Michael Pribil - Academia.edu (original) (raw)
Papers by Michael Pribil
Abstracts with programs, 2022
Environmental Toxicology and Chemistry
Historical mining left a legacy of abandoned mines and waste rock in remote headwaters of major r... more Historical mining left a legacy of abandoned mines and waste rock in remote headwaters of major river systems in the western United States. Understanding the influence of these legacy mines on culturally and ecological important downstream ecosystems is not always straight-forward because of elevated natural levels of mineralization in mining-impacted watersheds. To test the ecological effects of historic mining in the headwaters of the upper Salmon River watershed (USA), we measured multiple community and chemical endpoints in downstream linked aquatic-terrestrial food webs. Mining inputs impacted downstream food webs through increased mercury accumulation and decreased insect biodiversity. Total mercury (THg) in seston, aquatic insect larvae, adult aquatic insects, riparian spiders, and fish at sites up to 7.6 km downstream of mining was in much higher concentrations (1.3 to 11.3-fold) and isotopically distinct compared with sites immediately upstream of mining inputs. Methylmercury (MeHg) concentrations in bull trout and riparian spiders were sufficiently high (732 - 918 and 347 - 1,140 ng MeHg g-1 dw) to affect humans, birds, and piscivorous fish. Furthermore, the alpha-diversity of benthic insects was locally depressed by 12-20% within 4.3 to 5.7 km downstream of from the mine. However, because total insect biomass was not affected by mine inputs, the mass of mercury in benthic insects at a site (i.e., ng Hg m-2 ) was extremely elevated downstream (10 - 1,778-fold) compared with directly upstream of mining inputs. Downstream adult aquatic insect-mediated fluxes of total mercury were also high (~16 ng THg m-2 d-1 ). Abandoned mines can have ecologically important effects on downstream communities, including reduced biodiversity and increased mercury flux to higher order consumers, including fish, birds, and humans. This article is protected by copyright. All rights reserved. © 2022 SETAC.
Goldschmidt2022 abstracts, 2022
Gold, mercury, and other metals have been mined in the Salmon River Mountains of Idaho, USA, sinc... more Gold, mercury, and other metals have been mined in the Salmon River Mountains of Idaho, USA, since the early 1900s. The effects of historical mining were assessed using synoptic studies of biogeochemical and fisheries metrics in Sugar Creek and Monumental Creek watersheds. The Cinnabar mine site is at the headwaters of Cinnabar Creek, a tributary to Sugar Creek. Extraction and on-site processing of cinnabar and metacinnabar bearing rock through the 1970s left groundwater-flooded workings and a footprint of tailings. Mercury (Hg) and arsenic (As) were co-contaminants to downstream food webs. Concentrations of 257 ng Hg L-1 and 20.6 µg As L-1 were measured in unfiltered stream water collected approximately 4 km downstream from the Cinnabar mine site. Seston and periphyton acted as reactive biofilms where Hg was methylated. Total Hg accumulated in seston, aquatic insect larvae, adult aquatic insects, riparian spiders, and fish, at much higher concentrations (1.3 to 11.3-fold) with isotopically distinct Hg in downstream sites compared with background. Methylmercury (MeHg) concentrations in bull trout and riparian spiders (732 to 918 and 347 to 1,140 ng MeHg g-1 dry weight, respectively) were at levels concerning for consumption by humans and wildlife. The diversity of benthic insect communities was locally depressed by 12 to 20% immediately downstream of mining inputs with an absence of metal-sensitive sculpin. Monumental Creek, with historical gold mining and a geological Hg background, had Hg concentrations 2 to 3 orders of magnitude lower than in Cinnabar Creek, with eDNA confirming the presence of bull trout and sculpin in all sites. This further shows that the Cinnabar mine site has a magnified impact in the downstream ecosystem of Sugar Creek. Legacy mining activity can have ecologically important effects on downstream communities, including reduced biodiversity and increased mercury exposure of higher order consumers, including fish, birds, and humans.
