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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.
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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....
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This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age and type of surface outcrops of bedrock of Southeast Asia (Brunei, Indonesia, Cambodia, Laos, Malaysia, Papua New Guinea, Philippines, Singapore, Solomon Islands and Vietnam; and portions of Australia, China and Taiwan). It also includes shorelines and inland water bodies.
Categories: Web Site; Tags: 1100 - Geology, 1101 - General, AS, AS = Australia, Age, All tags...
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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...


    map background search result map search result map Generalized Geology of Southeast Asia (geo_3se) U-Pb detrital zircon data for: Select Pennsylvanian-Triassic sedimentary rocks from Colorado U-Pb detrital zircon data for: lower Paleozoic sedimentary rocks near Silverton, CO USA U-Pb zircon data for: Cretaceous plutonic rocks of western Glacier Bay National Park and Preserve U-Pb zircon data for: Cretaceous plutonic rocks of western Glacier Bay National Park and Preserve U-Pb detrital zircon data for: Select Pennsylvanian-Triassic sedimentary rocks from Colorado Generalized Geology of Southeast Asia (geo_3se)