Joseph R. Graney

Isotopic record of lead pollution in lake sediments from the northeastern United States

Abstract Although it is common knowledge that Pb concentrations have increased in lake sediments in the northeastern United States over the last 150 years, the processes responsible have been the subject of debate. In this study, differences in lead isotopic compositions and concentrations in sediment from large lakes (Lake Erie, Ontario, and Michigan) and small ones (Deep Lake and Lake Andrus) are used to infer temporal changes in the source(s) of anthropogenic Pb in the Great Lakes region. A natural (background) component of Pb is present in sediment deposited prior to 1860 in Lake Erie and the other lakes as indicated from low Pb concentrations and uniform lead isotopic compositions. Changes in isotopic ratios of lake sediment reflect differing sources of anthropogenic Pb superimposed on the natural component such as regional deforestation from 1860–1890 followed by coal combustion and ore smelting through 1930. Combustion of leaded gasoline was the dominant anthropogenic Pb source to the atmosphere (and by inference to lake sediment) from 1930–1980. Temporal changes in lead isotopic compositions in lake sediment suggest that the source of the Pb used in gasoline additives gradually changed from 1930 to present. The best example is a distinct shift in lead isotopic ratios in lake sediment deposited after 1970 which corresponds to increased Pb production from the Viburnum Trend deposits in Missouri (present in all lakes except Ontario). However, the changes in lead isotopic compositions are much less variable than and do not parallel those calculated on the basis of annual United States mine production and imports. Rather, anthropogenic recycling of Pb as well as natural mixing processes during emission, transport, and deposition of Pb in lake sediment control most of the variation in lead isotope ratios. Differences in lead isotopic ratios in Lake Michigan, Erie, and Deep Lake sediment preserve regional differences in lead isotopic ratios from U.S. and Canadian sources first noted in aerosols by Sturges and Barrie (1987). More localized sources of Pb (such as point discharges) are needed to explain the results from Lake Ontario and Andrus.

An investigation of source–receptor relationships for mercury in south Florida using event precipitation data

A recent pilot study suggested that local anthropogenic sources may play an important role in the atmospheric deposition of mercury (Hg) in South Florida. To examine the potential impacts of these local anthropogenic sources of Hg, the South Florida Atmospheric Mercury Monitoring Study (SoFAMMS) was conducted from 6 August to 6 September 1995. The major goals of the SoFAMMS were to investigate potential source–receptor relationships between anthropogenic point-source emissions in south-east Florida (Dade and Broward Counties) and the atmospheric deposition of Hg and other trace elements across this region, which includes the Florida Everglades. As part of SoFAMMS, daily event precipitation samples were collected concurrently at 17 sites across the study domain during the 1-month period. All samples were analyzed for Hg and other trace elements. The volume-weighted mean concentrations of Hg measured at the 17 sites during the study ranged from 13 to 31 ng l−1. While these monthly means indicated a significant site-to-site variation in Hg concentration, even greater differences between sites were observed on an event basis. Concentrations of Hg in individual daily event precipitation samples ranged from 5 to 113 ng l−1. Similar spatial and temporal variations in precipitation concentrations were observed for other trace elements as well. These variations could not be accounted for by rainfall amounts alone. The spatial and temporal patterns observed suggest that local sources strongly influence atmospheric wet deposition across this region. Extensive elemental composition and meteorological precipitation data (including WSR-88D radar data from Miami, FL) were combined in an effort to look at the history of precipitation storm cells impacting the sampling sites and their spatial relationships to potential anthropogenic sources. Two sample periods are presented which demonstrate not only the impacts of local anthropogenic sources, but that these impacts fluctuate as a function of the mesoscale meteorological transport conditions. These preliminary findings indicate that local sources of Hg to South Florida and the Everglades may be more substantial than previous estimates.

FACTORS AFFECTING GAS ANALYSIS OF INCLUSION FLUID BY QUADRUPOLE MASS SPECTROMETRY

Quadrupole mass spectrometric (QMS) analysis of small amounts of inclusion fluid ( < 1 milligram) released by crushing and decrepitation requires methods to: (1) determine the amount of molecular fragmentation and the relative sensitivity to water and other gases, (2) evaluate differential adsorption of gases in the analytical system, (3) calibrate detector response to amount of released fluid, and (4) detect gas from noninclusion fluid sources. Fragmentation of gases during ionization in the source is pressure dependent. Because the amount of fluid released from individual inclusions and crushed samples varies over a wide range, corrections are made for this pressure dependence during data reduction. This procedure is especially critical for water, the dominant component in most fluid inclusions. Adsorption of H2O is not quantitatively significant from decrepitated individual inclusions (over a range of 1 × 10−6 to 1 milligram) or crushed samples that contain > 1 × 10−4 milligram of H2O. However, adsorption of H2O onto newly created surfaces by crushing samples containing < 1 × 10−4 milligram of H2O will result in lower mol% water reported in the gas analysis than present in inclusion fluid prior to release. Gases from noninclusion fluid sources are incorporated into inclusion fluid during both release methods. N2, O2, and Ar from air in the inlet system are entrained into released inclusion fluid. Gases including SO2 and HCl can be generated when inclusion fluid is released into vacuum. Thermal decomposition of minerals and organic compounds can produce CO2, CH4, CO, N2, H2, and other gases that mix with those released from inclusion fluid. The relative contributions of gas from inclusion fluid vs. these other sources can be differentiated using real-time (direct) QMS analysis.

