Groundwater flow conceptualization of the Pahute Mesa–Oasis Valley Groundwater Basin, Nevada—A synthesis of geologic, hydrologic, hydraulic-property, and tritium data

Jackson, Tracie R.- tjackson@usgs.gov, Fenelon, Joseph M.-X jfenelon@usgs.gov, Paylor, Randall L.- · 2021 · Report

This report provides a groundwater-flow conceptualization that integrates geologic, hydrologic, hydraulic-property

Public-domain full text preserved in the Mountain Man Mining Library. Original source: pubs.usgs.gov.

Tanks Rainier Mesa caldera margin M25 fault M22 fault RD9 fault Bullfrog Hills - Ammonia caldera margin RD1 fault Ammonia Tanks caldera margin Rainier Mesa Big Burn fault Fluorospar Canyon detachment Rainier caldera Mesa margin Hot Spg RD2 fault caldera margin PBRCM BRA BFCU LCCU LCA RMICU UCCU PBRCM DVCM ATICU RMWTA RMWTA SCVCU ATWTA THCU ATWTA SCVCU RMICU UCCU LCCU1 MGCU SWA TMLVTA SWA ATWTA AA FCCM THCU YVCM TCVA TCVA ATCCU BWCU BWWTA FCLLFA FCCM FCWTA FCCM TCVA AA PCM YMCFCM AA TMWTA RMWTA YMCFCM THCU CHVTA LCA3 TMLWTA 2,000 4,000 -2,000 6,000 8,000 Timber Mountain caldera complex 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Oasis Valley 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 Distance along section, in feet Hydrostratigraphic Section Rainier Mesa Buckboard Mesa Timber Mountain ER-OV-04a Beatty Wash Terrace Well ER-OV-03c Beatty Wash Windmill Well ER-18-2 UE-18t WW-8 U-12s NNSS NTTR NTTR Beatty Wash Fortymile Canyon Beatty Wash Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) Tie point section I-I' Outside Pahute Mesa- Oasis Valley basin 4,000 2,000 6,000 8,000 Altitude above NGVD29, in feet Distance along section, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 Hydrologic Section Recharge Recharge Recharge Recharge 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet Springs Lower boundary of Pahute Mesa-Oasis Valley basin Amargosa River High gradient Low gradient High gradient Low gradient High gradient High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Discharge Area Discharge Area Northeast SouthwestA A' Hogback fault Timber Mountain caldera margin Tanks Ammonia Tanks caldera margin Timber Mountain caldera margin West Greeley fault East Greeley fault Almendro fault Rickey fault RM4 fault Scrugham Peak fault M27 fault M26 fault M24 fault M25 fault M23 fault RD1 fault RD9 fault Bullfrog Hills Ammonia M28 fault caldera margin RD5 fault RD7 fault N. Timber Mtn moat structural zone S. Pahute Mesa E. Thirsty Canyon E. Silent Canyon structural zone RM3 fault Split Ridge fault structural zone structural zone West Greeley fault - Fluorospar Canyon detatchment POOL SLED BACKBEACH INLET DVA LCCU RMICU RMWTA SCVCU ATWTA THCU FCLLFA FCWTA PBRCM LCA TMWTA FCCM FCULFA5 AA TCVA TCVA DVCM ATWTA THCU RMWTA ATICU SCVCU RMWTA FCLLFA FCCM TCVA BWCU BWWTA TCVA FCCM FCULFA3 ATCCU THLFA LCA PBRCM BRA CFCU CHLFA4 CHLFA1 PLFA CHZCM CHZCM TCA SPA MPCU UPCU FCCU THCM TMWTA THLFA PLFA IA BRA PBRCM BFCU CFCU SPA TMLVTA TMWTA TMWTA LPCU PVTA TCA TMLVTA CHVTA TCA KA MGCU PBRCM BRA UCCU LCCU1 PLFA TMLVTA TMWTA TMLVTA TMWTA CFCU PLFA BRA CFCU PBRCM PBRCM CFCU LCA ATWTA THCU FCCM RMWTA MPCU PLFA CHZCM THCU THCM YMCFCM TCVA TCA THLFA 2,000 4,000 -2,000 6,000 8,000 Timber Mountain caldera complex 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Pahute Mesa ER-OV-03a ER-OV-03b ER-20-4 UE-18r ER-20-2-1 U-19x UE-19i U-19p UE-19c WW UE-19fS Boiling Pot Rd Well Timber Mountain Silent Canyon Oasis Valley 