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G. Michael Reimer

Publications and source records attributed to G. Michael Reimer.

At least 19 recordsLinked to original sources
USGS1993

Understanding our fragile environment; Lessons from geochemical studies

An understanding of our fragile environment can begin with a recognition of the importance of certain elements, commonly called "minerals substances" (such as iron and zinc), in the lives of humans and animals and in the soils that support plants. This recognition is well deserved because these elements are essential for the life or optimum health of an organism. Some elements such as carbon, hydrogen, oxygen, magnesium, potassium, and phosphorus are required in relatively large amounts by organisms. However, others are required in smaller quantities; these are referred to as trace elements. Diseases have been related to the deficiency of about 20 elements in animals and humans and to the deficiency of approximately 13 elements in plants. At the same time, if these and other elements occur in quantities great enough, toxicity can result. An element, or any substance, that occurs in the environment and contains concentrations above what are considered to be background levels may be considered a contaminant. When contaminants occur at levels that are potentially harmful to organisms, they are labeled as hazards. Often the quantitative difference between essential amounts and toxic concentrations of these elements is very small. For example, the trace element selenium is required at a level of no less than 0.4 ppm in the diet of cattle but can be toxic at levels greater than approximately 4ppm. Elements that are required for survival by animals and plants are termed essential, while those not required are nonessential. Trace essential elements such as fluorine, copper, selenium, molybdenum, and others listed in the table on page 1 can be hazardous to life forms if present at high levels. Nonessential heavy metals such as arsenic, lead, mercury, cadmium, and chromium are usually toxic to organisms at much lower levels than trace essential elements. Depending on the association that these nonessential elements may form with natural geologic materials such as organic matter, other elements or minerals, and adsorbers (such as clays), these elements can range from being safe to being extremely toxic. The elemental composition of plants, animals, and humans correlates with the geologic makeup of the Earth, and life has evolved reflecting these natural occurrences. The science of environmental geochemistry examines the interrelationship of life with the physical and chemical Earth.

Circular↗
USGS1979

The use of soil-gas helium concentrations for earthquake prediction: Studies of factors causing diurnal variation

The diurnal variation in the soil-gas helium concentration was monitored at depths of 0.5-2 m. Barometric pressure, air temperature, wind speed, soil temperature, soil moisture, relative humidity, and precipitation were also monitored. The helium variation below a 1-m sampling depth usually did not exceed the analytical sensitivity limit of +10 ppb helium. The meteorological parameters that had the greatest effect on the helium variation is wind speed and precipitation; another factor causing variations was the atmospheric pumping created by air-temperature changes and its associated effect on the near-surface soil moisture content. The absolute helium variation rarely exceeded 1 percent of the background helium concentration in air. This minor variation could be corrected because it followed a regular daily pattern. Diurnal changes in the soil-gas helium concentration did not impose any severe limitations on the use of helium soil-gas data collected for earthquake prediction purposes.

Open-File Report↗
USGS1979

Helium in soil-gas and helium/radon in ground water in the vicinity of a south Texas uranium roll-type deposit

A survey was run in the vicinity of a south Texas uranium roll-type deposit to determine the general concentration of helium in the soil gas and helium/radon ratios in the ground water for deposits of this nature. The helium in soil-gas concentrations are typical of the concentrations found associated with other low-grade uranium deposits in other areas. The distribution of the values probably reflects local structure and is influenced by surface activities such as farming and mining. The helium/radon ratios in water strikingly reveal the known orebody, and some samples taken for background information may indicate the presence of nearby mineralized areas.

Texas↗
USGS1977

Reconnaissance survey of the helium content of soil gas in Black Hawk, Eldorado Springs, Evergreen, Golden, Morrison, Ralston Buttes, and Squaw Pass quadrangles, Colorado

A reconnaissance survey of the helium content of soil gas was performed in parts of Black Hawk, Eldorado Springs, Evergreen, Golden, Morrison, Ralston Buttes, and Squaw Pass quadrangles, Colorado. The intent of this survey was to obtain initial background information on the gross effects of structure, underlying rock type, and soil moisture content on the helium content of the soil gas. Sample localities were adjacent to roads and trails. The results, tentatively categorized as qualitative, suggest that structure and soil moisture content have pronounced observable effects, whereas effects of rock type could not be recognized in this study.

