Isotope and Chemical Methods for Mineral and Geoenvironmental Assessments and Support of USGS Science Strategy Active
This Project integrates several geochemical tools—stable isotope geochemistry, noble gas geochemistry, active gas geochemistry, single fluid inclusion chemistry, and fluid inclusion solute chemistry—in studies of the processes that form mineral deposits and the processes that disrupt them during mining or natural weathering. Research is directed toward fundamental scientific questions or, in collaboration with other Mineral Resources Projects, toward case studies of individual deposits, deposit types, or districts. The ultimate objective is to improve the scientific basis for mineral deposit models, and thereby improve the accuracy of assessments of the Nation’s mineral wealth.
Science Issue and Relevance
The core mandate of the Mineral Resources Program is to inform decision-makers on matters related to mineral resources on the Nation’s lands, including the consequences of mining and consequences natural weathering. To fulfill this mandate, genetic and geoenvironmental models must be developed for the various types of mineral deposits based on the best-available scientific understanding. This Project integrates several geochemical tools—stable isotope geochemistry, noble gas geochemistry, active gas geochemistry, single fluid inclusion chemistry, and fluid inclusion solute chemistry—in studies of the processes that form mineral deposits and the processes that destroy them during mining or natural weathering. Research is directed toward fundamental scientific questions or, in collaboration with other Mineral Resources Projects, toward case studies of individual deposits, deposit types, or districts. The ultimate objective is to improve the scientific basis for mineral deposit models, and thereby improve the accuracy of assessments of the Nation’s mineral wealth. The tools supported by this Project are applicable over a broad spectrum of Earth science research, so the Project also performs reimbursable work for other Programs consistent with the mandate of the USGS Science Strategy to leverage USGS skills in integrated studies that examine the Earth as a whole. This Project succeeds a similar Project that was summarized in U.S. Geological Survey Circular 1343.
Methods to Address Issue
Several labortories support the project objectives:
Stable Isotope Laboratory: Stable isotope geochemistry involves isotopic analysis of carbon, hydrogen, nitrogen, oxygen, and sulfur. These elements are abundant in common minerals and rocks, and they are the building blocks of most geologic fluids (surface waters, magmatic waters, hydrocarbon fluids, and others) and most biological compounds. Geologic metal deposits are in most cases precipitates from hot fluids. Stable isotope measurements can help to determine the source of the fluids, the sources of dissolved constituents, physicochemical parameters of ore formation such as temperature, and the trigger for metal precipitation. Stable isotope analysis can also reveal the broader geologic environment of ore formation, an essential part of any mineral deposit model.
Noble Gas Laboratory: Helium, neon, argon, krypton, xenon, and radon are inert "gases" that have multiple isotopes. The relative abundances of the isotopes can reveal whether rock or water constituents came from the mantle, the deep crust, the shallow crust, or the atmosphere. In studies of mineral deposits, noble gas analyses are complementary to other types of chemical or isotopic analyses because they reveal how ore-forming systems fit into larger frameworks of crustal evolution and magma generation.
Active gases contained in hydrothermal minerals also give insights on ore formation. Active gases that are routinely measured include N2, CO2, CH2, H2, H2S, SO2, HCl, HF, H2O, and the light hydrocarbons. The data can reveal volatile evolution in hydrothermal systems, magma degassing histories, and fluid-rock chemical buffering.
Single Fluid Inclusion & Melt Inclusion Laboratory: Inclusions trapped in hydrothermal minerals can contain remnants of the waters from which the minerals precipitated. Chemical and isotopic analysis of these miniscule inclusions provides a wealth of information on ancient hydrothermal systems and their role in the formation of mineral deposits. A variety of important parameters can be determined, including the mass of fluid required to produce the deposit, the chemical species that carried the metals, and the trigger that led to metal precipitation.
Fluid Inclusion Solute Laboratory: Certain cations and anions in fluid inclusions within hydrothermal minerals can be diagnostic of the source and history of the mineral-forming fluid. Particularly insightful are the abundances of the alkali metals lithium, sodium, and potassium, and the halides fluoride, chloride, bromide, and iodide. Analyses of these ions can reveal periods of evaporation, water-rock reactions within aquifers, and mixing of multiple fluids, all important inputs for mineral deposit models.
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center
Below are other science projects associated with this project.
