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From June 12-21, 2017, the Alaska Division of Geological & Geophysical Surveys (DGGS) geologists carried out geologic mapping and geochemical sampling in the northeastern Tanacross D-1, and parts of the C-1, and D-2 quadrangles. The project area lies within the Yukon-Tanana Uplands, and encompasses the boundary between Fortymile and Lake George assemblages. It includes porphyry copper-molybdenum-gold deposits and prospects including: Taurus, Fishhook (also known as SW Pika), and Pika Canyon, and is adjacent to the Fortymile Mining District to the north. Highlights of this geochemical report include sampling and characterization of the Pika Canyon, Fishhook, and Taurus prospects. This dataset contains four samples...
Mineral Resources Section personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a geologic field survey, including mapping and sampling, in the eastern part of the Bonnifield mining district in the Fairbanks A-1 and A-2 and the Healy D-1 and D-2 quadrangles, Alaska, from June 16 through July 18, 2008. The fieldwork provides basic information critical to building an understanding of Alaska's geology and is part of an integrated program of airborne geophysical surveys followed by geologic mapping. Specifically, this work provides geologic context for geophysical surveys conducted in 2006. Interpretation and synthesis of this data has been presented in professional and trade meetings....
More than 11,500 well records, such as geophysical logs, drilling descriptions, and published hydrogeologic framework information, were evaluated to help characterize the framework of hydrogeologic units in and near Gaines, Terry, and Yoakum Counties, Texas. Additional geophysical data were collected to improve the spatial coverage across the study area and to reduce uncertainty with regard to hydrogeologic unit extents. The evaluation of existing data plus the collection of new geophysical data provided that basis for developoing a refined understanding of how the saturated thickness of the Ogallala and Edwards-Trinity aquifers vary throughout the study area.
This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes a derivative map of geologic construction materials based on the resulting geologic maps, field investigations, and laboratory materials analyses.
Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The...
This data release presents zircon U-Pb LA-ICP-MS geochronology from igneous rocks exposed in a coastal exposure at Ursus Head, Iliamna C-2 Quadrangle. Sills and dikes exposed in a coastal exposure at Ursus Head are deformed within the Bruin Bay fault zone. Common dikes intruding late Triassic Kamishak Formation strata composing the hanging-wall of the Bruin Bay fault are cut by numerous small-scale, low-angle, bedding-parallel, and high angle contractional faults. Sample 09MAW006A collected from one of many dikes deformed in the fault zone produced a uni-modal distribution of zircon ages of with a weighted mean of 206.92 +/-0.96 (2 sigma, n=47) and an MSWD of 1.1. Sample 09BG020C collected from a sill of more mafic...
Declining groundwater levels in and near Gaines, Yoakum, and Terry Counties in the Texas Panhandle have raised concerns about the amount of available groundwater and the potential for water-quality changes resulting from dewatering and increased vertical groundwater movement between adjacent water-bearing hydrogeologic units. More than 9,800 well records, such as geophysical logs, drilling descriptions, and published hydrogeologic framework information, were evaluated to help characterize the framework of hydrogeologic units in the study area. Additional geophysical data were collected to improve the spatial coverage across the study area and to reduce uncertainty with regard to hydrogeologic unit extents. Of greatest...
The surface geology of each of the 53 counties of North Dakota was mapped and published as plates in a series of bulletins between 1962 and 2001. As of 2022, the 1:125,000-scale maps contain the most detailed dataset of surficial geologic information for 90% of the state. This collection contains some of these county maps, digitized and vectorized from scans of the original out-of-print warped and discolored paper maps.
Categories: Data;
Tags: Counties of North Dakota,
Geological Collection,
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ndc_collection,
This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) Wrangellia Mineral Assessment project, part of a multi-year effort focusing on improving the publicly available geoscientific information for the western Wrangellia terrane. The samples described in this report were selected and analyzed to improve our understanding of the geology and structural history of the Wrangellia Mineral Assessment project area. A metagabbro rock sample returned a Late Triassic crystallization age consistent with regional ages for Nikolai Greenstone-related magmatism; however, the two amphibole separates ages do not overlap,...
