Hydrothermal alteration of sediments associated with surface emissions from the Cerro Prieto geothermal field, Baja, California, Mexico

Conference · Thu Jan 01 04:00:00 EST 1981

OSTI ID:5911441

Valette-Silver, J N; Esquer-Patino, I; Elders, W A; Collier, P C; Hoagland, J R

Surface emissions from the Cerro Prieto geothermal reservoir are restricted to a 100 km/sup 2/ area on the western side of the field, near the volcano Cerro Prieto and the lake Laguna Vulcano. Some 57 surface emissions, explored in 1979, were classified into hot springs, mud pots, pools, fumaroles and geysers (Valette and Esquer-Patino, 1979). A study of the mineralogical changes associated with these hydrothermal vents was initiated with the aim of developing possible exploration tools for geothermal resources. The Cerro Prieto reservoir has already been explored by extensive deep drilling so that relationships between surface manifestations and deeper hydrothermal processes could be established directly. Approximately 120 samples of surface sediments were collected both inside and outside of the vents. The mineralogy of the altered sediments studied appears to be controlled by the type of emission. A comparison between the changes in mineralogy due to low temperature hydrothermal activity in the reservoir, seen in samples from boreholes, and mineralogical changes in the surface emission samples shows similar general trends below 180/sup 0/C: increase of quartz, feldspar and illite, with subsequent disappearance of kaolinite, montmorillonite, calcite and dolomite. These mineral assemblages seem to be characteristics of the discharge from high intensity geothermal fields.

• Research Organization: California Univ., Riverside (USA). Inst. of Geophysics and Planetary Physics; Comision Federal de Electricidad, Mexico City
• DOE Contract Number: AT03-80SF11458
• OSTI ID: 5911441
• Report Number(s): CONF-810399-2; ON: DE82001983
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150202* -- Geology & Hydrology of Geothermal Systems-- Non-USA-- (-1989)
150302 -- Geothermal Exploration & Exploration Technology-- Geochemical Techniques & Surveys
BOREHOLES
CAVITIES
CERRO PRIETO GEOTHERMAL FIELD
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMISTRY
CLAYS
EMISSION
FELDSPARS
FUMAROLES
GEOCHEMICAL SURVEYS
GEOCHEMISTRY
GEOTHERMAL FIELDS
GEYSERS
Geothermal Legacy
HOT SPRINGS
HYDROTHERMAL ALTERATION
ILLITE
MINERALOGY
MINERALS
OXIDES
OXYGEN COMPOUNDS
QUARTZ
SAMPLING
SEDIMENTS
SILICON COMPOUNDS
SILICON OXIDES
SURVEYS
THERMAL SPRINGS
WATER SPRINGS