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Gary C. Curtin

Publications and source records attributed to Gary C. Curtin.

18 recordsLinked to original sources
USGS1993

Mineralogical maps showing distribution of selected ore-related minerals in the nonmagnetic, heavy-mineral-concentrate fraction of stream sediment from the Mount Hayes 1 degree by 3 degrees Quadrangle, eastern Alaska Range, Alaska

Exploratory geochemical sampling was done in 1979, 1980, and 1981. The collection of composite samples of stream sediment or glacial debris was emphasized the first 2 years; the last year was spent collecting mineralized stream pebbles, float, and outcrop samples. The stream-sediment and heavy- mineral-concentrate samples were collected at 795 sites on tributary streams having drainage basins ranging from 1 to 5 mi 2 in area. The glacial debris samples were collected at 116 sites on tributary glaciers also having drainage basins ranging from 1 to 5 mi2 in area. All of these samples were analyzed for 31 elements by six-step semiquantitative emission spectrography (Grimes and Marranzino, 1968). In addition, all samples were analyzed for zinc by an atomic absorption method (Ward and others, 1969). The spectrographic and chemical results are available in O'Leary and others (1982).

Alaska↗
USGS1993

Mineral resource assessment of rare-earth elements, thorium, titanium, and uranium in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina

Mineral resources of the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina, were assessed between 1984 and 1990 under the Conterminuous United States Mineral Assessment Program (CUSMAP) of the U.S. Geological Survey (USGS). The mineral resource assessments were made on the basis of geologic, geochemical, and geophysical investigations and the presence of mines, prospects, and mineral occurrences from the literature. This report is an assessment of the rare-earth elements (REE), thorium, titanium, and uranium resources in the Greenville quadrangle and is based on heavy mineral concentrates collected in 1951-54 by the USGS (Overstreet and others, 1968; Caldwell and White, 1973; Cuppels and White, 1973); on the results of the U.S. Department of Energy, National Uranium Resource Evaluation (NURE) sampling program (Ferguson, 1978, 1979); on analyses of stream-sediment and heavy-mineral-concentrate samples (Jackson and Moore, 1992, G.C Cullin, USGS, unpub. data, 1992) on maps showing aerial gamma radiation in the Greenville quadrangle (D.L. Daniels, USGS, unpub. data, 1992); and on the geology as mapped by Nelson and others (1987, 1989).

Georgia, North Carolina, South Carolina↗
USGS1989

Summary and interpretation of geochemical maps for stream sediment and heavy mineral concentrate samples, Mount Hayes Quadrangle, eastern Alaska Range, Alaska

This report and accompanying maps summarize the results of geochemical exploration studies in the Mount Hayes quadrangle, Alaska. This is one of a series of maps and reports on the geological, geochemical, and geophysical studies of the quadrangle prepared as part of the Alaskan Mineral Resource Assessment Program (AMRAP) of the U.S. Geological Survey. These maps are part of the Mount Hayes l:250,000-scale folio. The geochemical studies were made in order to identify and define mineralized areas in the quadrangle and to aid in characterizing the nature of the mineral occurrences within these areas. The studies included the collection of composite samples of stream sediment or glacial debris and preparation of these samples, as described by O'Leary and others (1982), to yield a minus-80-mesh (0.2-mm) fraction and nonmagnetic heavy-mineral-concentrate fraction consisting of mineral grains having a specific gravity greater than 2.85. Samples were collected at 911 sites either from tributary streams or tributary glaciers with drainage basins ranging from 1 to 5 sq mi in area. The samples were analyzed for 30 elements by semiquantitative emission spectrography (O'Leary and others, 1982). The stream-sediment and glacial-debris samples also were analyzed for zinc by an atomic absorption method (Ward and others, 1969), and those results were used in preparing map A. The maps in this report show drainage basins in which the stream sediment or glacial debris contained anomalously high amounts of selected metals. The geologic base map aids in showing the geologic terranes of the quadrangle. The accompanying tables give frequencies and cumulative percents of the selected metals for all major geologic terranes within the quadrangle.

