Integrated model for the natural flow regime in the Cerro Prieto hydrothermal system, B. C. , Mexico, based upon petrological and isotope geochemical criteria [electronic resource]
Studies of cuttings and core at Cerro Prieto have now been extended to more than 50 boreholes. The aims of this petrological and isotopic work are to determine the shape of the reservoir, its physical properties, and its temperature distribution and flow regime before the steam field was produced. A...
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| Format: | Government Document Electronic eBook |
| Language: | English |
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Riverside, Calif. : Oak Ridge, Tenn. :
University of California, Riverside. Institute of Geophysics and Planetary Physics ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1981.
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| Summary: | Studies of cuttings and core at Cerro Prieto have now been extended to more than 50 boreholes. The aims of this petrological and isotopic work are to determine the shape of the reservoir, its physical properties, and its temperature distribution and flow regime before the steam field was produced. A map showing the first occurrence of hydrothermal epidote shows a dome-shaped top to the steam-producing zone. The hottest of the mapped mineral zones - the biotite vermiculite zone - shows a dome displaced to the northeast relative to the epidote zone. Patterns of mineral zones observed in wells are consistent with patterns of oxygen isotopic ratios in calcite and quartz. Using both criteria all of the boreholes so far studied were classified as belonging to one of four different regimes. These are: (a) the thermal plume of upward flowing water close to boiling, marked by a regular sequence of prograde mineral zones and large isotopic shifts; (b) the discharge system where fluid leaks to the surface, as indicated by the occurrence of only a few low temperature mineral zones, which extend over large depth intervals with little isotope exchange; (c) the horizontal flow zone, in which boreholes penetrate reversals of both mineral zones and isotope shifts with increasing depth; and (d) the recharge zone where cold water is descending. Plotting these four types of boreholes on a map reveals a simple, consistent, pattern. This is interpreted to have been produced by a thermal plume dipping at 45° to the northeast. Geothermal Legacy. |
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| Item Description: | Published through the Information Bridge: DOE Scientific and Technical Information. 01/01/1981. "conf-810399-3" "DE82001980" 3. symposium on the Cerro Prieto geothermal field in Baja California, Mexico, San Francisco, CA, USA, Mar 1981. Williams, A.E.; Elders, W.A.; Hoagland, J.R. |
| Physical Description: | Pages: 7 : digital, PDF file. |