Below are data or web applications associated with this project.
Below are publications associated with this project.
Thermochronology of Cretaceous batholithic rocks in the northern Peninsular Ranges batholith, southern California: Implications for the Late Cretaceous tectonic evolution of southern California
Hydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes
Descriptive and geoenvironmental model for Co-Cu-Au deposits in metasedimentary rocks
Holocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms
Evidence for high salinity of Early Cretaceous sea water from the Chesapeake Bay crater
Mercury in gray wolves (Canis lupus) in Alaska: Increased exposure through consumption of marine prey
Silicate melt inclusion evidence for extreme pre-eruptive enrichment and post-eruptive depletion of lithium in silicic volcanic rocks of the western United States: implications for the origin of lithium-rich brines
Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams
Ore genesis constraints on the Idaho cobalt belt from fluid inclusion gas, noble gas isotope, and ion ratio analyses--a reply
In situ quantification of Br and Cl in minerals and fluid inclusions by LA-ICP-MS: a powerful tool to identify fluid sources
Genesis of the Touissit-Bou Beker Mississippi Valley-type district (Morocco-Algeria) and its relation to the Africa-Europe collision
The Spar Lake strata-Bound Cu-Ag deposit formed across a mixing zone between trapped natural gas and metals-bearing brine
Below are partners associated with this project.
- Overview
This Project integrates several geochemical tools—stable isotope geochemistry, noble gas geochemistry, active gas geochemistry, single fluid inclusion chemistry, and fluid inclusion solute chemistry—in studies of the processes that form mineral deposits and the processes that disrupt them during mining or natural weathering. Research is directed toward fundamental scientific questions or, in collaboration with other Mineral Resources Projects, toward case studies of individual deposits, deposit types, or districts. The ultimate objective is to improve the scientific basis for mineral deposit models, and thereby improve the accuracy of assessments of the Nation’s mineral wealth.
Science Issue and Relevance
The core mandate of the Mineral Resources Program is to inform decision-makers on matters related to mineral resources on the Nation’s lands, including the consequences of mining and consequences natural weathering. To fulfill this mandate, genetic and geoenvironmental models must be developed for the various types of mineral deposits based on the best-available scientific understanding. This Project integrates several geochemical tools—stable isotope geochemistry, noble gas geochemistry, active gas geochemistry, single fluid inclusion chemistry, and fluid inclusion solute chemistry—in studies of the processes that form mineral deposits and the processes that destroy them during mining or natural weathering. Research is directed toward fundamental scientific questions or, in collaboration with other Mineral Resources Projects, toward case studies of individual deposits, deposit types, or districts. The ultimate objective is to improve the scientific basis for mineral deposit models, and thereby improve the accuracy of assessments of the Nation’s mineral wealth. The tools supported by this Project are applicable over a broad spectrum of Earth science research, so the Project also performs reimbursable work for other Programs consistent with the mandate of the USGS Science Strategy to leverage USGS skills in integrated studies that examine the Earth as a whole. This Project succeeds a similar Project that was summarized in U.S. Geological Survey Circular 1343.
Methods to Address Issue
Several labortories support the project objectives:
Stable Isotope Laboratory: Stable isotope geochemistry involves isotopic analysis of carbon, hydrogen, nitrogen, oxygen, and sulfur. These elements are abundant in common minerals and rocks, and they are the building blocks of most geologic fluids (surface waters, magmatic waters, hydrocarbon fluids, and others) and most biological compounds. Geologic metal deposits are in most cases precipitates from hot fluids. Stable isotope measurements can help to determine the source of the fluids, the sources of dissolved constituents, physicochemical parameters of ore formation such as temperature, and the trigger for metal precipitation. Stable isotope analysis can also reveal the broader geologic environment of ore formation, an essential part of any mineral deposit model.
Noble Gas Laboratory: Helium, neon, argon, krypton, xenon, and radon are inert "gases" that have multiple isotopes. The relative abundances of the isotopes can reveal whether rock or water constituents came from the mantle, the deep crust, the shallow crust, or the atmosphere. In studies of mineral deposits, noble gas analyses are complementary to other types of chemical or isotopic analyses because they reveal how ore-forming systems fit into larger frameworks of crustal evolution and magma generation.
