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Radiogenic and Stable Isotope Methods Active

By Geology, Energy & Minerals Science Center August 3, 2018

Our work focuses on collaborating with high-priority U.S. Geological Survey projects and other Federal and international agencies, and on providing radiogenic and stable isotope analyses to support mineral- and environmentally-related geologic investigations.

clean laboratory
Sources/Usage: Public Domain.
Radiogenic and stable isotope clean laboratory in Reston, VA. Cleanliness is defined based on the number of particles of a defined diameter per unit volume. According to U.S. Federal Standard, a Class 100 clean room must have no more than 100 particles of diameter 0.5 mm per cubic foot of air. Photo by USGS. (Public domain.)

Radiogenic Isotope Techniques

Radiogenic isotope techniques are used for analysis of materials, fluids, and fluid and solid inclusions from ancient and modern environments. Analytical procedures are improved and developed using thermal ionization mass spectrometry and inductively coupled plasma mass spectrometry for studies directed at: regional and site-specific metal mobilization, metal transport, redistribution processes, and sources of fluids for regional geologic, ore genesis, life-cycles, and environmental applications.

Stable Isotope Work

Stable isotope work includes developing new and refining existing analytical techniques for the following applications:

  1. oxygen isotope analysis of dissolved sulfate for studies of mine drainage, acid deposition and ecosystems;
  2. hydrogen isotope analysis of silicate and other hydrated minerals for studies of ore genesis; and
  3. sulfur isotope analysis of submilligram samples of sulfide and sulfate minerals using continuous-flow technology for environmental, ore genesis and ecosystem studies.

 

 

Return to Mineral Resources Program 

Below are data or web applications associated with this project.

GIS and Data Tables for Focus Areas for Potential Domestic Nonfuel Sources of Rare Earth Elements

In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.). Acquiring information on possible domestic sources of these critical minerals is the basis of the USGS Earth Mappi
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Earth Mapping Resources Initiative (Earth MRI)

Geochemical and Modal Data for Mesoproterozoic Igneous Rocks of the St. Francois Mountains, Southeast Missouri

This data release accompanies the Data Series report 'Compilation of new and previously published geochemical and modal data for Mesoproterozoic igneous rocks of the St. Francois Mountains, southeast Missouri (https://doi.org/10.3133/ds1080). The compilation includes recently acquired as well as previously published geochemical and modal petrographic data for igneous rocks in the St. Francois Moun
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Geochemical Database for Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri

The Geochemical Database for Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri (IOCG-REE_GX) contains new geochemical data compilations for samples from IOCG-REE type deposits in which each rock sample has one "best value" determination for each analyzed species, greatly improving speed and efficiency of use. IOCG-REE_GX was created and designed to compile whole-rock
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Below are publications associated with this project.

Filter Total Items: 35

The Mystic subterrane (partly) demystified: New data from the Farewell terrane and adjacent rocks, interior Alaska

The youngest part of the Farewell terrane in interior Alaska (USA) is the enigmatic Devonian–Cretaceous Mystic subterrane. New U-Pb detrital zircon, fossil, geochemical, neodymium isotopic, and petrographic data illuminate the origin of the rocks of this subterrane. The Devonian–Permian Sheep Creek Formation yielded youngest detrital zircons of Devonian age, major detrital zircon age probability p
Authors
Julie A. Dumoulin, James V. Jones, Stephen E. Box, Dwight C. Bradley, Robert A. Ayuso, Paul B. O'Sullivan
By
Alaska Science Center

Lead and strontium isotopes as monitors of anthropogenic contaminants in the surficial environment

Isotopic discrimination can be an effective tool in establishing a direct link between sources of Pb contamination and the presence of anomalously high concentrations of Pb in waters, soils, and organisms. Residential wells supplying water containing up to 1600 ppb Pb to houses built on the former Mohr orchards commercial site, near Allentown, Pennsylvania, United States, were evaluated to discern
Authors
Robert A. Ayuso, Nora K. Foley
By
Mineral Resources Program, Geology, Energy & Minerals Science Center

Geochemical and Pb isotopic characterization of soil, groundwater, human hair, and corn samples from the Domizio Flegreo and Agro Aversano area (Campania region, Italy)

A geochemical survey was carried out to investigate metal contamination in the Domizio Littoral and Agro Aversano area (Southern Italy) by means of soil, groundwater, human hair and corn samples. Pb isotope ratios were also determined to identify the sources of metals. Specifically, the investigation focused on topsoils (n = 1064), groundwater (n = 26), 25 human hair (n = 24) and corn samples (n =
Authors
Carmela Rezza, Stefano Albanese, Robert A. Ayuso, Annamaria Lima, Jaana Sorvari, Benedetto De Vivo
By
Geology, Energy & Minerals Science Center

Regional geologic and petrologic framework for iron oxide ± apatite ± rare earth element and iron oxide copper-gold deposits of the Mesoproterozoic St. Francois Mountains terrane, southeast Missouri, USA

This paper provides an overview on the genesis of Mesoproterozoic igneous rocks and associated iron oxide ± apatite (IOA) ± rare earth element, iron oxide-copper-gold (IOCG), and iron-rich sedimentary deposits in the St. Francois Mountains terrane of southeast Missouri, USA. The St. Francois Mountains terrane lies along the southeastern margin of Laurentia as part of the eastern granite-rhyolite p
Authors
Warren C. Day, John F. Slack, Robert A. Ayuso, Cheryl M. Seeger
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center

