Geology topics
G.W. Day
Publications and source records attributed to G.W. Day.
Distribution and abundance of molybdenum, determined by spectrographic analysis, in nonmagnetic fraction of heavy-mineral concentrates from stream sediments, Petersburg area, southeast Alaska
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Distribution and abundance of cobalt, determined by spectrographic analysis, in the nonmagnetic fraction of heavy-mineral concentrates from stream sediments, Petersburg area, southeast Alaska
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Distribution and abundance of chromium, determined by spectrographic analysis, in the nonmagnetic fraction of heavy-mineral concentrates from stream sediments, Petersburg area, southeast Alaska
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Distribution and abundance of tungsten, determined by spectrographic analysis, in nonmagnetic fraction of heavy-mineral concentrates from stream sediments, Petersburg area, southeast Alaska
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Analyses and descriptions of geochemical samples from the Rich Mountain Roadless Area, Fannin and Gilmer counties, Georgia
Semi-quantitative spectrographic analyses for 31 elements on rock, soil, fine-grained stream sediment, bulk stream sediment, and panned stream sediment samples collected in the Rich Mountain Roadless Area, Fannin and Gilmer Counties, Georgia, are reported here. Atomic absorption analyses for gold and fluorometric analyses for uranium are also reported. Brief descriptions of all rock samples analyzed are included.
Locality map for scintillometer and analytical data collected in 1981, Ugashik and Karluk quadrangles, Alaska
Scintillometer data were collected routinely in 1981 as part of the field investigations in the Ugashik and Karluk quadrangles. The instrument used was a Geometrics Model GR-101A, mounted in the helicopter. The data, in counts per second (cps), were obtained at most of the sites by the helicopter pilot (Svec) while geologists were occupying the sample site. Scintillometer localities are indicated on the map by a dot. The sites are concentrated in the southeastern part of the map area where previous work (OF 81-253) had outlined an area with anomalously high cps. The bedrock at these sites is a Late Tertiary hornblende granodiorite instrusive dated at 9.4 my. Hornfelsed sedimentary rock overlying the batholith gave cps nearly as high as the intrusive rock. Samples routinely checked by semiquantitative spectrographic analysis for thorium failed to detect the element. In general the Ugashik and Karluk quadrangles have a low level of gamma radiation. A majority of the sites, 52 percent, gave readings of less than 35 cps, and only 10 percent had values of greater than cps. Thick alluvium or glacial deposits generally gave low values. Readings from sedimentary bedrock were extremely erratic and no generalization can be made concerning their level of gamma radiation. The hornblende granodiorite and overlying hornfelsed sedimentary rock are all greater than 30 cps, but again, the values are somewhat erratic and no definitive pattern is readily apparent. Bedrock samples are collected for analysis are on the map by a triangle.
Distribution and abundance of molybdenum in minus-80-mesh stream-sediment and nonmagnetic heavy-mineral-concentrate samples, Chignik and Sutwik Island quadrangles, Alaska
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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).
Geochemical and generalized geologic maps showing distribution and abundance of gold and silver in the Talkeetna Quadrangle, Alaska
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Geochemical and generalized geologic maps showing distribution and abundance of tin, tungsten, and beryllium in the Talkeetna Quadrangle, Alaska
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Geochemical and generalized maps showing distribution and abundance of copper, lead, zinc, and molybdenum in the Talkeetna Quadrangle, Alaska
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Geochemical and generalized geologic maps showing distribution and abundance of chromium and nickel in the Talkeetna Quadrangle, Alaska
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Geochemical map showing the distribution and abundance of copper in stream sediments in the Seward and Blying Sound quadrangles, Alaska
Reconnaissance geochemical and mineralogical sampling was done in the Seward and Blying Sound quadrangles during 1975 and 1976 as part of the Alaska Mineral Resources Assessment Program (AMRAP). This map shows the distribution and abundance of copper in stream-sediment samples. Stream-sediment samples were collected at 569 sites from active stream channels and locally, from the interface of streambeds with intermediate- to low-tide beaches. Most of the stream sediment is fine- to coarse-grained sand, with a clay-silt fraction in streams discharging from glaciers. The stream sediment samples were air dried and sieved through a 80-mesh (0.2 mm) sieve, and the minus-80 mesh fraction was saved for analysis. A split of each sample was analyzed for copper and 15 other elements by a semiquantitative spectrographic method (Grimes and Marranzino, 1968). Other splits were analyzed for gold and zinc by atomic absorption methods (Warren and others, 1969). Sample sites and copper values (in parts per million) are indicated on the map by symbols identified in the histogram. The weakly anomalous values are considered to be significant only where they were detected in stream-sediment or heavy-mineral concentrate samples that also contained strongly anomalous values of other metals such as arsenic, gold, lead or tungsten. The map shows two populations for copper in stream sediments. One population consisting of generally lower copper values represents the samples collected from the sedimentary terrane in the central and western parts of the quadrangles. The other population consisting of generally higher copper values includes samples collected in areas of sheeted basalt dikes and pillow basalts in the eastern part of the quadrangles and from the sedimentary terrane of Latouche Island; in these areas chalcopyrite and pyrite were observed as fine-grained disseminations in the rocks and as mineral particles in the heavy-mineral concentrates.