Publications

Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil f

No abstract available.

This report presents data on the quantity and chemical quality of precipitation collected by the U.S. Geological Survey (USGS) from the USGS precipitation-collection station at Catoctin Mountain, in Cunningham Falls State Park, near Thurmont, Maryland, from January 1982 through December 1991. Data on the quantity of precipitation are presented as daily, monthly, and annual totals of precipitation,

Two small (100 ha) watersheds located on Catoctin Mountain in north-central Maryland were intensively instrumented in 1990 and have been hydrologically, chemically, and isotopically monitored for 3 years. Dissolved concentrations of major ions (Ca2+, Mg2+, Na+, K+, total AI, CI-, NO3-, SO42- , HCO3-, and SiO2) and stable isotopic (D and 18O) values have been analyzed for most types of water (preci

1. A replicated natural experiment was used to assess the influence of pH and low alkalinity on abundance and richness of invertebrate families in streams draining catchments that receive acid deposition. Individual streams were used as the unit of replication, allowing conclusions to refer to a class of streams rather than to particular streams.2. We also controlled for several factors other than

Catoctin Mountain receives some of the most acidic (lowest pH) rain in the United States. In 1990, the U.S. Geological Survey (USGS), in cooperation with the Maryland Department of the Environment (MDE) and the Maryland Department of Natural Resources (DNR), began a study of the effects of acid rain on the quality of streamwater on the part of Catoctin Mountain within Cunningham Falls State Park,

The U.S. Geological Survey (USGS) is the Nation's largest water-science and water-information agency. The mission of the Water Resources Division of the USGS is to provide the hydrologic information and understanding needed for the best management of the Nation's water resources. To fulfill this mission, the USGS conducts water-quality and other types of investigations of the Nation's surface- and

The report describes the results of a study to assess the sensitivity of streams to acidic deposition in Charles and Anne Arundel Counties, Maryland using a geology-based method. Water samples were collected from streams in July and August 1988 when streams were at base-flow conditions. Eighteen water samples collected from streams in Charles County, and 17 water samples from streams in Anne Arund

No abstract available.

The decline in loggerhead shrike (Lanius ludovicianus) populations is widespread and coincides with the use of organochlorines that began in the late 1940's and increased until the 1970's (Morrison 1981; Robbins et al. 1986; Tate 1986). An inhabitant of farmland areas, loggerhead shrikes prey on invertebrates and small vertebrates (Bent 1950), and thus risk exposure to pesticides and other agricul

Most studies in the USA of vegetation alteration and human impact along trails have been located in large western wilderness areas. The objective of this study was to determine vegetation changes occurring along trails in an eastern ecosystem supporting second-growth deciduous forest. The location of this study was Shenandoah National Park in Virginia, which has a long history of trail use by huma

Seismic reflection data reveal that the structural geometry of the central Appalachians of northern Virginia consists of three distinct thrust systems. Each thrust system is characterized by a unique internal geometry.The Blue Ridge thrust sheet is a composite thrust sheet composed primarily of imbricated Precambrian crystalline rocks. It over-rode Cambrian-Ordovician carbonates and formed a shear