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Sample records for galena lead isotope

  1. Sargipali galenas: Unusual lead-isotope data from eastern India

    NASA Astrophysics Data System (ADS)

    Vishwakarma, Rajesh K.; Ulabhaje, A. V.

    1991-04-01

    The Sargipali sulphide deposit, hosted by a sequence of metasediments of the Precambrian Gangpur Series, represents the stratiform and stratabound Pb-Cu mineralization. Lead-isotope analyses obtained from six galena samples of different forms and stratigraphical levels, yielded a model Pb age of 1665 Ma, which predates the episodes of deformation and metamorphism (˜ 850 Ma) as well as syn-to late-tectonic magmatism. The model Pb age, on the contrary, shows a relationship to the closing phase of the Gangpur sedimentation (1700 Ma) in a shallow-water marine environment. The notable paucity of the interlayered volcanic rock in the deposit and its Pb-rich nature possibly point to its being the sedimentary exhalative (SEDEX) type. Documentary evidence for the Pb component from the geological environment of the “upper continental crust” is revealed by an exceptionally high μ(= 238U/204Pb) and the slightly above average W(= 232Th/238U) values. These indicate that the source rock was initially rich in U-Th-Pb concentration. For the Sargipali ore Pb, the parent is assumed to be late Archean-lower Proterozoic soda granite.

  2. Preliminary lead isotope investigations of brine from the Red Sea, Galena from the Kingdom of Saudi Arabia, and galena from United Arab Republic (Egypt)

    USGS Publications Warehouse

    Delevaux, M.H.; Doe, B.R.; Brown, G.F.

    1967-01-01

    The isotopic composition of lead in Red Sea chloride brine containing 0.5 ppm Pb is found to be similar to that of some Cenozoic ore leads such as galena at Rabigh in Saudi Arabia that may have formed during mineralization accompanying Tertiary rifting. Bir Ranga galena in Miocene sediments from United Arab Republic (Egypt) is also isotopically similar to lead in Red Sea brine. The chlorine brine must be considered a possible mineralizing fluid. Lead isotopes show promise for use in mineral prospect evaluation in that galena from Samrah is isotopically similar to that from Mahd adh Dhahab, which has been the only ore producer in Saudi Arabia since 1945. Drilling at Samrah does indicate a possible economic mineralization. The lead isotope data coupled with available geologic knowledge and geochronometry are used to tentatively divide the ore prospects of the Kingdom of Saudi Arabia into relative categories of mineralization age. Two Mesozoic and Cenozoic mineralizations are distinguished on the basis of a 207Pb/204Pb difference; an early Paleozoic mineralization grouping is outlined; and a late Precambrian mineralization period is suggested. ?? 1967.

  3. Regional variations in the lead isotopic composition of galena from southern Korea with implications for the discrimination of lead provenance

    NASA Astrophysics Data System (ADS)

    Jeong, Youn-Joong; Cheong, Chang-sik; Shin, Dongbok; Lee, Kwang-Sik; Jo, Hui Je; Gautam, Mukesh Kumar; Lee, Insung

    2012-11-01

    This study presents a comprehensive database (n = 215) of lead isotopes in galena from the southern Korean peninsula using new and published data. Of the 69 metal mines examined, predominantly skarn- and hydrothermal-type Pb-Zn-Au-Ag-Cu deposits were observed and were associated with Mesozoic magmatic activities. Galena samples from each geotectonic unit showed discrete lead isotopic signatures. The Gyeongsang basin samples were characteristically unradiogenic and had restricted variations in lead isotopic composition (206Pb/204Pb = 18.16-18.59, 207Pb/204Pb = 15.48-15.64, 208Pb/204Pb = 37.87-38.77). Their 208Pb/204Pb range indicated an involvement of source materials less thorogenic than the associated granites. The galena samples from Cambro-Ordovician carbonate rocks of the northeastern Yeongnam massif and eastern Taebaeksan basin had the most radiogenic 206Pb/204Pb (19.28 ± 0.14) and 207Pb/204Pb (15.833 ± 0.027) ratios. Their lead isotopic trend indicated a combined contribution of ore lead from granitic magmas, Precambrian basements, and overlain host rocks. Less radiogenic galena samples from the middle to southwestern parts of the Yeongnam massif and Okcheon belt showed limited lead isotopic variations (206Pb/204Pb = 18.332 ± 0.065, 207Pb/204Pb = 15.693 ± 0.012, 208Pb/204Pb = 38.93 ± 0.07 on average), probably resulted from mixing with a common crustal basement. The differences in lead isotopes between the radiogenic and unradiogenic groups from the Yeongnam massif and Okcheon belt may reflect the spatial dissimilarity of involved crustal rocks. The old crust appears to have significantly contributed ore lead to galenas from the western Gyeonggi massif, but the geochronological meaning of their steep 207Pb/204Pb-206Pb/204Pb trend is not clear. The comprehensive database constructed by the present study suggests that lead province in the southern Korean peninsula may be subdivided into four discrete zones. Linear discriminant analysis showed that more

