Publications

The Louisiana black bear (Ursus americanus luteolus) is comprised of 3 subpopulations, each being small, geographically isolated, and vulnerable to extinction. Hurricanes Katrina and Rita struck the Louisiana and Mississippi coasts in 2005, potentially altering habitat occupied by this federally threatened subspecies. We used data collected on radio-telemetered bears from 1993 to 1995...

The element bromine is found principally as a dissolved species in seawater, evaporitic (salt) lakes and underground brines associated with petroleum deposits. Seawater contains about 65 parts per million of bromine or an estimated 100 Tt (110 trillion st). In the Middle East, the highly saline waters of the Dead Sea are estimated to contain 1 Gt (1.1billion st) of bromine. Bromine is...

This chapter discusses mercury cycling in the terrestrial landscape, including inputs from the atmosphere, accumulation in soils and vegetation, outputs in streamflow and volatilization, and effects of land disturbance. Mercury mobility in the terrestrial landscape is strongly controlled by organic matter. About 90% of the atmospheric mercury input is retained in vegetation and organic...

Here we establish a magnetostratigraphy susceptibility zonation for the three Middle Permian Global boundary Stratotype Sections and Points (GSSPs) that have recently been defined, located in Guadalupe Mountains National Park, West Texas, USA. These GSSPs, all within the Middle Permian Guadalupian Series, define (1) the base of the Roadian Stage (base of the Guadalupian Series), (2) the...

Manganese is a silver-colored metal resembling iron and often found in conjunction with iron. The earliest-known human use of manganese compounds was in the Stone Age, when early humans used manganese dioxide as pigments in cave paintings. In ancient Rome and Egypt, people started using it to color or remove the color from glass - a practice that continued to modern times. Today...

Analytical challenges in obtaining high quality measurements of rare earth elements (REEs) from small pore fluid volumes have limited the application of REEs as deep fluid geochemical tracers. Using a recently developed analytical technique, we analyzed REEs from pore fluids collected from Sites U1325 and U1329, drilled on the northern Cascadia margin during the Integrated Ocean Drilling...

This chapter reviews and synthesizes the lithostratigraphy, biostratigraphy, chronostratigraphy, and breccia types of the southwestern part of the great American carbonate bank in the southern Franklin Mountains (SFM), El Paso, Texas. Primary stratigraphic units of focus are the Lower Ordovician El Paso and Upper Ordovician Montoya Groups. These groups preserve breccias formed by...

The southern Appalachian part of the Cambrian–Ordovician passive margin succession of the great American carbonate bank extends from the Lower Cambrian to the lower Middle Ordovician, is as much as 3.5 km (2.2 mi) thick, and has long-term subsidence rates exceeding 5 cm (2 in.)/k.y. Subsiding depocenters separated by arches controlled sediment thickness. The succession consists of five

Magnesium is the eighthmost abundant element in Earth’s crust, and the second-most abundant metal ion in seawater. Although magnesium is found in more than 60 minerals, only brucite, dolomite, magnesite and carnallite are commercially important for their magnesium content. Magnesium and its compounds also are recovered from seawater, brines found in lakes and wells, and bitterns (salts).

Threshold detection methods are increasingly popular for assessing nonlinear responses to environmental change, but their statistical performance remains poorly understood. We simulated linear change in stream benthic macroinvertebrate communities and evaluated the performance of commonly used threshold detection methods based on model fitting (piecewise quantile regression [PQR]), data

A high prevalence of intersex or testicular oocytes (TO) in male smallmouth bass within the Potomac River drainage has raised concerns as to the health of the river. Studies were conducted to document biomarker responses both temporally and spatially to better understand the influence of normal physiological cycles, as well as water quality and land-use influences. Smallmouth bass were...

Spanning a latitudinal range typical for deserts, the Indian peninsula is fertile instead and sustains over a billion people through monsoonal rains. Despite the strong link between climate and society, our knowledge of the long‐term monsoon variability is incomplete over the Indian subcontinent. Here we reconstruct the Holocene paleoclimate in the core monsoon zone (CMZ) of the Indian...