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 Distance along section, in feet Hydrostratigraphic Section U-19i U-19f The Bench Kawich Canyon NNSS NTTR NTTR (south of section) (south of section) Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) BLM/Private Silent Canyon caldera complex Tie point section H-H' Tie point section I-I' 4,000 2,000 6,000 8,000 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Distance along section, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Recharge Recharge Recharge 200,000 Recharge Recharge Goss Springs Amargosa River High gradient Low gradient High gradient Low gradient High gradient Low gradient High gradient Lower boundary Pahute Mesa-Oasis Valley basin Discharge Area Discharge Area High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Hydrologic Section Northeast SouthwestB B' Hogback fault Timber Mountain caldera margin Tanks caldera margin Ammonia Tanks caldera margin Timber Mountain West Boxcar fault Buteo fault West Greeley fault East Greeley fault W. Almendro fault Almendro fault Rickey fault RM4 fault RM3 fault Boxcar fault W. Silent Canyon structural zone ER-20-8 fault Fleur-de-Lis M27 fault M26 fault Colson Pond fault M33 fault M32 fault M25 fault M31 fault M30 fault M29 fault M2 fault ER-20-8 S. fault N. Timber Mtn moat structural zone Bullfrog Hills - Fluorospar S. Pahute Mesa SZ ER-20-7 fault Ammonia fault Canyon detatchment Caldera margin KEARSARGE FONDUTTA MUENSTER (Offset south of section at U-19e) CYBAR SCOTCH BODIE CHESHIRE (offset east of section at U-20n) MOLBO DVA LCCU LCA PBRCM RMWTA ATWTA FCCM AA TMWTA FCWTA FCLLFA SCVCU TCVA BWWTA BWCU THCU FCCM ATWTA RMWTA SCVCU THCU BWCU TCVA BWWTA UCCU LCCU1 PBRCM BRA BFCU BFCU CFCU CHVTA CHVTA CFCU BRA PBRCM CFCM CHZCM CHZCM CHZCM CHLFA5 IA CHLFA4 TSA LPCU TCA THCM THLFA TMWTA FCCU BA UPCU SPA MPCU BA PBPCU TMLVTA TMWTA TCVA CHLFA1 UPCU TCA WWA BA TCVA UPCU TMLVTA TMLVTA TMWTA TCVA CHLFA5 CFCU CHLFA3 CHLFA1 PVTA PVTA PLFA TCA TMWTA KA BRA BFCU LCA PBRCM PBRCM BRA RMWTA RMICU BRA LCA MGCU PBRCM THCU TSA CFCM BFCU BFCU CHZCM CHZCM MPCU LPCU BA CHLFA4 CFCU BFCU BRA PBRCM BFCU CHVTA TMLVTA PVTA PLFA CFCU TMLVTA BRA BWCU CFCU TCVA CHLFA5 PBRCM CHVTA TMWTA FCCM RMWTA ATWTA ER-EC-5 ER-EC-14 ER-EC-12 ER-20-8 U-20ag U-20ax UE-20n1 U-20a2 WW U-20ap U-19aS U-19ar UE-19e WW U-19zS U-19ax NC-GWEOV-01 2,000 4,000 -2,000 6,000 8,000 Silent Canyon caldera complex 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet The Bench Timber Mountain caldera complex Pahute Mesa Oasis Valley Silent Canyon Kawich Canyon Lambs Canyon 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 210,000 Hydrostratigraphic Section NNSS NTTR NTTR UE-19z Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) BLM/Private Tie point section H-H' Tie point section I-I' Amargosa River 4,000 2,000 6,000 8,000 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Distance along section, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 60,000 Distance along section, in feet Hydrologic Section Recharge Recharge Recharge 210,000 Discharge Area Discharge Area High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient High gradient Low gradient High gradient Low gradient High gradient High gradient Lower boundary Pahute Mesa-Oasis Valley basin Low gradient High gradient Low gradient High gradient Recharge Altitude above NGVD29, in feet Northeast SouthwestC C' M3 fault Ammonia Tanks caldera margin Rainier Mesa caldera margin M2 fault SW