This publication contains previously unpublished geochemical analyses or re-analyses of lavas, magmatic inclusions, and a few gabbroic cumulate inclusions from Alaska volcanoes (Akutan, Augustine, Buzzard Creek, Dana, Douglas, Fourpeaked, Frosty, Great Sitkin, Iliamna, Kaguyak, Kiska, Okmok, Prindle Cone, Recheshnoi, Redoubt, Spurr, Ukinrek Maars, Vsevidof, Westdahl, Wrangell) collected by the authors and others over the past 35 years. It provides substantial data sets for three volcanoes (Vsevidof, Westdahl, and Douglas) for which little or no published data exist. All analyses were made by the GeoAnalytical laboratory at Washington State University in Pullman, WA. The ICP/MS data have been reduced using the 2006...
Between 1979 and 1982, the Alaska Division of Geological & Geophysical Surveys (DGGS) and the Geophysical Institute, University of Alaska Fairbanks, undertook an assessment of the states geothermal resources under a program jointly sponsored by the U.S. Department of Energy and the State of Alaska. During this period, reconnaissance investigations of more than 100 thermal spring sites and fumarole fields located in Alaska were conducted by DGGS.
This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes a derivative map of potential geologic hazards based on the resulting geologic maps, field investigations, and laboratory materials analyses.
The hydrogeology of the Cannon Air Force Base (AFB) in Curry County, is being investigated to better understand the mechanics of groundwater flow in the area, including the identification of preferential groundwater flow paths. Mapping the top of the Dockum Group was done to help identify potential paleochannels that may have eroded the surface of the Dockum Group and subsequently filled in with coarse-grained sediments of the overlying Ogallala Formation. The Dockum Group is composed of sandstone, siltstone, mudstone, and shale that were originally deposited in fluvial and lacustrine environments (McGowen and others, 1979). The upper part of the Dockum Group is a thick layer of red clay referred to locally as the...
Aerial photographs of the coastline from Nome to Elim were collected on August 23, 2015. The photographs were processed using Structure-from-Motion (SfM) photogrammetric techniques. Global Positioning System (GPS) checkpoints were collected via a Global Navigation Satellite System (GNSS) survey conducted between August 15 and September 14, 2015. For the purposes of open access to elevation and orthoimagery datasets in coastal regions of Alaska, this collection is being released as a Raw Data File with an open end-user license. This file is a single-band, 32-bit float DSM (digital surface model) which represents surface elevations of buildings, vegetation, and uncovered ground surfaces in meters with 20 cm GSD. The...
This report provides detailed (1:63,360-scale) mapping of portions of U.S. Geological Survey Circle B-2 (1955), B-3 (1955), B-4 (1952), C-2 (1955), C-3 (1955), and C-4 (1952) quadrangles. The area is part of the Circle mining district and adjacent to the Fairbanks mining district. This report includes detailed geologic, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.
This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed surficial geology, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.
The State of Alaska's Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska's statewide potential for strategic and critical mineral resources. The SCM Assessment project is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. For the geochemical part of the SCM Assessment project, thousands of geochemical-sample analyses and locations from historical U.S. Bureau of Mines (USBM), U.S. Geological Survey (USGS), Bureau of Land Management (BLM), DGGS, Alaska Territorial Department of Mines, Alaska Division of Mines and...
This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed bedrock, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.
Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km�equivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related...
This 1:50,000 scale geologic map describes the distribution of unconsolidated deposits, identifies local geologic hazards, and provides information about the depositional environment and basic engineering properties of common surficial-geologic materials in and around Shaktoolik, Alaska. Map units are the result of combined field observations and aerial imagery interpretation. A suite of local ground observations were collected over a two-week period in July 2011 by a helicopter-supported team of DGGS geologists and collaborators. Field investigations included soil test pits, sample collection, soil and rock description, oblique aerial photography, and documentation of landscape morphology.
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