Geological Society of America Abstracts with Programs
Applied Geochemistry, 2022
The Callahan Zn-Cu-Pb Mine in Brooksville, Maine produced ore enriched in pyrite, chalcopyrite, a... more The Callahan Zn-Cu-Pb Mine in Brooksville, Maine produced ore enriched in pyrite, chalcopyrite, and sphalerite from an open pit in a dammed tidal estuary (Goose Cove) during 1968-1972. The pit was about 180-300 m wide and 97 m deep. The dam was breached in 1972 and the pit filled with seawater. To understand the seasonal hydrodynamics and geochemistry of the pit lake, temperature sensors were deployed at multiple depths and continuous temperature records were obtained from April 2007 to June 2008. The water column was sampled in April and August 2007 and June 2008. Water samples were analyzed for acid-soluble and dissolved constituents, including stable metal isotopes of Cu, Fe, and Zn. Profiles of temperature, dissolved oxygen, and dissolved sulfide indicated that the pit lake is permanently stratified, and that the redox boundary became shallower (from 63 to 47 m) during the study period. Concentrations of dissolved oxygen between 10 and 60 m decreased by 150 µM between the April ...
Microscopy and Microanalysis, 2008
Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New M... more Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Journal of Volcanology and Geothermal Research, 2014
Hyperacidic lakes and associated solfatara in active volcanoes are the expression of magmatic gas... more Hyperacidic lakes and associated solfatara in active volcanoes are the expression of magmatic gas expansion from source to surface. Here we show for the first time, that the vein system that comprises the~2 Ma highsulfidation, Lepanto copper-gold deposit in the Mankayan district (Philippines) was associated with a contemporary hyperacidic volcanic lake complex-possibly the first such lake recognized in the geological record. A 15-20‰ difference in sulfur isotopic composition between barite and sulfides and sulfosalts in the vent fumarole encrustations supports the interpretation that SO 2-rich volcanic gas vented into the base of the lake and marginal to it and ties the mineralization directly to magmatic gas expansion, fracture propagation, and mineralization that occurred through a series of decompression steps within the feeder fracture network. These data confirm that crater lake environments such as Kawah Ijen (Java, Indonesia) provide modern day analogs of the Lepanto and other high sulfidation Cu-Au depositing environments. We also provide extensive analysis of sulfosalt-sulfide reactions during vein formation within the hyperacidic lake complex. Pyrite ± silica deposited first at high temperature followed by enargite that preserves the vapor-solid diffusion of, for example, antimony, tin, and tellurium into the vapor from the crystallizing solid. Subsolidus, intra-crystalline diffusion continued as temperature declined. Pyrite and enargite are replaced by Fe-tennantite in the lodes which initially has low Sb/(Sb + As) atomic ratios around 13.5% close to the ideal tennantite formula, but evolves to higher ratios as crystallization proceeds. Fumarole encrustation clasts and sulfosalts in the lake sediment are more highly evolved with a larger range of trace element substitutions, including antimony. Substitution of especially Zn, Te, Ag, and Sn into tennantite records metal and semi-metal fractionation between the expanding magmatic gas and deposited sulfide sublimates provides a rare insight into the fate of metals and semi-metals in the shallower parts of fracture arrays that feed modern hyperacidic lakes. These data support a growing understanding of the formation of high-sulfidation gold deposits as the consequence of single-phase expansion of gas from magmatic-gas reservoirs beneath the surface of active volcanoes without the intervention of a later aqueous fluid including groundwater. Aggressive sulfide-sulfosalt reactions, including pitting and the almost complete dissolution of earlier minerals, are persistent characteristics of the vein assemblages and precious metals typically occur late in pits or along brittle fractures. These characteristics support a hypothesis of mineral deposition at temperatures of the order of 600°C in contrast to available fluid inclusion data from enargite that record temperatures following phase transitions in the sulfosalt during the retrograde devolution of the deposit in the presence of groundwater.
