DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY PRELIMINARY MINERAL RESOURCE ASSESSMENT OF THE TUCSON AND NOGALES 1° by 2° QUADRANGLES, ARIZONA Edited by Jocelyn A. Peterson Open-File Report 90-276 This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American stratigraphic code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. CONTENTS Page Preface................................................................................................. 1 Introduction.......................................................................................... 2 Topographic coverage .......................................................................... 2 Indian lands ...................................................................................... 2 Geology, by Jocelyn A. Peterson, Joel R. Bergquist, Stephen J. Reynolds, and Susan S. Page-Nedell.............;........................................................ 8 Data coverage and map compilation........................................................... 8 Geologic summary.............................................................................. 8 Selected references.............................................................................. 14 Geochemistry, by Maurice A. Chaffee........................................................... 19 Data coverage.................................................................................... 19 Evaluation of USGS stream-sediment data .................................................. 19 Tucson Quadrangle.................................................................. 20 NogalesQuadrangle ................................................................. 22 References cited...................................................................... 40 Geophysics - gravity and magnetic methods, by David A. Ponce ..................... 41 Gravity methods................................................................................. 41 Data coverage......................................................................... 41 Density data........................................................................... 41 Interpretation.......................................................................... 41 Magnetic methods............................................................................... 42 Data coverage......................................................................... 42 Susceptibility data.................................................................... 42 Interpretation.......................................................................... 42 Selected references.............................................................................. 54 Geophysics - remote sensing, by Susanne Hummer-Miller and Daniel H. Knepper, Jr................................................................. 57 Landsat multispectral scanner and thematic mapper......................................... 57 Data coverage......................................................................... 57 Interpretation.......................................................................... 57 Gamma-ray spectrometry....................................................................... 58 Data coverage......................................................................... 58 Interpretation.......................................................................... 59 References cited................................................................................. 64 Geophysics electrical and seismic methods, by Robert J. Bisdorf .................. 65 Electrical methods............................................................................... 65 Seismic methods ................................................................................ 65 Comments........................................................................................ 65 Selected references.............................................................................. 66 Mineral resources, by Gail M. Jones............................................................ 68 Production and occurrence data ............................................................... 68 Metals.................................................................................. 68 Nonmetals............................................................................. 69 Fuels and Energy Resources........................................................ 69 Mineral resource potential...................................................................... 70 Delineated deposit types............................................................. 70 Porphyry copper............................................................ 70 Skarn and replacement deposits........................................... 71 Epithermal precious-metal deposits ....................................... 72 Polymetallicveins .......................................................... 72 Flat-fault gold deposits..................................................... 73 Deposit types not delineated ........................................................ 73 Tungsten deposits........................................................... 73 Placer gold................................................................... 74 Rare-earth pegmatites....................................................... 74 Uranium veins and vanadium veins....................................... 74 Titaniferous magnetite in alluvium........................................ 74 Selected references.............................................................................. 83 Appendix List of mines and prospects....................................................................102 11 FIGURES 1. Index map showing geographic locations............................................. 3 2. Index to topographic maps.............................................................. 4-7 Distribution of sample sites for: 3. <100-mesh stream sediment, NUREdatabase....................................... 30 4. <100-mesh soil, NUREdatabase...................................................... 31 5. Spring water, NUREdatabase......................................................... 32 6. Stream water, NUREdatabase......................................................... 33 7. Well water, NURE data base............................................................ 34 8. Rock, RASS and PLUTO data bases.................................................. 35 9. Stream sediment, RASS data base ..................................................... 36 10. Magnetic heavy-mineral concentrate, RASS data base............................... 37 11. Nonmagnetic heavy-mineral concentrate, RASS data base.......................... 38 12. Well and spring water, RASS data base............................................... 39 13. Index map of gravity station locations................................................. 48 14. Index map showing density of gravity stations....................................... 49 15. Complete Bougergravity map.......................................................... 50 16. Isostatic gravity map..................................................................... 51 17. Index map showing boundaries of aeromagnetic surveys........................... 52 18. Aeromagnetic map........................................................................ 53 Gray-scale contour maps of element distribution in Arizona, scale 1:3,500,000: 19. Uranium ................................................................................... 61 20. Potassium................................................................................. 62 21. Thorium................................................................................... 63 22. Location map of mining districts ....................................................... 82 TABLES 1. Published maps by the USGS that cover parts of the study area................... 12 2. Thesis work used in the compilation of the Tucson quadrangle .................... 13 3. Summary of analytical information for RASS, PLUTO, andNURE data bases, Tucson quadranlge....................................................................... 26 4. Summary of analytical information for RASS, PLUTO, and NURE data bases, Nogalesquadrangle...................................................................... 27 5. Summary of statistical information for the USGS stream-sediment data base .... 28 6. Summary of background and anomaly data for 14 selected ore-related elements. 29 7. List of gravity data sources.............................................................. 44 8. Density data............................................................................... 45 9. Aeromagnetic surveys.................................................................... 46 10. Magnetic susceptibility data............................................................. 47 11. Rank by copper production of the main copper producers in the study area...... 75 12. Principal deposit types and cumulative production in mining districts.............. 76 13. List of mines with significant production and (or) reserves......................... 77 14. Deposit types considered in preassessment........................................... 78 15. Criteria used to delineate tracts permissive for deposits ............................. 79 16. Matrix showing