Aqueous Crystal Growth and Dissolution Kinetics of Calcium Carbonate Minerals at the Amarigosa Desert Research Site, Nevada
The USGS studies calcium carbonate mineral reactions in soils at the Amarigosa Desert Research Site (ADRS) near Beatty, Nevada, in order to better understand carbon dioxide transport to and from the soil surface, as well as sequestration of toxic elements in the soil.
Calcium Carbonate Reactions in Arid Soils at the Amargosa Desert Research Site (ADRS) Located Near Beatty, Nevada
Carbonate mineral reaction in ADRS soils is examined to identify surface-soil carbonate crusts and other soil carbonate features participating in carbon dioxide transport to and from the soil surface, and sequestration of toxic elements such as arsenic, strontium-90, and uranium. WEBMOD, which simulates hydrologic fluxes and solute concentrations using process modules coupled within the United States Geological Survey (USGS) Modular Modeling System (MMS), is used for modeling carbonate mineral reaction at the ADRS, broadening plot-scale studies to landscapes. ADRS plot photographs and surveys of carbonate encrusted surface rock are also done.
Surveys at ADRS identify carbonate reactions participating in carbon dioxide transport to and from the soil surface and contaminant sequestration. Measurements of single crystals at the ADRS Grid Area include: weight and dimension changes, repeat macro photography, and Environmental Scanning Electron Microscopy (ESEM).
Calcite single crystals, under glass domes at ADRS study plots, characterize calcite crystal reactivity in the absence of wind, and reduced water vapor transport from the soil surface. Grid plot photographs and crystal macro photographs document changes in carbonate crust occurrence at two grid locations over time. Calcium ion release rate from volcanic rock at ADRS study plots are examined to determine their contribution to calcium carbonate mineral reaction.
On-site measurements of calcium carbonate single crystals (surrogates for soil carbonate crusts) at two grid locations assess carbonate mineral reactivity in ADRS surface soils.
Measurements of single crystal weight changes show that crystals have not had a statistically significant weight change over a 21 month exposure, suggesting that measureable calcium carbonate crust development occurs at long time scales and/or occurs preferentially on volcanic substrates.
ADRS rock crusts were also examined by (ESEM) with Energy Dispersive X-ray Analysis (EDXA). This examination demonstrated each crust exhibits complex mineral morphology and chemical composition.
Aqueous Crystal Growth and Dissolution Kinetics of Earth Surface Materials
The USGS studies calcium carbonate mineral reactions in soils at the Amarigosa Desert Research Site (ADRS) near Beatty, Nevada, in order to better understand carbon dioxide transport to and from the soil surface, as well as sequestration of toxic elements in the soil.
Calcium Carbonate Reactions in Arid Soils at the Amargosa Desert Research Site (ADRS) Located Near Beatty, Nevada
Carbonate mineral reaction in ADRS soils is examined to identify surface-soil carbonate crusts and other soil carbonate features participating in carbon dioxide transport to and from the soil surface, and sequestration of toxic elements such as arsenic, strontium-90, and uranium. WEBMOD, which simulates hydrologic fluxes and solute concentrations using process modules coupled within the United States Geological Survey (USGS) Modular Modeling System (MMS), is used for modeling carbonate mineral reaction at the ADRS, broadening plot-scale studies to landscapes. ADRS plot photographs and surveys of carbonate encrusted surface rock are also done.
Surveys at ADRS identify carbonate reactions participating in carbon dioxide transport to and from the soil surface and contaminant sequestration. Measurements of single crystals at the ADRS Grid Area include: weight and dimension changes, repeat macro photography, and Environmental Scanning Electron Microscopy (ESEM).
Calcite single crystals, under glass domes at ADRS study plots, characterize calcite crystal reactivity in the absence of wind, and reduced water vapor transport from the soil surface. Grid plot photographs and crystal macro photographs document changes in carbonate crust occurrence at two grid locations over time. Calcium ion release rate from volcanic rock at ADRS study plots are examined to determine their contribution to calcium carbonate mineral reaction.
On-site measurements of calcium carbonate single crystals (surrogates for soil carbonate crusts) at two grid locations assess carbonate mineral reactivity in ADRS surface soils.
Measurements of single crystal weight changes show that crystals have not had a statistically significant weight change over a 21 month exposure, suggesting that measureable calcium carbonate crust development occurs at long time scales and/or occurs preferentially on volcanic substrates.
ADRS rock crusts were also examined by (ESEM) with Energy Dispersive X-ray Analysis (EDXA). This examination demonstrated each crust exhibits complex mineral morphology and chemical composition.