Robert R. Seal
Robert (Bob) Seal is a Research Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Science and Products
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Thermodynamic data for modeling acid mine drainage problems: compilation and estimation of data for selected soluble iron-sulfate minerals
Enthalpy of formation, Gibbs energy of formation, and entropy values have been compiled from the literature for the hydrated ferrous sulfate minerals melanterite, rozenite, and szomolnokite, and a variety of other hydrated sulfate compounds. On the basis of this compilation, it appears that there is no evidence for an excess enthalpy of mixing for sulfate-H2O systems, except for the first H2O mole
Authors
Bruch S. Hemingway, Robert R. Seal, I-Ming Chou
Determination of melanterite-rozenite and chalcanthite-bonattite equilibria by humidity measurements at 0.1 MPa
Melanterite (FeSO4·7H2O)-rozenite (FeSO4·4H2O) and chalcanthite (CuSO4·5H2O)-bonattite (CuSO4·3H2O) equilibria were determined by humidity measurements at 0.1 MPa. Two methods were used; one is the gas-flow-cell method (between 21 and 98 °C), and the other is the humiditybuffer method (between 21 and 70 °C). The first method has a larger temperature uncertainty even though it is more efficient. Wi
Authors
I.-Ming Chou, R.R. Seal, B. S. Hemingway
Sulfur and lead isotope geochemistry of hypogene mineralization at the Barite Hill Gold Deposit, Carolina Slate Belt, southeastern United States: A window into and through regional metamorphism
The Barite Hill gold deposit, at the southwestern end of the Carolina slate belt in the southeastern United States, is one of four gold deposits in the region that have a combined yield of 110 metric tons of gold over the past 10 years. At Barite Hill, production has dominantly come from oxidized ores. Sulfur isotope data from hypogene portions of the Barite Hill gold deposit vary systematically w
Authors
Robert R. Seal, Robert A. Ayuso, Nora K. Foley, Sandra H. B. Clark
The Gibbs free energy of nukundamite (Cu3.38Fe0.62S4): A correction and implications for phase equilibria
The Gibbs free energy of formation of nukundamite (Cu3.38Fe0.62S4) was calculated from published experimental studies of the reaction 3.25 Cu3.38Fe0.62S4 + S2 = 11 CuS + 2 FeS2 in order to correct an erroneous expression in the published record. The correct expression describing the Gibbs free energy of formation (kJ·mol−1) of nukundamite relative to the elements and ideal S2 gas is ΔfG°nukundamit
Authors
Robert R. Seal, E. E. Inan, Bruce S. Hemingway
Stable isotope systematics of sulfate minerals
Stable isotope studies of sulfate minerals are especially useful for unraveling the geochemical history of geological systems. All sulfate minerals can yield sulfur and oxygen isotope data. Hydrous sulfate minerals, such as gypsum, also yield oxygen and hydrogen isotope data for the water of hydration, and more complex sulfate minerals, such as alunite and jarosite also yield oxygen and hydrogen i
Authors
Robert R. Seal, Charles N. Alpers, Robert O. Rye
Environmental processes that affect mineral deposits in the eastern United States
A thorough understanding of the environmental processes that affect mineral deposits and mine wastes has become increasingly important as the Nation wrestles with how to meet our current demand for metals without compromising the environment and how to mitigate the damage caused by the mining practices of previous generations. Regulatory requirements are dominated by empirical approaches to enviro
Authors
Robert R. Seal
Stable isotopes and mineral resource investigations in the United States
The elements oxygen, hydrogen, sulfur, and carbon are important constituents of hydrothermal ore-forming systems and the weathering processes of mineral deposits in the surficial environment. They also play key roles in volcanic activity, ecosystem dynamics, climate change, and hydrologic and atmospheric processes. Therefore, study of the stable isotopes of these elements can provide powerful insi
Authors
Robert R. Seal
Geochemical data including mercury speciation for surface waters at the abandoned Greenwood mine area, Prince William Forest Park, Virginia
No abstract available.
