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The alkaline stock at Mount Monadnock, Vermont, described briefly by Wolff (1929), has been restudied in detail. Its petrography and structure are discussed here and conclusions are drawn as to its mode of emplacement. The stock consists of plutonic and hypabyssal rocks which intrude folded Ordovician (?) schist and quartzite. The longer axis, trending north-northwest across the strike of the country...

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Cobalt and nickel of possible commercial interest have been discovered in the Silver Summit mine, Coeur d'Alene district, Idaho. Assay data indicate that an ore shoot contained about 0.40 percent cobalt and about 1.0 percent nickel in addition to the copper and rich silver ores. The cobalt-nickel mineral gersdorffite occurs...

Copper, largely in the mineral chalcocite, is found in the lowermost beds of the Nonesuch shale over many square miles near White Pine, Ontonagon County, Mich. The Nonesuch shale, of late Keweenawan age, is about 600 feet thick and is composed largely of gray siltstone. It overlies 2,300 to 5,500...

The Moenkopi formation of Triassic age is composed of a series of deposits that form a wedge thinning eastward from a maximum of about 2000 feet in western Utah and southern Nevada to the vanishing point along an irregular margin in western Colorado, northeastern Arizona, and western New Mexico. Partly marine and partly continental in the...

The oldest part of the Caribbean region proper is in northern Central America, where Permian (?) and Lower Permian marine deposits rest on metamorphic rocks of unknown, possibly middle Paleozoic, age. According to present dating, geosynclinal deposition spread eastward in Late Jurassic time to include Cuba, farther eastward and southward...

A botanical sampling program has been completed by the U.S. Geological Survey on La Ventana Mesa, Sandoval County, N. Mex. A uranium-bearing coal in the Allison-Gibson members of the Cretaceous Mesaverde formation crops out in erosional remnants of the mesa.The coal is capped by a well-fractured 65-foot sandstone bed through...

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Records of water levels in limesink ponds in southwestern Georgia and of water‐table levels in the vicinity of these ponds are used to demonstrate: (1) some ponds with highly impermeable beds are virtually unaffected by water‐table levels, except when water‐table levels are above the rim of the impervious materials; (2) interchange of water between pond and water table occurs when beds are relatively permeable. Three phases in the relation between pond level and water‐table level are recognized: (1) water‐table level higher than pond level causing ground‐water flow into the pond; (2) ground‐water level below pond level but in direct contact...

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The gold pan is ordinarily regarded as a tool for sampling placer deposits. Another and very important application is shown to be the sampling and study of decomposed bedrock, in regions where outcrops of hardrock are scarce or lacking. This technique was proposed and used by Derby, an American geologist...

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A drafting instrument which provides a ruling edge for drawing arcs of circles the radii of which are unusually long is described. A complete range of arcs of different curvature, within the limits prescribed by the construction of the instrument, are obtainable. This instrument was developed originally to allow accurate construction of circular arcs of very low...

Total‐intensity aeromagnetic surveys of the Aleutian Marshall, and Bermuda Islands were completed in 1948. The anomalies associated with the Aleutian volcanoes are attributed mainly to topographic relief and are not an indication of the degree of volcanic activity. Eniwetok presents a magnetic pattern that would be produced by an irregular‐shaped rimmed depression in the basement, modified by the two adjoining seamounts, and differs from...

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An epizoological study of Plasmodium infections in wild birds of Kern County, California, in the years 1946 through 1951 greatly extended knowledge of the occurrence of these parasites and their behavior in nature. Examination of 10,459 blood smears from 8,674 birds representing 73 species resulted in the observation of Plasmodium...

Abasic Question that must be answered for any archaeological site is, how old is it? Although some archaeological sites can be dated on the basis of archaeological correlations alone and although dendrochronological (Giddings, 1952, pp. 105-110) and radiocarbon methods give absolute ages for other sites, many sites can be dated only by methods based on the geologists' knowledge of geographic and...

This investigation was made to determine the surface and subsurface geological conditions along the proposed relocation of Route 138 in the vicinity of the Torrey Street crossing in Brockton, Mass. The field work was done in April 1952 as part of cooperative program of the Commonwealth of Massachusetts, Department of...

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