Skip to main content
Advanced Search

Filters: Tags: Plutonic Rocks (X)

18 results (8ms)   

View Results as: JSON ATOM CSV
thumbnail
This data set maps and describes the geology of the San Bernardino Wash 7.5 minutequadrangle, Riverside County, southern California. The quadrangle, situated inJoshua Tree National Park in the eastern Transverse Ranges physiographic andstructural province, encompasses parts of the northwestern Eagle Mountains,east-central Pinto Basin, and eastern Pinto Mountains.The quadrangle is underlain by a basement terrane comprising metamorphosedProterozoic strata, Mesozoic plutonic rocks, and Jurassic and Mesozoic and (or)Cenozoic hypabyssal dikes. The basement terrane is capped by a widespread Tertiaryerosion surface preserved in remnants in the Pinto and Eagle Mountains and buriedbeneath Cenozoic deposits in Pinto Basin....
thumbnail
In 2016, with National Park Service support, several previously undated plutons were sampled in Glacier Bay National Park and Preserve along the west side of Glacier Bay for age determinations. Geochronologic analyses were conducted to determine the ages of the plutonic rocks in the Glacier Bay area. Five samples were collected by Frederic Wilson (USGS Alaska Science Center), from Dundas Bay and Geikie Inlet, and dated by laser ablation-inductively coupled plasma mass spectrometry U-Pb methods. The dates obtained ranged from approximately 112-118 Ma, indicating that these samples are younger than the Saint Elias plutonic suite (ca. 160 Ma-130Ma), which runs along the same trend as the sampled rocks to the south.
thumbnail
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...
thumbnail
The Preliminary Interpretive Report 2004-3B, "Bedrock geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska," is the bedrock geologic map of an approximately 123-square-mile area in the central Livengood Quadrangle, Alaska.
thumbnail
This data file presents 40Ar/39Ar step-heating geochronology results for a granite sample from the Livengood mining district. The Livengood area is a historically productive placer mining area approximately 80 road miles north of Fairbanks, Alaska. This data is a component of a geologic map and accompanying report that synthesizes recently collected and previously published agency and industry geologic data in a 1:50,000-scale comprehensive geologic map to build a better understanding of the geology and mineral-resource potential of the Livengood area.
thumbnail
This data set maps and describes the geology of the Fawnskin 7.5' quadrangle, San BernardinoCounty, California and contains original U.S. Geological Survey data generated by detailedfield observation and by interpretation of aerial photographs. The geologic map covers partof the northern San Bernardino Mountains. Bedrock units in the San Bernardino Mountains aredominated by large Cretaceous and Jurassic granitic bodies ranging in composition frommonzogranite to gabbro, and include lesser Triassic monzonite. These granitic rocks intrudehighly faulted and folded Late Proterozoic and Paleozoic formations representative of thosefound in the southern Great Basin. Low-angle thrust faults, many of them complexly folded,cut...
thumbnail
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,...
thumbnail
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...
thumbnail
This report provides a digital version of the Geologic map of theStillwater Complex, Montana originally published by N. Page andW. Nokleberg (1974). Paper copies of the four geologic mapsheets from the original report were scanned and initiallyattributed by Optronics Specialty Company (Northridge, CA) andremitted to the U.S. Geological Survey for further attributionand publication of the geospatial digital files. The resultingdigital geologic dataset can be queried in a geographicinformation system (GIS) in many ways to produce a variety ofgeological maps.
A study conducted collected 57 surface rock samples from nine types of intrusive rock to reexamine the chemistry and metallic content of the major rock units of the Iron Hill complex
thumbnail
This data set maps and describes the geology of thePorcupine Wash 7.5 minute quadrangle, Riverside County,southern California. The quadrangle, situated in JoshuaTree National Park in the eastern Transverse Rangesphysiographic and structural province, encompasses partsof the Hexie Mountains, Cottonwood Mountains, northernEagle Mountains, and south flank of Pinto Basin. It isunderlain by a basement terrane comprising Proterozoicmetamorphic rocks, Mesozoic plutonic rocks, and Mesozoicand Mesozoic or Cenozoic hypabyssal dikes. The basementterrane is capped by a widespread Tertiary erosionsurface preserved in remnants in the Eagle and CottonwoodMountains and buried beneath Cenozoic deposits in PintoBasin. Locally, Miocene...
