Publications

In March 2008, we collected gravity data along 12 traverses across newly-mapped faults in the Moapa Valley region of Clark County, Nevada. In areas crossed by these faults, the traverses provide better definition of the gravity field and, thus, the density structure, than prior gravity observations. Access problems prohibited complete gravity coverage along all of the planned gravity traverses, an

Cenozoic basins in eastern Nevada and western Utah constitute major ground-water recharge areas in the eastern part of the Great Basin, and our continuing studies are intended to characterize the geologic framework of the region. Prior to these investigations, regional gravity coverage was variable over the region, adequate in some areas and very sparse in others. The current study in Nevada provi

In 2004, the U.S. Geological Survey (USGS), the Geological Survey of Canada (GSC), and the Mexican Geological Survey (Servicio Geologico Mexicano, or SGM) initiated pilot studies in preparation for a soil geochemical survey of North America called the Geochemical Landscapes Project. The purpose of this project is to provide a better understanding of the variability in chemical composition of soil

Two‐dimensional inversion of audiomagnetotelluric (AMT) sounding data define buried resistivity distributions that reflect subsurface geology and structure within the upper kilometer beneath Pleasant Valley, a 1–2 km‐deep pull‐apart basin in Joshua Tree National Park, southern California. The Park lies within the Eastern California Shear Zone just east of the San Andreas Fault, and is surrounded b

Water and debris flows exiting confined valleys have a tendency to deposit sediment on steep fans. On alluvial fans where water transport of gravel predominates, channel slopes tend to decrease downfan from ~0.10–0.04 to ~0.01 across wide ranges of climate and tectonism. Some have argued that this pattern reflects grain-size fining downfan such that higher threshold slopes are required just to ent

The general location and age of more than 33,500 mostly foraminifer samples from Chevron surface localities in nearly 600 U.S. Geological Survey (USGS) 7.5' quadrangles from California were provided by Brabb and Parker (2003). Barren and non-diagnostic samples plus many that have no paleontologic information were omitted to provide a revised list for more than 27,000 of these samples by Brabb and

One-dimensional burial and thermal history modeling of the Yukon Flats basin, east-central Alaska, was conducted as part of an assessment of the region’s undiscovered oil and gas resources. No deep exploratory wells have been drilled in the Yukon Flats region, and the subsurface geology of the basin is inferred from seismic reflection, gravity and magnetic surveys, and studies of shallow core hole

The U.S. Geological Survey (USGS) has completed an assessment of undiscovered conventional oil and gas resources in all areas north of the Arctic Circle. Using a geology-based probabilistic methodology, the USGS estimated the occurrence of undiscovered oil and gas in 33 geologic provinces thought to be prospective for petroleum. The sum of the mean estimates for each province indicates that 90 bil

Discovery of a 3-foot thick sandstone bed with abundant Turritellid gastropods of late Paleocene age about 4 miles northeast of Fairfield and on the southwest flank of Cement Hill, Solano County provides an opportunity to reevaluate the relationships of lower Tertiary formations in this part of California. Cement Hill is named for travertine deposits in and on top of sandstone of Late Cretaceous a

Analytical results on sediment and associated ground water from the Canadian River alluvium collected subsequent to those described in Breit and others (2005) are presented in this report. The data presented herein were collected primarily to evaluate the iron and sulfur species within the sediment at well sites IC 36, IC 54, and IC South located at the USGS Norman Landfill study site. Cored sedim

Ground- and surface-water samples were collected in the vicinity of the Standard Mine in west-central Colorado in order to characterize the local ground-water flow system, determine metal concentrations in local ground water, and better understand factors controlling the discharge of metal-rich waters from the mine. The sampling program included a one-time sampling of springs, mine adits, and expl

Seventy sites from the southwestern United States provide paleomagnetic results that meet certain minimum criteria and can be considered for the Time‐Averaged Field Initiative (TAFI). The virtual geomagnetic poles for these 70 units are circularly distributed, and their mean is nearly coincident with the rotational axis. When other published data for the southwestern United States are included (N