Stable Isotope Geochemistry Group
This task provides base funding for the stable isotope laboratory such that it is fully operational at state-of-the-art status. This laboratory supports stable isotope geochemistry based projects in the Minerals Program and throughout the USGS mission areas.
The basic costs required to make the stable isotope laboratory operational (exclusive of the costs of analyses which are charged to individual projects) are covered in this task. This includes costs of the pumps, electronics, computers and other supporting mechanical and electronic devices which are subject to breakdown and/or which need to be upgraded. In addition plans are made to finance the aquistion of new peripherals and mass spectrometers as needed to maintain the state-of-the-art status of the laboratory so it can continue to function as a major USGS resource.
The laboratory will continue to be a state of the art facility dedicated to cutting edge science in support of USGS mission projects. In addition to annual maintenance on pumps and replacement of electronics new or upgraded computers and software will be installed on the mass spectrometers and the database handling system will be improved. Development of the laser ablation system will continue. Development of the ion trap time-of-flight mass spectrometer will continue. The laboratory will continue to facilitate interdisciplinary science throughout USGS mission areas (Energy and Minerals, Natural Hazards, Climate and Land-Use Change, Ecosystems, Water) by meeting requests for stable isotope geochemistry in a timely fashion.
Highlights & Key Findings
Natural Hazards: The Stable Isotope Laboratory has provided all of the stable isotope data and geochemistry interpretation for the Resources and Hazards of the Hydrothermal Systems in Cascade Volcanoes project.
Energy and Minerals: Stable isotopic data, and input on interpretations where needed, were provided to numerous projects involving both ore genesis and mining-environmental questions.
- organic-bound sulfur in Athabasca tar sand deposits
- gold deposits throughout the world
- base metals in northern Alaska
- MVT deposits in north Africa
- Alaska massive sulfides, Yellowstone and Big Bend hydrothermal rocks, midocean ridge samples
- prairie potholes of northern Great Plains grasslands
- acid sulfate geochemistry
- Cascade volcano hazards, aqueous sulfate
- Nevada gold deposits
- hydrothermal signatures in marine isotopic records
- western US volcanic/hydrothermal systems), G Plumlee (LUSI mud volcano, fire and volcano ash hazards
- Rocky Mt alpine waters
- Sheep Creek Co-Cu deposit, MT
- Guelb Moghrein deposit, Mauritania; Greens Ck deposit, AK
- isotopic characterization of standards
- high carbon soils
- considerable additional work on fundamental processes in the genesis of ores and the environmental consequences of mining was carried out by staff of the stable isotope laboratory
Climate and Land Use Change Recent technique developments in the Stable Isotope Laboratory to analyze sulfur isotope composition of very small amounts of sulfur in various matrices such as organic matter, shells, soil and dust has lead to initial work to test the technique to identify the origin of sulfur in dust in two projects located in the southwest. Carbon and oxygen isotope analyses on charophytes in lake sediments were provided. Isotopic analyses of carbonate minerals to constrain the fluid history of the Rio Grande Rift/northern San Luis Basin were conducted.
Water: The laboratory has supported the Yucca Mountain Project by providing unlimited isotopic data on waters, carbonates, and aqueous sulfate. Closing calibrations were also carried out for the termination of the project. Isotopic analyses of carbonate in sediment cores were provided as part of a major study of the hydrology of the Bonneville (UT) basin in Quaternary time.
Ecosystems: The laboratory supported over a dozen projects on diverse topics, mainly through the efforts of Craig Stricker, an Ecosystems researcher who is embedded in the laboratory.
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