Area 20 fault N. Timber Mtn moat structural zone ER-20-7 fault West Boxcar fault Boxcar fault Buteo fault West Greeley fault West Silent Canyon structural zone East Greeley fault North Silent Canyon structural zone Moor Hen Meadow structural zone Kawich Range West fault Kawich Range East fault Kawich Range East fault Belted Range West fault TYBO BENHAM GOLDSTONE PIPKIN COMSTOCK JEFFERSON REX KASSERI GREELEY SCROLL CHARTREUSE (Offset south of section at U-19d) MAST (Offset north of section at U-19u) ATWTA BWCU BWWTA FCCM FCULFA4 FCWTA1 FCULFA2 FCULFA1 FCULFA1 TMWTA FCCU CPA PBPCU FCCU THCM THCU BRA BA UPCU THCM TCA LPCU TSA CHZCM PBRCM THLFA CFCU TCVA AA THCU SCVCU LCA PBRCM CFCU RMWTA CHZCM TSA LPCU TCA THLFA TCVA BRA CFCM TCVA BFCU BRA BRA BFCU BFCU BRA PBRCM BFCU BRA PBRCM CHZCM TSA LPCU TMWTA CFCM IA CHZCM CHZCM CFCM CFCU TSA TCA BA UPCU TMLVTA TMLVTA TCVA CHLFA4 CHLFA3 CHLFA5 TMWTA CHLFA5 UCCU LCCU1 PBRCM CHVTA TMWTA TMLVTA CHLFA2 PLFA CHZCM TMLVTA PVTA CHVTA TMLVTA CFCU AA UCCU TCVA PBRCM PBRCM PBRCM PBRCM AA AA LCCU1 LCA3 LCCU1 UCCU UCCU LCA3 TMLVTA BRA BRA TMWTA TMWTA TCVA TMWTA BFCU BFCU LCA BRA IA BRA CHLFA5 UPCU TCA TMWTA PLFA TMLVTA PLFA CHZCM CHLFA3 CHLFA3 CHZCM CHZCM CHZCM CHZCM CHZCM CHLFA4 CFCU CHLFA2 TMLVTA TMWTA CFCU LCA3 LCA LCA BRA LPCU BA TCA LPCU FCCM TMWTA PVTA TMWTA TCVA LCCU1 FCWTA1 PBPCU TMLVTA TMWTA 2,000 4,000 -2,000 6,000 8,000 Silent Canyon caldera complex 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Timber Mountain caldera complex ER-EC-6 ER-EC-11 ER-20-7 U-20c U-20ao U-20b U-20ai UE-20h U-20z U-20g U-19n UE-19h U-19d2 U-20ay ER-20-5-1 U-20y Lamb well ER-EC-2A Pahute Mesa Silent Canyon Grass Spring Canyon Kawich Valley The Bench Basket Valley Hydrostratigraphic Section 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 Distance along section, in feet 190,000 200,000 210,000 220,000 230,000 240,000 250,000 Tie point section H-H' Tie point sections E-E', I-I' NNSS NTTR ER-20-5-3 Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) 4,000 2,000 6,000 8,000 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Distance along section, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 Hydrologic Section Recharge Recharge Recharge Recharge Recharge Recharge 200,000 210,000 220,000 230,000 240,000 250,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Lower boundary Pahute Mesa-Oasis Valley basin High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient High gradient Low gradient High gradient Mixed Low and High gradient Low gradient Northeast SouthwestD D' M3 fault Ammonia Tanks Rainier Mesa caldera margin M2 fault SW Area 20 fault N Timber Mtn moat structural zone West Boxcar fault Grouse Canyon NW structural margin Moor Hen Meadows structural zone Gold Flat 4 fault caldera margin Gold Flat 4 fault West Silent Canyon structural zone TENABO HORNITOS FONTINA CABRA BOXCAR JORUM FCULFA2 FCULFA1 TCVA FCCM FCULFA4 FCWTA1 BWWTA BWCU ATWTA RMWTA PBRCM BRA CFCU CHZCM TSA LPCU TCA UPCU BA CPA FCCU TMWTA THCM THLFA TCVA CHZCM CFCM BFCU IA CHZCM CHLFA5 LPCU TCA UPCU BA TMLVTA TMWTA TCVA BRA CHZCM CHLFA5 TMWTA CFCM CHLFA3 CHLFA2 TMLVTA PLFA UCCU AA AA PBRCM AA BFCU PBRCM PBRCM CFCM BFCU PBPCU LCA THCU AA PBRCM TCVA TCVA TCVA LCCU1 UCCU TMWTA TMLVTA BRA CHZCM CHZCM TCA PBPCU BRA TSA 2,000 4,000 -2,000 6,000 8,000 Silent Canyon caldera complex 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Timber Mountain caldera complex Pahute Mesa Basalt Ridge The Bench Hydrostratigraphic