The GEC Science Center supports a laboratory facility that includes sample preparation labs, class-10,000 or better clean labs for chemical processing, and an instrument lab with multiple thermal ionization mass spectrometers (TIMS).
DRIL Facilities
[The use of firm, trade, and brand names is for identification purposes only and does not constitute endorsement by the U.S. government.]
The GEC and G3 Science Centers jointly support a laboratory facility located in Building 95 of the Denver Fed Center that includes sample preparation labs, two class-10,000 or better clean labs for chemical processing, and an instrument lab for thermal ionization mass spectrometers (TIMS). The lab is effectively shared between Science Centers and provides a model for efficient use of space and communal resources.
Sources/Usage: Public Domain.
Sources/Usage: Public Domain.
The facility maintains two multi-collector TIMS instruments, including an IsotopX Phoenix (installed July 2017) and Thermo Finnigan Triton (installed 2004). These instruments are capable of running in fully automated modes or remotely through a secured internet connection. Both have moveable faraday cups allowing static or dynamic simultaneous multi-collection of large ion beams. Small ion beams are measured by single-collector peak-hopping methods using either a discrete-dynode electron multiplier or Daly-knob /photomultiplier collector.
Sources/Usage: Public Domain.
Sources/Usage: Public Domain.
Prior to TIMS analyses, chemical processing is required to separate and purify the element of interest. This typically involves acid-digestion and evaporation followed by ion chromatographic exchange on small, resin-filled columns. The clean labs include multiple HEPA-filtered work stations and evaporation boxes that provide class-1000 or better work spaces. As a result, samples are exposed to minimal environmental contamination during processing allowing analyses of very small samples.
Sources/Usage: Public Domain.
Sources/Usage: Public Domain.
Sources/Usage: Public Domain.
Staff
The Denver Radiogenic Isotope Lab is cooperatively run by a number of principle investigators, post-docs, and support staff:
- Adam Hudson (ahudson@usgs.gov): Research Geologist (Principal Investigator), GECSC
- Richard Moscati (rmoscati@usgs.gov): Research Geologist (Principal Investigator), G3SC
- Ryan Frazer (rfrazer@usgs.gov): Research Geologist (Postdoctoral Fellow), GECSC
- Neil Griffis (ngriffis@usgs.gov): Research Geologist (Postdoctoral Fellow), G3SC
- Hannah Tompkins (htompkins@usgs.gov): Geologist (Lab Manager), GECSC
- Miriam Primus (mprimus@usgs.gov): Geologist (USGS Intern), GECSC
- James Paces (jbpaces@usgs.gov): Research Geologist (Emeritus), GECSC
- Leonid Neymark (lneymark@usgs.gov): Research Chemist (Emeritus), G3SC
- Wayne Premo (wpremo@usgs.gov): Geologist (Emeritus), GECSC
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This data release includes a table of concentrations (Sr, U) and radiogenic-isotope compositions (87Sr/86Sr, 234U/238U) for samples of modern lake water as well as a table of isotopic compositions (87Sr/86Sr and 234U/238U) for carbonate-rich samples from a 12.4-m-long composite core of lacustrine sediment from Lower Pahranagat Lake in southeastern Nevada, USA. Stratigraphic and geochronologic cont
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Archaeologists and researchers in allied fields have long sought to understand human colonization of North America. Questions remain about when and how people migrated, where they originated, and how their arrival affected the established fauna and landscape. Here, we present evidence from excavated surfaces in White Sands National Park (New Mexico, United States), where multiple in situ human foo
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Strontium isotope chronostratigraphic age of a sirenian fossil site on Santa Rosa Island, Channel Islands National Park, California
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Filter Total Items: 26
Strontium isotope chronostratigraphic age of a sirenian fossil site on Santa Rosa Island, Channel Islands National Park, California
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On active alluvial fans, debris-flow deposits and frequent avulsions produce a rough topographic surface. As is the case in many initially rough landforms produced by catastrophic processes, the topography of alluvial fans is progressively smoothed, producing textural differences useful in establishing relative age criteria for fans. Here, we outline an approach for defining a quantitative, numeriAuthorsSamuel Johnstone, Adam M. Hudson, Sylvia Nicovich, Chester A. Ruleman, Robert M. Sare, Ren A. ThompsonReview of the geochemistry and metallogeny of approximately 1.4 Ga granitoid intrusions of the conterminous United States
The conterminous United States hosts numerous volumetrically significant and geographically dispersed granitoid intrusions that range in age from 1.50 to 1.32 billion years before present (Ga). Although previously referred to as A-type granites, most are better described as ferroan granites. These granitoid intrusions are distributed in the northern and central Rocky Mountains, the Southwest, theAuthorsEdward A. du Bray, Christopher S. Holm-Denoma, Karen Lund, Wayne R. PremoMiocene−Pleistocene deformation of the Saddle Mountains: Implications for seismic hazard in central Washington, USA
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