Chemical Geology, 2010
An increased interest in high precision Cu isotope ratio measurements using multi-collector induc... more An increased interest in high precision Cu isotope ratio measurements using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) has developed recently for various natural geologic systems and environmental applications, these typically contain high concentrations of sulfur, particularly in the form of sulfate (SO 4 2−) and sulfide (S). For example, Cu, Fe, and Zn concentrations in acid mine drainage (AMD) can range from 100 µg/L to greater than 50 mg/L with sulfur species concentrations reaching greater than 1000 mg/L. Routine separation of Cu, Fe and Zn from AMD, Cu-sulfide minerals and other geological matrices usually incorporates single anion exchange resin column chromatography for metal separation. During chromatographic separation, variable breakthrough of SO 4 2− during anion exchange resin column chromatography into the Cu fractions was observed as a function of the initial sulfur to Cu ratio, column properties, and the sample matrix. SO 4 2− present in the Cu fraction can form a polyatomic 32 S-14 N-16 O-1 H species causing a direct mass interference with 63 Cu and producing artificially light δ 65 Cu values. Here we report the extent of the mass interference caused by SO 4 2− breakthrough when measuring δ 65 Cu on natural samples and NIST SRM 976 Cu isotope spiked with SO 4 2− after both single anion column chromatography and double anion column chromatography. A set of five 100 µg/L Cu SRM 976 samples spiked with 500 mg/L SO 4 2− resulted in an average δ 65 Cu of − 3.50‰ ± 5.42‰ following single anion column separation with variable SO 4 2− breakthrough but an average concentration of 770 µg/L. Following double anion column separation, the average SO 4 2− concentration of 13 µg/L resulted in better precision and accuracy for the measured δ 65 Cu value of 0.01‰ ± 0.02‰ relative to the expected 0‰ for SRM 976. We conclude that attention to SO 4 2− breakthrough on sulfur-rich samples is necessary for accurate and precise measurements of δ 65 Cu and may require the use of a double ion exchange column procedure.
Applied Geochemistry, 2013
Concentrations and isotopic compositions of Hg and Pb were measured in a sediment core collected ... more Concentrations and isotopic compositions of Hg and Pb were measured in a sediment core collected from Lake Ballinger, near Seattle, Washington, USA. Lake Ballinger has been affected by input of metal contaminants emitted from the Tacoma smelter, which operated from 1887 to 1986 and was located about 53 km south of the lake. Concentrations and loadings of Hg and Pb in Lake Ballinger increased by as much as three orders of magnitude during the period of smelting as compared to the pre-smelting period. Concentrations and loadings of Hg and Pb then decreased by about 55% and 75%, respectively, after smelting ended. Isotopic compositions of Hg changed considerably during the period of smelting (d 202 Hg = À2.29‰ to À0.38‰, mean À1.23‰, n = 9) compared to the pre-smelting period (d 202 Hg = À2.91‰ to À2.50‰, mean À2.75‰, n = 4). Variations were also observed in 206 Pb/ 207 Pb and 208 Pb/ 207 Pb isotopic compositions during these periods. Data for D 199 Hg and D 201 Hg indicate mass independent fractionation (MIF) of Hg isotopes in Lake Ballinger sediment during the smelting and post-smelting period and suggest MIF in the ore smelted, during the smelting process, or chemical modification at some point in the past. Negative values for D 199 Hg and D 201 Hg for the pre-smelting period are similar to those previously reported for soil, peat, and lichen, likely suggesting some component of atmospheric Hg. Variations in the concentrations and isotopic compositions of Hg and Pb were useful in tracing contaminant sources and the understanding of the depositional history of sedimentation in Lake Ballinger.
Applied Geochemistry, 2014
Abstract Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil sampl... more Abstract Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil samples were used to investigate the potential for off-site air transport of Pb from a former white Pb processing facility to neighboring residential homes in a six block area on Staten Island, NY. Surface and subsurface soil samples collected on the Jewett White Pb site were found to range from 1.122 to 1.138 for 206Pb/207Pb and 2.393 to 2.411 for 208Pb/207Pb. The off-site surface soil samples collected from residential backyards, train trestle, near site grass patches and background areas varied from 1.144 to 1.196 for 206Pb/207Pb and 2.427 to 2.464 for 208Pb/207Pb. Two soil samples collected along Richmond Terrace, where Jewett site soils accumulated after major rain events, varied from 1.136 to 1.147 for 206Pb/207Pb and 2.407 to 2.419 for 208Pb/207Pb. Lead concentration for on-site surface soil samples ranged from 450 to 8000 ug/g, on-site subsurface soil samples ranged from 90,000 to 240,000 ug/g and off-site samples varied from 380 to 3500 ug/g. Lead concentration and isotopic composition for the Staten Island off-site samples were similar to previously published data for other northeastern US cities and reflect re-suspension and re-mobilization of local accumulated Pb. The considerable differences in both the Pb isotopic composition and Pb concentration of on-site and off-site samples resulted in the ability to geochemically trace the transport of particulate Pb. Data in this study indicate minimal off-site surface transport of Pb from the Jewett site into the neighboring residential area.