Section 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 Distance along section, in feet 190,000 200,000 Tie point section H-H' Tie point sections D-D', I-I' NNSS NTTR ER-EC-2A ER-EC-13 ER-EC-15 ER-20-1 U-20bb U-20bc UE-20f U-20i U-20aj U-20e UE-20e 1 Gold Flat 1 TTR Well 53 Gold Flat NNSS NTTR U-20f Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) 4,000 2,000 6,000 8,000 Altitude above NGVD29, in feet Distance along section, in feet Hydrologic Section Recharge Recharge 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 200,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Lower boundary Pahute Mesa-Oasis Valley basin High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient High gradient Low gradient High gradient Low gradient High gradient Recharge Recharge Northeast SouthwestE E' M5 North fault Ribbon Cliff structural zone N. Timber Mtn moat structural zone Trappman Hills fault Handley fault HANDLEY PBRCM PBRCM BRA TCVA TMWTA TMLVTA CHZCM PBRCM CHLFA5 UPCU LPCU TCA BFCU TCVA TMWTA THLFA FCCM PBRCM THCM CPA FCCU TMUWTA TMWTA FCCM YVCM AA UCCU LCCU TCVA Thirsty Canyon BRA AA LCA TCVA UCCU TMWTA LPCU PBRCM BRA PBRCM CHZCM UPCU TCA BRA BFCU TCVA BRA TCVA LCA LCA 2,000 4,000 -2,000 6,000 8,000 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Pahute Mesa Hydrostratigraphic Section 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 Distance along section, in feet 190,000 200,000 Tie point section H-H' Tie point section I-I' NNSS NTTR ER-OV-06a, ER-OV-06a2 ER-EC-4 PM-3 ER-20-12 Gold Flat 2 Gold Flat NNSS NTTR 210,000 UE-20j U-20m PM-2 Trail Ridge East Fork Thirsty Canyon Cactus Range Trappman Hills TTR Sulfide Mine Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) Thirsty Canyon West Fork Thirsty Canyon East Fork Thirsty Canyon 4,000 2,000 6,000 8,000 Altitude above NGVD29, in feet Distance along section, in feet Hydrologic Section Recharge Recharge 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 170,000 180,000 30,000 40,000 50,000 60,000 70,000 130,000 140,000 150,000 160,000 190,000 200,000 200,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Lower boundary Pahute Mesa-Oasis Valley basin High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient High gradient Low gradient High gradient Low gradient High gradient Recharge Recharge High gradient Low gradient 210,000 Northeast SouthwestF F' Fleur-de-Lis fault Bullfrog Hills - Fluorospar Canyon detachment Beatty Wash fault LCCU DVA TCVA TMWTA DVCM DVCM AA LCCU LCCU AA PBRCM DVCM AA 2,000 4,000 -2,000 6,000 8,000 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet 10,000 20,000 30,000 40,000 50,000 Tie point section I-I' NTTR BLM/Private Springdale Lower Well BLM Springdale Well Springdale Upper Well Springdale Windmill Well ER-OV-05 Oasis Valley Hydrostratigraphic Section Distance along section, in feet Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) Springdale, NV 4,000 2,000 6,000 8,000 Altitude above NGVD29, in feet Distance along section, in feet Hydrologic Section 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet 10,000 20,000 30,000 40,000 50,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient Discharge Area Discharge Area High gradient Springs North SouthG G' West Greeley fault Ammonia Tanks caldera margin Rainier Mesa Boxcar fault ER-20-7 fault M2 fault SW Area 20 caldera margin N Timber Mtn moat structural zone Thirsty Canyon lineament Black Mtn Handley fault M3 fault Black Mtn caldera