Geothermal Hydrology of Valles Caldera and the Southwestern Jemez Mountains, New Mexico
Total Page:16
File Type:pdf, Size:1020Kb
GEOTHERMAL HYDROLOGY OF VALLES CALDERA AND THE SOUTHWESTERN JEMEZ MOUNTAINS, NEW MEXICO U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 00-4067 Prepared in cooperation with the OFFICE OF THE STATE ENGINEER GEOTHERMAL HYDROLOGY OF VALLES CALDERA AND THE SOUTHWESTERN JEMEZ MOUNTAINS, NEW MEXICO By Frank W. Trainer, Robert J. Rogers, and Michael L. Sorey U.S. GEOLOGICAL SURVEY Water-Resources Investigations Report 00-4067 Prepared in cooperation with the OFFICE OF THE STATE ENGINEER Albuquerque, New Mexico 2000 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. For additional information write to: Copies of this report can be purchased from: District Chief U.S. Geological Survey U.S. Geological Survey Information Services Water Resources Division Box 25286 5338 Montgomery NE, Suite 400 Denver, CO 80225-0286 Albuquerque, NM 87109-1311 Information regarding research and data-collection programs of the U.S. Geological Survey is available on the Internet via the World Wide Web. You may connect to the Home Page for the New Mexico District Office using the URL: http://nm.water.usgs.gov CONTENTS Page Abstract............................................................. 1 Introduction ........................................ 2 Purpose and scope......................................................................................................................... 3 Previous investigations and availability of data............................................................................ 3 Acknowledgments......................................................................................................................... 5 Regional setting..................................................................................................................................... 5 Geography..................................................................................................................................... 5 Geology......................................................................................................................................... 6 Hydrology..................................................................................................................................... 6 Wles Caldera.......................................................................................^ 11 Geology......................................................................................................................................... 11 Hydrologic setting......................................................................................................................... 13 Nonthermal ground water............................................................................................................. 14 Surface and near-surface geothermal features............................................................................... 15 Thermal meteoric water........................................................................................................ 15 Acid sulfate water................................................................................................................. 17 Hydrothermal alteration........................................................................................................ 24 Geothermal anomaly............................................................................................................. 24 Geothermal reservoir..................................................................................................................... 26 Geometry and hydrologic properties.................................................................................... 26 Areal extent................................................................................................................... 28 Thickness...................................................................................................................... 29 Temperature and pressure distributions........................................................................ 29 Hydraulic properties..................................................................................................... 30 Geochemistry of geothermal fluids....................................................................................... 32 Fluid flow in the reservoir..................................................................................................... 35 Southwestern.JemezMountains............................................................................................................ 37 Descriptive hydrochemistry.......................................................................................................... 39 Mixtures of water.......................................................................................................................... 39 Mineral water near the caldera as derivatives of geothermal fluids.............................................. 46 Mineral water in Canon de San Diego.......................................................................................... 50 Area near rim of caldera....................................................................................................... 53 Jemez Springs and Soda Dam............................................................................................... 58 Fluctuations in constituent concentrations............................................................................ 62 Stable isotopes as evidence of mixing.................................................................................. 68 Origin of mineral water................................................................................................................. 68 Wells GT-2, PC-1, and PC-2................................................................................................. 68 Well VC-1............................................................................................................................. 75 Jemez Springs and Soda Dam............................................................................................... 78 Page Ground-water system............................................................................................................................. 79 Principal aquifers........................................................................................................................... 79 Canon de San Diego San Ysidro area......................................................................................... 80 Discharge from the geothermal reservoir...................................................................................... 89 Ground-water underflow....................................................................................................... 90 Conduit flow in bedrock........................................................................................................ 90 Streamflow............................................................................................................................ 91 Perched ground water in bedrock.................................................................................................. 93 Quantitative modeling of the geothermal system.................................................................................. 94 Conceptual models of the geothermal system............................................................................... 95 Existing numerical models............................................................................................................ 96 Quantitative constraints................................................................................................................. 97 Modeling system response to development................................................................................... 99 Monitoring hydrochemical discharge in the southwestern Jemez Mountains....................................... 101 Historical monitoring............................................................................................................................. 10 Summary.......................................................................................^ Selected references.................................................................................................................................! 11 FIGURES 1-7. Maps showing: 1. Geographic setting of the Jemez Mountains region........................................................... 4 2. Generalized geology of the Jemez Mountains and adjacent Rio Grande Rift zone........................................................................................................................... 7 3. Regional geologic setting of the Jemez Mountains............................................................ 9 4. (A) Geologic features in the Valles Caldera and (B) generalized geologic section of the Valles Caldera............................................................................................ 10 5. Location of selected geothermal boreholes and hot springs in the Valles Caldera region............................................................................................................................... 12 6. Principal streams in the Valles Caldera region and location of discontinued