Gases and trace elements in soils at the North Silver Bell deposit, Pima County, Arizona - Reply
No abstract available.
Geology topics
Publications and source records attributed to G.M. Reimer.
No abstract available.
Explore the source record for details and available documents.
A reconnaissance soil-gas helium survey was made of the Ely, Nevada and Delta, Utah 1? x 2? quadrangles in the Basin and Range Province. Helium concentrations in 510 samples ranged from -147 to 441 ppb He with respect to ambient air. The median helium value for the study area was 36 ppb. Concentrations of more than 100 ppb He, and less than -20 ppb He, occur more commonly in the Ely Quadrangle and are especially numerous in the western one-half of this quadrangle. The data are presented both in figures and tables, and some of the geologic factors that may affect the helium distribution are discussed.
No abstract available.
A mobile mass spectrometer to measure He concentrations has been developed by the U.S. Geological Survey. This instrument has been tested in areas of known uranium deposits, and He anomalies have been found in both soil gas and water. A gas sample is collected in a hypodermic syringe, injected into the spectrometer, and analyzed for He. Over 100 analyses a day can be performed with a sensitivity of 10 parts per billion (ppb). One detailed study conducted in Weld County, Colorado, shows that values for He in soil gas can be contoured to outline an anomalous area and that the anomaly is displaced from the deposit in the direction of groundwater flow. Other studies include the Schwartzwalder uranium mine, Jefferson County, Colorado, where He anomalies may be related to geologic structure; near Ambrosia Lake, New Mexico, where the location of He anomalies are related to groundwater movement; and tests for diurnal effects showing only slight variations probably related to soil-moisture content. ?? 1979.
A survey of the helium concentration in soil-gas was conducted in the Red Desert Area, Sweetwater County, Wyoming. The area studied is directly over a low-grade uranium deposit that may be suitable for recovery by in-situ leaching techniques. The area was sampled twice, once in December, 1977, and again in July, 1978. Wind was a significant factor affecting the helium concentrations. Wind gusts exceeded 110 km/hr (70 mph) during the December, 1977, sampling; wind gusts did not exceed 30 km/hr (20 mph) during the July, 1978, sampling. The average helium concentration for all the July, 1978, soil-gas samples was about twice the average of the December, 1977, samples. In addition, a contour plot of the July, 1978, soil-gas samples showed an area of higher helium values that corresponds to the location of anomalies detected by other exploration techniques, and may be associated with the uranium deposit.
The fission track technique, utilizing the neutron-induced fission of uranium-235, provides a versatile analytical method for the routine analysis of uranium in liquid samples of natural water. A detector is immersed in the sample and both are irradiated. The fission track density observed in the detector is directly proportional to the uranium concentration. The specific advantages of this technique are: (1) only a small quantity of sample, typically 0.1–1 ml, is needed; (2) no sample concentration is necessary; (3) it is capable of providing analyses with a lower reporting limit of 1 μg per liter; and (4) the actual time spent on an analysis can be only a few minutes. This paper discusses and describes the method.