margin SW Area 20 caldera margin caldera margin caldera margin LCA PBRCM TCVA BRA TMLVTA TCVA SCVCU BMICU PBRCM BRA UPCU LPCU TCA TMLVTA TMWTA TCVA BRA BFCU CFCM IA CHZCM TSA LPCU TCA TSA UPCU CPA FCCU BA CHZCM CFCU CFCU PBRCM BRA THCM THCM TMWTA TMWTA PBPCU THLFA THLFA TCVA TCVA UPCU PLFA MPCU SPA FCCU RMWTA FCULFA3 FCCM ATWTA ATCCU THLFA THCU LCA CHZCM BFCU BRA PBRCM LCA TCA LPCU UPCU TMWTA SCVCU LCCU THCU BA FCCU THCM THLFA CPA AA LCA AA AA 2,000 4,000 -2,000 6,000 8,000 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Hydrostratigraphic Section 10,000 20,000 80,000 90,000 100,000 110,000 30,000 40,000 50,000 60,000 70,000 Distance along section, in feet Tie point section B-B' NTTR ER-EC-12 The Bench UE-18r ER-EC-15 ER-EC-1 PM-3 Thirsty Canyon Black Mountain caldera Rocket Wash NNSS Tie point section C-C' Tie point section E-E' Tie point section F-F' Pahute Mesa Ribbon Cliff Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) Tie point section D-D' Pahute Mesa E. Fork Thirsty Canyon Timber Mtn caldera complex Silent Canyon caldera complex Black Mountain 4,000 2,000 6,000 8,000 Altitude above NGVD29, in feet Distance along section, in feet Hydrologic Section 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet 10,000 20,000 80,000 90,000 100,000 110,000 30,000 40,000 50,000 60,000 70,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Lower boundary Pahute Mesa-Oasis Valley basin High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient High gradient Low gradient High gradient High gradient Low gradient Recharge Recharge Recharge Flow to southwest, perpendicular to section Northwest SoutheastH H' Bullfrog Hills - Fluorospar Canyon detachment Beatty Wash fault Beatty Wash fault Fleur-deLis fault Colson Pond fault Hogback fault M33 fault M5 South fault M4 fault Ammo nia T ank s

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DVCM DVA LCA RMWTA ATWTA FCCM TMWTA PBRCM ATWTA PBRCM BWCU FCWTA1 FCULFA2 BWWTA FCWTA TCVA TMUWTA AA LCA THCU FCLLFA UCCU LCCU LCCU LCCU LCA AA LCA TCVA BWCU BWWTA FCCM FCCM DVA 2,000 4,000 -2,000 6,000 8,000 4,000 2,000 -2,000 6,000 8,000 Altitude above NGVD29, in feet Altitude above NGVD29, in feet Hydrostratigraphic Section 10,000 20,000 80,000 90,000 100,000 110,000 120,000 30,000 40,000 50,000 60,000 70,000 Distance along section, in feet Tie point section A-A' NTTR Narrows South Well 2 NC-GWE-OV-02 ER-EC-8 ER-OV-06a, ER-OV-06a2 OVU Lower ET Well OVM ET Well NC-GWEOV-01 Boiling Pot Rd Well Beatty Wash Terrace Well Springdale Lower Well BGC-1 Well Beatty Well No. 3 Beatty Well No. 2 Central Beatty Well Beatty Well No. 1 ER-EC-2A Tie point section B-B' Tie point section C-C' Tie point section G-G' Tie point section F-F' Tie point sections D-D', E-E' Beatty, NV Amargosa Narrows BLM/Private Timber Mountain caldera complex Geology source: Pahute Mesa-Oasis Valley hydrostratigraphic framework model (U.S. Department of Energy, 2020a) Oasis Valley Rocket Wash 4,000 2,000 6,000 8,000 Altitude above NGVD29, in feet Distance along section, in feet Hydrologic Section 2,000 4,000 6,000 8,000 Altitude above NGVD29, in feet 10,000 20,000 80,000 90,000 100,000 110,000 120,000 30,000 40,000 50,000 60,000 70,000 High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone High transmissivity zone Low transmissivity zone Low transmissivity zone High transmissivity zone Low gradient Low to High gradient Lower boundary Pahute MesaOasis Valley basin High gradient Colson Pond and Spring