Publications

By direct comparison of devitrified and granophyrically crystallized specimens with nonhydrated glassy materials from the same units, Rosholt and coworkers (Rosholt and Noble, 1969; Rosholt et al., 1971) showed that specimens of primarily crystallized but otherwise unaltered peralkaline and subalkaline rhyolite from the western United States had lost from 30 to 80 percent of the uranium that they

No abstract available.

CO2‐rich springs occur worldwide along major zones of seismicity. They are mostly in young orogenic belts, but some are in areas of rifting continental platforms. Analyses of 13C content indicate that much of the CO2 is derived from the mantle and that other important sources are the metamorphism of marine carbonate‐bearing sedimentary rocks and the degradation of organic material. The presence of

No abstract available.

Study of uraniferous silica precipitates in the Shirley Basin, Wyoming, identified areas where ancient uraniferous ground water once ponded. Chalcedony collected from and directly beneath thick accumulations of rhyolite ash contain as much as 250 ppm uranium in a pre-ash topographic low and lesser concentrations (10 to 160 ppm) elsewhere. Differences in the U concentration of chalcedony collected

No abstract available.

Resource estimates alone will not give advance warning of encroaching production difficulties. An analysis of the general stages in the evolution of petroleum production and discovery and of industry statistics provides an estimate of when the stage characterised by increasing production in the market economy countries outside the United States and Canada will end. The analysis indicates that the

The lower Upper Cretaceous strata in northeastern Wyoming, which have yielded major quantities of oil and gas, were sampled at boreholes in Converse, Johnson, and Weston Counties. Cores of noncalcareous shale of largely nearshore-marine origin were obtained from the Frontier Formation and the overlying Cody Shale at depths of 3,780.6 to 3,879.9 m in Converse County, near the axis of the Powder Riv

No abstract available.

No abstract available.

Sea cliffs 40 km east of Almeria, southeastern Spain, expose upper Miocene reefs and patch reefs of the Plomo formation. These reefs are formed of scleractinian corals, calcareous algae, and mollusks. The reef cores are as much as 65 m thick and several hundred meters wide. Fore-reef talus beds extend 1,300 m across and are 40 m thick. The reefs and reef breccias are composed of calcitic dolomite.

The metamorphic complex of the northern Ruby Mountains in northeastern Nevada exposes Paleozoic strata that are metamorphosed to sillimanite grade, migmatized, and recumbently folded. Nappes are variously overturned to the east, north, south, and west. The deeper part of this metamorphic infrastructure is a migmatitic zone pervaded by pegmatitic two-mica granite. A structurally higher transition z