  4. Galena oxidation investigations on oxygen and sulphur isotopes.

    PubMed

    Heidel, Claudia; Tichomirowa, Marion

    2011-06-01

    Batch experiments with the lead sulphide ore mineral galena were carried out in order to get information about the oxidation mechanisms and to contribute to the understanding of field data, especially those obtained from the mining-affected sites. Results indicate that oxygen and sulphur isotopes of dissolved sulphate may be useful tools for the investigation of galena oxidation mechanisms. However, some methodological modifications are necessary to obtain sufficient sulphate yields, which are a prerequisite for the reduction of the analytical uncertainty. Surface and hydrochemical investigations indicated that galena was dissolved non-oxidatively during the experiment at initial pH 2, whereas the oxidative dissolution of galena dominated in experiments at initial pH 6 and 8. No isotope results could be obtained from the experiment at initial pH 2 due to the low sulphate production. The oxidative dissolution of galena resulted in somewhat higher sulphate yields. Thus, the oxygen isotope composition of sulphate produced from galena oxidation could be determined for the first time. Oxygen in sulphate derived largely from water molecules; but minor amounts of molecular oxygen could be also observed. Both molecular oxygen and ferric iron may act as oxidants of galena. A variety of intermediate reactions allow for a variable oxygen isotope composition of sulphate. Sulphur isotopes of sulphate showed an enrichment of (32)S in sulphate (relative to galena), which increases with increasing pH. Sulphur isotope enrichment processes may be associated with the formation of anglesite.

  5. Clean galena, contaminated lead, and soft errors in memory chips

    NASA Astrophysics Data System (ADS)

    Lykken, G. I.; Hustoft, J.; Ziegler, B.; Momcilovic, B.

    2000-10-01

    Lead (Pb) disks were exposed to a radon (Rn)-rich atmosphere and surface alpha particle emissions were detected over time. Cumulative 210Po alpha emission increased nearly linearly with time. Conversely, cumulative emission for each of 218Po and 214Po was constant after one and two hours, respectively. Processing of radiation-free Pb ore (galena) in inert atmospheres was compared with processing in ambient air. Galena processed within a flux heated in a graphite crucible while exposed to an inert atmosphere, resulted in lead contaminated with 210Po (Trial 1). A glove box was next used to prepare a baseline radiation-free flux sample in an alumina crucible that was heated in an oven with an inert atmosphere (Trials 2 and 3). Ambient air was thereafter introduced, in place of the inert atmosphere, to the radiation-free flux mixture during processing (Trial 4). Ambient air introduced Rn and its progeny (RAD) into the flux during processing so that the processed Pb contained Po isotopes. A typical coke used in lead smelting also emitted numerous alpha particles. We postulate that alpha particles from tin/lead solder bumps, a cause of computer chip memory soft errors, may originate from Rn and RAD in the ambient air and/or coke used as a reducing agent in the standard galena smelting procedure.

  6. Lead-isotopic, sulphur-isotopic, and trace-element studies of galena from the Silesian-Cracow Zn-Pb ores, polymetallic veins from the Gory Swietokrzyskie MTS, and the Myszkow porphyry copper deposit, Poland

    USGS Publications Warehouse

    Church, S.E.; Vaughn, R.B.; Gent, C.A.; Hopkins, R.T.

    1996-01-01

    Lead-isotopic data on galena samples collected from a paragenetically constrained suite of samples from the Silesian-Cracow ore district show no regional or paragenetically controlled lead-isotopic trends within the analytical reproducibility of the measurements. Furthermore, the new lead-isotopic data agree with previously reported lead-isotopic results (R. E. Zartman et al., 1979). Sulfur-isotopic analyses of ores from the Silesian-Cracow district as well as from vein ore from the Gory Swietokrzyskie Mts. and the Myszkow porphyry copper deposit, when coupled with trace-element data from the galena samples, clearly discriminate different hydrothermal ore-forming events. Lead-isotopic data from the Permian and Miocene evaporite deposits in Poland indicate that neither of these evaporite deposits were a source of metals for the Silesian-Cracow district ores. Furthermore, lead-isotopic data from these evaporite deposits and the shale residues from the Miocene halite samples indicate that the crustal evolution of lead in the central and western European platform in southern Poland followed normal crustal lead-isotopic growth, and that the isotopic composition of crustal lead had progressed beyond the lead-isotopic composition of lead in the Silesian-Cracow ores by Permian time. Thus, Mesozoic and Tertiary sedimentary flysch rocks can be eliminated as viable source rocks for the metals in the Silesian-Cracow Mississippi Valley-type (MVT) deposits. The uniformity of the isotopic composition of lead in the Silesian-Cracow ores, when coupled with the geologic evidence that mineralization must post-date Late Jurassic faulting (E. Gorecka, 1991), constrains the geochemical nature of the source region. The source of the metals is probably a well-mixed, multi-cycle molasse sequence of sedimentary rocks that contains little if any Precambrian metamorphic or granitic clasts (S. E. Church, R. B. Vaughn, 1992). If ore deposition was post Late Jurassic (about 150 m. y.) or later

