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Cook Inlet has been recognized as the second-largest petroleum province in Alaska, second only to the North Slope. The south-central Tyonek Quadrangle is an area of significant geologic interest because it is the only location in Cook Inlet where the entire producing stratigraphy of the basin is exposed on the surface. Additionally, this area encompasses the structural boundary between the forearc basin and its sediment source rocks. To better understand the petroleum system and the geologic relationships between the exhumed arc intrusive rocks and adjacent Cenozoic stratigraphy of the Cook Inlet forearc basin, during the summer of 2010 the Alaska Division of Geological & Geophysical Surveys conducted a federally-funded...
This dataset is intended to provide seamless, integrated geologic mapping of the U.S. Intermountain West region as a contribution to The National Geologic Map supported by the National Cooperative Geologic Mapping Program of the U.S. Geological Survey. Surficial and bedrock geology are included in this data release as independent datasets at a variable resolution from 1:50,000 to 1:250,000 scale. No original interpretations are presented in this dataset; rather, all interpretive data are assimilated from referenceable publications. Derivative polygon features created for this dataset demonstrate the distribution of SIGMa-GeMS Geologic Provinces derived from the distribution of map units. Initial contributions to...
This child item contains zipped monthly folders for data collected during 2021.
The geology of an area of 660 square miles mostly in the northeastern corner of Tennessee and small adjacent areas in Virginia and North Carolina is the subject of this report. The region lies principally in the Unaka province, with extensions northwestward into the Appalachian Valley and southwestward into the Blue Ridge province. The report combines results of surveys made between 1941 and 1953 by the U. S. Geological Survey, the Tennessee Division of Geology, and the Tennessee Valley Authority, and is published in cooperation with the Tennessee Division of Geology. Northeasternmost Tennessee is a region of widespread mineralization and was formerly important for mineral production. Iron, manganese, and bauxite...
This dataset contains a point cloud and orthophoto of the Nelson Slides area, Mushroom Rock region, northeastern California created using structure-from-motion. It is Dataset S3 in the related manuscript.
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Northeastern California,
fault,
structure from motion,
volcanic rocks
This dataset contains a point cloud and orthophoto of the Curtis Lake North area, Mushroom Rock region, northeastern California created using structure-from-motion. It is Dataset S1 in the related manuscript.
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: Northeastern California,
fault,
structure from motion,
volcanic rocks
Hills of volcanic rocks north of Belmont road. Nye County, Nevada. 1915. Plate 4 in U.S. Geological Survey. Bulletin 723. 1924.
Categories: Image;
Tags: Ferguson, H.G. Collection,
Nye County, Nevada,
Photographers,
Volcanic Rocks,
photo print
This child item contains zipped monthly folders for data collected during 2019.
This data set contains boundaries and tags for major geologic units in Alaska, Hawaii, Puerto Rico and the U.S. Virgin Islands. In addition to the polygons representing the areal extent of geologic units, it identifies major faults and continental glaciation in Alaska. The data depict the geology of the bedrock that lies at or near the land surface, but not the distribution of surficial materials such as soils, alluvium, and glacial deposits. This map complements the Generalized Geologic Map of the Conterminous United States by Reed and Bush. The data are generalized from a compilation prepared for use in the Geologic Map of North America, published as a paper map by the Geological Society of America and...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: AK,
Alaska,
Bedrock,
Faults,
Geologic History,
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...
This geologic database is a digitized version of the original 1:24,000-scale analog geologic map titled "Geologic map of the Vidal, California, and Parker SW, California-Arizona quadrangles", published by the U.S. Geological Survey (USGS) in 1980. The map area straddles the Arizona-California border, and is located approximately 9.0 km (5.6 mi) west-southwest of Parker, CA, immediately south of the unincorporated communities of Vidal and Vidal Junction, CA. The map area includes the northern Riverside Mountains, which contain a prominent suite of Permian, Mesozoic, and potentially Precambrian metamorphic and metasedimentary rocks. These rocks predominantly consist of gneisses, schists, limestones, and dolomites,...
A total of 100 samples were collected from two proximal sections of Keanakākoʻi, Tephra unit D deposits. Samples were analyzed on Microtrac CAMSIZER® P4 and X2 instruments for grain size and shape data in the USGS Hawaiian Volcano Observatory (HVO) tephra lab. Data release includes sample descriptions, half phi grain size distributions, and statistical output from DECOLOG deconvolution modeling of grain size distributions. Grain size is reported using the sieve compatible Xcmin parameter (CAMSIZER® manual, 2020). Data of 2D shape parameter means of sphericity, Krumbein roundness and compactness of samples as well as for half phi grain size bins at 4, 3, 2, 1, 0, and -1 phi are also included. Please refer to associated...
Categories: Data;
Tags: Camsizer,
Grain shape,
Grain size,
Hawaii Volcanoes National Park,
Kīlauea Volcano,
We depict changing eruptive features within the summit caldera of Kīlauea volcano, Island of Hawaiʻi with rapid-response digital elevation models (DEMs) acquired since a series of caldera-filling effusive eruptions began on December 20, 2020. These eruptions follow the caldera collapse of 2018, with new lava progressively filling the approximately 1-cubic-kilometer pit that formed between May and August of that year. The majority of the provided DEMs were constructed via structure-from-motion (SfM) photogrammetry from either helicopter or uncrewed aircraft system (UAS) overflight images, with the remainder constructed via terrestrial laser scanning (TLS) from the Halemaʻumaʻu crater rim. These data were collected...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Basalt,
Halemaʻumaʻu,
Hawaii,
Kaluapele,
Kīlauea,
This DGGS Raw Data File presents 40Ar/39Ar age dating results for selected igneous rocks encountered in the Styx River area of the western Alaska Range. Crystallization ages on biotite and hornblende from plutonic rocks range from about ~60 to ~63 Ma, while a sericite alteration age in plutonic rocks altered by a dike swarm also is around ~63 Ma. Sericite alteration associated with a copper-molybdenum porphyry ranges from ~10 to ~11 Ma. Analyses were performed by the University of Alaska Fairbanks Geochronology Laboratory, and results were reported by Paul Layer and Jeff Benowitz. This data release includes the following products: a summary of sample collection methods, the laboratory report, analytical data tables...
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.
The Orange Tuff is an informally named tephra-fall deposit that crops out extensively in the volcanic highlands to the south and southwest of Bogor, West Java, Indonesia. The data included in this data release documents the deposit thickness and maximum sizes of lithics present at sites throughout its distribution. Additional tables document dispersal areas calculated from within hand-drawn isopach and lithic isopleth maps based on the aforementioned thickness and lithic size data. Such area measurements will be used in the related subsequent publication listed in the metadata to derive eruption and deposit characteristics such as bulk volume and column height and to help determine the source volcano. The isopach...
Medicine Lake volcano (MLV) is a very large shield-shaped volcano located in northern California where it forms part of the southern Cascade Range of volcanoes. It has erupted hundreds of times during its half-million-year history, including nine times during the past 5,200 years, most recently 950 years ago. This record represents one of the highest eruptive frequencies among Cascade volcanoes and includes a wide variety of different types of lava flows and at least two explosive eruptions that produced widespread fallout. Compared to those of a typical Cascade stratovolcano, eruptive vents at MLV are widely distributed, extending 55 km north-south and 40 km east-west. The total area covered by MLV lavas is >2,000...
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