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Compilation of gas geochemistry and isotopic analyses from The Geysers geothermal field: 1978-1991

January 1, 1999

We present 45 chemical and isotopic analyses from well discharges at The Geysers geothermal field and summarize the most notable geochemical trends. H2 and H2S concentrations are highest in the Southeast Geysers, where steam samples have δD and δ18O values that reflect replenishment by meteoric water. In the Northwest Geysers, samples are enriched in gas/steam, CO2, CH4, and N2/Ar relative to the rest of the field, and contain steam that is elevated in δD and δ18O, most likely due to substantial contributions from Franciscan-derived fluids. The δ13C of CO2, trends in CH4 vs. N2, and abundance of NH3 indicate that the bulk of the non-condensable gases are derived from thermal breakdown of organic materials in Franciscan meta-sediments.

Citation Information

Publication Year 1999
Title Compilation of gas geochemistry and isotopic analyses from The Geysers geothermal field: 1978-1991
DOI
Authors Jacob B. Lowenstern, Cathy Janik, Lynne Fahlquist, Linda S. Johnson
Publication Type Article
Publication Subtype Journal Article
Series Title Geothermal Resources Council Transactions
Series Number
Index ID 70020977
Record Source USGS Publications Warehouse
USGS Organization

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