Zobrazeno 1 - 10
of 37
pro vyhledávání: '"J.A. Welhan"'
Publikováno v:
Geochimica et Cosmochimica Acta. 57:5087-5097
Isotopically anomalous CH4-rich gas deposits are found in mining sites on both the Canadian and Fennoscandian shields. With δ 13CCH4 values from −22.4 to −48.5% and δDCH4 values from −133 to −372%, these methane deposits cannot be accounted
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e2573fe74d3a40be7692c7b41731a6b3
https://doi.org/10.1016/0016-7037(93)90610-9
https://doi.org/10.1016/0016-7037(93)90610-9
Evidence for bacterially generated hydrocarbon gas in Canadian shield and fennoscandian shield rocks
Autor:
Stephen A. Macko, J.A. Welhan, B. Sherwood Lollar, Peter Fritz, Shaun K. Frape, R. Blomqvist, P.W. Lahermo
Publikováno v:
Geochimica et Cosmochimica Acta. 57:5073-5085
Hydrocarbon-rich gases found in crystalline rocks on the Canadian and Fennoscandian shields are isotopically and compositionally similar, suggesting that such gases are a characteristic feature of Precambrian Shield rocks. Gases occure in association
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3c45c1b57b34c52813b691609bdf92d3
https://doi.org/10.1016/0016-7037(93)90609-z
https://doi.org/10.1016/0016-7037(93)90609-z
Publikováno v:
Geochimica et Cosmochimica Acta. 56:4221-4228
Gas samples from seventeen high-temperature and twenty-two low-temperature geothermal systems have been analyzed for chemistry and 3 He 4 He ratios. Within the Neo-Volcanic Zone the 3 He 4 He ratios show a consistent regional pattern: 14–19 times t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::bac2307d4039c651ab244e128693cfb6
https://doi.org/10.1016/0016-7037(92)90262-h
https://doi.org/10.1016/0016-7037(92)90262-h
Autor:
J.A. Welhan, M. McCurry
This report summarizes results of groundwater analyses for samples collected from wells USGS-44, -45, -46 and -59 in conjunction with the INEL Oversight Program straddle-packer project between 1992 and 1995. The purpose of this project was to develop
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b57607a087a6a7b16e1b3d31fde3e4b7
https://doi.org/10.2172/395664
https://doi.org/10.2172/395664
Publikováno v:
Journal of Volcanology and Geothermal Research. 34:201-209
Systematic trends in helium isotope ratios and gas compositions in Long Valley caldera hot-spring and fumarole gases reflect subsurface processes and conditions in the hydrothermal system. High 3 He 4 He ratios (to 6.5 × atmospheric) indicate a magm
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2c5357c2cf348610475f2ba93fd7def7
https://doi.org/10.1016/0377-0273(88)90033-9
https://doi.org/10.1016/0377-0273(88)90033-9
Autor:
J.A Welhan, Peter Fritz
Publikováno v:
Geochimica et Cosmochimica Acta. 41:682-686
The stable isotope content of moisture (δE) removed by evaporation from a well mixed water body with no inflow is related to the isotopic content of the liquid (δ) by the equation m = (δE − δ)/(δ − δs). where δs is the isotopic 'steady sta
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f8c187dd59c601dd5fc1230fa0cc005b
https://doi.org/10.1016/0016-7037(77)90306-4
https://doi.org/10.1016/0016-7037(77)90306-4
Publikováno v:
Journal of Volcanology and Geothermal Research. 34:185-199
Helium isotope ratios in gases of thirty hot springs and geothermal wells and of five natural gas wells in the western United States show no relationship to regional conductive heat flow, but do show a correlation with magma-based thermal activity an
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::003cd96795e7fc23f5655c3eb6d54599
https://doi.org/10.1016/0377-0273(88)90032-7
https://doi.org/10.1016/0377-0273(88)90032-7
Publikováno v:
Geothermics. 8:241-244
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
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::91819cc367737fc6f39cd59f9ebfdb33
https://doi.org/10.1016/0375-6505(79)90046-4
https://doi.org/10.1016/0375-6505(79)90046-4
Publikováno v:
Chemical Geology. 71:223-236
Methane is ubiquitous and discharging freely from numerous exploration boreholes in the Canadian Shield. Methane concentrations in the free gas phase vary from a few % to over 80%. The gas occurs in association with He (up to 20%), Ar (up to 4%) and
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::27c92bb53b55a64318c5339feb6c71d9
https://doi.org/10.1016/0009-2541(88)90117-9
https://doi.org/10.1016/0009-2541(88)90117-9
Hydrocarbon and helium geochemistry in the crystalline environment — The Canadian and baltic shields
Autor:
P.W. Lahermo, Stephen A. Macko, R. Blomqvist, B. Sherwood, J.A. Welhan, Shaun K. Frape, S.M. Weise, Peter Fritz
Publikováno v:
Chemical Geology. 70:40
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ed7e2ba3632748040cfd349d43d25f9e
https://doi.org/10.1016/0009-2541(88)90293-8
https://doi.org/10.1016/0009-2541(88)90293-8