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Quartz diorite bedrock underlying the Luquillo Mountains of eastern Puerto Rico undergoes weathering at one of the fastest documented rates for granitic rocks in the world. Although tropical temperatures and precipitation promote rapid weathering in this location, increased bacterial densities in the regolith immediately above the bedrock suggest that microorganisms...

The movement and transmission of avian influenza viral strains via wild migratory birds may vary by host species as a result of migratory tendency and sympatry with other infected individuals. To examine the roles of host migratory tendency and species sympatry on the movement of Eurasian low-pathogenic avian influenza (LPAI)...

Groundwater in the Newark basin aquifer flows primarily through discrete water-bearing zones parallel to the strike and dip of bedding, whereas flow perpendicular to the strike is restricted, thereby imparting anisotropy to the groundwater flow field. The finite-element model SUTRA was used to represent bedrock structure in the aquifer by...

In 2010, a two-dimensional hydrodynamic and water-quality model (CE-QUAL-W2) of Lake Ashtabula, North Dakota, was developed by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission to understand the dynamics of chemical constituents in the reservoir and to provide a tool for the management and operation...

The Greater Platte River Basin area spans a central part of the Midcontinent and Great Plains from the Rocky Mountains on the west to the Missouri River on the east, and is defined to include drainage areas of the Platte, Niobrara, and Republican Rivers, the Rainwater Basin, and other adjoining...

The superlative hot springs, geysers, and fumarole fields of Yellowstone National Park are vivid reminders of a recent volcanic past. Volcanism on an immense scale largely shaped the unique landscape of central and western Yellowstone Park, and intimately related tectonism and seismicity continue even now. Furthermore, the volcanism that gave...

What are the roles of deep Precambrian basement deformation zones in the localization of subsequent shallow-crustal deformation zones and magmas? The Paleoproterozoic Great Falls tectonic zone and its included Boulder batholith (Montana, United States) provide an opportunity to examine the importance of inherited deformation fabrics in batholith emplacement and the...

The San Jacinto right-lateral strike-slip fault zone is crucial for understanding plate-boundary dynamics, regional slip partitioning, and seismic hazards within the San Andreas fault system of southern California, yet its age of initiation and long-term average slip rate are controversial. This synthesis of prior and new detailed studies in the...

The hydrogeology of the stratified-drift aquifer in the Sprout Creek and Fishkill Creek valleys in southern Dutchess County, New York, previously investigated by the U.S. Geological Survey (USGS) in 1982, was updated through the use of new well data made available through the New York State Department of Environmental Conservation's...

This report documents selected age data interpreted from measured concentrations of environmental tracers in groundwater from 1,399 National Water-Quality Assessment (NAWQA) Program groundwater sites across the United States. The tracers of interest were chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), and tritium/helium-3 (3H/3He).Tracer data compiled for this analysis primarily were from wells...

Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at...

Rusa unicolor (Kerr, 1792), or sambar, is the largest Oriental deer. Seven subspecies occur in varied habitats and elevations from India and Sri Lanka throughout southeastern Asia. Body mass and antler length decrease from west to east. R. unicolor is considered ancestral relative to the form of its male-only antlers...

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces...

During 2007 and 2008, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, collected quarterly depth-discrete measurements of fluid pressure and temperature in six boreholes located in the eastern Snake River Plain aquifer of Idaho. Each borehole was instrumented with a multilevel monitoring system consisting of a...

In late 2007, a perched lava channel, built up to 45 m above the preexisting surface, developed during the ongoing eruption near Pu‘u ‘Ō‘ō cone on Kīlauea Volcano’s east rift zone. The lava channel was segmented into four pools extending over a total of 1.4 km. From late October to mid-December, a...

The Eocene (34 Ma) Caetano caldera in north-central Nevada offers an exceptional opportunity to study the physical and petrogenetic evolution of a large (20 km by 10–18 km pre-extensional dimensions) silicic magma chamber, from precursor magmatism to caldera collapse and intrusion of resurgent plutons. Caldera-related rocks shown on this map...

An energetic seismic swarm accompanied an eruption of Kasatochi Volcano in the central Aleutian volcanic arc in August of 2008. In retrospect, the first earthquakes in the swarm were detected about 1 month prior to the eruption onset. Activity in the swarm quickly intensified less than 48 h prior to...

The 2008 Wells earthquake occurred on a northeast-striking, southeast-dipping fault that is clearly delineated by the aftershock swarm to a depth of 10-12 km below sea level. However, Cenozoic rocks and structures around Wells primarily record east-west extension along north- to north-northeast-striking, west-dipping normal faults that formed during the middle...

In central Idaho, Neoproterozoic stratified rocks are engulfed by the Late Cretaceous Idaho batholith and by Eocene volcanic and plutonic rocks of the Challis event. Studied sections in the Gospel Peaks and Big Creek areas of west-central Idaho are in roof pendants of the Idaho batholith. A drill core section...

Most of eastern North America receives elevated levels of atmospheric deposition of sulfur (S) that result from anthropogenic SO2 emissions from fossil fuel combustion. Atmospheric S deposition has acidified sensitive terrestrial and aquatic ecosystems in this region; however, deposition has been declining since the 1970s, resulting in some recovery in previously...

Rapid changes in ground tilt and GPS positions on Kīlauea Volcano, Hawai'i, are interpreted as resulting from a shallow, two-segment dike intrusion into the east rift zone that began at 1217 UTC (0217 HST) on 17 June 2007 and lasted almost 3 days. As a result of the intrusion, a...

Antecedent geology plays a crucial role in determining the inner-shelf, nearshore, and onshore geomorphology observed in coastal systems. However, the influence of the geologic framework on a system is difficult to extract when evaluating responses to changes due to storms and anthropogenic modifications, and few studies have quantified the potential...

This report describes the bituminous coal deposits of the Olmos Formation (Navarro Group, Upper Cretaceous; Figures 1, 2) of Maverick County in south Texas. Although these were not evaluated quantitatively as part of the current Gulf Coastal Plain coal-resource assessment, a detailed review is presented in this chapter.Prior to the...

The lignite deposits within the upper Eocene Yegua Formation (Claiborne Group) and the overlying Jackson Group are among the coal resources that were not quantitatively assessed as part of the U.S. Geological Survey's (USGS) National Coal Resource Assessment (NCRA) program in the Gulf Coastal Plain coal province. In the past,...

This review of the lignite deposits of western Tennessee and the Jackson Purchase area in western Kentucky (Figure 1) is an updated report on part of the U.S. Geological Survey's National Coal Resource Assessment of the Gulf Coastal Plain Coal Province (see Ruppert et al., 2002; Hackley et al., 2006;...