Carma A San Juan
Carma San Juan is a Physical Scientist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 18
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Filter Total Items: 31
Reconnaissance of weathering rates in alpine catchments of central Colorado, USA Reconnaissance of weathering rates in alpine catchments of central Colorado, USA
No abstract available.
Authors
R.E. Wanty, P. L. Verplanck, C. Bern, T. Todoro, C. San Juan, E.H. deWitt, T. L. Klein, D. Fey, T.S. Schmidt, S. E. Church
Development of a new toxic-unit model for the bioassessment of metals in streams Development of a new toxic-unit model for the bioassessment of metals in streams
Two toxic-unit models that estimate the toxicity of trace-metal mixtures to benthic communities were compared. The chronic criterion accumulation ratio (CCAR), a modification of biotic ligand model (BLM) outputs for use as a toxic-unit model, accounts for the modifying and competitive influences of major cations (Ca2+, Mg2+, Na+, K+, H+), anions (HCO3−, CO32−,SO42−, Cl−, S2−) and...
Authors
Travis S. Schmidt, W.H. Clements, K.A. Mitchell, Stanley E. Church, Richard B. Wanty, David L. Fey, Philip L. Verplanck, Carma A. San Juan
Environmental effects of hydrothermal alteration and historical mining on water and sediment quality in Central Colorado Environmental effects of hydrothermal alteration and historical mining on water and sediment quality in Central Colorado
The U.S. Geological Survey conducted an environmental assessment of 198 catchments in a 54,000-km2 area of central Colorado, much of which is on Federal land. The Colorado Mineral Belt, a northeast-trending zone of historical base- and precious-metal mining, cuts diagonally across the study area. The investigation was intended to test the hypothesis that degraded water and sediment...
Authors
S. E. Church, D. L. Fey, T. L. Klein, T.S. Schmidt, R. B. Wanty, E.H. deWitt, B.W. Rockwell, Juan C.A. San
Geochemistry of surface water in alpine catchments in central Colorado, USA: Resolving host-rock effects at different spatial scales Geochemistry of surface water in alpine catchments in central Colorado, USA: Resolving host-rock effects at different spatial scales
The US Geological Survey is conducting a study of surface-water quality in the Rocky Mountains of central Colorado, an area of approximately 55,000 km2. Using new and existing geologic maps, the more than 200 rock formations represented in the area were arranged into 17 groups based on lithologic similarity. The dominant regional geologic feature affecting water quality in central...
Authors
R. B. Wanty, P. L. Verplanck, Juan C.A. San, S. E. Church, T.S. Schmidt, D.L. Fey, E.H. deWitt, T. L. Klein
Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining
Stream water and sediment toxicity to aquatic insects were quantified from central Colorado catchments to distinguish the effect of geologic processes which result in high background metals concentrations from historical mining. Our sampling design targeted small catchments underlain by rocks of a single lithology, which allowed the development of biological and geochemical baselines...
Authors
T.S. Schmidt, S. E. Church, W.H. Clements, K.A. Mitchell, D. L. Fey, R. B. Wanty, P. L. Verplanck, Juan C.A. San, T. L. Klein, E.H. deWitt, B.W. Rockwell
Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries
Large amounts of limestone fines co-produced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point sources such as cement manufacturing. AWL reactants are readily available, inexpensive...
Authors
William H. Langer, Carma A. San Juan, Greg H. Rau, Ken Caldeira
Science and Products
Filter Total Items: 18
No Result Found
Filter Total Items: 31
Reconnaissance of weathering rates in alpine catchments of central Colorado, USA Reconnaissance of weathering rates in alpine catchments of central Colorado, USA
No abstract available.
Authors
R.E. Wanty, P. L. Verplanck, C. Bern, T. Todoro, C. San Juan, E.H. deWitt, T. L. Klein, D. Fey, T.S. Schmidt, S. E. Church
Development of a new toxic-unit model for the bioassessment of metals in streams Development of a new toxic-unit model for the bioassessment of metals in streams
Two toxic-unit models that estimate the toxicity of trace-metal mixtures to benthic communities were compared. The chronic criterion accumulation ratio (CCAR), a modification of biotic ligand model (BLM) outputs for use as a toxic-unit model, accounts for the modifying and competitive influences of major cations (Ca2+, Mg2+, Na+, K+, H+), anions (HCO3−, CO32−,SO42−, Cl−, S2−) and...
Authors
Travis S. Schmidt, W.H. Clements, K.A. Mitchell, Stanley E. Church, Richard B. Wanty, David L. Fey, Philip L. Verplanck, Carma A. San Juan
Environmental effects of hydrothermal alteration and historical mining on water and sediment quality in Central Colorado Environmental effects of hydrothermal alteration and historical mining on water and sediment quality in Central Colorado
The U.S. Geological Survey conducted an environmental assessment of 198 catchments in a 54,000-km2 area of central Colorado, much of which is on Federal land. The Colorado Mineral Belt, a northeast-trending zone of historical base- and precious-metal mining, cuts diagonally across the study area. The investigation was intended to test the hypothesis that degraded water and sediment...
Authors
S. E. Church, D. L. Fey, T. L. Klein, T.S. Schmidt, R. B. Wanty, E.H. deWitt, B.W. Rockwell, Juan C.A. San
Geochemistry of surface water in alpine catchments in central Colorado, USA: Resolving host-rock effects at different spatial scales Geochemistry of surface water in alpine catchments in central Colorado, USA: Resolving host-rock effects at different spatial scales
The US Geological Survey is conducting a study of surface-water quality in the Rocky Mountains of central Colorado, an area of approximately 55,000 km2. Using new and existing geologic maps, the more than 200 rock formations represented in the area were arranged into 17 groups based on lithologic similarity. The dominant regional geologic feature affecting water quality in central...
Authors
R. B. Wanty, P. L. Verplanck, Juan C.A. San, S. E. Church, T.S. Schmidt, D.L. Fey, E.H. deWitt, T. L. Klein
Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining Aquatic ecosystems in Central Colorado are influenced by mineral forming processes and historical mining
Stream water and sediment toxicity to aquatic insects were quantified from central Colorado catchments to distinguish the effect of geologic processes which result in high background metals concentrations from historical mining. Our sampling design targeted small catchments underlain by rocks of a single lithology, which allowed the development of biological and geochemical baselines...
Authors
T.S. Schmidt, S. E. Church, W.H. Clements, K.A. Mitchell, D. L. Fey, R. B. Wanty, P. L. Verplanck, Juan C.A. San, T. L. Klein, E.H. deWitt, B.W. Rockwell
Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries
Large amounts of limestone fines co-produced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point sources such as cement manufacturing. AWL reactants are readily available, inexpensive...
Authors
William H. Langer, Carma A. San Juan, Greg H. Rau, Ken Caldeira