Geology and geothermal waters of Lightning Dock region, Animas Valley and Pyramid Mountains, Hidalgo County, New Mexico

Technical Report · Sat Jan 01 00:00:00 EST 1983

DOI:https://doi.org/10.2172/5228760· OSTI ID:5228760

Elston, W E; Deal, E G; Logsdon, M J

This circular covers the geology of the Pyramid Peak, Swallow Fork Peak, Table Top Mountain, and South Pyramid Peak 7-1/2-min quadrangles, which include the Lightning Dock KGRA. Hot wells (70 to 115.5/sup 0/C) seem to be structurally controlled by intersections of the ring-fracture zone of an Oligocene ash-flow tuff cauldron (Muir cauldron), a Miocene-to-Holocene north-trending basin-and-range fault (Animas Valley fault), and a northeast-trending lineament that appears to control anomalously heated underground waters and Pliocene-Pleistocene basalt cones in the San Bernardino, San Simon, and Animas Valleys. The Muir cauldron, approximately 20 km in diameter, collapsed in two stages, each associated with the eruption of a rhyolite ash-flow-tuff sheet and of ring-fracture domes. Most of the hydrothermal alteration of the Lightning Dock KGRA is related to the first stage of eruption and collapse, not to the modern geothermal system. Contrary to previous reports, no silicic volcanic rocks younger than basin-and-range faulting are known; unconformities beneath rhyolite ring-fracture domes are caused by Oligocene caldera collapse, not by basin-and-range faulting. The Animas Valley is the site of widespread post-20 My travertine deposits and near-surface veins of calcite, fluorite, and/or psilomelane, controlled by north- or northwest-trending basin-and-range faults. The fluoride-bearing waters of the Lightning Dock KGRA may be a late stage of this hydrothermal activity. Distribution of Pliocene-Pleistocene basalt suggests that deep-seated basalt near the solids may be the ultimate heat source.

• Research Organization: New Mexico Bureau of Mines and Mineral Resources, Socorro (USA)
• OSTI ID: 5228760
• Report Number(s): NMEX-4900830; ON: DE84900830
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
NEW MEXICO
GEOLOGY
GEOTHERMAL RESOURCES
BASALT
DISTRIBUTION
GEOCHEMISTRY
GEOLOGIC STRUCTURES
GEOTHERMAL FLUIDS
KGRA
MINERALIZATION
STRATIGRAPHY
THERMAL WATERS
WATER CHEMISTRY
CHEMISTRY
FEDERAL REGION VI
FLUIDS
IGNEOUS ROCKS
NORTH AMERICA
RESOURCES
ROCKS
USA
VOLCANIC ROCKS
Geothermal Legacy
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