Active gases contained in hydrothermal minerals also give insights on ore formation. Active gases that are routinely measured include N2, CO2, CH2, H2, H2S, SO2, HCl, HF, H2O, and the light hydrocarbons. The data can reveal volatile evolution in hydrothermal systems, magma degassing histories, and fluid-rock chemical buffering.
Single Fluid Inclusion & Melt Inclusion Laboratory: Inclusions trapped in hydrothermal minerals can contain remnants of the waters from which the minerals precipitated. Chemical and isotopic analysis of these miniscule inclusions provides a wealth of information on ancient hydrothermal systems and their role in the formation of mineral deposits. A variety of important parameters can be determined, including the mass of fluid required to produce the deposit, the chemical species that carried the metals, and the trigger that led to metal precipitation.
Fluid Inclusion Solute Laboratory: Certain cations and anions in fluid inclusions within hydrothermal minerals can be diagnostic of the source and history of the mineral-forming fluid. Particularly insightful are the abundances of the alkali metals lithium, sodium, and potassium, and the halides fluoride, chloride, bromide, and iodide. Analyses of these ions can reveal periods of evaporation, water-rock reactions within aquifers, and mixing of multiple fluids, all important inputs for mineral deposit models.
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center
- Science
Below are other science projects associated with this project.
- Data
Below are data or web applications associated with this project.
- Publications
Below are publications associated with this project.
Filter Total Items: 73Thermochronology of Cretaceous batholithic rocks in the northern Peninsular Ranges batholith, southern California: Implications for the Late Cretaceous tectonic evolution of southern California
The thermochronology for several suites of Mesozoic metamorphic and plutonic rocks collected throughout the northern Peninsular Ranges batholith (PRB) was studied as part of a collaborative isotopic study to further our understanding of the magmatic and tectonic history of southern California. These sample suites include: a traverse through the plutonic rocks across the northern PRB (N = 29), a trAuthorsDaniel P. Miggins, Wayne R. Premo, Lawrence W Snee, Ross Yeoman, Nancy D. Naeaer, Charles W. Naeser, Douglas M. MortonHydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes
This study addresses the geologic and hydrogeochemical processes operating at a range of scales within the prairie pothole region (PPR). The PPR is a 750,000 km2portion of north central North America that hosts millions of small wetlands known to be critical habitat for waterfowl and other wildlife. At a local scale, we characterized the geochemical evolution of the 92-ha Cottonwood Lake study areAuthorsMartin B. Goldhaber, Christopher T. Mills, Jean Morrison, Craig A. Stricker, David M. Mushet, James W. LaBaughDescriptive and geoenvironmental model for Co-Cu-Au deposits in metasedimentary rocks
IntroductionThis report is a revised model for a specific type of cobalt-copper-gold (Co-Cu-Au) deposit that will be evaluated in the next U.S. Geological Survey (USGS) assessment of undiscovered mineral resources in the United States (see Ferrero and others, 2012). Emphasis is on providing an up-to-date deposit model that includes both geologic and geoenvironmental aspects. The new model presenteAuthorsJohn F. Slack, Craig A. Johnson, J. Douglas Causey, Karen Lund, Klaus J. Schulz, John E. Gray, Robert G. EppingerHolocene dynamics of the Florida Everglades with respect to climate, dustfall, and tropical storms
Aeolian dust is rarely considered an important source for nutrients in large peatlands, which generally develop in moist regions far from the major centers of dust production. As a result, past studies assumed that the Everglades provides a classic example of an originally oligotrophic, P-limited wetland that was subsequently degraded by anthropogenic activities. However, a multiproxy sedimentaryAuthorsPaul H. Glaser, Barbara C. S. Hansen, Joseph J. Donovan, Thomas J. Givnish, Craig A. Stricker, John C. VolinEvidence for high salinity of Early Cretaceous sea water from the Chesapeake Bay crater
