Publications

The US Geological Survey recently assessed the potential for undiscovered conventional petroleum in the Arctic. Using a new map compilation of sedimentary elements, the area north of the Arctic Circle was subdivided into 70 assessment units, 48 of which were quantitatively assessed. The Circum-Arctic Resource Appraisal (CARA) was a geologically based, probabilistic study that relied...

Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that define three temporally...

The Lomonosov microcontinent is an elongated continental fragment that transects the Arctic Ocean between North America and Siberia via the North Pole. Although it lies beneath polar pack ice, the geological framework of the microcontinent is inferred from sparse seismic reflection data, a few cores, potential field data and the geology of its conjugate margin in the Barents–Kara Shelf...

For national or global resource estimation of frequencies of metals, a lognormal distribution has commonly been recommended but not adequately tested. Tests of frequencies of Cu, Zn, Pb, Ag, and Au contents of 1 984 well-explored mineral deposits display a poor fit to the lognormal distribution. When the same metals plus Mo, Co, Nb2O3, and REE2O3 are grouped into 19 geologically defined...

The Goodsprings district, Clark County, Nevada, includes zinc-dominant carbonate replacement deposits of probable late Paleozoic age, and lead-dominant carbonate replacement deposits, copper ± precious metal-platinum group element (PGE) deposits, and gold ± silver deposits that are spatially associated with Late Triassic porphyritic intrusions. The district encompasses ~500 km2 although...

Evaluation of paleosol ages in the vicinity of Yucca Mountain, Nevada, at the time the site of a proposed high-level nuclear waste repository, is important for fault-displacement hazard assessment. Uranium-series isotope data were obtained for surface and subsurface calcrete samples from trenches and boreholes in Midway Valley, Nevada, adjacent to Yucca Mountain. 230Th/U ages of 33...

We used a hydrodynamics model to assess the consequences of climate warming and contemporary geomorphic evolution for thermal conditions in a large, shallow Alaskan lake. We evaluated the effects of both known climate and landscape change, including rapid outlet erosion and migration of the principal inlet stream, over the past 50 yr as well as future scenarios of geomorphic restoration...

Drainage channels are among the most conspicuous surficial features of deserts, but little quantitative analysis of their influence on plant distributions is available. We analysed the effects of desert stream channels (‘washes’) on Larrea tridentata and Ambrosia dumosa density and cover on an alluvial piedmont in the Mojave Desert, based on a spatial analysis of transect data...

Melt inclusions trapped in phenocryst phases are important primarily due to their potential of preserving a significant proportion of the diversity of magma composition prior to modification of the parent magma array during transport through the crust. The goal of this investigation was to evaluate the impact of formational and post-entrapment processes on the composition of melt...

Annual non-metallic minerals are typically twice the value of metallic minerals, which takes a little of the sparkle out of gold.

Among the many European millstones, the geology of the French burrstone was prized for the effect of its quartz grain.

This report, which is one of a series of reports on metals recycling, defines and quantifies the flow of tungsten-bearing materials in the United States from imports and stock releases through consumption and disposition in 2000, with particular emphasis on the recycling of industrial scrap (new scrap) and used products (old scrap). Because of tungsten's many diverse uses, numerous types...