Filters: Tags: Geochronology (X)
172 results (46ms)|
Filters
Date Range
Extensions Types
Contacts
Categories
Tag Types
|
This dataset accompanies planned publication 'Timing of Hydrothermal Alteration and Au-Sb-W Mineralization, Stibnite-Yellow Pine District, Idaho'. The Ar/Ar data is for samples that record the mineralization of the area. The geochronology provides time constraints for the mineralization studied in the manuscript. Samples were collected from the Yellow Pine region, and collection was done by numerous USGS scientists, who sent them to the USGS Denver Argon Geochronology Laboratory for Ar/Ar analysis.
Categories: Data;
Tags: 40Ar/39Ar,
Argon Geochronology Laboratory,
GGGSC,
Geochemistry,
Geology, Geophysics, and Geochemistry Science Center,
Thin loess deposits on the uplands of the southeastern Colorado Plateau have previously not been well studied. We sampled deposits and soils from trenches on Hatch Point mesa near Canyonlands National Park, Utah, and from two outcrops in Mesa Verde National Park, Colorado. At Hatch Point, the oldest buried unit yielded two OSL ages of 10,370 and 7,555 yr; the middle unit yielded 10 OSL ages from 6220 to 1385 yr; and the youngest unit has a single age of 1740 yr. At Mesa Verde, three loess units are preserved in the two outcrops we examined; six OSL ages range from 51 to 17 ka. At least one buried soil is present between two units with ages of about 50 and 40 ka. The ages of the loess units in both study areas correspond...
Categories: Data;
Tags: Canyonlands National Park,
Colorado,
Colorado Plateau,
Colorado River,
Geochemistry,
This U.S. Geological Survey (USGS) data release provides whole rock isotope geochemistry, zircon hafnium isotope geochemistry, feldspar mineral chemistry, and zircon, monazite, and xenotime geochronology for a paragneiss sampled from a drill core from North Dakota. The sample was collected from the 9-11R E-M Larson well in order to constrain the depositional age, provenance, metamorphic history, and geochemical character of basement terranes.
Categories: Data;
Tags: Geochemistry,
North Dakota,
USGS Science Data Catalog (SDC),
geochemistry,
geochronology,
This data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) U-Pb zircon geochronology data from four samples collected from fault-bounded bedrock units in northwestern Oregon. Samples were collected from a paleoseismic trench excavated across the Scoggins Valley strand of the Gales Creek Fault and nearby quarry. The trench is located on a ridge top saddle on the Scoggins Creek-Tualatin River divide, where it crosses a lidar scarp trending 300°, up to the east, with suggestion of dextral slip. Trench trends 060° across scarp, is 35 m long in bedrock. Loess, paleosols, and colluvium overlie bedrock. The trench exposes tuffaceous sediments of the Keasey Formation, which records...
Categories: Data;
Tags: Detrital Zircon,
GGGSC,
Gales Creek,
Geochronology,
Geology, Geophysics, and Geochemistry Science Center,
This collection consists of processed rock samples as well as unprocessed geological hand samples associated with the research of USGS scientist Robert E. Zartman. Zartman was an early contributor to USGS geochemistry and geochronology research and many of these samples are likely associated with his lab work with K-Ar, Rb-Sr, Sm-Nd, fission track, and U-Th-Pb dating methods. This collection contains one pallet of geological samples and one pallet of laboratory equipment.
Categories: Collection,
Data;
Tags: Collection,
EARTH SCIENCE,
EARTH SCIENCE > SOLID EARTH > GEOCHEMISTRY,
Geochronology,
Geologic History,
This data release provides radiocarbon data for burned plant material collected from deposits following two wildfires in southern California. For the 2020 Bobcat Fire we collected deposits in five stream channels within the Pallett Creek drainage in 2021. For the 2013 Grand Fire near Frazier Mountain, we sampled from two shallow pits excavated into alluvium deposited in 2014. The types of taxa present at each sample location were identified and radiocarbon samples were selected based on the types of material present. This report should be used as the supplementary materials for any publication(s) that uses the radiocarbon dates or taxa identification reported herein.