Springs OVU Culvert Springs Springdale Culvert Springs Torrance Spring Hot Springs Ute Springs Ute Springs Springs Burrell Hot Spring Beatty Springs Spring Narrows Spring Northeast SouthwestI I' Scientific Investigations Report 2020-5134 Hydrostratigraphic and Hydrologic sections—PLATE 2 Prepared in cooperation with the U.S. DEPARTMENT OF ENERGY U.S. Department of the Interior U.S. Geological Survey Hydrostratigraphic and hydrologic sections in the Pahute Mesa-Oasis Valley groundwater basin, Nevada By Tracie R. Jackson, Joseph M. Fenelon, and Randall L. Paylor No vertical exaggeration Scale 1:50,000 National Geodetic Vertical Datum of 1929 0 2 4 6 8 10 MILES 0 2 4 6 8 10 KILOMETERS Description of hydrogeologic units shown on hydrologic sections— Modified from three-dimensional hydrostratigraphic framework model (U.S. Department of Energy, 2020a) U-20y HYDROSTRATIGRAPHIC- AND HYDROLOGIC-SECTION EXPLANATION Alluvial aquifer— Saturated extent of alluvial deposits Composite volcanic— Saturated extent of undifferentiated volcanic rocks composed of lava flows, vitric tuffs, welded tuffs, and nonwelded or bedded tuffs Lava-flow and welded-tuff aquifers— Saturated extent of lava flows and welded tuffs Potentiometric surface Borehole and saturated part of open interval(s) — Open intervals are shown where water levels have been measured. Open intervals include boreholes that have been destroyed, such as nuclear-test boreholes. Unsaturated part of hydrogeologic units—Uncolored areas on hydrologic sections portray areas where units are above the regional potentiometric surface Trace of hydrostratigraphic and hydrologic sections Saturated extent of siliciclastic and Computed sphere with a radius of three-cavity radii, as intersected by the section. Size shown on the section is determined by the three-dimensional intersection of the sphere and the plane of the section. For tests that lie on the plane of the section, the radius is equal to threecavity radii. For tests that lie off the plane of the section, the radius is less than three-cavity radii. Clastic confining unit, granite confining unit, and intra-caldera intrusive confining unit— Vitric-tuff aquifer— Tuff confining unit — Saturated extent of nonwelded or bedded tuffs Carbonate aquifer— Saturated extent of carbonate rocks Low-transmissivity zone— Cross-hatch area represents less permeable saturated zone where transmissivity generally is less than 10 feet squared per day and groundwater flow is minor Property boundary— Boundaries between land ownership areas. NNSS, Nevada National Security Site; NTTR, Nevada Test and Training Range; BLM, Bureau of Land Management; Private, private land. INSET MAP EXPLANATION Boundary for the Pahute Mesa-Oasis Valley groundwater basin— defines the contributing recharge area for discharge to Oasis Valley Saturated extent of vitric tuffs NNSS NTTR Vertical hydraulic gradients— Hydraulic gradients computed from head differences between selected measured well pairs in the Pahute Mesa-Oasis Valley basin. Includes nuclear test holes that have been subsequently filled and destroyed. Arrow indicates direction of vertical gradient in the aquifer system. Selected open intervals are shaded in blue where upward or downward vertical gradients were computed (see Table 2) Flow arrow— Indicates general groundwater-flow direction along each hydrologic section. Upper two arrows show flow parallel to section; lower two arrows show flow into the section.