ABSTRACT Chemical weathering of geological materials is a primary process affecting landscape dev... more ABSTRACT Chemical weathering of geological materials is a primary process affecting landscape development. Hydrochemical examination of 97 rivers and streams along a ~400 km transect across Panama from the Bayano region in the east to the Costa Rica border in the west documents large variations, e.g. SPC = 38-2924 mS/cm, Si = 0.005-3.02 mM & Ca/Mg = 0.68-5.32 for large streams and rivers compared to SPC = 32-1736 mS/cm, Si = 0.011-1.601 mM, & Ca/Mg = 0.66-33.7 for soil seeps and small streams. Watershed lithology exerts the major control on riverine chemistry, as illustrated by two adjacent watersheds in central Panama. The Rio Pacora watershed (374 km2) is predominantly composed of mafic bedrocks consisting of Late Cretaceous gabbro and diorite, as compared to the Rio Chagres watershed (580 km2) which is developed on more a compositionally and lithologically varied bedrock that ranges from hydrothermally altered Late Cretaceous igneous lithologies (gabbro to granite, basalt to dacite) and Mid-Tertiary volcanic rocks. In order to better determine the rocks/minerals undergoing weathering in each watershed, 20 samples from soil seeps and low-order headwater streams to the main stem rivers were analyzed for their 87Sr/86Sr signatures and compared to bedrock compositions. Data for the two watersheds form a linear trend on a 87Sr/86Sr versus 1/Sr plot, with no difference observed between the soil seeps, headwater streams, and main channel river waters. Rio Chagres waters are enriched in 87Sr and depleted in Sr and also have lower TDS levels and Ca/Mg ratios compared to Rio Pacora waters, clearly documenting lithologic control on water chemistry throughout the two watersheds. Less-radiogenic Sr-isotope water ratios are equivalent to values measured for the least-altered rocks in the two watersheds, whereas the more radiogenic values suggest an input from weathering of minerals produced via early post-deposition alteration of volcanic lithologies by seawater.
Water and sediment samples were collected by the U.S. Geological Survey in cooperation with the U... more Water and sediment samples were collected by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency at or near baseflow conditions from 2015-2017 in the East Fork South Fork Salmon River watershed near Yellow Pine, Valley County, Idaho. Soil, rock and tailings samples were collected in June 2015. Sampling focused on Cinnabar Creek, which flows through the Cinnabar mine site, and Sugar Creek, with additional sites selected to place the data into a larger watershed context. Grab samples were taken of the snowpack in January 2017. The water, soil, sediment, and rock samples were as described and the results are presented as separate water and solid data sets.
The isotopic composition of Pb in fugitive dust suspended by a vehicle from 13 unsurfaced roads i... more The isotopic composition of Pb in fugitive dust suspended by a vehicle from 13 unsurfaced roads in Missouri was measured to identify the source of Pb within an established long-term mining area. A three end member model using 207Pb/206Pb and concentration as tracers resulted in fugitive dust samples plotting in the mixing field of well characterized heterogeneous end members. End members selected for this investigation include the 207Pb/206Pb for 1) a Pb-mixture representing mine tailings, 2) aerosol Pb impacted soils within close proximity to the Buick secondary recycling smelter, and 3) an average of soils, rock cores and drill cuttings representing the background characteristics. Aqua regia total concentrations and 207Pb/206Pb of mining area dust suggest that 35.4- 84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1 to 52.7% is associated with the smelter mixture, and 0 to 21.6% is associated with background materials. Isotope ratios varied minimally ...
