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Increasing interest in potentially harmful substances utilized and discarded by man has raised question about the normal distribution of chemical elements in the natural environment.  This interest prompted a baseline study of a pristine region off the northern coast of Alaska.  Information was gathered on currents, water clarity, nutrients, temperature...

Reconnaissance mapping on St. Lawrence Island, Alaska has revealed seven epizonal granitic plutons of mid-Cretaceous age with a combined outcrop area of about 350 square miles. The plutonic rocks are dominantly quartz monzonite, but include minor amounts of granodiorite, monzonite, syenite, syenodiorite, and alaskite.The plutons are structurally and petrologically similar...

Based on a study of minor occurrences of zinc, barite, and iron in East Tennessee, certain deposits are interpreted to have formed during early Middle Ordovician time. Principal lines of evidence supporting this age are: (1) the occurrence of barite, sphalerite, and pyrite associated with synsedimentary collapse breccias which span...

The large, low-grade copper and gold deposit at Copper Canyon, Lander County, Nevada, formed in the contact metasomatic environment adjacent to a shallow Tertiary intrusion. Vein and disseminated chalcopyrite-pyrite-pyrrhotite-arsenopyrite mineralization, with lesser amounts of gold, galena, sphalerite, marcasite, and siderite occur in the Upper Cambrian...

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Pertinent physical properties of the upper Keweenawan rocks can be measured or inferred within a sufficiently narrow range to make the quantitative evaluation of various paleohydrologic models for the origin of the White Pine copper deposit feasible. The approach is illustrated here by calculations for...

Data are given on the composition, temperature, pressure, and density of the hydrothermal fluids present in the central Cu-Mo core of the deposit at Bingham, Utah, and in its related but not necessarily coeval peripheral Pb-Zn deposits. These data are based on a study of...

A complete characterization of natural waters includes a determination of the concentrations of 30 or more minor elements. Emission spectrochemical methods are uniquely suited to the determination of a comparatively large number...

The geochemist can contribute much information of value toward assessing the effect of environment, including inorganic pollution, on health....

Iridium is determined in mineralized mafic rocks by atomic absorption after fire-assay concentration into a gold bead. Interelement interferences in the atomic-absorption determination are removed and Ir sensitivity is increased by buffering the solutions with a mixture of copper and sodium sulphates. Substantial amounts of Ag,...

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The areas covered by this report lies in the eastern Cordillera of the Colombian Andes in the region around Bucaramanga. This part of the eastern Cordillera consists of a structurally complex core of metamorphic and igneous rocks of Precambrian to Mesozoic age, flanked to east and west by faulted and...

The mineral resources of an area of 40,000 sq km, principally in the Department of Antioquia, but including small parts of the Departments of Caldas, C6rdoba, Risaralda, and Tolima, were investigated during the period 1964-68. The area is designated Zone II by the Colombian Inventario Minero Nacional(lMN). The geology of...

The Sierra Nevada de Santa Maria on the north coast of Colombia is an isolated triangular mountain area that reaches altitudes of almost 19,000 feet. The exceedingly complex geology is shown on the 1:200,000 geologic map. Despite five major periods of granitic intrusion, three major periods of metamorphism, and extensive...

The proposed disposal of copper-mine tailings in karst terrane of the Rio Tanama basin presents a number of unique problems about potential sediment and chemical pollution of Rio Tanama....

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The Wadi Bidah district in southwest Saudi Arabia contains several ancient mines and mineral-prospects. The Precambian rocks of the district are steeply dipping and highly folded and faulted. They are divided into three major units: (1) older metavolcanic rocks, (2) metasedimentary rocks, and (3) younger metavolcanic rocks. Massive sulfide-type deposits...

Two centers of gold mineralization in the Clearwater Mountains have been identified during a recent geochemical sampling program in the Healy A-1, B-1 quadrangles, Alaska. Both the Timberline Creek center and the Black Creek center are located near the same E-W trending fault system.Sites of structural weakness along the zone...

Placer gold grains from the modern streams originating in the Colorado Mineral Belt were examined for silver and copper content on a quantitative basis utilizing the electron microprobe. The variation among grains from a particular locality is large, but the mean silver content of the...

Uranium deposits of the Wyoming roll type and the Colorado Plateau peneconcordant type are the principal domestic resources of uranium. Both types occur in lenticular sandstone beds of continental origin, have a similar suite of elements and minerals, are associated with mildly altered rock, and...

All trematodes which cause infections and diseases in humans (zoonoses) require snails for their first intermediate host. Some have additional intermediate hosts such as crustaceans, fishes and frogs.In this paper I have discussed the use of various procedures for controlling snail populations thereby reducing the population of trematodes whose cercariae...

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Macusanite, originally believed to be a type of tektite because of its sculpture, is shown to be related to sillar of the Macusani region, Peru. K-Ar measurements establish identical Pliocene ages (4.2 m.y.) for macusanite and sillar and relate these deposits to the extensive ash...