thumbnail
This data set maps and describes the geology of the Pinto Mountain 7.5 minutequadrangle, Riverside County, southern California. The quadrangle, situated inJoshua Tree National Park in the eastern Transverse Ranges physiographic andstructural province, encompasses parts of the northeastern Hexie Mountains,central Pinto Mountains, and central Pinto Basin.The quadrangle is underlain by a basement terrane comprising Proterozoicmetamorphic rocks, Mesozoic plutonic rocks, and Mesozoic and Mesozoic and (or)Cenozoic hypabyssal dikes. The basement terrane is capped by a widespreadTertiary erosion surface preserved in remnants in the Hexie and Pinto Mountainsand buried beneath Cenozoic deposits in Pinto Basin. Locally, a...
thumbnail
This geologic map and report depicts portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles. The Livengood area is a historically productive placer mining area approximately 80 road miles north of Fairbanks, Alaska. This report synthesizes recently collected and previously published agency and industry geologic data in a 1:50,000-scale comprehensive geologic map to build a better understanding of the geology and mineral-resource potential of the Livengood area. It expands and updates the Alaska Division of Geological & Geophysical Surveys (DGGS) Preliminary Interpretive Report (PIR) 2004-3 with the addition of new DGGS mapping and drillhole data from ITH, and integrates previously published DGGS surficial...
thumbnail
This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) Talkeetna Mountains C-4 Quadrangle and Adjoining Areas geologic mapping project. Hornblende-bearing gabbro returned a Late Triassic crystallization age consistent with regional results for Nikolai Greenstone-related magmatism. We determined Early Jurassic metamorphic ages for hornblende and sericite from two samples of upper greenschist to amphibolite grade metavolcanic rocks. Our results indicate that a granodiorite pluton intruding Wrangellia in the study area has a Middle Jurassic age consistent with the Talkeetna Arc, indicating that the Wrangellia...
thumbnail
40Ar/39Ar data from seven plutonic samples and one metamorphic sample collected during mineral assessment studies in 1991 show that various rock units in the Selawik Hills plutonic complex were emplaced in the order syenite/monzonite (nonfoliated, 106.6 ± 0.8 Ma; foliated, 101.7 ± 0.7 Ma; both on hornblende), followed by nepheline syenite (103.7 ± 0.8 Ma on hornblende) and then quartz monzonite (100.4 ± 3.7 Ma on biotite). 40Ar/39Ar data from Granite Mountain hornblendes yielded ages slightly older, but overlapping, those from Selawik Hills. In this suite, the silica-undersaturated phase appears to be younger (105.7 ±0.8 Ma) than the silica-saturated phase(s) (106.8 ± 0.8 Ma and 107.1 ± 0.8 Ma).
thumbnail
In conjunction with hosting field trips for the Association of American State Geologists 2016 annual meeting in Girdwood, Alaska, Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected rock samples and obtained geochemical analysis from several readily accessible, but relatively unstudied outcrops. Samples were collected from Turnagain Arm (mile 104 Seward Highway), Whittier, Crow Pass, and Panorama Mountain (roughly mile 217 Parks Highway). Mineralized samples from veins and veinlets in granitic rocks from the Crow Pass and Whittier sites contain anomalous levels of gold ranging from 0.129 to 0.650 parts per million (ppm). Although none of the samples are from areas open to mineral entry, geochemical...