Geographic Information Systems, spatial data management, and petroleum-generation
Geological Society of America Abstracts with Programs
Abstracts with programs, 2022
Environmental Toxicology and Chemistry
Historical mining left a legacy of abandoned mines and waste rock in remote headwaters of major r... more Historical mining left a legacy of abandoned mines and waste rock in remote headwaters of major river systems in the western United States. Understanding the influence of these legacy mines on culturally and ecological important downstream ecosystems is not always straight-forward because of elevated natural levels of mineralization in mining-impacted watersheds. To test the ecological effects of historic mining in the headwaters of the upper Salmon River watershed (USA), we measured multiple community and chemical endpoints in downstream linked aquatic-terrestrial food webs. Mining inputs impacted downstream food webs through increased mercury accumulation and decreased insect biodiversity. Total mercury (THg) in seston, aquatic insect larvae, adult aquatic insects, riparian spiders, and fish at sites up to 7.6 km downstream of mining was in much higher concentrations (1.3 to 11.3-fold) and isotopically distinct compared with sites immediately upstream of mining inputs. Methylmercury (MeHg) concentrations in bull trout and riparian spiders were sufficiently high (732 - 918 and 347 - 1,140 ng MeHg g-1 dw) to affect humans, birds, and piscivorous fish. Furthermore, the alpha-diversity of benthic insects was locally depressed by 12-20% within 4.3 to 5.7 km downstream of from the mine. However, because total insect biomass was not affected by mine inputs, the mass of mercury in benthic insects at a site (i.e., ng Hg m-2 ) was extremely elevated downstream (10 - 1,778-fold) compared with directly upstream of mining inputs. Downstream adult aquatic insect-mediated fluxes of total mercury were also high (~16 ng THg m-2 d-1 ). Abandoned mines can have ecologically important effects on downstream communities, including reduced biodiversity and increased mercury flux to higher order consumers, including fish, birds, and humans. This article is protected by copyright. All rights reserved. © 2022 SETAC.
Goldschmidt2022 abstracts, 2022
Gold, mercury, and other metals have been mined in the Salmon River Mountains of Idaho, USA, sinc... more Gold, mercury, and other metals have been mined in the Salmon River Mountains of Idaho, USA, since the early 1900s. The effects of historical mining were assessed using synoptic studies of biogeochemical and fisheries metrics in Sugar Creek and Monumental Creek watersheds. The Cinnabar mine site is at the headwaters of Cinnabar Creek, a tributary to Sugar Creek. Extraction and on-site processing of cinnabar and metacinnabar bearing rock through the 1970s left groundwater-flooded workings and a footprint of tailings. Mercury (Hg) and arsenic (As) were co-contaminants to downstream food webs. Concentrations of 257 ng Hg L-1 and 20.6 µg As L-1 were measured in unfiltered stream water collected approximately 4 km downstream from the Cinnabar mine site. Seston and periphyton acted as reactive biofilms where Hg was methylated. Total Hg accumulated in seston, aquatic insect larvae, adult aquatic insects, riparian spiders, and fish, at much higher concentrations (1.3 to 11.3-fold) with isotopically distinct Hg in downstream sites compared with background. Methylmercury (MeHg) concentrations in bull trout and riparian spiders (732 to 918 and 347 to 1,140 ng MeHg g-1 dry weight, respectively) were at levels concerning for consumption by humans and wildlife. The diversity of benthic insect communities was locally depressed by 12 to 20% immediately downstream of mining inputs with an absence of metal-sensitive sculpin. Monumental Creek, with historical gold mining and a geological Hg background, had Hg concentrations 2 to 3 orders of magnitude lower than in Cinnabar Creek, with eDNA confirming the presence of bull trout and sculpin in all sites. This further shows that the Cinnabar mine site has a magnified impact in the downstream ecosystem of Sugar Creek. Legacy mining activity can have ecologically important effects on downstream communities, including reduced biodiversity and increased mercury exposure of higher order consumers, including fish, birds, and humans.
