Research Geologist
Florence Bascom Geoscience Center
Email:
rmcaleer@usgs.gov
Office Phone:
703-648-6052
Fax:
703-648-6953
Location
John W Powell FB
12201 Sunrise Valley Drive
Reston
, VA
20192-0002
US
Supervisor:
Gregory J Walsh
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These data are U-Pb sensitive high-resolution ion microprobe (SHRIMP) geochronology data from quartz porphyry dikes for the study of the Butte mining district, U.S.A. Results of the study are described and interpreted in Lund and others (2018).
Categories: Data;
Tags: 40Ar/39Ar geochronology,
Ag-polymetallic lodes,
BSE,
Butte,
CL, All tags...
Cu lodes,
GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
MRP,
Mineral Resources Program,
Montana,
SHRIMP,
U-Pb geochronology,
United States,
alteration,
backscatter electron,
copper,
economic geology,
geochronology,
geoscientificInformation,
molybdenum,
panchromatic cathodoluminescent,
quartz porphyry dikes,
radiometric dating,
sensitive high-resolution ion microprobe,
silver,
zinc, Fewer tags
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Germanium (Ge) is an increasingly important element used in critical technologies for communication, defense, and computing. However, Ge is scarce, and there is no United States (U.S.) primary production. Additionally, the environmental behavior of Ge is poorly understood. Germanium does not generally form its own minerals, but is instead recovered as a byproduct of zinc mining or of coal fly ash. It has been deemed critical by the U.S. and globally, and investigations of its geologic concentration, environmental fate and transport, and potential for recovery are crucial for maintaining a sustainable supply. A relevant study site to explore questions of environmental behavior and the potential to recover...
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This data release includes 40Ar/39Ar data from the U.S. Geological Survey for samples from Old Mine Park Area, Trumbull, Connecticut. Mineral samples were collected by Robert Wintsch and Harold Moritz. Potassium-bearing mineral grains were separated from the bulk sample and analyzed by argon geochronology at the U.S. Geological Survey Bascom ARgon Dating (BARD) Laboratory in Reston, Virginia. The data provide age constraints on units in the relevant geologic mapping area.
Categories: Data;
Tags: 40Ar/39Ar,
Bascom ARgon Dating Laboratory,
Connecticut,
Economic Geology,
FBGC, All tags...
Fairfield County,
Geochemistry,
Mineral Resources,
Structural Geology,
U.S. Geological Survey,
USGS,
USGS Science Data Catalog (SDC),
geologic mapping, Fewer tags
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The refractory nature of zircon to temperature and pressure allows even a single zircon grain to preserve a rich history of magmatic, metamorphic, and hydrothermal processes. Isotopic dating of micro-domains exposed in cross-sections of zircon grains allows us to interrogate this history. Unfortunately, our ability to select the zircon grains in a heavy mineral concentrate that records the most geochronologic information is limited by our inability to predict internal zonation from observations of whole zircon grains. Here we document the use of a petrographic microscope to observe and image the photoluminescence (PL) response of whole zircon grains excited under ultraviolet (UV) light, and the utility of this PL...
Categories: Data;
Tags: Adirondacks, NY,
Beauty Spot, NC,
Geochemistry,
Geochronology,
Sussex County, VA, All tags...
USGS Science Data Catalog (SDC),
Woodbury, CT, Fewer tags
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The Ironwood Iron-Formation, part of the Gogebic Iron Range in Wisconsin, is a Paleoproterozoic Superior-type banded iron formation (BIF) with substantial iron resource potential. The development of a Mesoproterozoic contact metamorphic aureole related to the emplacement of the Mellen Intrusive Complex resulted in the production of a variety of silicate minerals in the western portion of the Ironwood Iron-Formation, including amphibole, pyroxene, and olivine. The presence of amphibole minerals, some of which occur in a fibrous habit, has complicated development of this resource due to potential human health impacts. This data release provides information related to amphibole and other minerals in order that commercial,...
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