  7. Bed performance in the direct electrowinning of lead from suspension galena anodes

    NASA Astrophysics Data System (ADS)

    Paramguru, R. K.; Kammel, R.

    1988-02-01

    Additive effects have been examined in the performance of suspension electrolysis of galena concentrate anode. A better conducting additive of properly selected size fraction, compatible with the relative size and specific gravity of galena, was found to improve the dissolution characteristics. With optimization of parameters such as current density, lead ion additions to the bath, electrolysis time, etc., and by withdrawing accumulated elemental sulfur intermittently, it was possible to dissolve lead with 79 pct current efficiency and energy consumption of 0.54 Kwh per kilogram of lead.

  8. Direct electrowinning of lead from suspension galena concentrate anode in different electrolytes

    NASA Astrophysics Data System (ADS)

    Paramguru, R. K.; Küzeci, E.; Kammel, R.

    1988-02-01

    Electrochemical extraction of lead from galena by suspension electrolysis has been examined. Galvanostatic studies with slurry electrode as well as voltametric studies with carbon paste electrode in various electrolytes have been made in order to evaluate bath performance. Sodium hydroxide has been found to result in poor dissolution whereas ionic conduction through the electrolyte as well as oxide formation at the anode hinders lead dissolution in perchlorate media. Acetate bath results in substantial amount of oxide formation at anode even though solid bed conduction dominates. Sodium chloride bath has been found to have good prospects for producing lead ions and elemental sulfur with good current efficiencies.

  9. Isotopic composition of ice cores and meltwater from upper fremont glacier and Galena Creek rock glacier, Wyoming

    USGS Publications Warehouse

    DeWayne, Cecil L.; Green, J.R.; Vogt, S.; Michel, R.; Cottrell, G.

    1998-01-01

    Meltwater runoff from glaciers can result from various sources, including recent precipitation and melted glacial ice. Determining the origin of the meltwater from glaciers through isotopic analysis can provide information about such things as the character and distribution of ablation on glaciers. A 9.4 m ice core and meltwater were collected in 1995 and 1996 at the glacigenic Galena Creek rock glacier in Wyoming's Absaroka Mountains. Measurements of chlorine-36 (36Cl), tritium (3H), sulphur-35 (35S), and delta oxygen-18 (??18O) were compared to similar measurements from an ice core taken from the Upper Fremont Glacier in the Wind River Range of Wyoming collected in 1991-95. Meltwater samples from three sites on the rock glacier yielded 36Cl concentrations that ranged from 2.1 ?? 1.0 X 106 to 5.8??0.3 X 106 atoms/l. The ice-core 36Cl concentrations from Galena Creek ranged from 3.4??0.3 X 105 to 1.0??0.1 X 106 atoms/l. Analysis of an ice core from the Upper Fremont Glacier yielded 36Cl concentrations of 1.2??0.2 X 106 and 5.2??0.2 X 106 atoms/l for pre- 1940 ice and between 2 X 106 and 3 X 106 atoms/l for post-1980 ice. Purdue's PRIME Lab analyzed the ice from the Upper Fremont Glacier. The highest concentration of 36Cl in the ice was 77 ?? 2 X 106 atoms/l and was deposited during the peak of atmospheric nuclear weapons testing in the late 1950s. This is an order of magnitude greater than the largest measured concentration from both the Upper Fremont Glacier ice core that was not affected by weapons testing fallout and the ice core collected from the Galena Creek rock glacier. Tritium concentrations from the rock glacier ranged from 9.2??0.6 to 13.2??0.8 tritium units (TU) in the meltwater to -1.3??1.3 TU in the ice core. Concentrations of 3H in the Upper Fremont Glacier ice core ranged from 0 TU in the ice older than 50 years to 6-12 TU in the ice deposited in the last 10 years. The maximum 3H concentration in ice from the Upper Fremont Glacier deposited in the

  10. Lead isotopic studies of the Samail ophiolite, Oman

    SciTech Connect

    Chen, J.H.; Pallister, J.S.