Geological Society of America Abstracts with Programs
Applied Geochemistry, 2022
The Callahan Zn-Cu-Pb Mine in Brooksville, Maine produced ore enriched in pyrite, chalcopyrite, a... more The Callahan Zn-Cu-Pb Mine in Brooksville, Maine produced ore enriched in pyrite, chalcopyrite, and sphalerite from an open pit in a dammed tidal estuary (Goose Cove) during 1968-1972. The pit was about 180-300 m wide and 97 m deep. The dam was breached in 1972 and the pit filled with seawater. To understand the seasonal hydrodynamics and geochemistry of the pit lake, temperature sensors were deployed at multiple depths and continuous temperature records were obtained from April 2007 to June 2008. The water column was sampled in April and August 2007 and June 2008. Water samples were analyzed for acid-soluble and dissolved constituents, including stable metal isotopes of Cu, Fe, and Zn. Profiles of temperature, dissolved oxygen, and dissolved sulfide indicated that the pit lake is permanently stratified, and that the redox boundary became shallower (from 63 to 47 m) during the study period. Concentrations of dissolved oxygen between 10 and 60 m decreased by 150 µM between the April ...
Microscopy and Microanalysis, 2008
Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New M... more Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008
Journal of Volcanology and Geothermal Research, 2014
Hyperacidic lakes and associated solfatara in active volcanoes are the expression of magmatic gas... more Hyperacidic lakes and associated solfatara in active volcanoes are the expression of magmatic gas expansion from source to surface. Here we show for the first time, that the vein system that comprises the~2 Ma highsulfidation, Lepanto copper-gold deposit in the Mankayan district (Philippines) was associated with a contemporary hyperacidic volcanic lake complex-possibly the first such lake recognized in the geological record. A 15-20‰ difference in sulfur isotopic composition between barite and sulfides and sulfosalts in the vent fumarole encrustations supports the interpretation that SO 2-rich volcanic gas vented into the base of the lake and marginal to it and ties the mineralization directly to magmatic gas expansion, fracture propagation, and mineralization that occurred through a series of decompression steps within the feeder fracture network. These data confirm that crater lake environments such as Kawah Ijen (Java, Indonesia) provide modern day analogs of the Lepanto and other high sulfidation Cu-Au depositing environments. We also provide extensive analysis of sulfosalt-sulfide reactions during vein formation within the hyperacidic lake complex. Pyrite ± silica deposited first at high temperature followed by enargite that preserves the vapor-solid diffusion of, for example, antimony, tin, and tellurium into the vapor from the crystallizing solid. Subsolidus, intra-crystalline diffusion continued as temperature declined. Pyrite and enargite are replaced by Fe-tennantite in the lodes which initially has low Sb/(Sb + As) atomic ratios around 13.5% close to the ideal tennantite formula, but evolves to higher ratios as crystallization proceeds. Fumarole encrustation clasts and sulfosalts in the lake sediment are more highly evolved with a larger range of trace element substitutions, including antimony. Substitution of especially Zn, Te, Ag, and Sn into tennantite records metal and semi-metal fractionation between the expanding magmatic gas and deposited sulfide sublimates provides a rare insight into the fate of metals and semi-metals in the shallower parts of fracture arrays that feed modern hyperacidic lakes. These data support a growing understanding of the formation of high-sulfidation gold deposits as the consequence of single-phase expansion of gas from magmatic-gas reservoirs beneath the surface of active volcanoes without the intervention of a later aqueous fluid including groundwater. Aggressive sulfide-sulfosalt reactions, including pitting and the almost complete dissolution of earlier minerals, are persistent characteristics of the vein assemblages and precious metals typically occur late in pits or along brittle fractures. These characteristics support a hypothesis of mineral deposition at temperatures of the order of 600°C in contrast to available fluid inclusion data from enargite that record temperatures following phase transitions in the sulfosalt during the retrograde devolution of the deposit in the presence of groundwater.