Discharge area and springs— Upward arrow shows zone of discharge in Oasis Valley. Mapped springs are indicated on the section if they are within 500 feet of the section line. High gradient Low gradient Horizontal hydraulic gradients— Generalized areas of low or high gradients along the potentiometric surface of the Pahute Mesa-Oasis Valley groundwater basin. High gradients are greater than 50 feet per mile, and low gradients less than 50 feet per mile. M6 Fault Fault or caldera margin— Represents major structural feature; arrows show directions of offset Tie point section H-H' Section tie point — Intersection between sections. See inset map for section locations A A' F F' Boreholes— Small circle indicates borehole where water levels were measured in one or more wells. Large circle indicates nuclear test hole that is shown on section ER-EC-5 U-19z Internal operational area boundary of the Nevada National Security Site Recharge areas— Downward arrow shows recharge zones where infiltration recharges the flow system. intrusive rocks Nuclear test cavity. Estimated size of cavity based on reported maximum yield, depth of burial, and overburden density (from Pawloski, 1999). Shown only for cavities that lie on the plane of the section. Chimney Three cavity radii Collapse chimney and rubble column — Estimated chimney height based on reported maximum yield, depth of burial, and overburden density (from Pawloski, 1999). 116°10' 116°20' 116°30' 116°40' 116°50' 37°40' 37°30' 37°20' 37°10' 37°0 ' ER-OV-03c Narrows South Well 2 Beatty Wash Terrace Well ER-OV-04a BGC-1 Well Beatty Well No. 3 Beatty Well No. 2 Central Beatty Well Beatty Well No. 1 Boiling Pot Rd ER-OV-03a NC-GWE-OV-01 A A' B' C' D D' E E' F F' G G' H ' H I'

Miles B ER-OV-03c Narrows South Well 2 Beatty Wash Terrace Well ER-OV-04a BGC-1 Well Beatty Well No. 3 Beatty Well No. 2 Central Beatty Well Beatty Well No. 1 Boiling Pot Rd Well ER-OV-03a ER-OV-03b ER-EC-5 ER-OV-06a ER-OV-05 OVU Lower ET Well Springdale Windmill Well Springdale Lower Well Springdale Upper Well NC-GWE-OV-01 OVM ET Well Beatty Wash Windmill Well BLM Springdale ER-EC-8 ER-EC-2A ER-18-2 UE-18t WW-8 U-12s UE-19c WW U-19p U-19i, UE-19i U-19x U-19f, UE-19fS ER-20-2-1 ER-20-4 UE-18r ER-EC-14 ER-EC-12 ER-20-8 U-20ag U-20ax U-20ap U-20a2 WW U-19aS U-19ar UE-19z, U-19zS U-19ax Lamb Well U-19d2 UE-19h U-19n U-20g U-20z UE-20h U-20ai U-20ay U-20b U-20ao U-20c U-20y ER-20-5-1,3 ER-20-7 ER-20-1 ER-EC-13 ER-EC-15 ER-EC-1 ER-EC-11 ER-EC-6 PM-3 U-20bb U-20bc

U-20i U-20aj U-20e UE-20e1 Gold Flat 1 Gold Flat 2 PM-2 TTR Well 53 UE-20j ER-20-12 ER-EC-4 TTR Sulfide Mine U-20m U-20n U-19e, U-19d U-19u Nevada Test and Training Range Nevada Test and Training Range Nevada National Security Site Nevada National Security Site Area 18 Area 18 Area 19 Area 19 Area 20 Area 20 Area 12 Area 12 BLM and private land BLM and private land NC-GWE-OV-02 NC-GWE-OV-02 UE-20n 1 UE-20n 1 UE-19e WW UE-19e WW U-20f, UE-20f U-20f, UE-20f Beatty Beatty FCWTA1 Fortymile Canyon welded-tuff aquifer #1, welded tuff IA Inlet aquifer, lava flow KA Kearsarge aquifer, lava flow LCA Lower carbonate aquifer, carbonate rock LCA3 Lower carbonate aquifer-thrust plate, carbonate rock LCCU Lower clastic confining unit, siliciclastic rock LCCU1 Lower clastic confining unit-thrust plate, siliciclastic rock LPCU Lower Paintbrush confining unit, nonwelded tuff MGCU Mesozoic granite confining unit, intrusive