    1981-04-10

    The isotopic composition of Pb and the concentrations of U, Th, and Pb have been determined for samples from various lithologic units and massive sulfides of the Samail ophiolite. The observed /sup 206/Pb//sup 204/Pb ratios range from 17.90 to 19.06, /sup 207/Pb//sup 204/Pb ratios from 15.43 to 15.63, and /sup 208/Pb//sup 204/Pb from 37.66 to 38.78. In Pb isotopic evolution diagrams, the initial Pb isotopic compositions of most of the samples from the Samail ophiolite plot within the field of oceanic basalt, clearly distinct from island arc data, and define some of the least radiogenic Pb observed from oceanic rocks. Lead data from the Samail are compatible with a model involving magma generation from an oceanic mantle source and formation of the ophiolite at an oceanic spreading center. U--Th--Pb isotopic systematics demonstrate that vertical heterogeneity in the oceanic crust can be created through differential concentration of U, Th, and Pb during crystal fractionation and alteration at, or near, the spreading ridge. Calcite form amygdules in the ophiolite basalt has similar Pb isotopic composition to the igneous rocks, suggesting precipitation of the calcite from seawater which contained Pb derived mostly from the oceanic crust. Lead isotopic data on Fe--Cu sulfides are also similar to the results from the igneous suite suggesting that the source of the sulfides is predominently from the oceanic crust. Lead data from serpentinized peridotite and a galena sample from below the ophiolite suggest that part of the serpentinization process and the formation of galena could involve addition of radiogenic Pb from either a continental source or from oceanic sediments.

  11. Human exposure to lead and other potentially harmful elements associated with galena mining at New Zurak, central Nigeria

    NASA Astrophysics Data System (ADS)

    Lar, U. A.; Ngozi-Chika, C. S.; Ashano, E. C.

    2013-08-01

    Galena mining in New Zurak, central Nigeria is currently increasing in intensity, with widespread artisanal mining taking place alongside mechanised mining. These activities are causing immeasurable damage to the environment. The prolonged human exposure and ingestion of Pb and other potentially harmful elements (PHEs) such as U, Cd, Se, Zn and As that are released from ores during these (mining) activities is a cause of great concern to populations that live in the vicinity of these mine fields. Many of the communities make their living from subsistence farming, growing food from the surroundings, and obtaining drinking water from nearby surface and sub-surface water resources. An overall assessment of the degree of contamination or toxicity of Pb and other PHEs was carried out using the indices of geoaccumulation (Igeo) and contamination factors (CFs), in the different media sampled - farmland soils, uncultivated lands, mine tailings/dumps, natural waters and vegetables. Results reveal that the mine tailings and dumps are highly contaminated with Pb and other PHEs followed in decreasing degree of contamination by the uncultivated lands, farmlands and natural waters. These findings suggest that release of Pb and other PHEs from the galena mining activity has contributed significantly to the enrichment of these elements in the surrounding environment, including the natural water bodies, and are disposed to subsequent entry into the human body through the food chain. As such these PHE accumulations pose significant risks to the environment and human health, especially of children and pregnant women who are the most vulnerable groups in the area. In order to forestall a reoccurrence of the Zamfara Pb poisoning episode in northwestern Nigeria in 2010, where more than 400 children died, the authorities concerned should ensure that mining in New Zurak is done in a more environmentally friendly manner, ensuring the maintenance of an environmental quality adequate for

  12. Lead in petrol. The isotopic lead experiment

    SciTech Connect

    Facchetti, S. )

    1989-10-01

    Many studies were dedicated to the evaluation of the impact of automotive lead on the environment and to the assessment of its absorption in the human population. They can be subdivided into two groups, those based on changes of air and blood lead concentrations and those based on changes of air and blood lead isotopic compositions. According to various authors, 50-66% of the lead added to petrol is mobilized in the atmosphere, while most of the remainder adheres to the walls of the exhaust system from which it is expelled by mechanical and thermal shocks in the forms of easily sedimented particles. The fraction directly emitted by engine exhaust fumes is found in the form of fine particles, which can be transferred a long way from the emitting sources. However important the contribution of petrol lead to the total airborne lead may be, our knowledge does not permit a straightforward calculation of the percentage of petrol lead in total blood lead, which of course can also originate from other sources (e.g., industrial, natural). To evaluate this percentage in 1973, the idea of the Isotopic Lead Experiment (ILE project) was conceived to label, on a regional scale, petrol with a nonradioactive lead of an isotopic composition sufficiently different from that of background lead and sufficiently stable in time. This Account summarizes the main results obtained by the ILE project.

  13. Lead-isotope study of the sulphide ore and alteration zone, Bleikvassli zinc-lead deposit, northern Norway

    NASA Astrophysics Data System (ADS)

    Skauli, H.; Bjørlykke, A.; Thorpe, R. I.