Chemical Geology, 2010
An increased interest in high precision Cu isotope ratio measurements using multi-collector induc... more An increased interest in high precision Cu isotope ratio measurements using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) has developed recently for various natural geologic systems and environmental applications, these typically contain high concentrations of sulfur, particularly in the form of sulfate (SO 4 2−) and sulfide (S). For example, Cu, Fe, and Zn concentrations in acid mine drainage (AMD) can range from 100 µg/L to greater than 50 mg/L with sulfur species concentrations reaching greater than 1000 mg/L. Routine separation of Cu, Fe and Zn from AMD, Cu-sulfide minerals and other geological matrices usually incorporates single anion exchange resin column chromatography for metal separation. During chromatographic separation, variable breakthrough of SO 4 2− during anion exchange resin column chromatography into the Cu fractions was observed as a function of the initial sulfur to Cu ratio, column properties, and the sample matrix. SO 4 2− present in the Cu fraction can form a polyatomic 32 S-14 N-16 O-1 H species causing a direct mass interference with 63 Cu and producing artificially light δ 65 Cu values. Here we report the extent of the mass interference caused by SO 4 2− breakthrough when measuring δ 65 Cu on natural samples and NIST SRM 976 Cu isotope spiked with SO 4 2− after both single anion column chromatography and double anion column chromatography. A set of five 100 µg/L Cu SRM 976 samples spiked with 500 mg/L SO 4 2− resulted in an average δ 65 Cu of − 3.50‰ ± 5.42‰ following single anion column separation with variable SO 4 2− breakthrough but an average concentration of 770 µg/L. Following double anion column separation, the average SO 4 2− concentration of 13 µg/L resulted in better precision and accuracy for the measured δ 65 Cu value of 0.01‰ ± 0.02‰ relative to the expected 0‰ for SRM 976. We conclude that attention to SO 4 2− breakthrough on sulfur-rich samples is necessary for accurate and precise measurements of δ 65 Cu and may require the use of a double ion exchange column procedure.
Applied Geochemistry, 2013
Concentrations and isotopic compositions of Hg and Pb were measured in a sediment core collected ... more Concentrations and isotopic compositions of Hg and Pb were measured in a sediment core collected from Lake Ballinger, near Seattle, Washington, USA. Lake Ballinger has been affected by input of metal contaminants emitted from the Tacoma smelter, which operated from 1887 to 1986 and was located about 53 km south of the lake. Concentrations and loadings of Hg and Pb in Lake Ballinger increased by as much as three orders of magnitude during the period of smelting as compared to the pre-smelting period. Concentrations and loadings of Hg and Pb then decreased by about 55% and 75%, respectively, after smelting ended. Isotopic compositions of Hg changed considerably during the period of smelting (d 202 Hg = À2.29‰ to À0.38‰, mean À1.23‰, n = 9) compared to the pre-smelting period (d 202 Hg = À2.91‰ to À2.50‰, mean À2.75‰, n = 4). Variations were also observed in 206 Pb/ 207 Pb and 208 Pb/ 207 Pb isotopic compositions during these periods. Data for D 199 Hg and D 201 Hg indicate mass independent fractionation (MIF) of Hg isotopes in Lake Ballinger sediment during the smelting and post-smelting period and suggest MIF in the ore smelted, during the smelting process, or chemical modification at some point in the past. Negative values for D 199 Hg and D 201 Hg for the pre-smelting period are similar to those previously reported for soil, peat, and lichen, likely suggesting some component of atmospheric Hg. Variations in the concentrations and isotopic compositions of Hg and Pb were useful in tracing contaminant sources and the understanding of the depositional history of sedimentation in Lake Ballinger.
Applied Geochemistry, 2014
Abstract Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil sampl... more Abstract Lead (Pb) concentration and Pb isotopic composition of surface and subsurface soil samples were used to investigate the potential for off-site air transport of Pb from a former white Pb processing facility to neighboring residential homes in a six block area on Staten Island, NY. Surface and subsurface soil samples collected on the Jewett White Pb site were found to range from 1.122 to 1.138 for 206Pb/207Pb and 2.393 to 2.411 for 208Pb/207Pb. The off-site surface soil samples collected from residential backyards, train trestle, near site grass patches and background areas varied from 1.144 to 1.196 for 206Pb/207Pb and 2.427 to 2.464 for 208Pb/207Pb. Two soil samples collected along Richmond Terrace, where Jewett site soils accumulated after major rain events, varied from 1.136 to 1.147 for 206Pb/207Pb and 2.407 to 2.419 for 208Pb/207Pb. Lead concentration for on-site surface soil samples ranged from 450 to 8000 ug/g, on-site subsurface soil samples ranged from 90,000 to 240,000 ug/g and off-site samples varied from 380 to 3500 ug/g. Lead concentration and isotopic composition for the Staten Island off-site samples were similar to previously published data for other northeastern US cities and reflect re-suspension and re-mobilization of local accumulated Pb. The considerable differences in both the Pb isotopic composition and Pb concentration of on-site and off-site samples resulted in the ability to geochemically trace the transport of particulate Pb. Data in this study indicate minimal off-site surface transport of Pb from the Jewett site into the neighboring residential area.
