Hydrothermal outflow plume of Valles caldera, New Mexico, and a comparison with other outflow plumes

Journal Article · Fri Jun 10 00:00:00 EDT 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB093iB06p06041· OSTI ID:6959285

Goff, F; Shevenell, L; Gardner, J N; Vuataz, F; Grigsby, C O

Stratigraphic, temperature gradient, hydrogeochemical, and hydrologic data have been integrated with geologic data from previous studies to show the structural configuration of the Valles caldera hydrothermal outflow plume. Hydrologic data suggest that 25--50% of the discharge of the Valles outflow is confined to the Jemez fault zone, which predates caldera formation. Thermal gradient data from bores penetrating the plume show that shallow gradients are highest in the vicinity of the Jemez fault zone (up to 190 /sup 0/C/km). Shallow heat flow above the hydrothermal plume is as high as 500 mW m/sup -2/ near core hole VC-1 (Jemez fault zone) to 200 mW m/sup -2/ at Fenton Hill (Jemez Plateau). Chemical and isotopic data indicate that two source reservoirs within the caldera (Redondo Creek and Sulphur Springs reservoirs) are parents to mixed fluids flowing in the hydrothermal plume. However, isotopic data, borehole data, basic geology, and inverse relations between temperature and chloride content at major hot springs indicate that no single reservoir fluid and no single diluting fluid are involved in mixing. The Valles caldera hydrothermal plume is structurally dominated by lateral flow through a belt of vertical conduits (Jemez fault zone) that strike away from the source reservoir. Stratigraphically confined flow is present but dispersed over a wide area in relatively impermeable rocks. The Valles configuration is contrasted with the configuration of the hydrothermal plume at Roosevelt Hot Springs, which is dominated by lateral flow through a near-surface, widespread, permeable aquifer. Data from 12 other representative geothermal systems show that outflow plumes occur in a variety of magmatic and tectonic settings, have varying reservoir compositions, and have different flow characteristics.

• Research Organization: Los Alamos National Laboratory, New Mexico
• OSTI ID: 6959285
• Journal Information: J. Geophys. Res.; (United States), Vol. 93:B6
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
HYDROTHERMAL SYSTEMS
PLUMES
TEMPERATURE GRADIENTS
NEW MEXICO
CALDERAS
BOREHOLES
FLUID FLOW
GEOLOGY
HEAT FLOW
ISOTOPE APPLICATIONS
MAGMA
VOLCANISM
CAVITIES
ENERGY SYSTEMS
FEDERAL REGION VI
GEOTHERMAL SYSTEMS
NORTH AMERICA
USA
150201* - Geology & Hydrology of Geothermal Systems- USA- (-1989)