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Samples of 17 volcanic rocks of Tertiary and Quaternary age from Adak and Kanaga islands have been chemically analyzed and studied microscopically. Spectrograms have been made of 10 of them. The rocks from Adak represent one center of possibly older Tertiary age and two centers of younger Tertiary or Quaternary age. The rocks from Kanaga Island represent both a shield volcano of possibly Tertiary age, partly destroyed by the formation of a caldera, and a young cone of Quaternary age that...

Reconnaissance field work along the Alaska Highway in northern British Columbia and southeastern Yukon furnishes preliminary data on the later Quaternary history of the region, and on the processes and results of intensive frost action. Extensive erosion surfaces were developed prior to glaciation, such as the Alberta Plateau of northeastern British Columbia and the Yukon Plateau in southern Yukon. In the region from Dawson Creek to Fort Nelson, British Columbia, the drift is dominantly...

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Part I, T. S. Lovering. Preliminary work in the Tintic district, Utah, determined the relative distance of migration of ore metals in moist carbonate and silicic wall rocks near ore, and in ground water having a very sluggish circulation through mineralized ground. The analyses of efflorescences in the Tintic Standard mine openings at suitable localities indicated that under the conditions existing during the past 25 years lead has not...

The Fish Lake Plateau, nearly centrally located among the High Plateaus of Utah, exhibits glacial and other geomorphic features of regional significance. The plateau is divided into two areas by Fish Lake and the wide valley of Sevenmile Creek. The Fish Lake trough is a structural basin; Sevenmile Valley may be largely erosional. Volcanic rocks of Tertiary age underlie most of the plateau;...

The age of igneous rocks is determinable by a method based on the included accessory minerals. In the common igneous rocks, most of the lead is concentrated in the potassium minerals, and most of the radioactivity is in the zircon and other accessory minerals. The lead in the potassium minerals is believed to be mostly primary lead; that in zircon is probably chiefly radiogenic lead. By...

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I was an employee of the Texas State Board of Water Engineers in charge of the Fort Stockton field office at the time that the data for this paper were gathered. Since I have done both extensive and detailed ground‐water work in the Fort Stockton area, including the setting and...

A mathematical theory is given for the discharge of a well of constant drawdown, discharging as by natural flow from an effectively infinite aquifer of uniform transmissibility and uniform compressibility. This theory is based on the solution by L. P. Smith of the analogous problem in heat conduction. The mathematical...

A mathematical theory is given for the discharge of a well of constant drawdown, discharging as by natural flow from an effectively infinite aquifer of uniform transmissibility and uniform compressibility. This theory is based on the solution by L. P. Smith of the analogous problem in heat conduction. The mathematical...

Tonight I will try to present to you the chief facts we have observed that have a bearing on the old problem of how the black shales originated. Some of the ideas have been used before, and some are new. Some of those that have been used before, have been used to...

Approximately 300 digestive tracts of fur animals obtained mostly during the winter trapping season and 560 scats from animals live-trapped on the Patuxent Research Refuge near Laurel, Maryland, were analyzed. The resulting data are summarized and a brief description of the area...

Patterns formed by the networks of furrows separating the natural mounds of pimpled plains in eastern Oklahoma are regarded as attributable to shrinkage-polygon systems of coarse texture comparable to those occurring (1) in mound-studded parts of the northwestern United States that are underlain by vertically jointed basalt, (2) in tracts of Alaskan tundra that are occupied...

Because of the common association of uranium and copper in several of the commercial uranium deposits in the Colorado Plateau Province, a reconnaissance was made of several known deposits of copper disseminated through sandstone to determine whether they might be a source of uranium. In order to obtain more information...

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Activities of the Committee on Land Erosion, since the present Committee was appointed in September, 1950, have been confined mainly to correspondence among members as a means of becoming better acquainted and of deciding on a suitable program for consideration of the Committee Erosion being such a far-flung and complex...

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Several radioactivity anomalies and a few specimens of sooty pitchblende and other uranium minerals have been found on the mine dumps of formerly productive base-and precious-metal mines along the Comet-Gray Eagle shear zone in the Comet area in southwestern Montana. The shear zone is from 50 to 200 feet wide...

The geographic pattern of known igneous rocks and ore deposits on the Colorado Plateau suggests a zonal arrangement of several types of ore deposits around centers of igneous activity. Spectrographic analyses of rocks and ores on the Plateau have been obtained in an effort to determine the distribution of elements and...