Reports

This report summarizes and interprets results of the work in the Ahankashan Area of Interest in northwestern Afghanistan and four study areas—the Ahankashan Prospect Area, Syahsang-Kushkak, Taghab-Soni, and Zakak-e ‘Olya—delineated for their potential undiscovered mineral occurrences with specific emphasis on porphyry copper and related occurrence types. The Area of Interest is underlain...

Urban stormwater in the Albuquerque metropolitan area was sampled by the U.S. Geological Survey in cooperation with the City of Albuquerque, the Albuquerque Metropolitan Arroyo Flood Control Authority, the New Mexico Department of Transportation, and the University of New Mexico. Stormwater was sampled from a network of monitoring stations from 2003 to 2012 by following regulatory...

Absolute gravity data were collected at 32 stations in the vicinity of the Sanford Underground Research Facility from 2007 through 2014 for the purpose of monitoring groundwater storage change during dewatering of the former Homestake gold mine in the Black Hills of South Dakota, the largest and deepest underground mine in North America. Eight underground stations are at depths from 300...

In cooperation with the U.S. Environmental Protection Agency (EPA), Region 3, the U.S. Geological Survey (USGS) is participating in an ongoing study to aid in the identification of subsurface heterogeneities that may act as preferential pathways for contaminant transport in and around the Lower Darby Creek Area (LDCA) Superfund Site, Philadelphia Pa. Lower Darby Creek, which flows into...

The effects of concentrated animal feeding operations (CAFOs) on water quality were investigated at 54 agricultural stream sites throughout the North Carolina Coastal Plain during 2012 and 2013. Three general watershed land-use types were examined during the study, including 18 background watersheds with no active CAFOs (BK sites), 18 watersheds with one or more active swine CAFOs but no...

Georges Bank is a shallow submarine bank that lies south of Nova Scotia and east of Cape Cod and bounds the seaward side of the Gulf of Maine. The international boundary between Canada and the United States transects the bank, and the eastern part of the bank (~7500 square kilometres) lies in Canadian territory. This map shows the surficial geology of a part of Georges Bank at a scale of...

The use of acoustic and other parameters as surrogates for suspended-sediment concentrations (SSC) in rivers has been successful in multiple applications across the Nation. Tools to process and evaluate the data are critical to advancing the operational use of surrogates along with the subsequent development of regression models from which real-time sediment concentrations can be made...

The U.S. Geological Survey (USGS) uses data collection, modeling tools, and scientific analysis to help water managers plan for, and assess, hydrologic issues that can cause “undesirable results” associated with groundwater use. This information helps managers understand trends and investigate and predict effects of different groundwater-management strategies.

The General Accounting Office has identified a need for better information on the effectiveness of post-fire emergency stabilization and rehabilitation methods used by the U.S. Forest Service and Department of Interior (DOI) agencies. Since reviews were published on treatment effectiveness in the early 2000s, treatment choices have changed and increased monitoring has been done. Greater...

This report is a companion to the new Geologic Map of Mauritania (Bradley and others, 2015; referred to herein as “Deliverable 51”) and the new Structural Geologic Map of Mauritania (Bradley and others, 2015a; referred to herein as “Deliverable 52”). Section 1 contains explanatory information for these two digital maps. Section 2 covers the analytical methods used in obtaining new U-Pb...

Aeromagnetic and radiometric data were used to map shallow Precambrian basement lithology and structure and determine the depth to magnetic basement, which in most cases, corresponds to the depth to crystalline basement of interest for mineral exploration. These depths, along with those determined from gravity data, help identify basins with hydrologic potential. In addition, the...

Tellurium is one of the least common elements on Earth. Most rocks contain an average of about 3 parts per billion tellurium, making it rarer than the rare earth elements and eight times less abundant than gold. Grains of native tellurium appear in rocks as a brittle, silvery-white material, but tellurium more commonly occurs in telluride minerals that include varied quantities of gold...