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G.I. Smith

Publications and source records attributed to G.I. Smith.

22 records · Page 2Linked to original sources
USGS1972

Studies of quaternary saline lakes-I. Hydrogen isotope fractionation in saline minerals

Borax, gaylussite, nahcolite and trona were synthesized in aqueous solution at temperatures ranging from 8° to 35°C. Except for borax, deuterium was always depleted in these hydrated minerals relative to the solutions from which they were crystallized. In borax, no significant fractionation was found. The fractionation factor of D H "> DH for the trona-water system exhibited a marked temperature dependence. By combining the deuterium contents of trona and the solution from which trona was crystallized, the following thermometer scale was obtained: In ( D H ) trona ( D H )water = 1.420 × 10 4 T 2 + 23.56 T "> (DH) trona(DH)water =1.420 × 104T2+23.56T (1) An attempt to establish a geothermometer based on C 13 C 12 "> C13C12 fractionation between carbonate minerals and carbonate ions in aqueous solution was not successful.

Geochimica et Cosmochimica Acta↗
USGS1972

Deuterium content of snow as an index to winter climate in the Sierra Nevada area

The winter of 1968-69 produced two to three times the amount of precipitation in the Sierra Nevada area, California and Nevada, as the winter of 1969-70. The deuterium content in snow cores collected at the end of each winter at the same sites, which represents the total snowfall of each interval, shows a depletion in 1968-69 of approximately 20 per mil. The higher snowfall in 1968-69 and the depletion of deuterium can be explained by an uncommonly strong westward flow of cold air over and down the western slopes of the Sierras, which interacted with an eastward flow of moist Pacific air that overrode and mixed with the cold air; this resulted in precipitation that occurred in greater than normal amounts and at a lower than normal temperature. Pluvial periods of the Pleistocene may have had the same shift in air-mass trajectory as the wet 1968-69 year. Snow cores collected in the normal 1970-71 winter have deuterium concentrations that resemble those of the normal 1969-70 winter. Small and nonsystematic differences in samples from these two normal winters are due to variations in climatic character as well as to factors inherent in the sampling sites.

California, Nevada↗
USGS1970

Deuterium content of snow cores from Sierra Nevada area

The relative deuterium content was measured on 37 snow cores collected in April 1969 in the Sierra Nevada. The deuterium content varies inversely with altitude of collection (approximately 40 per mil per 1000 meters) but is unrelated to latitude. The altitude relationship is particularly well defined west of the crest of the range but is not well defined east of the crest. However, samples from east of the crest tend to be depleted by about 10 to 15 per mil relative to samples collected at the same elevation west of the crest. We propose that the deuterium content of snow cores, collected so as to include the total winter's precipitation, can be used as a climatic indicator to compare the climate of one winter with that of another.

California, Nevada↗