Alaska↗
USGS1980

Histograms and correlation table for selected elements in samples of the ash of black spruce needles from the Tanacross Quadrangle, Alaska

These histograms and correlation table show the distribution and abundance of, and correlations between, the populations of 21 elements in the ash of black spruce (Picea Mariana B.S.P.) needles collected throughout most of the Tanacross 1:250,000-scale quadrangle. The samples were collected during reconnaissance geochemical studies as part of the U.S. Geological Survey's Alaskan Mineral Resource Assessment Program. Related data for black spruce are presented in other reports (Day, Curtin, and Tripp, 1979 a,b,c) , and background information on the mineral resource assessment of the Tanacross quadrangle is presented in a U.S. Geological Survey Circular (Foster and others, 1976).

Alaska↗
USGS1980

Histograms and correlation table for selected elements in samples of the ash of ground birch leaves from the Tanacross Quadrangle, Alaska

These histograms and correlation table show the distribution and abundance of, and correlations between, the populations of 21 elements in the ash of ground birch (Betula rotundifolia Sarg.) leaves collected throughout most of the Tanacross 1:250,000-scale quadrangle. The samples were collected during reconnaissance geochemical studies as part of the U.S. Geological Survey's Alaskan Mineral Resource Assessment Program. Related data for ground birch are presented in other reports (Day, Curtin, and Tripp, 1979 a,b,c), and background information on the mineral resource assessment of the Tanacross quadrangle is presented in a U.S. Geological Survey Circular (Foster and others, 1976).

Alaska↗
USGS1979

The concentration and mobility of elements in subalpine forest soils in Colorado and Idaho

Leaching studies of subalpine forest soils collected at seven sites in Colorado and Idaho show that copper, cobalt, chromium, magnesium, barium, tin, strontium, and yttrium are highly mobile elements in these soils; that zirconium, lanthanum, nickel, and scandium are moderately mobile; and that titanium is rather immobile. Furthermore, the results of the studies indicate that elements are most highly concentrated in the ash of the mull (02) horizon. In these soils, the mull horizon is a more favorable zone for the accumulation of metals and other elements than are the mineral (A,B,C) soil horizons.

Colorado, Idaho↗
USGS1974

Antimony and other metal anomalies south of Stibnite, Valley County, Idaho

Results of geochemical investigations south of Stibnite, Valley County, Idaho, show that the distribution of Sb, As, Au, Zn, Ag, and Mo in mull ash and of Hg, in soil forms a highly anomalous area which is more than 1.5 km long and 1 km wide along the trace of the Meadow Creek fault, a major northstriking fault zone. In the report area the Meadow Creek fault is covered by deposits of Quaternary glacial debris ranging in thickness from several meters to more than 30 meters. Two other highly anomalous areas--one of Au, Zn, and Hg, and one of Zn, Ag, Hg, and Mo--correlate with silicified granodiorite along the trace of the Meadow Creek fault. These anomalies are not related to hnown Ore deponits and merit further investigation. The enrichment of metals in mull ash in the area of thick glacial debris suggests that the metals migrate from bedrock upward through the glacial debris, are taken up by the forest vegetation, and are concentrated in the mull as the litter from the vegetation-decays. The findings indicate that mull is the most useful geochemical sampling medium in the stibnite area because the bedrock is deeply buried beneath deposits of transported material such as colluvium or glacial debris.

Open-File Report↗
USGS1968

Utilization of humus-rich forest soil (mull) in geochemical exploration for gold

Distribution of gold in humus-rich forest soil (mull) reflects the known distribution of gold deposits in bedrock in the Empire district, Colorado. Gold from the bedrock is accumulated by pine and aspen trees and is concentrated in the mull by the decay of organic litter from the trees. Anomalies in mull which do not coincide with known gold deposits merit further exploration. The gold anomalies in soil (6- to 12-inch depth) and in float pebbles and cobbles poorly reflect the known distribution of gold deposits in bedrock beneath the extensive cover of colluvium and glacial drift.

Circular↗