Categories: Data;
Tags: Forestry,
Frazier Mountain,
Geomorphology,
Pallett Creek,
San Gabriel Mountains,
This dataset includes tables of 3He-isotopic data used to calculate surface exposure ages for samples of basalt, and U- and Th-isotopic data used to calculate uranium-series age estimates (230Th/U method) and initial 234U/238U activity ratios for samples of pedogenic carbonate formed in soils on alluvial fans in the San Luis Valley, Colorado, USA. These data are included in the publication: Ruleman, C.A., Hudson, A.M., Thompson, R.A., Miggins, D.P., Paces, J.B., Goehring, B.M., 2019, Middle Pleistocene formation of the Rio Grande Gorge, San Luis Valley, south-central Colorado and north-central New Mexico, USA: process, timing, and downstream implications. Quaternary Science Reviews 223, https://doi.org/10.1016/j.quascirev.2019.07.028.
This dataset contains apatite and zircon U-Th(He)data, 4He/3He thermochronologic data, and apatite fission-track data from the southern Stillwater Range, Nevada
40Ar/39Ar data from plutonic and volcanic samples collected during preliminary mapping of the Tyonek D-6 and parts of Tyonek D-5, D-7 and C-6 quadrangles yield results indicating three discrete igneous events at about 55, 60 and 68 Ma. Igneous clasts from a boulder conglomerate retain Early Cretaceous ages.
The dataset includes whole-rock geochemistry, phenocryst/mineral trace element compositions, zircon U–Pb geochronology, and zircon in situ Lu–Hf isotopes for intrusions associated with the Oligocene Platoro caldera complex of the San Juan volcanic locus in Colorado features numerous exposed plutons, both within the caldera and outside its margins, enabling investigation of the timing and evolution of postcaldera magmatism. Intrusion and , coupled with new document distinct pulses of magma derived from different depths beneath the caldera complex. Fourteen intrusions, the Chiquito Peak Tuff, and the dacite of Fisher Gulch were dated, showing intrusive magmatism began after the 28.8 Ma-eruption of the Chiquito Peak...
Categories: Data,
Data Release - In Progress;
Tags: Conejos County,
Jasper,
Platoro,
Rio Grande County,
Summitville,
This laser ablation ICPMS U-Pb zircon data set supports stratigraphic, biostratigraphic and age interpretations of the of the fossil-plant-bearing El Gameño Formation of west-central Sonora, Mexico and the potentially age-correlative fossil-plant-bearing Santa Clara and Coyote formations of southeastern Sonora, Mexico. The zircon data provides minimum age constraints (maximum depositional ages) for Late Triassic to Jurassic sedimentary rocks that don’t have precisely known absolute ages.
Zircon (ZrSiO4) and cassiterite (SnO2) samples were collected by the U.S. Geological Survey (USGS) from the Yazov Granite, Transbaikalia region, Eastern Siberia, Russia. Samples (in the form of mounted loose grains) were prepared and analyzed for direct age dating on a laser ablation inductively coupled plasma mass spectrometer (LA–ICPMS) system at the USGS in Denver, Colorado from February 2017 to June 2019. The data indicate that high tin concentrations in the Yazov Granite are caused by inheritance of older cassiterite crystals and may imply that these granites cannot be genetically related to primary tin ore deposits of the region. These results have broad implications in understanding how critical elements,...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: GGGSC,
Geochemistry,
Geology, Geophysics, and Geochemistry Science Center,
LA–ICPMS,
MRP,
These data are for a regional geochronologic study of Mesoproterozoic rocks in the St. Francois Mountains, southeast Missouri. Zircon, plus one sample of titanite, from fifty samples of metaigneous rocks were dated by sensitive high resolution ion microprobe (SHRIMP).