    1992-09-01

    The Bleikvassli Zn-Pb deposit is located in the Uppermost Allochthon of the northern Norwegian Caledonides and is enclosed in amphibolite facies, multiply deformed supracrustal rocks. The stratiform orebody occurs stratigraphically above a sequence of gneiss and amphibolite and below a thick carbonate unit. The orebody, spatially associated with a footwall microcline gneiss that contains as much as 12wt‰ K2O, occurs in the lower part of the Mine Sequence which also comprises (kyanite-) mica schist and quartzo-feldspathic to siliceous rocks. The host rock lithology and the metal content of the Bleikvassli orebody are consistent with a SEDEX origin of the deposit. Field relationships and chemistry suggest that the microcline gneiss represents a potassic alteration of pelitic sediments related to the ore-forming process. A 464 ± 22 Ma Rb-Sr isochron for the microcline gneiss is interpreted to be a metamorphic age resulting from resetting of the Rb-Sr isotopic system during the Caledonian orogeny. The U-Pb in the whole rock shows evidence of recent mobilization of uranium and a partial or total resetting of the system during peak metamorphism. As with most SEDEX deposits, the lead isotope composition of the Bleikvassli ore plots close to the orogen growth curve. The geological setting of the ore and the leadisotope compositions of the galenas indicate a Cambrian age of mineralization. However, the slope of the lead isotope data indicate an age of about 1000 Ma, which is also a maximum age of ore deposition. The lead isotope data for the galena, in conjunction with the compositions of the microcline gneiss during peak metamorphism, support a model whereby the microcline rock was formed as an alteration product by the ore forming fluid and the initial lead isotope composition of the microcline rock was similar to that of the galenas during ore deposition.

  14. New lead isotope determination from five Proterozoic sulfide deposits, Skellefte district, Sweden

    NASA Astrophysics Data System (ADS)

    Vaasjoki, M.; Vivallo, W.

    1990-01-01

    Lead isotope analyses of 25 sulfide samples (galenas, iron sulfides, and sulfosalts) from five different mines of the Skellefte district, northern Sweden, demonstrate that the Pb-isotopic composition of galenas and other sulfides rich in lead varies between individual deposits within the district. This contrasts with many other base-metal districts, where ore lead is isotopically homogeneous on a regional basis. Although all of the Skellefte leads are depleted in 207Pb relative to average global lead evolution models, thus suggesting a large mantle-derived component in their sources, the Nasliden deposit lying at the contact of the host volcanic rocks and the overlying metasediments contains a significant component of crustal lead. It is concluded that while the Pb-isotope data are consistent with a volcanic exhalative origin of the ores of the Skellefte district, they also demonstrate that older crustal lead was incorporated into the sulfides during their emplacement and the subsequent period of magmatic and metamorphic activity which followed their deposition.

  15. Lead and strontium isotopes as indicators for mixing processes of waters in the former mine 'Himmelfahrt Fundgrube', Freiberg (Germany).

    PubMed

    Heidel, Claudia; Tichomirowa, Marion; Matschullat, Jörg

    2007-12-01

    To pinpoint the origin and mixing processes of mine waters, different mine water types from the polymetallic sulphide ore deposit 'Himmelfahrt Fundgrube' (Freiberg, Germany) were analysed by thermal ionisation mass spectrometry using lead and strontium isotope ratios. Results show that the lead isotope composition of different mine waters results from a mixture of at least two sources: released lead from oxidised sulphide ores (mainly galena) and anthropogenic lead from groundwater. Furthermore, there are indications for an additional lead source. Strontium isotopes in mine waters identify at least three different sources: released strontium from weathered host rock (Grey Gneisses), released strontium from weathered gangue carbonates, and probably strontium from anthropogenic inputs. Contrary to former oxygen and sulphur isotope studies, strontium isotope compositions as well as hydrochemical parameters show the important role of gangue carbonates as an element source in mine waters.

  16. Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors.

    PubMed

    Thomas, Vernon G; Scheuhammer, Anton M; Bond, Della E

    2009-05-15

    Leg and foot bones of adult and juvenile red grouse (Lagopus lagopus scoticus) were collected from hunter-shot birds on two Scottish estates (Glendye and Invermark) and one Yorkshire estate in September, 2003. The lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (Pb(204, 206, 207, 208)) by inductively coupled plasma mass spectrometry. At the Glendye (N=111) and Invermark (N=85) estates, relatively few birds (5.4% and 3.5%, respectively) had highly elevated bone lead concentrations (>20 microg/g dry weight). In bones of these highly exposed birds, a combination of Pb(206):Pb(207) and Pb(208):Pb(207)ratios was consistent with ingestion of lead gunshot available in Europe. By contrast, Yorkshire grouse experienced a high incidence (65.8%) of bone lead >20 microg/g. The Pb(206):Pb(207) and Pb(208):Pb(207)ratios in bones of these highly exposed birds were consistent with a combined exposure to ingested lead gunshot and lead from galena mining in the region. Lead isotope ratios also indicated that lead from UK gasoline combustion and fallout from atmospheric particles was not a likely source of elevated lead in bones of either Scottish or Yorkshire grouse. Suggested management options for the three moors include adopting nontoxic shot for all game shooting on the estates, allowing heather (Calluna vulgaris) vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.

