Geology Reports⌕ Search

Geology topics

G.M. Reimer

Publications and source records attributed to G.M. Reimer.

16 recordsLinked to original sources
USGS2012

Helium soil-gas variations associated with recent central California earthquakes: Precursor or coincidence?

Decreases in the helium concentration of soil-gas have been observed to precede six of eight recent central California earthquakes. Ten monitoring stations were established near Hollister, California and along the San Andreas Fault to permit gas collection. The data showed decreases occurring a few weeks before the earthquakes and concentrations returned to prequake levels either shortly before or after the earthquakes.

Geophysical Research Letters↗
USGS2012

Reconnaissance techniques for determining soil-gas radon concentrations: an example from Prince Georges County, Maryland

Preliminary field measurements of soil-gas radon (Rn) concentrations can provide an initial assessment of the Rn potential in any location and aid in designing a larger or more detailed sampling program. Radon reconnaissance requires some special considerations because a large area must be covered in a short period of time and analyses must be made soon after collection because of Rn decay. A simple approach to collection and field analysis consists of a small-diameter probe pounded into the ground to a depth of at least 0.75 m. Analysis is by an alpha-scintillometer. Soil-gas samples collected along a traverse in Prince Georges County, Maryland, demonstrate the utility of the technique. Although this region in the Coastal Plain province might be considered to possess the type of geologic setting that would not contribute to significant Rn potential, the reconnaissance sampling revealed Rn soil-gas concentrations of up to 2500 pCi/L (picocuries per liter) indicating that the potential exists for indoor accumulations in excess of 4 pCi/L.

Geophysical Research Letters↗
USGS2005

Indoor radon risk potential of Hawaii

A comprehensive evaluation of radon risk potential in the State of Hawaii indicates that the potential for Hawaii is low. Using a combination of factors including geology, soils, source-rock type, soil-gas radon concentrations, and indoor measurements throughout the state, a general model was developed that permits prediction for various regions in Hawaii. For the nearly 3,100 counties in the coterminous U.S., National Uranium Resource Evaluation (NURE) aerorad data was the primary input factor. However, NURE aerorad data was not collected in Hawaii, therefore, this study used geology and soil type as the primary and secondary components of potential prediction. Although the radon potential of some Hawaiian soils suggests moderate risk, most houses are built above ground level and the radon soil potential is effectively decoupled from the house. Only underground facilities or those with closed or recirculating ventilation systems might have elevated radon potential. ?? 2005 Akade??miai Kiado??.

Journal of Radioanalytical and Nuclear Chemistry↗
USGS1999

Volcano-tectonic structures, gravity and helium in geothermal areas of Tuscany and Latium (Vulsini volcanic district), Italy

Since the early 1980s, geological and structural mapping, gravity, and helium soil-gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of > 100??C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N-S and E-W structures that appear to be superimposed on older NW-SE and NE-SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.Since the early 1980s, geological and structural mapping, gravity, and helium soil-gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of > 100??C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N-S and E-W structures that appear to be superimposed on older NW-SE and NE-SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.

Geothermics↗
USGS1998

Consideration of measurement error when using commercial indoor radon determinations for selecting radon action levels

An examination of year-long, in-home radon measurement in Colorado from commercial companies applying typical methods indicates that considerable variation in precision exists. This variation can have a substantial impact on any mitigation decisions, either voluntary or mandated by law, especially regarding property sale or exchange. Both long-term exposure (nuclear track greater than 90 days), and short-term (charcoal adsorption 4-7 days) exposure methods were used. In addition, periods of continuous monitoring with a highly calibrated alpha-scintillometer took place for accuracy calibration. The results of duplicate commercial analysis show that typical results are no better than ??25 percent with occasional outliers (up to 5 percent of all analyses) well beyond that limit. Differential seasonal measurements (winter/summer) by short-term methods provide equivalent information to single long-term measurements. Action levels in the U.S. for possible mitigation decisions should be selected so that they consider the measurement variability; specifically, they should reflect a concentration range similar to that adopted by the European Community.

Conference Paper↗
USGS1992

Methodology for rapid assessment of the radon potential of soils

A technique using a small diameter probe and a portable alpha-particle scintillometer for sample collection and analysis has been developed. It is fast, efficient, cost-effective, and can be modified to accommodate a wide spectrum of sampling conditions. When soil-gas sampling for radon is combined with geophysical gamma-ray measurements, pedological characteristics of surficial materials, and geologic knowledge of bedrock, the combination forms a powerful technological basis for estimating radon potential of soils. The method can help provide information on a short time-frame so that local governments, land developers, and builders can take appropriate measures when planning new construction.

Conference Paper↗
USGS1992

Using soil gas radon and geology to estimate regional radon potential

Two important parameters have been identified in order to estimate the radon potential of a region. They are the soil gas radon concentration and the geological rock type from which soils are derived. A simple soil gas collection and analytical technique has been developed to provide information on soil gas radon concentrations. The application of these techniques has demonstrated a clear relationship between the estimate of the radon potential and indoor radon measurements. This information is particularly important when evaluating the radon potential of areas that will be subject to population expansion in the future. Other factors, such as gamma radiation measurements and soil permeability can be included to improve the estimate of radon potential, but geology and soil gas measurements are the most important factors. Although this approach is useful for regional estimates, it can also be used for site-specific evaluations.

Conference Paper↗
USGS1991

Tritium concentrations in the active Pu'u O'o crater, Kilauea volcano, Hawaii: implications for cold fusion in the Earth's interior

The assertion that deuterium-deuterium fusion may occur at low temperature suggests a potential new source of geothermal heat. If a cold-fusion-like process occurs within the Earth, then a test for its existence would be a search for anomalous tritium in volcanic emissions. The Pu'u O'o crater is the first point at which large amounts of water are degassed from the magma that feeds the Kilauea system. The magma is probably not contaminated by meteoric-source ground water prior to degassing at Pu'u O'o, although mixing of meteoric and magmatic H2O occurs within the crater. Tritium contents of samples from within the crater are lower than in samples taken simultaneously from the nearby upwind crater rim. These results provide no evidence in support of a cold-fusion-like process in the Earth's interior. ?? 1991.

Physics of the Earth and Planetary Interiors↗
USGS1989

A direct correlation among indoor Rn, soil gas Rn and geology in the Reading Prong near Boyertown, Pennsylvania

We feel that this study suggests a relationship among geology, soil gas Rn and the potential for indoor Rn accumulation in this portion of the Reading Prong. There are deviations from a perfect correlation but these are related to inhomogeneities in the geologic environment and perhaps variations in construction techniques of homes in the area. This study also demonstrates that several analyses in a small area may be necessary to adequately determine the Rn distribution for a particular geologic unit. That scale would be determined by the complexity of the local geology. Where no discrete source of elevated Rn supply is found for dwellings having a significant Rn accumulation, the implication is that overall gross permeability may be sufficient to supply Rn from a larger volume of soil and rock.

Health Physics↗
USGS1983

Helium concentrations in soil gas of the Ely and Delta 1° x 2° quadrangles, Basin and Range Province

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.

Nevada, Utah↗
USGS1979

Soil-gas helium concentrations in the vicinity of a uranium deposit, Red Desert, Wyoming

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.

Wyoming↗
USGS1975

Uranium determination in natural water by the fissiontrack technique

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.

Journal of Geochemical Exploration↗