Map Releases

The U.S. Geological Survey and the Idaho Department of Water Resources measured groundwater levels during spring 2022 and autumn 2022 to create detailed potentiometric-surface maps for the alluvial aquifer in the Big Lost River Valley in south-central Idaho. Wells were assigned to shallow, intermediate, and deep water-bearing units based on well depth, groundwater potentiometric-surface altitude,

Fern Cave in Jackson County, Alabama, is a 15.6-mile-long (25.1-kilometer) cave system, managed by the U.S. Fish and Wildlife Service and Southeastern Cave Conservancy, that has the second highest biodiversity of any cave in the southeastern United States. Groundwater in karst ecosystems is known to be susceptible to impacts from human-induced land-use activities in watersheds that contribute rech

Aeromagnetic surveys were conducted to improve understanding of the geology and structure in northeastern California, a region predominantly covered by Quaternary and Tertiary, mainly Neogene, volcanic rocks including Medicine Lake volcano. New aeromagnetic data are a substantial improvement over existing data and reveal structural details not resolved by older surveys. Here we show how these data

Introduction The Mississippi Alluvial Plain is one of the most important agricultural regions in the United States, and crop productivity relies on groundwater irrigation from an aquifer system whose full capacity is unknown. Groundwater withdrawals from the Mississippi River Valley alluvial aquifer have resulted in substantial groundwater-level declines and reductions in base flow in streams with

This pamphlet and accompanying geologic and geophysical maps are the products of cooperative efforts by the California Geological Survey (CGS) and United States Geological Survey (USGS) to compile a comprehensive, digital representation of the bedrock geology, Quaternary surficial deposits, and potential-field anomalies within the boundaries of the Stockton 30’ × 60’ quadrangle. The Stockton 30’ ×

Introduction Abandoned railroads and infrastructure from the anthracite coal-mining industry are significant features in abandoned mine lands and are an important part of history; however, these features are often lost and masked by the passage of time and the regrowth of forests. The application of modern light detection and ranging (lidar) topographic analysis, combined with field verification,

Declining water levels and the potential impact on water resources on and around Cannon Air Force Base (AFB), New Mexico, has necessitated an up-to-date review of the potentiometric surface to evaluate the availability of water resources for future use. Analysis of groundwater-flow directions and hydraulic gradients can provide an understanding of depletion by heavy groundwater pumping and recharg

DiscussionThe winter rainy season of 2016–2017 brought abundant rainfall to the State of California and to the San Francisco Bay region. In January and February of 2017, intense rainfall from strong winter storms saturated soils in the region and triggered thousands of shallow landslides. The highest concentration of these landslides was in the eastern part of the bay region, where landslides in t

IntroductionThe Wallula Fault Zone is composed of a series of northwest-trending faults and folds that coincide with a prominent magnetic anomaly that extends uninterrupted for approximately 120 kilometers within the Cascadia back arc of southeastern Washington and northeastern Oregon. It is part of the geologic structures associated with the topographic lineament known as the Olympic-Wallowa line

Several laboratories have been investigating the feasibility of in situ K-Ar dating for use in future landing planetary missions. One drawback of these laboratory demonstrations is the insufficient analogy of the analyzed analog samples with expected future targets. We present the results obtained using the K-Ar laser experiment (KArLE) on two old and K-poor chondritic samples, Pułtusk and Hvittis

This three-dimensional (3D) geologic map displays the subsurface geology in the upper ~4 kilometers of the Earth’s crust in the southeastern Gabbs Valley geothermal area of west-central Nevada. The 3D map was constructed by integrating the results from detailed geologic mapping, 3D gravity inversion modeling, and potential-field-geophysical studies. This effort was undertaken as part of the Nevada

This report includes an updated geologic map and cross sections of the upper Santa Cruz River basin, southern Arizona. The map and cross sections describe the geometry, thickness, and structure of the Miocene to Holocene units which form the main aquifers in the basin. The report also includes results of new hydrogeologic studies including (1) mapping and defining depth to bedrock based on geophys