Source apportionment of ambient fine and coarse particulate matter at the Fort McKay community site, in the Athabasca Oil Sands Region, Alberta, Canada

An ambient air particulate matter sampling study was conducted at the Wood Buffalo Environmental Association (WBEA) AMS-1 Fort McKay monitoring station in the Athabasca Oil Sand Region (AOSR) in Alberta, Canada from February 2010 to July 2011. Daily 24h integrated fine (PM2.5) and coarse (PM10-2.5) particulate matter was collected using a sequential dichotomous sampler. Over the duration of the study, 392 valid daily dichotomous PM2.5 and PM10-2.5 sample pairs were collected with concentrations of 6.8±12.9μgm-3 (mean±standard deviation) and 6.9±5.9μgm-3, respectively. A subset of 100 filter pairs was selected for element analysis by energy dispersive X-ray fluorescence and dynamic reaction cell inductively coupled plasma mass spectrometry. Application of the U.S. EPA positive matrix factorization (PMF) receptor model to the study data matrix resolved five PM2.5 sources explaining 96% of the mass including oil sands upgrading (32%), fugitive dust (26%), biomass combustion (25%), long-range Asian transport lead source (9%), and winter road salt (4%). An analysis of historical PM2.5 data at this site shows that the impact of smoke from wildland fires was particularly high during the summer of 2011. PMF resolved six PM10-2.5 sources explaining 99% of the mass including fugitive haul road dust (40%), fugitive oil sand (27%), a mixed source fugitive dust (16%), biomass combustion (12%), mobile source (3%), and a local copper factor (1%). Results support the conclusion of a previous epiphytic lichen biomonitor study that near-field atmospheric deposition in the AOSR is dominated by coarse fraction fugitive dust from bitumen mining and upgrading operations, and suggest that fugitive dust abatement strategies targeting the three major sources of PM10-2.5 (e.g., oil sand mining, haul roads, bulk material stockpiles) would significantly reduce near-field atmospheric deposition gradients in the AOSR and reduce ambient PM concentrations in the Fort McKay community.

Application of gas analysis of jasperoid inclusion fluids to exploration for micron gold deposits

Graney, J.R., Kesler, S.E. and Jones, H.D., 1991. Application of gas analysis ofjasperoid inclusion fluids to exploration for micron gold deposits. In: S.E. Kesler (Editor), Fluid Inclusion Gas Analyses in Mineral Exploration. J. Geochem. Explor., 42: 91-106. Quadrupole mass spectrometric analyses of inclusion gases in jasperoid from the Carlin and Standard sediment-hosted micron gold deposits in Nevada show that mineralized areas exhibit better correlations between H20-CO2 and H20-N2, higher H2S/CO., and higher 02 ratios than dojasperoids from unmineralized areas. N2 and Ar in all jasperoids are strongly correlated, with an average ratio near that of air-saturated meteoric water. Speciation and reaction progress calculations show that fluids with high H2S/CO., ratios, such as are associated with mineralization in these deposits, would carry more gold than fluids with lower H2S/CO2 ratios. These calculations confirm that boiling would be a more efficient depositional mechanism than cooling or mixing ofthe ore fluid with groundwater. Although poor optical resolution makes it impossible to determine whether the jasperoids contain distinct liquid-rich and gas-rich fluid inclusions, the strong H20-CO2 and H20-N2 correlations in mineralized areas could be of that origin. Thus, jasperoids associated with mineralization could be recognized by high H2S: (02 ratios, which reflect a strong gold-carrying capacity for the fluid, and strong H:O-CO, and H20-N., correlations, which probably reflect gold deposition by boiling.

