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Regional Hydrology Of The Dixie Valley Geothermal Field, Nevada: Preliminary Interpretations Of Chemical And Isotopic Data, Gregory Nimz, Cathy Janik, Fraser Goff, Charles Dunlap, Mark Huebner, Dale Counce, Stuart Johnson
Regional Hydrology Of The Dixie Valley Geothermal Field, Nevada: Preliminary Interpretations Of Chemical And Isotopic Data, Gregory Nimz, Cathy Janik, Fraser Goff, Charles Dunlap, Mark Huebner, Dale Counce, Stuart Johnson
Charles Dunlap
Chemical and isotopic analyses of Dixie Valley regional waters indicate several distinct groups ranging in recharge age from Pleistocene (<20 ka) to recent (<50a). Valley groundwater is older than water from perennial springs and artesian wells in adjacent ranges, with Clan Alpine range (east) much younger (most <50a) than Stillwater range (west; most > 1OOOa).Geothermal field fluids (-12-14 ka) appear derived from water similar in composition to non-thermal groundwater observed today in valley artesian wells (also -14 ka). Geothermal fluid interaction with mafic rocks (Humboldt Lopolith) appears to be common, and significant reaction with granodiorite may also occur. Despite widespread occurrence of carbonate rocks, largescale chemical interaction appears minor. Age asymmetry of the ranges, more extensive interaction with deep- seated waters in the west, and distribution of springs and artesian wells suggest the existence …
“Every Breath You Take... ”: The Demographics Of Toxic Air Releases In Southern California, James Sadd, Manuel Pastor, J. Boer, Lori Snyder
“Every Breath You Take... ”: The Demographics Of Toxic Air Releases In Southern California, James Sadd, Manuel Pastor, J. Boer, Lori Snyder
James Sadd
In this article, the authors investigate the relationship between ethnicity and potential environmental hazards in the metropolitan Los Angeles area. Using a variety of techniques, including geographic information systems (GIS) mapping, univariate comparisons, and logit, ordered logit, and tobit regression analysis, the authors find that, even controlling for other factors such as income and the extent of manufacturing employment and land use, minority residents tend to be disproportionately located in neighborhoods surrounding toxic air emissions. The results generally support the propositions of the proponents of “environmental justice”; in the conclusion, they consider what this might mean for urban land use …
A Synthesis Of Lead Isotopes In Two Millennia Of European Air, Charles Dunlap, Eiliv Steinnes, A. Russell Flegal
A Synthesis Of Lead Isotopes In Two Millennia Of European Air, Charles Dunlap, Eiliv Steinnes, A. Russell Flegal
Charles Dunlap
Four airborne particulate records from ombrotrophic peat bogs in southern Norway, extending back 300 years, have been measured for chronology, lead concentration, and lead isotope composition. Since southern Norway receives an airborne lead signal that accumulates emissions from the European continent, the trend in the four bog records can be used to correlate previously reported measurements from France, Switzerland, England, and Greenland that cover different ranges of time. When these are compiled, the integrated European record that emerges spans the last 2300 years of human influence on lead in the air over Europe and suggests human control of lead in …