Tags: Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, Base Metals, All tags...
thumbnail
This data set maps and describes the geology of the ConejoWell 7.5 minute quadrangle, Riverside County, southernCalifornia. The quadrangle, situated in Joshua TreeNational Park in the eastern Transverse Rangesphysiographic and structural province, encompasses part ofthe northern Eagle Mountains and part of the south flankof Pinto Basin. It is underlain by a basement terranecomprising Proterozoic metamorphic rocks, Mesozoicplutonic rocks, and Mesozoic and Mesozoic or Cenozoichypabyssal dikes. The basement terrane is capped by awidespread Tertiary erosion surface preserved in remnantsin the Eagle Mountains and buried beneath Cenozoicdeposits in Pinto Basin. Locally, Miocene basalt overliesthe erosion surface. A sequence...
thumbnail
In conjunction with hosting field trips for the Association of American State Geologists 2016 annual meeting in Girdwood, Alaska, Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected rock samples and obtained geochemical analysis from several readily accessible, but relatively unstudied outcrops. Samples were collected from Turnagain Arm (mile 104 Seward Highway), Whittier, Crow Pass, and Panorama Mountain (roughly mile 217 Parks Highway). Mineralized samples from veins and veinlets in granitic rocks from the Crow Pass and Whittier sites contain anomalous levels of gold ranging from 0.129 to 0.650 parts per million (ppm). Although none of the samples are from areas open to mineral entry, geochemical...
Tags: Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, Base Metals, All tags...


    map background search result map search result map Generalized Geologic Map of the United States Geologic map of the Stillwater Complex, Montana: a digital database Geologic map and digital database of the Porcupine Wash 7.5minute quadrangle, Riverside County, California Geologic map and digital database of the Conejo Well 7.5minute quadrangle, Riverside County, California Geologic map and digital database of the Pinto Mountain 7.5minute quadrangle, Riverside County, California Geologic map and digital database of the San Bernardino Wash7.5 minute quadrangle, Riverside County, California Geologic map of the Fawnskin 7.5' quadrangle, San Bernardino County, California Bedrock geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska 40Ar/39Ar ages from the Selawik A-2, A-3 and A-4 and Candle B-5 quadrangles, Alaska 40Ar/39Ar data, Styx River map area, Lime Hills C-1 Quadrangle, Alaska 40Ar/39Ar data from the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska 40Ar/39Ar data from rocks collected in the 2015 Wrangellia mineral assessment project area, Mount Hayes A-5, Mount Hayes B-6, and Talkeetna Mountains D-2 quadrangles, Alaska Major-oxide and trace-element geochemical data from rocks collected near Panorama Mountain, Mile 104 Seward Highway, Crow Pass, and Whittier, Alaska Major-oxide and trace-element geochemical data from rocks collected near Panorama Mountain, Mile 104 Seward Highway, Crow Pass, and Whittier, Alaska Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district, Alaska Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district, Alaska U-Pb zircon data for: Cretaceous plutonic rocks of western Glacier Bay National Park and Preserve Geologic map and digital database of the Porcupine Wash 7.5minute quadrangle, Riverside County, California Geologic map and digital database of the Conejo Well 7.5minute quadrangle, Riverside County, California Geologic map and digital database of the Pinto Mountain 7.5minute quadrangle, Riverside County, California Geologic map and digital database of the San Bernardino Wash7.5 minute quadrangle, Riverside County, California Geologic map of the Fawnskin 7.5' quadrangle, San Bernardino County, California U-Pb zircon data for: Cretaceous plutonic rocks of western Glacier Bay National Park and Preserve 40Ar/39Ar data, Styx River map area, Lime Hills C-1 Quadrangle, Alaska Bedrock geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska Geologic map of the Stillwater Complex, Montana: a digital database Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district, Alaska 40Ar/39Ar data from rocks collected in the 2015 Wrangellia mineral assessment project area, Mount Hayes A-5, Mount Hayes B-6, and Talkeetna Mountains D-2 quadrangles, Alaska 40Ar/39Ar ages from the Selawik A-2, A-3 and A-4 and Candle B-5 quadrangles, Alaska Major-oxide and trace-element geochemical data from rocks collected near Panorama Mountain, Mile 104 Seward Highway, Crow Pass, and Whittier, Alaska Major-oxide and trace-element geochemical data from rocks collected near Panorama Mountain, Mile 104 Seward Highway, Crow Pass, and Whittier, Alaska Generalized Geologic Map of the United States