Comparison of decrepitation, microthermometric and compositional characteristics of fluid inclusions in barren and auriferous mesothermal quartz veins of the Cowra Creek Gold District, New South Wales, Australia

Fluid inclusions in quartz from barren and Au-sulfide-bearing veins from the Cowra Creek Gold District, New South Wales, Australia, have been characterized based on their decrepitation behavior and gas geochemistry. Inclusions in Au-sulfide veins, and some regional sulfide-bearing veins, show distinctly higher CO2CH4 ratios compared to barren quartz-only and quartz-sulfid veins from the deposit environment. Additionally, the occurrence of low-temperature peaks in acoustic decrepigrams from Au-sulfide veins that had previously been attributed to the presence of CO2-bearing fluid inclusions has been confirmed using optical techniques. This characteristic peak is absent from quartz-sulfide and quartz-only veins. These results suggest that the gas content of fluid inclusions can distinguish Au-bearing from barren quartz veins, and that the acoustic decrepitation technique may provide a rapid and simple means of identifying different generations of quartz, and potentially productive veins in mesothermal environments.

Coupling meteorology, metal concentrations, and Pb isotopes for source attribution in archived precipitation samples.

A technique that couples lead (Pb) isotopes and multi-element concentrations with meteorological analysis was used to assess source contributions to precipitation samples at the Bondville, Illinois USA National Trends Network (NTN) site. Precipitation samples collected over a 16month period (July 1994-October 1995) at Bondville were parsed into six unique meteorological flow regimes using a minimum variance clustering technique on back trajectory endpoints. Pb isotope ratios and multi-element concentrations were measured using high resolution inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) on the archived precipitation samples. Bondville is located in central Illinois, ~250km downwind from smelters in southeast Missouri. The Mississippi Valley Type ore deposits in Missouri provided a unique multi-element and Pb isotope fingerprint for smelter emissions which could be contrasted to industrial emissions from the Chicago and Indianapolis urban areas (~125km north and east, of Bondville respectively) and regional emissions from electric utility facilities. Differences in Pb isotopes and element concentrations in precipitation corresponded to flow regime. Industrial sources from urban areas, and thorogenic Pb from coal use, could be differentiated from smelter emissions from Missouri by coupling Pb isotopes with variations in element ratios and relative mass factors. Using a three endmember mixing model based on Pb isotope ratio differences, industrial processes in urban airsheds contributed 56±19%, smelters in southeast Missouri 26±13%, and coal combustion 18±7%, of the Pb in precipitation collected in Bondville in the mid-1990s.

Watershed-Based Integration of Hydrology, Geochemistry, and Geophysics in an Environmental Geology Curriculum

Inquiry-based study focused on the campus watershed was initiated at Binghamton University after creation of an undergraduate Environmental Geology Track within the Geological Sciences curriculum. Use of the watershed in environmental geology courses has been implemented to 1) promote active learning outside of the classroom; 2) allow students to work with state of the art field and laboratory equipment and “real world” data; and 3) encourage interdisciplinary thinking. The longer-term goal is to enable undergraduates to conduct meaningful, field based, “capstone” research projects. A grant from the National Science Foundation supported instrumentation of the entire campus watershed into a readily accessible field laboratory; included are groundwater monitoring wells, equipment for measuring and sampling stream flow, a meteorological station, a wet and dry deposition collector for sampling atmospheric quality, and portable environmental monitoring equipment. In addition, geophysical equipment, including seismic refraction and reflection, DC electrical resistivity, and gravity anomaly measurements, is used to determine subsurface structure at various locations on campus. The undergraduates are now able to explore differences in physical and chemical processes between and within the atmosphere, hydrosphere, and lithosphere on real-time scales. The use of this equipment and the watershed focus has been fully incorporated into three inquiry-based undergraduate courses (Environmental Hydrology, Environmental Geophysics, and Environmental Measurements) to foster interdisciplinary learning about the complexity of watershed-based processes. This manuscript describes the campus field stations, presents examples of field exercises, and assesses the impacts of the program to date.

Groundwater Effects from Highway Tire Shred Use

Approximately 250,000 shredded tires have been used to construct a highway exit ramp as part of a demonstration project. One upgradient well was installed before the tire shreds were put in place. Two downgradient wells and two tire fill sampling ports were installed during the project. Levels of organic compounds and metals have been monitored since the project was completed in May of 2001 . Organic compounds were not detected in the leachate or downgradient groundwater in significant amounts. Arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), selenium (Se), silver (Ag), and zinc (Zn) were quantified in both filtered and unfiltered samples. Of most concern is the source of elevated levels of Ba, Cd, Fe, Mn, and Zn in filtered samples when compared with water quality standards. Zn, Cd, and Ba are elevated in one of the tire fill ports, whereas Fe and Mn have been consistently elevated in the downgradient wells. The elevated Zn, Cd, and Ba may be related to the use of shredded tires. The elevated Fe and Mn may be associated with traffic on the adjacent interstate and ramp and the hydrogeology of the site. The concentrations of iron and manganese in the downgradient groundwater would be a public health concern if the water were used for human consumption. It is important to evaluate the combined long-term effects of tire shreds and runoff from roadways on groundwater quality where tire shreds are used in highway construction.