1. Gas chemistry and helium isotopes at Cerro Prieto
- Author
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J.A. Welhan, R. Poreda, J.E. Lupton, and Harmon Craig
- Subjects
Hot spring ,Renewable Energy, Sustainability and the Environment ,Stable isotope ratio ,business.industry ,Earth science ,Geothermal energy ,Analytical chemistry ,chemistry.chemical_element ,Geology ,Geotechnical Engineering and Engineering Geology ,Methane ,chemistry.chemical_compound ,Helium-4 ,chemistry ,Helium-3 ,Astrophysics::Earth and Planetary Astrophysics ,business ,Isotopes of helium ,Helium - Abstract
Seven producing wells and seven hot springs in the Cerro Prieto geothermal field were sampled during April and September 1977, for determination of gas chemistry and helium isotope ratios. Well gases are remarkably uniform in gas chemistry and helium isotope ratio, showing high 3 He/ 4 He ratios characteristic of mantle-derived helium, and higher than expected N 2 /Ar ratios. Comparison with the hot spring data suggests that the deep gas component observed in wells is modified during transit to the hot springs by addition of crustal helium, dissolved air and possibly organic methane; alternatively, chemical re-equilibration at lower temperatures may be responsible for increasing the CH 4 /H 2 ratio.
- Published
- 1979
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