Geochemistry, Nd-Pb Isotopes, and Pb-Pb Ages of the Mesoproterozoic Pea Ridge Iron Oxide-Apatite–Rare Earth Element Deposit, Southeast Missouri

Iron oxide-apatite and iron oxide-copper-gold deposits occur within ~1.48 to 1.47 Ga volcanic rocks of the St. Francois Mountains terrane near a regional boundary separating crustal blocks having contrasting depleted-mantle Sm-Nd model ages (TDM). Major and trace element analyses and Nd and Pb isotope data were obtained to characterize the Pea Ridge deposit, improve identification of exploration t
Authors
Robert A. Ayuso, John F. Slack, Warren C. Day, Anne E. McCafferty
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center

Beryllium—A critical mineral commodity—Resources, production, and supply chain

Beryllium is a lightweight metallic element used in a wide variety of specialty and industrial applications. As a function of its unique chemical and physical properties, such as a high stiffness-to-weight ratio, resistance to temperature extremes, and high thermal conductivity, beryllium cannot be easily replaced by substitute materials in applications where combinations of these properties make
Authors
Graham W. Lederer, Nora K. Foley, Brian W. Jaskula, Robert A. Ayuso
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, National Minerals Information Center

Pb-Sr isotopic and geochemical constraints on sources and processes of lead contamination in well waters and soil from former fruit orchards, Pennsylvania, USA: A legacy of anthropogenic activities

Isotopic discrimination can be an effective tool in establishing a direct link between sources of Pb contamination and the presence of anomalously high concentrations of Pb in waters, soils, and organisms. Residential wells supplying water containing up to 1600 ppb Pb to houses built on the former Mohr orchards commercial site, near Allentown, PA, were evaluated to discern anthropogenic from geoge
Authors
Robert A. Ayuso, Nora K. Foley
By
Geology, Energy & Minerals Science Center, Pennsylvania Water Science Center

Soil geochemical survey of abandoned mining sites in the Eastern-Central Peloritani Mountains, Sicily, Italy

This investigation focused on topsoils (n = 122) and vertical profiles (n = 6) distributed over an area of 250 km2 in the eastern-central Peloritani Mountains, northeastern Sicily. Georeferenced concentration of 53 elements (including potentially harmful ones), determined by ICP-MS after an aqua regia leach, were used to produce geochemical maps by means of a GIS-aided spatial interpolation proces
Authors
A. Consenza, A. Lima, Robert A. Ayuso, Nora K. Foley, S. Albanese, A. Messina, B. De Vivo
By
Geology, Energy & Minerals Science Center

REE enrichment in granite-derived regolith deposits of the southeast United States: Prospective source rocks and accumulation processes

The Southeastern United States contains numerous anorogenic, or A-type, granites, which constitute promising source rocks for REE-enriched ion adsorption clay deposits due to their inherently high concentrations of REE. These granites have undergone a long history of chemical weathering, resulting in thick granite-derived regoliths, akin to those of South China, which supply virtually all heavy RE
Authors
Nora K. Foley, Robert A. Ayuso
By
Geology, Energy & Minerals Science Center

Reconstruction of an early Paleozoic continental margin based on the nature of protoliths in the Nome Complex, Seward Peninsula, Alaska

The Nome Complex is a large metamorphic unit that sits along the southern boundary of the Arctic Alaska–Chukotka terrane, the largest of several micro continental fragments of uncertain origin located between the Siberian and Laurentian cratons. The Arctic Alaska–Chukotka terrane moved into its present position during the Mesozoic; its Mesozoic and older movements are central to reconstruction of
Authors
Alison B. Till, Julie A. Dumoulin, Robert A. Ayuso, John N. Aleinikoff, Jeffrey M. Amato, John F. Slack, W.C. Pat Shanks
By
Groundwater and Streamflow Information Program, Geology, Energy & Minerals Science Center, Alaska Science Center

Pb-Sr-Nd isotopes in surficial materials at the Pebble Porphyry Cu-Au-Mo Deposit, Southwestern Alaska: can the mineralizing fingerprint be detected through cover?

The Cretaceous Pebble porphyry Cu-Au-Mo deposit is covered by tundra and glacigenic sediments. Pb-Sr-Nd measurements were done on sediments and soils to establish baseline conditions prior to the onset of mining operations and contribute to the development of exploration methods for concealed base metal deposits of this type. Pebble rocks have a moderate range for 206Pb/204Pb = 18.574 to 18.874, 2
Authors
Robert A. Ayuso, Karen D. Kelley, Robert G. Eppinger, Francesca Forni
By
Geology, Energy & Minerals Science Center

Gold deposits of the Carolina Slate Belt, southeastern United States--Age and origin of the major gold producers

Gold- and iron sulfide-bearing deposits of the southeastern United States have distinctive mineralogical and geochemical features that provide a basis for constructing models of ore genesis for exploration and assessment of gold resources. The largest (historic) deposits, in approximate million ounces of gold (Moz Au), include those in the Haile (~ 4.2 Moz Au), Ridgeway (~1.5 Moz Au), Brewer (~0.2
Authors
Nora K. Foley, Robert A. Ayuso
By
Geology, Energy & Minerals Science Center