Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: a telescoped low pressure/temperature metamorphic facies series

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

DOI:https://doi.org/10.2172/6011812· OSTI ID:6011812

Schiffman, P; Elders, W A; Williams, A E; McDowell, S D; Bird, D K

In the Cerro Prieto geothermal field, carbonate-cemented, quartzofeldspathic sediments of the Colorado River delta are being actively metasomatized into calc-silicate metamorphic rocks by reaction with alkali chloride brines between 200/sup 0/ and 370/sup 0/C, low fluid and lithostatic pressures, and low oxygen fugacities. Petrologic investigations of drill cores and cutting from over 50 wells in this field identified a prograde series of calc-silicate mineral zones which include as index minerals: wairakite, epidote, prehnite, and clinopyroxene. Associated divariant mineral assemblages are indicative of a very low pressure/temperature metamorphic facies series which encompasses the clay-carbonate, zeolite, greenschist, and amphibolite facies. This hydrothermal metamorphic facies series, which is becoming increasingly recognized in other active geothermal systems, is characterized by temperature-telescoped dehydration and decarbonation mineral equilibria. Its equivalent should now be sought in fossil hydrothermal systems.

• Research Organization: California Univ., Riverside (USA). Inst. of Geophysics and Planetary Physics; Michigan Technological Univ., Houghton (USA). Dept. of Geology and Geological Engineering; Stanford Univ., CA (USA). Dept. of Geology
• DOE Contract Number: FC07-80ID12145
• OSTI ID: 6011812
• Report Number(s): UCR/IGPP-83/6; ON: DE83016725
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
CERRO PRIETO GEOTHERMAL FIELD
METAMORPHISM
PETROLOGY
AMPHIBOLITES
CLAYS
DRILL CORES
EPIDOTES
HYDROTHERMAL ALTERATION
MINERALOGY
SCHISTS
WAIRAKITE
WATER WELLS
ZEOLITES
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CALCIUM COMPOUNDS
CALCIUM SILICATES
GEOLOGY
GEOTHERMAL FIELDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IRON COMPOUNDS
IRON SILICATES
MATERIALS
METAMORPHIC ROCKS
MINERALS
OXYGEN COMPOUNDS
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WELLS
Geothermal Legacy
150202* - Geology & Hydrology of Geothermal Systems- Non-USA- (-1989)