION GEOLOGY ORE MINERALS HISTORY AND DEVELOPMENT PRODUCTION REFERENCES Sanchez NE1/4sec. 26 Secondary copper minerals in veins Oxide minerals--chryso­ Old shaft indicates considerable About metric 100, 190, 191. (Safford Inspiration) T. 6 S., and disseminations in quartz monzon­ colla, brochant1te --- early underground development. In tons Cu R. 27 E. ite porphyry pluton and host 1970's developed for leaching opera­ andesite volcanics tion. Inactive in 1980. Deposit contains 72 million metric tons of 0.18% Cu in oxide ore 6 SOL Sees. 23, Sulfide system in monzonite pluton Primary minerals--chalco­ Discovered in 1970's by geophysical None 210 24, 25, 26 and host andesite volcanics overlain pyrite(?) --- and geochemical surveys. Extensive­ T. 7 S., by as much as 200 m of Quaternary ly drilled. Inactive in 1980. R. 27 E. and Tertiary lacustrine and alluvial Deposit contains 3-15% sulfides deposits Cu Vein Deposits Same geologic environment as the porphyry copper deposits. Early activity in the Lone Star mining district was restricted chiefly to exploration and mining of these high grade oxidized veins that are localized in shear zones generally peripheral to the known porphyry deposits. Only a few of the many vein deposits in the district are described below. Ben Hur N1/2sec. 36 Secondary copper minerals and quartz Chrysocolla Old shallow shaft and trenches. --------- T. 5 s •• in 0.5 m-wide shear zone (N75°E, Inactive in 1980 R. 26 E. 85°s) along contact of brecciated felsic dike and Late Cretaceous andesite volcanics Au NE1/4sec. 8 Secondary copper minerals and thin Chrysocol1a Old shaft, >10 m deep, and trench. --- -- ---- T. 6 s •• quartz stringers in shear zone Inactive in 1980 R. 27 E. (N65°E, vert) in Late Cretaceous an- desite volcanics group of 5 prospects SE1/4sec. 8, Secondary copper and iron minerals Chrysocolla Old shafts, adits, and pits. Inac- -- ---- --- SW1/4sec. 9, and quartz ·tn thin (<1 m) shear ttve in 1980 NW1/4sec. 16 zones trending between N7 5°E and F.-W NE1/4sec. 17 in Late Cretaceous andesite T. 6 s •• volcanics R. 27 E. 10 Lone Star C sec. 7 Secondary copper and iron minerals, Chrysocolla Old shafts and pits. Inactive in Possibly as much 100 T. 6 s •• quart>'!, and jarosite in shear zones 1980 as 15,000 metric R. 27 E. in Late Cretaceous andesite volcan- tons Cu, 170 kg ics Ag, and 11 kg Au. Figures may include production from other mines in district MAP NO. NAME LOCATION GEOLOGY ORE MINERALS HISTORY AND DEVELOPMENT PRODUCTION REFERENCES Ag (Au) Vein Deposits Veins restricted to sequence of amygdaloidal andesite and basaltic andesite of middle Tertiary age. Early (1900-1936) mining activity and production record virtually .unknown. 11 Ash Peak SE1/4sec. 3, Quartz- and calcite-filled fissure Argentite Discovered about- 1900. By 1919 had Probably more than 35, 100, 122, (Shamrock and NW1/4sec. 11 vein, as wide as 6 m, along 3 km been developed by 2 shafts and more 97,000 kg Ag and 135 Commerce Shafts) T. 8 S., length of major fault zone trending than 2000 m of underground workings.