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Economic Geology,
GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
MRP,
Mineral Resources,
Cassiterite (SnO2) samples were collected throughout the underground Sullivan Mine near Kimberley, British Columbia. Samples (in the form of mounted loose grains, polished thin sections, and rock mounts) were prepared and analyzed for direct age dating on a laser ablation inductively coupled plasma mass spectrometer (LA-ICPMS) system at the U.S. Geological Survey in Denver, Colorado in February and April 2018. This data release accompanies the publication, 'Origin of Tin Mineralization in the Sullivan Pb-Zn-Ag Deposit, British Columbia: Constraints from Textures, Geochemistry, and LA-ICP-MS U-Pb Geochronology of Cassiterite.' (Slack and others, 2020). The publication constrains the timing of cassiterite ore mineralization...
Categories: Data;
Tags: British Columbia,
Canada,
GGGSC,
Geochemistry,
Geology, Geophysics, and Geochemistry Science Center,
Apatite [Ca5(PO4)3F], titanite [CaTiSiO5], and rutile [TiO2] samples were collected by the U.S. Geological Survey (USGS) from the Coles Hill uranium deposit, Virginia. The samples (in the form of polished thin sections) were prepared and analyzed for direct age dating on a laser ablation inductively coupled plasma mass spectrometer (LA–ICPMS) system at the USGS in Denver, Colorado from August 2017 to March 2019.
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Coles Hill uranium deposit,
GGGSC,
Geochemistry,
Geology, Geophysics, and Geochemistry Science Center,
LA-ICPMS,
From 2017-2019, framework metallogenic studies were completed in the eastern Yukon-Tanana upland in eastern Alaska. Numerous previously undated plutons known or suspected to contain components of porphyry, epithermal, and intrusion-related gold systems and associated deposit types were sampled for age and zircon trace element determinations between the Black Mountain area and the Yukon border, north of the Tanana River and south of the Yukon River. A collection of 54 samples were collected by Douglas Kreiner (USGS, Alaska Science Center). Zircon grains were separated from each sample. The samples were examined by U-Pb analysis by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) in a USGS laboratory...
This Data Release accompanies the planned publication, "Paleogene sedimentary basin development in southern Nevada, USA." Included here are U-Pb detrital zircon and Ar/Ar feldspar geochronologic data for middle Cenozoic sedimentary and volcanic rocks collected by Jens-Erik Lundstern and Theresa M. Schwartz in several parts of southern Nevada, U.S. The target strata are the lowest Cenozoic sedimentary rocks deposited above the base-Cenozoic unconformity. U-Pb detrital zircon data were obtained at the University of Arizona LaserChron Center in Tucson, Arizona in February 2021, October 2021, and January 2023. 40Ar/39Ar geochronologic data were collected at the U.S. Geological Survey in Denver, Colorado.
Categories: Data;
Tags: Cenozoic,
Central Nevada Desert Basins,
Desert National Wildlife Range,
Eocene,
Geochemistry,
This U.S. Geological Survey (USGS) data release provides zircon U-Pb geochronology and whole rock isotope geochemistry for drill core samples from Montana, Nebraska, Nevada and Wyoming. The drill core samples were obtained from the USGS Core Research Center in Denver, Colorado. The samples were in order to constrain the age, provenance, metamorphic history, and geochemical character of basement terranes in the United States.
This Alaska Division of Geological & Geophysical Surveys (DGGS) Raw Data File presents 40Ar/39Ar age dating results for a volcanic whole-rock sample, selected minerals from various metamorphic rocks and igneous dikes, and white mica from both metamorphic- and hydrothermal-mineralization-related veins encountered on the southern Seward Peninsula, as well as select minerals from one plutonic rock from Cape Denbeigh, eastern Norton Sound, Alaska. Cooling ages on glaucophane, barroisite, amphibole, paragonite, and biotite from metamorphic rocks range from 84 Ma to 209 Ma. The cooling age of white mica in a possible fault zone is 144 Ma. Cooling ages on late-stage metamorphic minerals (winchite and white mica) from veins...
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).
|
|
