BULLETIN 72 Mineral Deposits of Luna County, New Mexico by GEORGE B. GRISWOLD 1961 STATE BUREAU OF MINES AND MINERAL RESOURCES NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY CAMPUS STATION SOCORRO, NEW MEXICO NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY E. J. Workman, President STATE BUREAU OF MINES AND MINERAL RESOURCES Alvin J. Thompson, Director THE REGENTS MEMBERS Ex OFFICIO The Honorable Edwin L. Mechem ....................... Governor of New Mexico Tom Wiley ......................................... Superintendent of Public Instruction APPOINTED MEMBERS William G. Abbott .......................................................................... Hobbs Holm 0. Bursum, Jr. .................................................................... Socorro Thomas M. Cramer ................................................................... Carlsbad Frank C. DiLuzio ................................................................ Albuquerque Eva M. Larrazolo (Mrs. Paul F.) ....................................... Albuquerque For sale by the New Mexico Bureau of Mines & Mineral Resources Campus Station, Socorro, N. Mex.—Price $3.00 Contents Page ABSTRACT ................................................................................................. 1 INTRODUCTION ........................................................................................ 2 Purpose and scope ..................................................................................... 2 Method of investigation ............................................................................. 2 Previous work ............................................................................................. 2 Acknowledgments ..................................................................................... 3 GEOGRAPHY .............................................................................................. 4 Location ..................................................................................................... 4 Topography ............................................................................................... 4 Climate and vegetation .............................................................................. 4 Maps and aerial photographs ..................................................................... 7 GEOLOGY ................................................................................................... 8 Introduction ............................................................................................... 8 Stratigraphy ............................................................................................... 8 Precambrian .......................................................................................... 8 Cambrian-Ordovician ............................................................................ 9 Bliss sandstone .................................................................................. 9 Ordovician ............................................................................................. 9 El Paso limestone .............................................................................. 9 Montoya group .................................................................................. 9 Silurian ................................................................................................ 10 Fusselman dolomite ........................................................................ 10 Devonian ............................................................................................. 11 Percha shale .................................................................................... 11 Mississippian ....................................................................................... 11 Lake Valley and Kelly formations .................................................. 12 Escabrosa and Paradise formations ................................................. 12 Pennsylvanian ..................................................................................... 14 Permian ............................................................................................... 15 Cretaceous ........................................................................................... 17 Sarten sandstone ............................................................................. 17 Colorado shale ................................................................................ 17 Howells Ridge formation ................................................................ 18 Lobo formation ............................................................................... 18 Other Cretaceous sediments ............................................................ 18 iii Page Tertiary .......................................................................................................... 19 Intervolcanic sediments ......................................................................... 19 Gila(?) conglomerate .............................................................................. 19 Quaternary .................................................................................................... 19 Igneous rocks .................................................................................................. 20 General .......................................................................................................... 20 Extrusive rocks ............................................................................................ 21 Early Cretaceous extrusive rocks ......................................................... 21 Tertiary extrusive rocks ......................................................................... 22 Quaternary basalt .................................................................................... 23 Intrusive rocks ............................................................................................. 23 Cooks Peak granodiorite porphyry ...................................................... 23 Fluorite Ridge granodiorite porphyry ................................................. 25 Tres Hermanas quartz monzonite ....................................................... 25 Other intrusive bodies ........................................................................... 25 Structural features ........................................................................................... 26 General .......................................................................................................... 26 Summary of tectonic history ..................................................................... 26 Folds .............................................................................................................. 26 Faults ............................................................................................................. 27 Northwest-striking fault belts ............................................................... 27 North-striking fault belts ....................................................................... 28 Northeast-striking fault belts ................................................................ 29 East-striking fault belts and the Texas lineament ............................. 29 Relationship of ore districts to structural trends .................................... 29 MINING IN LUNA COUNTY ...................................................................... 31 History .............................................................................................................. 31 Production ....................................................................................................... 34 Gold, silver, copper, lead, and zinc .......................................................... 35 Manganese and fluorspar ........................................................................... 35 MINERAL DEPOSITS .................................................................................... 37 Geographic distribution ................................................................................ 37 Classification ................................................................................................... 37 Ore minerals .................................................................................................... 38 Future possibilities ......................................................................................... 39 DESCRIPTION OF DEPOSITS ................................................................... 40 Tres Hermanas mining district ..................................................................... 40 General .......................................................................................................... 40 iv Page Geology ......................................................................................................... 41 Sedimentary rocks .................................................................................. 41 Tertiary igneous rocks ............................................................................ 42 Basalt dikes .............................................................................................. 45 Quaternary rocks .................................................................................... 45 Description of mines and prospects ........................................................ 45 General ..................................................................................................... 45 Mahoney mining area ............................................................................