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Maurice A. Chaffee

Publications and source records attributed to Maurice A. Chaffee.

At least 19 recordsLinked to original sources
USGS2008

Living in Yellowstone's Caldera: A geochemical trophic cascade in elk

Though the geology of earth's rare geothermal environments and their associated microbial communities are intensely studied, less scientific attention has focused on their potential effects through the plant-herbivore-carnivore trophic chain. The west-central portion of Yellowstone National Park contains a 2000-km 2 volcanic caldera with 2- to 60-million-year-old, predominantly rhyolitic, rocks that produce relatively infertile soils. The caldera area contains one of the largest concentrations of active geothermal features in the world, including thousands of geysers, fumaroles , hot springs, and mud pots. In many other chapters of this book, we address the ecological impacts of this unique geology to the ecology of the large mammals that live within the caldera, primarily through the effects of geothermal heat on snow pack. In this chapter, we explore the unique geochemistry of the geothermal environments and the consequences of this geochemistry to elk and perhaps other herbivores that reside within the caldera. These studies were prompted by behavioral and demographic observations of elk during the initial years of our studies that we could not explain and, in turn, led us to formulate hypotheses about potential geochemical influences on elk ecology. Specifically, we contrast the concentrations of fluoride (F) and silica (SiO 2 ) found in the Madison headwaters area with areas on Yellowstone's northern range located approximately 50 km to the northwest, where geothermal features are rare or absent. We then trace the consequences of geochemical differences through abiotic and biotic linkages in the ecosystem.

Book↗
USGS2002

A Geochemical Trophic Cascade in Yellowstone's Geothermal Environments

We contrast the geochemistry of the Madison drainage, which has high concentrations of geothermal features, with the Lamar drainage of Yellowstone National Park, USA, and trace the consequences of geochemical differences through abiotic and biotic linkages in the ecosystem. Waters in the geothermal-dominated drainage contained anomalously high levels of fluoride (F) and silica (SiO 2 ). Soils, stream sediments, and surface waters that interact or mix with geothermal waters, in turn, had elevated F and SiO 2 concentrations compared to similar samples from the Lamar drainage. The geochemical differences were reflected in the chemistry of forage plants, with some plants from geothermally influenced areas containing four- to eightfold higher concentrations of F and SiO 2 than similar plants in the Lamar drainage. Geothermal heat reduced snowpack, and we found that elk (Cervus elaphus) concentrated in these refugia as snowpack increased each winter. The consequent high dietary intake of F in animals associated with the geothermal areas was confirmed by the finding that bone samples from elk living in the Madison drainage contained sixfold higher concentrations of F than samples collected from animals wintering in the Lamar drainage. High F exposure resulted in compromised dentition due to fluoride toxicosis, which was undoubtedly exacerbated by the abrasive action of silica. The consequent accelerated and aberrant tooth wear resulted in early onset of senescence, reduced life span, and an abbreviated age structure. We speculate that these altered demographics, combined with spatial heterogeneity of snowpack, will result in increased vulnerability of this large herbivore population to wolf predation and less resiliency to compensate demographically for predation.

Wyoming↗
USGS2000

Analytical results and sample locality map for rock, stream-sediment, and soil samples, Northern and Eastern Colorado Desert BLM Resource Area, Imperial, Riverside, and San Bernardino counties, California

In 1996-1998 the U.S. Geological Survey (USGS) conducted a geochemical study of the Bureau of Land Management’s (BLM) 5.5 million-acre Northern and Eastern Colorado Desert Resource Area (usually referred to as the NECD in this report), Imperial, Riverside, and San Bernardino Counties, southeastern California (figure 1). This study was done in support of the BLM’s Coordinated Management Plan for the area. This report presents analytical data from this study.

California↗
USGS2000

Analytical results and sample locality map for rock, stream-sediment, and soil samples, Northern and Eastern Colorado Desert BLM Resource Area, Imperial, Riverside, and San Bernardino Counties, California

In 1996-1998 the U.S. Geological Survey (USGS) conducted a geochemical study of the Bureau of Land Management's (BLM) 5.5 million-acre Northern and Eastern Colorado Desert Resource Area (usually referred to as the NECD in this report), Imperial, Riverside, and San Bernardino Counties, southeastern California (figure 1). This study was done in support of the BLM's Coordinated Management Plan for the area. This report presents analytical data from this study. To provide comprehensive coverage of the NECD, we compiled and examined all available geochemical data, in digital form, from previous studies in the area, and made sample-site plots to aid in determining where sample-site coverage and analyses were sufficient, which samples should be re-analyzed, and where additional sampling was needed. Previous investigations conducted in parts of the current study area included the National Uranium Resource Evaluation (NURE) program studies of the Needles and Salton Sea 1° x 2° quadrangles; USGS studies of 12 BLM Wilderness Study Areas (WSAs) (Big Maria Mountains, Chemehuevi Mountains, Chuckwalla Mountains, Coxcomb Mountains, Mecca Hills, Orocopia Mountains, Palen-McCoy, Picacho Peak, Riverside Mountains, Sheephole Valley (also known as Sheep Hole/Cadiz), Turtle Mountains, and Whipple Mountains); and USGS studies in the Needles and El Centro 1° x 2° quadrangles done during the early 1990s as part of a project to identify the regional geochemistry of southern California. Areas where we did new sampling of rocks and stream sediments are mainly in the Chocolate Mountain Aerial Gunnery Range and in Joshua Tree National Park, which extends into the west-central part of the NECD, as shown in figure 1 and figure 2. This report contains analytical data for 132 rock samples and 1,245 stream-sediment samples collected by the USGS, and 362 stream-sediment samples and 189 soil samples collected during the NURE program. All samples are from the Northern and Eastern Colorado Desert BLM Resource Area and vicinity. Included in the 1,245 stream-sediment samples collected by the USGS are 284 samples collected as part of the current study, 817 samples collected as part of investigations of the12 BLM WSAs and re-analyzed for the present study, 45 samples from the Needles 1° x 2° quadrangle, and 99 samples from the El Centro 1° x 2° quadrangle. The NURE stream-sediment and soil samples were re-analyzed as part of the USGS study in the Needles quadrangle. Analytical data for samples from the Chocolate Mountain Aerial Gunnery Range, which is located within the area of the NECD, were previously reported (King and Chaffee, 1999a). For completeness, these results are also included in this report. Analytical data for samples from the area of Joshua Tree National Park that is within the NECD have also been reported (King and Chaffee, 1999b). These results are not included in this report. The analytical data presented here can be used for baseline geochemical, mineral resource, and environmental geochemical studies.

