Reports

Layered, ultramafic to mafic intrusions are uncommon in the geologic record, but host magmatic ore deposits containing most of the world's economic concentrations of platinum-group elements (PGE) (figs. 1 and 2). These deposits are mined primarily for their platinum, palladium, and rhodium contents (table 1). Magmatic ore deposits are derived from accumulations of crystals of metallic...

What are the most important factors affecting dissolved radium concentrations in principal aquifers used for drinking water in the United States? Study results reveal where radium was detected and how rock type and chemical processes control radium occurrence. Knowledge of the geochemical conditions may help water-resource managers anticipate where radium may be elevated in groundwater...

Water, bed sediment, and biota were sampled in streams from Butte to near Missoula, Montana, as part of a monitoring program in the upper Clark Fork basin. The sampling program was conducted by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency to characterize aquatic resources in the Clark Fork basin of western Montana, with emphasis on trace...

Using a geology-based assessment methodology, the U.S. Geological Survey assessed means of (1) 141 million barrels of oil (MMBO), 502 billion cubic feet of natural gas (BCFG), and 16 million barrels of natural gas liquids (MMBNGL) in the conventional Eagle Ford Updip Sandstone Oil and Gas Assessment Unit (AU); (2) 853 MMBO, 1,707 BCFG, and 34 MMBNGL in the continuous Eagle Ford Shale Oil...

Concentrations of the lanthanide series or rare earth elements and yttrium were determined for lacustrine oil shale samples from the Eocene Green River Formation in the Piceance Basin of Colorado and the Uinta Basin of Utah. Unprocessed oil shale, post-pyrolysis (spent) shale, and leached shale samples were examined to determine if oil-shale processing to generate oil or the remediation...

Chloride flux has been used to estimate heat flow in volcanic environments since the method was developed in New Zealand by Ellis and Wilson (1955). The method can be applied effectively at Yellowstone, because nearly all of the water discharged from its thermal features enters one of four major rivers (the Madison, Yellowstone, Snake, and Falls Rivers) that drain the park, and thus...

Evansville, Indiana, has experienced minor damage from earthquakes several times in the past 200 years. Because of this history and the fact that Evansville is close to the Wabash Valley and New Madrid seismic zones, there is concern about the hazards from earthquakes. Earthquakes currently cannot be predicted, but scientists can estimate how strongly the ground is likely to shake as a...

The region surrounding Evansville, Indiana, has experienced minor damage from earthquakes several times in the past 200 years. Because of this history and the proximity of Evansville to the Wabash Valley and New Madrid seismic zones, there is concern among nearby communities about hazards from earthquakes. Earthquakes currently cannot be predicted, but scientists can estimate how...

Proper interpretation of water quality requires consideration of the effects that contamination bias and sampling variability might have on measured analyte concentrations. The effect of contamination bias and sampling variability on major ion and total dissolved solids data in water samples collected in 48 of the 52 National Water-Quality Assessment Program study units from 1992–2010 is...

Using a geology-based assessment methodology, the U.S. Geological Survey estimated volumes of undiscovered, technically recoverable, conventional petroleum resources for the Amu Darya Basin and Afghan–Tajik Basin Provinces of Afghanistan, Iran, Tajikistan, Turkmenistan, and Uzbekistan. The mean volumes were estimated at 962 million barrels of crude oil, 52 trillion cubic feet of natural...

The U.S. Geological Survey, in cooperation with the C.P. Gillette Museum of Arthropod Diversity (Colorado State University, Fort Collins, Colorado), compiled collection record data to document the historical and present-day occurrence of mayfly, stonefly, and caddisfly species in the South Platte River Basin. Data were compiled from records collected between 1873 and 2010 to identify...

This report summarizes a preliminary assessment of bed-material transport, vertical and lateral channel changes, and existing datasets for the Rogue River basin, which encompasses 13,390 square kilometers (km2) along the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that:The Rogue River in its lowermost 178.5...