  17. Lead Isotopes in Highway Runoff

    NASA Astrophysics Data System (ADS)

    Ferreira, M.; Lau, S.; Green, P. G.; Stenstrom, M. K.

    2011-12-01

    Lead (Pb) isotopes have been used extensively to study the provenance of lead pollution on air, water, and sediments. In this study, we measured Pb isotopes and Pb aqueous concentration in highway runoff in three west Los Angeles sites. Those three sites, part of a long-term study sponsored by the California Department of Transportation, represent small catchment areas, and host heavy traffic. In addition, there were no inputs of sand or salt to the highway because the sites are almost completely impervious and also due to the lack of snow to be controlled. Highway runoff from the three sites was collected for 7 storms during the 2004-2005 Winter. Grab samples were collected every 15 minutes during the first hour, and hourly afterwards. A total of 202 samples were collected and filtered into five size fractions (<0.45μm, 0.45-8μm, 8-20μm, 20-100μm, >100μm). Aqueous concentration of Pb range from 0.08μg/L to 46.95μg/L (7.98±10.89μg/L) and it is not correlated with any of the lead isotope ratios. The 208Pb/206Pb ratio ranges from 1.983 to 2.075 (2.024±0.026) and there is no statistical difference for the mean value of the 208Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). However, the 208Pb/206Pb ratio of nearby soils yield 2.060±0.021 and it is statistically different from the ratios obtained for the highway runoff. This hints that the lead present in highway runoff does not come from local soils. The 207Pb/206Pb ratio ranges from 0.804 to 0.847 (0.827±0.011) and there is no statistical difference for the mean value of the 207Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). Surprisingly, there is also no statistical difference with the 207Pb/206Pb ratio of nearby soils (0.833±0.009).

  18. Lead isotope study of Zn-Pb ore deposits associated with the Basque-Cantabrian basin and Paleozoic basement, Northern Spain

    NASA Astrophysics Data System (ADS)

    Velasco, F.; Pesquera, A.; Herrero, J. M.

    1996-01-01

    A total of forty-three galena samples from syngenetic and epigenetic Pb-Zn mineralizations emplaced in the Lower Cretaceous Basque-Cantabrian basin and Paleozoic basement of the Cinco Villas massif in the western Pyrenees, have been analyzed for Pb-isotopic composition. Galena from sedex mineralizations hosted in Carboniferous clastic rocks in the Cinco Villas massif display an homogeneous lead isotopic signature (206Pb/2044Pb ≈ 18.43, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.69) suggesting a single lead reservoir. These values are slightly more radiogenic than lead from other European Hercynian deposits, possibly reflecting the influence of a more evolved upper crustal source. Underlying Paleozoic sediments are proposed as lead source for the Cinco Villas massif ores. Analyses from twenty-six galena samples from the four strata-bound ore districts hosted in Mesozoic rocks reveal the existence of two populations regarding their lead isotopic composition. Galena from the western Santander districts (e.g., Reocin) is characterized by more radiogenic isotope values (206Pb/204Pb ≈ 18.74, 207Pb/204Pb ≈ 15.67, 208Pb/ 204Pb ≈ 38.73) than those from the central and eastern districts (Troya-Legorreta, Central and Western Vizcaya, 206Pb/204Pb ≈ 18.59, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.73). In all districts, the most likely source for these mineralizations was the thick sequence of Lower Cretaceous clastic sediments. The existence of two separate lead isotopic populations could be the result of regional difference in the composition of the basement rocks and the clastic sediments derived of it or different evolution histories. In both sub-basins, isotopic ratios indicate an increase in crustal influence as the age of the ores decreases.

  19. Lead and barium sources in Cambrian siliciclastics and sediment provenance of a sector of the Taconic Orogen, Quebec: a mixing scenario based on Pb-isotopic evidence

    USGS Publications Warehouse

    Schrijver, K.; Zartman, R.E.; Williams-Jones, A. E.