Colorado↗
USGS1977

Linear-traverse surveys of helium and radon in soil gas as a guide for uranium exploration, central Weld County, Colorado

Linear-traverse surveys of helium and radon in soil gas were performed and evaluated as a guide for uranium exploration in central Weld County, Colo. Repeated sampling over a 5-month period eventually delineated a helium anomaly along the main 11.2 km traverse, and that anomaly may be related to a uranium occurrence. A single traverse is difficult to interpret. A grid sampling pattern, no more time consuming than a repeated linear traverse, is preferred. Radon anomalies along the traverses are from radon-220, the thorium decay series member, and do not show a positive correlation with the helium analyses.

Open-File Report↗
USGS1976

Uranium analysis of single drops of natural waters using the fission-track technique

The fission-track technique has been applied to uranium analysis of natural waters using a single drop of water. Samples may be collected in the field by evaporating a drop of water on a detector, and samples may then be analyzed by returning the detector to the laboratory. A sample collecting kit has been assembled, which facilitates the designed sampling method. Some unique advantages of this technique are picogram sensitivity (10 -12 g) for uranium on single drops of water, maintenance of sample integrity during transport and storage, and the ability to discern whether the uranium is in solution or in the suspended material. Counting the tracks is the most time-consuming part of the analysis, but it can be reduced by using automatic counting systems. The analytical error is generally ± 10 percent over the entire range of concentrations.

Open-File Report↗
USGS1976

Helium detection as a guide for uranium exploration

Helium, a byproduct of radioactive decay, may prove to be a valuable indicator of the presence and distribution of uranium deposits. Recent technological advances permit the development of instrumentation not previously adapted for this purpose. Commercially available equipment can provide high sensitivity at low cost and allow reasonable mobility for field use. A truck-mounted mass-spectrometer, tuned for helium-4, permits immediate adjustment or modification of sampling patterns in response to accumulating data. The inlet system of the spectrometer has been designed to allow flexibility in gas analyses from various sample types--soil gas, atmosphere, or gases in water. Sensitivity of the instrument is better than 50 parts of helium per 10 9 parts of gas. Replicate samples and standards can be analyzed in only 3 minutes. Helium in soil gas is being used for the initial evaluation of the technique. A hollow probe, as much as 2 m long, is driven into the ground; and a 10-cc syringe is used to purge the probe and extract the gas. This sample is then injected into the inlet system and introduced into the spectrometer at constant pressure. The output signal is displayed on a chart recorder. Investigations can be performed on a qualitative, relative basis, or on a quantitative basis by comparison to calibrated helium standards. Preliminary field testing includes studies of the responses to variations in wind speed, temperature, barometric pressure, moisture, and sampling depth over extended time periods, as well as studies of geologic controls on the helium content in soil gas. Surveys over known uranium occurrences reveal some anomalous helium distributions. This report describes an updated technological approach to an old idea: that of using helium, a byproduct of uranium radioactive decay, as an exploration tool for uranium. Helium is the sixth most abundant gas found in the earth's atmosphere (Table 1). It is an inert gas and very mobile, mixing rapidly. When the alpha particles from the radioactive decay of uranium and thorium pick up two electrons, atoms of the isotope helium-4 are formed. Several helium-4 atoms are produced from each decay series of U-238, U-235, and Th-232 (fig. 1). The half-lives of the parent isotopes are5also shown in figure 1. One gram of uranium will produce ~10 5 atoms of helium-4 per second, and one gram of thorium produces ~2.5 x 10 4 atoms of helium-4 per second (fig. 2). Calculations of the helium produced from the crust and mantle reveal that 1,125 x 10 30 atoms per year are produced, but only 7 x 10 30 atoms per year escape from the earth (Damon and Kulp, 1958). More is being produced than is being lost; in fact, the total atmospheric content of helium could be produced in only 2 million years (MacDonald, 1963)! However, all the crustal and mantle helium-4 does not degas into the atmosphere as it is formed. It is trapped in crystal lattices and in pore spaces within the earth. What this means is that there is excess helium-4 in the earth--excess, that is, compared to the atmospheric concentration in equilibrium with the helium-4 escape rate into space and the helium-4 flux from the crust and mantle (Nicolet, 1957). Near-surface pockets of high helium-4 concentrations are known, and some natural gas fields are so enriched that they are the source for commercial production of helium. Work by Roberts and others (1975) has shown high helium concentration in the soil gas associated with geothermal areas; and work by Clark and Kugler (1973), Dyck (1975), and Goldak (1974), for example, has noted high helium concentrations in soils and waters in the vicinity of uranium deposits. These latter studies certainly indicate the potential of helium detection for use as an exploration tool for uranium.

Open-File Report↗