Authors
R.R. Seal, D.P. Haffner, A. L. Meier
Stable isotopes in mid-ocean ridge hydrothermal systems: Interactions between fluids, minerals, and organisms
Studies of abundance variations of light stable isotopes in nature have had a tremendous impact on all aspects of geochemistry since the development, in 1947, of a gas source isotope ratio mass spectrometer capable of measuring small variations in stable isotope ratios (Nice, 1947]. Stable isotope geochemistry is now a mature field, as witnessed by the proliferation of commercially available mass
Authors
Wayne C. Shanks, John K. Böhlke, Robert R. Seal
Science and Products
Filter Total Items: 24
No Result Found
Filter Total Items: 93
Thermodynamic data for modeling acid mine drainage problems: compilation and estimation of data for selected soluble iron-sulfate minerals
Enthalpy of formation, Gibbs energy of formation, and entropy values have been compiled from the literature for the hydrated ferrous sulfate minerals melanterite, rozenite, and szomolnokite, and a variety of other hydrated sulfate compounds. On the basis of this compilation, it appears that there is no evidence for an excess enthalpy of mixing for sulfate-H2O systems, except for the first H2O mole
Authors
Bruch S. Hemingway, Robert R. Seal, I-Ming Chou
Determination of melanterite-rozenite and chalcanthite-bonattite equilibria by humidity measurements at 0.1 MPa
Melanterite (FeSO4·7H2O)-rozenite (FeSO4·4H2O) and chalcanthite (CuSO4·5H2O)-bonattite (CuSO4·3H2O) equilibria were determined by humidity measurements at 0.1 MPa. Two methods were used; one is the gas-flow-cell method (between 21 and 98 °C), and the other is the humiditybuffer method (between 21 and 70 °C). The first method has a larger temperature uncertainty even though it is more efficient. Wi
Authors
I.-Ming Chou, R.R. Seal, B. S. Hemingway
Sulfur and lead isotope geochemistry of hypogene mineralization at the Barite Hill Gold Deposit, Carolina Slate Belt, southeastern United States: A window into and through regional metamorphism
The Barite Hill gold deposit, at the southwestern end of the Carolina slate belt in the southeastern United States, is one of four gold deposits in the region that have a combined yield of 110 metric tons of gold over the past 10 years. At Barite Hill, production has dominantly come from oxidized ores. Sulfur isotope data from hypogene portions of the Barite Hill gold deposit vary systematically w
Authors
Robert R. Seal, Robert A. Ayuso, Nora K. Foley, Sandra H. B. Clark
The Gibbs free energy of nukundamite (Cu3.38Fe0.62S4): A correction and implications for phase equilibria
The Gibbs free energy of formation of nukundamite (Cu3.38Fe0.62S4) was calculated from published experimental studies of the reaction 3.25 Cu3.38Fe0.62S4 + S2 = 11 CuS + 2 FeS2 in order to correct an erroneous expression in the published record. The correct expression describing the Gibbs free energy of formation (kJ·mol−1) of nukundamite relative to the elements and ideal S2 gas is ΔfG°nukundamit
Authors
Robert R. Seal, E. E. Inan, Bruce S. Hemingway
Stable isotope systematics of sulfate minerals
Stable isotope studies of sulfate minerals are especially useful for unraveling the geochemical history of geological systems. All sulfate minerals can yield sulfur and oxygen isotope data. Hydrous sulfate minerals, such as gypsum, also yield oxygen and hydrogen isotope data for the water of hydration, and more complex sulfate minerals, such as alunite and jarosite also yield oxygen and hydrogen i
Authors
Robert R. Seal, Charles N. Alpers, Robert O. Rye
Environmental processes that affect mineral deposits in the eastern United States
A thorough understanding of the environmental processes that affect mineral deposits and mine wastes has become increasingly important as the Nation wrestles with how to meet our current demand for metals without compromising the environment and how to mitigate the damage caused by the mining practices of previous generations. Regulatory requirements are dominated by empirical approaches to enviro
Authors
Robert R. Seal
Stable isotopes and mineral resource investigations in the United States
The elements oxygen, hydrogen, sulfur, and carbon are important constituents of hydrothermal ore-forming systems and the weathering processes of mineral deposits in the surficial environment. They also play key roles in volcanic activity, ecosystem dynamics, climate change, and hydrologic and atmospheric processes. Therefore, study of the stable isotopes of these elements can provide powerful insi
Authors
Robert R. Seal
Geochemical data including mercury speciation for surface waters at the abandoned Greenwood mine area, Prince William Forest Park, Virginia
No abstract available.
Authors
R.R. Seal, D.P. Haffner, A. L. Meier
Stable isotopes in mid-ocean ridge hydrothermal systems: Interactions between fluids, minerals, and organisms
Studies of abundance variations of light stable isotopes in nature have had a tremendous impact on all aspects of geochemistry since the development, in 1947, of a gas source isotope ratio mass spectrometer capable of measuring small variations in stable isotope ratios (Nice, 1947]. Stable isotope geochemistry is now a mature field, as witnessed by the proliferation of commercially available mass
Authors
Wayne C. Shanks, John K. Böhlke, Robert R. Seal