    1994-01-01

    To test the hypothesis that siliciclastic rocks constituted the major source of Pb and Ba in barite-galena deposits of the Taconic Orogen, we determined Pb-isotope ratios in galena, barren rocks and contained minerals, as well as concentrations of Pb, U, Th and Ba in the latter (detrital feldspars, sandstones, mudstones, rock clasts and carbonate cements and clasts). Ranges in 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb of 28 galena samples are 17.96-18.05, 15.56-15.59 and 37.75-37.93, respectively; ranges for 41 barren rocks and minerals are 16.17-23.31, 15.26-15.86 and 35.98-42.51, respectively. The lowest ratios are in feldspar, and the highest in carbonate and mudstone. Values of the mudstones samples overlap those of galena when corrected for in situ decay of U and Th since galena precipitation (???450 Ma). We thus propose that mudstones constituted a source of lead. Corrected ratios for anomalously Pb-rich mudstones are virtually identical to galena-Pb ratios and may be due to contamination by lead-bearing brines. Assuming that burial diagenesis did not disturb the Pb-isotope values of sandstones, these rocks contributed only a minor fraction of lead to the galena, estimated at ???20% for one deposit. The source of barite-Ba was probably perthite. Low Ba and Pb concentrations of sandstone adjacent to this deposit, compared to high concentrations remote from it, support leaching of barium (and minor lead) from feldspar penecontemporaneous with feldspar dissolution. Geological data indicate that the provenance of the siliciclastic rocks was mainly from Grenville terrane. A comparison of our Pb-isotopic data for Taconic perthite with those of Grenville K-feldspar, as well as ratios of trace elements, support this provenance for both sandstones and mudstones. The presence of carbonate platforms peripheral to the orogen, and the Middle Ordovician-Middle Devonian depositional range of the studied and Mississippi Valley type deposits north (Newfoundland) and south (U

  20. Lead isotopes in environmental sciences: a review.

    PubMed

    Komárek, Michael; Ettler, Vojtech; Chrastný, Vladislav; Mihaljevic, Martin

    2008-05-01

    Lead (Pb) isotopic analyses proved to be a very efficient tool for tracing the sources of local and global Pb pollution. This review presents an overview of literature published on the use of Pb isotopic analyses of different environmental matrices (atmospheric aerosols, lichens, tree rings, peat deposits, lake, stream, marine sediments, soils, etc.). In order to gain more insight, the isotopic compositions of major sources of Pb in the environment as determined by several authors are described in detail. These include, above all, the former use of leaded gasoline, coal combustion, industrial activities (e.g., metallurgy) and waste incineration. Furthermore, this review summarises analytical techniques (especially ICP-MS) used for the determination of Pb isotopes in environmental samples.

  1. Lead isotope ratios in urban road runoff.

    PubMed

    Shinya, M; Funasaka, K; Katahira, K; Ishikawa, M; Matsui, S

    2006-01-01

    Lead isotopic analyses of road runoff and airborne particulate matter have been carried out to elucidate sources of lead pollution at urban and suburban sites. While lead is often observed in road runoff in suspended form, suspended particle size had no relation to the lead isotopic distribution, as a result of comparison between runoff samples with total suspended solids and those with minute particles passed through a 75 microm sieve. Lead isotope ratios in airborne particulate matter in urban areas fell within a wider range than those in road runoff. Since there was little difference of the ratios between a heavy traffic-flow site and residential sites, airborne lead derived from vehicle exhaust was found to make little contribution to the contamination of road runoff. On the other hand, the ratios in road runoff at a suburban site showed the same range as those at an urban site. Lead in road runoff was therefore suggested to be produced on site by traffic related substances, such as tire wear, other than vehicle exhaust.

  2. Lead Isotopes from the Upper Mississippi Valley District: A Regional Perspective

    USGS Publications Warehouse

    Millen, Timothy M.; Zartman, Robert E.; Heyl, Allen Van

    1995-01-01

    New lead isotopic data on galena from within and peripheral to the Upper Mississippi Valley lead-zinc district make it possible, by extending coverage to outlying locations, to trace the pathway traversed by the mineralizing fluids beyond the boundary of the main district. All but one of the samples exhibit elevated ratios of the radiogenic isotopes typical of the Upper Mississippi Valley ore deposits; 206PbP04Pb ranges from 19.38 to 24.46, 207PbP04Pb ranges from 15.73 to 16.24, and 208PbP04Pb ranges from 39.24 to 43.69. Galena from the Pints quarry near Waterloo, Iowa, has distinctly lower values of these ratios and may not be related paragenetically to the other samples. Otherwise, the lowest ratios are for samples in the southern part of the region in north-central Illinois, and the highest ratios are for samples to the northeast of the main district in the vicinity of Madison, Wisconsin. Thus, an isotopic pattern rather similar to that observed originally by Heyl and others (1966) prevails regionally, although the predominant fluid flow is now believed to have emanated from the Illinois Basin rather than from the Forest City Basin. Metal-bearing brines being driven northward out of the Illinois Basin probably played the key role in mineralization of the Upper Mississippi Valley district. Both the new and the previously reported lead ratios for the Upper Mississippi Valley district are plotted on 207PbP04Pb and Pb208/pb204Pb versus 206PbP04Pb diagrams, which permit their comparison and the calculation of refined slopes for the expanded data set. A two-stage model age for the time of mineralization can be determined from the 207PbP04Pb_Pb206/Pb204 slope, provided that the source age of the lead is known. With our limited know ledge of this source age, the time of mineralization cannot be tightly constrained but is permissive of a Permian or younger lateral secretion event, as suggested by other geochronological results.