ABSTRACT Chemical weathering of geological materials is a primary process affecting landscape dev... more ABSTRACT Chemical weathering of geological materials is a primary process affecting landscape development. Hydrochemical examination of 97 rivers and streams along a ~400 km transect across Panama from the Bayano region in the east to the Costa Rica border in the west documents large variations, e.g. SPC = 38-2924 mS/cm, Si = 0.005-3.02 mM & Ca/Mg = 0.68-5.32 for large streams and rivers compared to SPC = 32-1736 mS/cm, Si = 0.011-1.601 mM, & Ca/Mg = 0.66-33.7 for soil seeps and small streams. Watershed lithology exerts the major control on riverine chemistry, as illustrated by two adjacent watersheds in central Panama. The Rio Pacora watershed (374 km2) is predominantly composed of mafic bedrocks consisting of Late Cretaceous gabbro and diorite, as compared to the Rio Chagres watershed (580 km2) which is developed on more a compositionally and lithologically varied bedrock that ranges from hydrothermally altered Late Cretaceous igneous lithologies (gabbro to granite, basalt to dacite) and Mid-Tertiary volcanic rocks. In order to better determine the rocks/minerals undergoing weathering in each watershed, 20 samples from soil seeps and low-order headwater streams to the main stem rivers were analyzed for their 87Sr/86Sr signatures and compared to bedrock compositions. Data for the two watersheds form a linear trend on a 87Sr/86Sr versus 1/Sr plot, with no difference observed between the soil seeps, headwater streams, and main channel river waters. Rio Chagres waters are enriched in 87Sr and depleted in Sr and also have lower TDS levels and Ca/Mg ratios compared to Rio Pacora waters, clearly documenting lithologic control on water chemistry throughout the two watersheds. Less-radiogenic Sr-isotope water ratios are equivalent to values measured for the least-altered rocks in the two watersheds, whereas the more radiogenic values suggest an input from weathering of minerals produced via early post-deposition alteration of volcanic lithologies by seawater.
Water and sediment samples were collected by the U.S. Geological Survey in cooperation with the U... more Water and sediment samples were collected by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency at or near baseflow conditions from 2015-2017 in the East Fork South Fork Salmon River watershed near Yellow Pine, Valley County, Idaho. Soil, rock and tailings samples were collected in June 2015. Sampling focused on Cinnabar Creek, which flows through the Cinnabar mine site, and Sugar Creek, with additional sites selected to place the data into a larger watershed context. Grab samples were taken of the snowpack in January 2017. The water, soil, sediment, and rock samples were as described and the results are presented as separate water and solid data sets.
The isotopic composition of Pb in fugitive dust suspended by a vehicle from 13 unsurfaced roads i... more The isotopic composition of Pb in fugitive dust suspended by a vehicle from 13 unsurfaced roads in Missouri was measured to identify the source of Pb within an established long-term mining area. A three end member model using 207Pb/206Pb and concentration as tracers resulted in fugitive dust samples plotting in the mixing field of well characterized heterogeneous end members. End members selected for this investigation include the 207Pb/206Pb for 1) a Pb-mixture representing mine tailings, 2) aerosol Pb impacted soils within close proximity to the Buick secondary recycling smelter, and 3) an average of soils, rock cores and drill cuttings representing the background characteristics. Aqua regia total concentrations and 207Pb/206Pb of mining area dust suggest that 35.4- 84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1 to 52.7% is associated with the smelter mixture, and 0 to 21.6% is associated with background materials. Isotope ratios varied minimally ...
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Geological Society of America Abstracts with Programs