rock MPCU Middle Paintbrush confining unit, nonwelded tuff PBPCU Post-Benham Paintbrush confining unit, nonwelded tuff PBRCM Pre-Belted Range composite unit, nonwelded tuff/welded tuff/lava flow PCM Paintbrush composite unit, welded tuff/lava flow/nonwelded tuff PLFA Paintbrush lava-flow aquifer, lava flow PVTA Paintbrush vitric-tuff aquifer, vitric tuff RMICU Rainier Mesa intrusive confining unit, intrusive rock RMWTA Rainier Mesa welded-tuff aquifer, welded tuff SCVCU Subcaldera volcanic confining unit, nonwelded tuff SPA Scrugham Peak aquifer, lava flow SWA Stockade Wash aquifer, welded tuff TCA Tiva Canyon aquifer, welded tuff TCVA Thirsty Canyon volcanic aquifer, welded tuff/lava flow, lesser vitric tuff THCM Tannenbaum Hill composite unit, nonwelded tuff, lesser welded tuff THCU Tannenbaum Hill confining unit, nonwelded tuff THLFA Tannenbaum Hill lava-flow aquifer, lava flow, minor vitric tuff/nonwelded tuff TMLVTA Timber Mountain lower vitric-tuff aquifer, vitric tuff TMUWTA Timber Mountain upper welded-tuff aquifer, welded tuff, lesser lava flow/nonwelded tuff TMWTA Timber Mountain welded-tuff aquifer, welded tuff, minor vitric tuff TSA Topopah Spring aquifer, welded tuff UCCU Upper clastic confining unit, siliciclastic rock UPCU Upper Paintbrush confining unit, nonwelded tuff WWA Windy Wash aquifer, lava flow YMCFCM Yucca Mountain-Crater Flat composite unit, lava flow/welded tuff/nonwelded tuff YVCM Younger volcanic composite unit, lava flow/welded tuff/vitric tuff AA Alluvial aquifer, alluvium ATCCU Ammonia Tanks caldera confining unit, nonwelded tuff ATICU Ammonia Tanks intrusive confining unit, intrusive rock ATWTA Ammonia Tanks welded-tuff aquifer, welded tuff BA Benham aquifer, lava flow BFCU Bullfrog confining unit, nonwelded tuff BMICU Black Mountain intrusive confining unit, intrusive rock BRA Belted Range aquifer, lava flow/welded tuff, lesser nonwelded tuff BWCU Buttonhook Wash confining unit, nonwelded tuff BWWTA Buttonhook Wash welded-tuff aquifer, welded tuff CFCM Crater Flat composite unit, lava flow, intercalcated with nonwelded tuff CFCU Crater Flat confining unit, nonwelded tuff CHLFA1 Calico Hills lava-flow aquifer #1, lava flow CHLFA2 Calico Hills lava-flow aquifer #2, lava flow CHLFA3 Calico Hills lava-flow aquifer #3, lava flow CHLFA4 Calico Hills lava-flow aquifer #4, lava flow CHLFA5 Calico Hills lava-flow aquifer #5, lava flow CHVTA Calico Hills vitric-tuff aquifer, vitric tuff CPA Comb Peak aquifer, lava flow DVA Detached volcanics aquifer, welded tuff/lava flow DVCM Detached volcanics composite unit, welded tuff/lava flow/nonwelded tuff FCCM Fortymile Canyon composite unit, nonwelded tuff FCCU Fluorspar Canyon confining unit, nonwelded tuff FCLLFA Fortymile Canyon lower lava-flow aquifer, lava flow FCULFA1 Fortymile Canyon upper lava-flow aquifer #1, lava flow FCULFA2 Fortymile Canyon upper lava-flow aquifer #2, lava flow FCULFA3 Fortymile Canyon upper lava-flow aquifer #3, lava flow FCULFA4 Fortymile Canyon upper lava-flow aquifer #4, lava flow FCULFA5 Fortymile Canyon upper lava-flow aquifer #5, lava flow FCWTA Fortymile Canyon welded-tuff aquifer, welded tuff, lesser vitric tuff/nonwelded tuff Calico Hills zeolitic composite unit, nonwelded tuff CHZCM Description of hydrostratigraphic units shown on hydrostratigraphic sections Units from three-dimensional hydrostratigraphic framework model (U.S. Department of Energy, 2020a)