Filters: Tags: Th (X) > partyWithName: Christopher S Holm-Denoma (X)
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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.
This Laser ablation ICPMS U-Pb detrital zircon data set supports mapping and stratigraphic interpretations of the Upper Devonian Ignacio Formation in southwestern Colorado (Silverton area). All samples were collected from a measured stratigraphic section called "Sultan Creek South" located at 37.710010 and -107.67530 (Evans and others, 2019). The Ignacio Formation was previously interpreted as Cambrian, but evidence that it is Devonian includes reexamined fossil data and detrital zircon U-Pb geochronology. The Ignacio Formation has a stratigraphic trend of detrital zircon ages shifting from a single ca. 1.7 Ga age peak to bimodal ca. 1.4 Ga and ca. 1.7 Ga age peaks, which represents local source-area unroofing history....
Categories: Data;
Tags: Colorado,
Detrital Zircon,
East Lime Creek Conglomerate,
GGG,
Geochronology,
This data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) U-Pb zircon geochronology data to determine the ages of Challis igneous rocks in the Thunder Mountain volcanic field and dikes west of the volcanic field, especially in and near the Stibnite-Yellow Pine mining district, ID. These efforts were made to help understand the stratigraphy and lithologic characteristics of the Challis igneous rocks by determining their absolute ages.
Categories: Data;
Tags: Challis,
GGGSC,
Geochronology,
Geology, Geophysics, and Geochemistry Science Center,
Idaho,
This dataset includes U-Pb detrital zircon age data for samples from the Ingleside and Lyons formations in north-central Colorado collected from Owl Canyon and Park Creek Reservoir, from the Molas and Hermosa formations in southwestern Colorado collected from Molas Pass, and from the Lykins formation and its equivalents along the Front Range and in southeastern Colorado. It accompanies publications 'The Permian-Triassic Transition in Colorado' published in Unfolding the Geology of the West: Geological Society of America Field Guide 44, and 'Detrital zircon geochronology of Pennsylvanian-Permian strata in Colorado: evidence for Appalachian-derived sediment and implications for the timing of Ancestral Rocky Mountains...
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.
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...
These data are for a geochronologic study of emplacement ages for plutons of the Cretaceous Idaho batholith and detrital zircon ages for metasedimentary rocks, west-central Idaho. Zircon from six samples of discrete plutons across a regional transect were dated by sensitive high resolution ion microprobe (SHRIMP). SHRIMP U-Pb ages of igneous rocks connect the igneous activity to structural history, crustal depths, and origins of epigenetic gold-silver-antimony-tungsten±mercury mineral deposits. Zircon from four samples of metasedimentary rocks in the southern part of the central Idaho mineral province were dated—three by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) methods and one by SHRIMP...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: "Mineral Resources"],
"Structural Geology",
Detrital Zircon,
GGGSC,
Geochronology,
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