Filters: partyWithName: U.S. Geological Survey (X) > partyWithName: Craig A Johnson (X)
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This U.S. Geological Survey (USGS) data release contains analytical data from a suite of rock and mineral samples collected from drill core within the Elk Creek alkaline complex, southeast Nebraska. This complex hosts the Elk Creek carbonatite, a multilithologic carbonatite enriched in niobium, rare earth elements (REEs), scandium, and titanium. Mineralized carbonatites are the world’s primary source of rare earth elements (REEs) and niobium, but only a few deposits are responsible for meeting the current demand of these critical elements such that there is increasing interest in other carbonatites that have the potential to help meet future demands. This study focuses on the Elk Creek carbonatite, the largest...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Economic Geology,
Elk Creek,
Elk Creek carbonatite,
Geochemistry,
Johnson County,
Elemental concentrations and stable oxygen and carbon isotope ratios are reported for five mammillary calcite specimens collected from the groundwater-filled fissures Devils Hole and Devils Hole II in the southern Amargosa Desert, south-western Nevada. Previous studies of these specimens yielded oxygen and carbon isotope chronologies of paleoclimatic and paleo hydrologic conditions over an approximately 500,000-year time period as defined by uranium series dates (Winograd and others, 1992, 2006; Landwehr and others, 1997, 2011). The elemental concentration measurements reveal additional chronologies in the mammillary calcite. The specimens were sampled by milling contiguous 0.050-inch-thick layers (1.27 millimeters)...
Categories: Data;
Tags: Amargosa Valley,
Climatology,
Death Valley National Park,
Devils Hole,
GGGSC,
These data are sulfur isotope determinations (34S/32S ratios) for sulfur-bearing minerals collected from epithermal veins in the Lowland mining district, Montana, USA and from metasedimentary rocks that host the Black Angel zinc-lead-silver deposit, Greenland. The samples were collected by cooperators as parts of larger ore genesis studies. The determinations were performed between February 2019 and March 2021 on 35 samples of pyrite, sphalerite, galena, and chalcopyrite from Lowland vein occurrences and 5 samples of anhydrite from Black Angel host rocks.
Categories: Data;
Tags: <1GB,
GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
Greenland,
Jefferson County,
This dataset provides geochronologic, geochemical, and isotopic data for selected igneous rock samples collected in the Lane Mountain area about 20 kilometers northeast of Barstow, California. Uranium-lead (U-Pb) zircon geochronologic and whole-rock geochemical data were obtained for 62 samples of which 28 are from Permian to Triassic plutonic rocks and dikes, 24 are from Late Jurassic plutonic rocks, 6 are from Late Cretaceous plutonic rocks and dikes, and 4 are from Miocene volcanic rocks, Rubidium-strontium (Rb-Sr) isotopic data were obtained for 8 of the Permian to Triassic samples, 9 of the Late Jurassic samples, and 4 of the Late Cretaceous samples. Oxygen isotope data were obtained for 2 Permian to Triassic...
Stable isotope compositions (the ratios deuterium/hydrogen, oxygen-18/oxygen-16, and sulfur-34/sulfur-32) are reported for alunite, jarosite, kaolinite, silica, cinnabar, marcasite, and native sulfur from outcrops in and around the workings of the Sulphur Bank mercury mine, Lake County, California, and chemical compositions are reported, from electron microprobe analyses, for alunite and buddingtonite. Isotope analyses are given also for hydrogen sulfide gas from active fumaroles and for soluble sulfate in samples of mine waste. The waste results reflect fine grained material (particles less than 0.063 millimeter in diameter) that were taken from composites, each composite representing a particular waste pile that...
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