High salinity groundwater more than 1000 metres deep in the Atlantic Coastal Plain of the United States has been documented in several locations1,2, most recently within the 35 million-year-old Chesapeake Bay impact crater3,4,5. Suggestions for the origin of increased salinity in the crater have included evaporite dissolution6, osmosis6, and evaporation from heating7 associated with the bolide impAuthorsWard E. Sanford, Michael W. Doughten, Tyler B. Coplen, Andrew G. Hunt, Thomas D. BullenMercury in gray wolves (Canis lupus) in Alaska: Increased exposure through consumption of marine prey
Mercury (Hg) bioaccumulates in the tissues of organismsand biomagnifies within food-webs. Graywolves (Canis lupus) in Alaska primarily acquire Hg through diet; therefore, comparing the extent of Hg exposure inwolves, in conjunction with stable isotopes, from interior and coastal regions of Alaska offers important insight into their feeding ecology. Liver, kidney, and skeletal muscle samples fromAuthorsAshley K. McGrew, Lora R. Ballweber, Sara K. Moses, Craig A. Stricker, Kimberlee B. Beckmen, Mo D. Salman, Todd M. O’HaraSilicate melt inclusion evidence for extreme pre-eruptive enrichment and post-eruptive depletion of lithium in silicic volcanic rocks of the western United States: implications for the origin of lithium-rich brines
To evaluate whether anatectic and/or highly fractionated lithophile element-enriched rhyolite tuffs deposited in arid lacustrine basins lose enough lithium during eruption, lithification, and weathering to generate significant Li brine resources, pre-eruptive melt compositions, preserved in inclusions, and the magnitude of post-eruptive Li depletions, evident in host rhyolites, were documented atAuthorsAlbert H. Hofstra, T.I. Todorov, C.N. Mercer, D.T. Adams, E.E. MarshSeasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams
Spawning salmon deliver annual pulses of marine-derived nutrients (MDN) to riverine ecosystems around the Pacific Rim, leading to increased growth and condition in aquatic and riparian biota. The influence of pulsed resources may last for extended periods of time when recipient food webs have effective storage mechanisms, yet few studies have tracked the seasonal persistence of MDN. With this as oAuthorsDaniel J. Rinella, Mark S. Wipfi, Coowe M. Walker, Craig A. Stricker, Ron A. HeintzOre genesis constraints on the Idaho cobalt belt from fluid inclusion gas, noble gas isotope, and ion ratio analyses--a reply
Burlinson (2013) questions the veracity of the H2 concentrations reported for fluid inclusion extracts from minerals in the Idaho cobalt belt (Table 2; Landis and Hofstra, 2012) and suggests that they are an analytical artifact of electron-impact mass spectrometry. He also declares that H2 should not be present in fluid inclusions because it is invariably lost by diffusion and is never detected inAuthorsAlbert H. Hofstra, Gary P. LandisIn situ quantification of Br and Cl in minerals and fluid inclusions by LA-ICP-MS: a powerful tool to identify fluid sources
Bromine and chlorine are important halogens for fluid source identification in the Earth's crust, but until recently we lacked routine analytical techniques to determine the concentration of these elements in situ on a micrometer scale in minerals and fluid inclusions. In this study, we evaluate the potential of in situ Cl and Br measurements by LA-ICP-MS through analysis of a range of scapolite gAuthorsJohannes Hammerli, Brian Rusk, Carl Spandler, Poul Emsbo, Nicholas H.S. OliverGenesis of the Touissit-Bou Beker Mississippi Valley-type district (Morocco-Algeria) and its relation to the Africa-Europe collision
The Mississippi Valley-type deposits of the Touissit-Bou Beker district are hosted by a 25 m thick sequence of diagenetically and hydrothermally dolomitized carbonate platform rocks of Aalenian-Bajocian age. The sulfide mineralization consists principally of galena and sphalerite and occurs as open-space fillings of voids and moderate to massive replacement of the medium- to coarse-grained host doAuthorsMohammed Bouabdellah, Donald F. Sangster, David L. Leach, Alex C. Brown, Craig A. Johnson, Poul EmsboThe Spar Lake strata-Bound Cu-Ag deposit formed across a mixing zone between trapped natural gas and metals-bearing brine
Ore formation at the Spar Lake red bed-associated strata-bound Cu deposit took place across a mixing and reaction zone between a hot oxidized metals-transporting brine and a reservoir of “sour” (H2S-bearing) natural gas trapped in the host sandstones. Fluid inclusion volatile analyses have very high CH4 concentrations (≥1 mol % in most samples), and a sample from the fringe of the deposit has betwAuthorsTimothy S. Hayes, Gary P. Landis, Joseph F. Whelan, Robert O. Rye, Richard J. Moscati - Partners
Below are partners associated with this project.