Petrochemical profiling of the aureole of the Kakkonda granite using cuttings samples along the well Wd-1a, northeast Japan
- Geological Survey of Japan, Ibaraki (Japan)
Multi-component chemical analyses were carried out on 186 cuttings samples taken from every 20 in depth interval along the well WD-1a that was drilled into a depth of 3,729 m in the Kakkonda geothermal field, Japan and penetrated an upper part of a neo-granitic pluton below 2,860 in. Profiling of the various components with depths provides information on the magma chamber, contact metamorphism, water-rock interactions and geothermal reservoirs. Combination of the components CaO, CO{sub 2} and S or heavy metals indicates the distribution of older fractures as well as the present lost circulation zones. A cavity-rich zone in only 1m depth interval of the inner plutonic rim that has been observed in core samples is petrochemically recognized as the greater anomaly in a 110 in depth interval. The profile of the H{sub 2}O (+) component is broadly proportional to that of the MgO component due to the prevalence of chlorite. A dehydration trend toward the plutonic contact by contact metamorphism is probably first given in detail. High concentration of low angular fractures in the high grade metamorphic aureole is explained by the hydraulic fracturing at the dehydration front of a cordierite-forming reaction.
- OSTI ID:
- 602691
- Report Number(s):
- CONF-971048-; TRN: 98:001318-0041
- Resource Relation:
- Conference: Geothermal Resources Council (GRC) annual meeting, San Francisco, CA (United States), 12 Oct 1997; Other Information: PBD: 1997; Related Information: Is Part Of Meeting the challenge of increased competition; PB: 665 p.
- Country of Publication:
- United States
- Language:
- English
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