California↗
USGS1986

Summary geochemical maps for samples of rock, stream sediment, and nonmagnetic heavy-mineral concentrate, Sweetwater Roadless Area, Mono County, California and Lyon and Douglas Counties, Nevada

The Sweetwater Roadless Area lies between Yerington, Nevada, and Bridgeport, California, along the California-Nevada boundary. The area encompasses approximately 72,240 acres in Toiyabe National Forest in Mono County, California, and Lyon and Douglas Counties, Nevada. This roadless area, which lies just east of the Sierra Nevada range, exhibits rugged topography. Elevations range from about 6,160 feet near Devil's Gate to 11,673 feet at Mount Patterson. Geochemical sampling was conducted during 1978, 1979, and 1980. This report summarizes the results of that investigation and provides details of the geochemical evaluation used in producing the final mineral resource assessment of the study area (Brem and others, 1984). Map A shows the locations of all sites where rock samples were collected for this report and the distributions of anomalous concentrations for 12 elements in the 127 rock samples collected. In a similar manner, map B shows the collection sites for 59 samples of minus-60-mesh stream sediment, and 59 samples of nonmagnetic heavy-mineral concentrate derived from stream sediment and also shows the distributions of anomalous concentrations for 13 elements in the stream-sediment samples and 17 elements in the concentrate samples. Map C shows outlines of those drainage basins containing samples of stream sediment and concentrate with anomalous element concentrations and also shows weighted values for each outlined basin based on the number of elements with anomalous concentrations in each stream-sediment and concentrate sample and on the degree to which these concentrations are anomalous in each sample.

California, Nevada↗
USGS1975

Geochemical Exploration Techniques Applicable in the Search for Copper Deposits

Geochemical exploration is an important part of copper-resource evaluation. A large number of geochemical exploration techniques, both proved and untried, are available to the geochemist to use in the search for new copper deposits. Analyses of whole-rock samples have been used in both regional and local geochemical exploration surveys in the search for copper. Analyses of mineral separates, such as biotite, magnetite, and sulfides, have also been used. Analyses of soil samples are widely used in geochemical exploration, especially for localized surveys. It is important to distinguish between residual and transported soil types. Orientation studies should always be conducted prior to a geochemical investigation in a given area in order to determine the best soil horizon and the best size of soil material for sampling in that area. Silty frost boils, caliche, and desert varnish are specialized types of soil samples that might be useful sampling media. Soil gas is a new and potentially valuable geochemical sampling medium, especially in exploring for buried mineral deposits in arid regions. Gaseous products in samples of soil may be related to base-metal deposits and include mercury vapor, sulfur dioxide, hydrogen sulfide, carbon oxysulfide, carbon dioxide, hydrogen, oxygen, nitrogen, the noble gases, the halogens, and many hydrocarbon compounds. Transported materials that have been used in geochemical sampling programs include glacial float boulders, glacial till, esker gravels, stream sediments, stream-sediment concentrates, and lake sediments. Stream-sediment sampling is probably the most widely used and most successful geochemical exploration technique. Hydrogeochemical exploration programs have utilized hot- and cold-spring waters and their precipitates as well as waters from lakes, streams, and wells. Organic gel found in lakes and at stream mouths is an unproved sampling medium. Suspended material and dissolved gases in any type of water may also be useful media. Samples of ice and snow have been used for limited geochemical surveys. Both geobotanical and biogeochemical surveys have been successful in locating copper deposits in many parts of the world. Micro-organisms, including bacteria and algae, are other unproved media that should be studied. Animals can be used in geochemical-prospecting programs. Dogs have been used quite successfully to sniff out hidden and exposed sulfide minerals. Tennite mounds are commonly composed of subsurface material, but have not as yet proved to be useful in locating buried mineral deposits. Animal tissue and waste products are essentially unproved but potentially valuable sampling media. Knowledge of the location of areas where trace-element-associated diseases in animals and man are endemic as well as a better understanding of these diseases, may aid in identifying regions that are enriched in or depleted of various elements, including copper. Results of analyses of gases in the atmosphere are proving valuable in mineral-exploration surveys. Studies involving metallic compounds exhaled by plants into the atmosphere, and of particulate matter suspended in the atmosphere are reviewed these methods may become important in the future. Remote-sensing techniques are useful for making indirect measurements of geochemical responses. Two techniques applicable to geochemical exploration are neutron-activation analysis and gamma-ray spectrometry. Aerial photography is especially useful in vegetation surveys. Radar imagery is an unproved but potentially valuable method for use in studies of vegetation in perpetually clouded regions. With the advent of modern computers, many new techniques, such as correlation analysis, regression analysis, discriminant analysis, factor analysis, cluster analysis, trend-surface analysis, and moving-average analysis can be applied to geochemical data sets. Selective use of these techniques can provide new insights into the interpretatio

Professional Paper↗