  3. Lead isotope studies of mare basalt 70017

    NASA Technical Reports Server (NTRS)

    Mattinson, J. M.; Tilton, G. R.; Todt, W.; Chen, J. H.

    1977-01-01

    Uranium, thorium, and isotopic lead data for components of basalt 70017 are reported, and it is found that the whole rock, pyroxene, and ilmenite points in a concordia diagram plot along a chord intersecting the curve at 3.7 and 4.33 eons. The plagioclase data do not seem to lie on this line. The data for 70017 appear to plot along a distinctly different chord in a concordia diagram than do the data for 75055 and 75035, two other Apollo 17 mare basalts. The lead data are in accord with Sm-Nd results. A 3.7 eon crystallization age for 70017 would be consistent with the same kind of parentless lead that is indicated by previous studies of soils and soil breccias from stations at Taurus-Littrow. The Th/U ratio in ilmenite is 2.2, and the concentrations of these two elements are approximately twice those in pyroxene.

  4. Lead isotope profiling in dairy calves.

    PubMed

    Buchweitz, John; McClure-Brinton, Kimberly; Zyskowski, Justin; Stensen, Lauren; Lehner, Andreas

    2015-03-01

    Lead (Pb) is a common cause of heavy metal poisonings in cattle. Sources of Pb on farms include crankcase oil, machinery grease, batteries, plumbing, and paint chips. Consequently, consumption of Pb from these sources may negatively impact animal health and Pb may be inadvertently introduced into the food supply. Therefore, the scope of poisoning incidents must be clearly assessed and sources of intoxication identified and strategies to mitigate exposure evaluated and implemented to prevent future exposures. Stable isotope analysis by inductively-coupled plasma mass spectrometry (ICP-MS) has proven itself of value in forensic investigations. We report on the extension of Pb stable isotope analysis to bovine tissues and profile comparisons with paint chips and soils collected from an affected dairy farm to elucidate the primary source. Pb occurs naturally as four stable isotopes: (204)Pb, (206)Pb, (207)Pb, and (208)Pb. Herein a case is reported to illustrate the use of (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios to link environmental sources of exposure with tissues from a poisoned animal. Chemical Pb profiling provides a valuable tool for field investigative approaches to Pb poisoning in production agriculture and is applicable to subclinical exposures.

  5. Lead isotope systematics of mare basalt 75075

    NASA Technical Reports Server (NTRS)

    Chen, J. H.; Tilton, G. R.; Mattinson, J. M.; Vidal, P.

    1978-01-01

    Uranium, thorium and isotopic lead data are reported for two bulk samples and separated pyroxene, ilmenite and plagioclase from basalt 75075. In a concordia diagram the whole rock, ilmenite and four pyroxene samples define a chord intersecting the concordia curve at approximately 4.25 and 2.8 AE. Three plagioclase samples plot distinctly off the chord. The crystallization age of 75075 is accurately determined at 3.74 AE by Rb-Sr, Sm-Nd and K-Ar measurements from other laboratories. It is not possible to adjust the isotopic composition of initial lead so as to reconcile the U-Pb data with a crystallization age of 3.74 AE. The data therefore indicate some type of post-crystallization disturbance of the U-Pb system that is not detected by the other systems. The 75075 data are one of the few examples of this type of age pattern found on the moon. If the disturbance was a single event, it probably occurred around 2.8 AE ago, the time indicated by the pyroxene, whole rock and ilmenite data.

  6. Atomic vapor laser isotope separation of lead-210 isotope

    DOEpatents

    Scheibner, Karl F.; Haynam, Christopher A.; Johnson, Michael A.; Worden, Earl F.

    1999-01-01

    An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207.

  7. Atomic vapor laser isotope separation of lead-210 isotope

    DOEpatents

    Scheibner, K.F.; Haynam, C.A.; Johnson, M.A.; Worden, E.F.

    1999-08-31

    An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207. 5 figs.

  8. The lead isotope systematics of ophiolite complexes

    NASA Astrophysics Data System (ADS)

    Hamelin, Bruno; Dupré, Bernard; Allègre, Claude J.

    1984-03-01

    Samples of eleven ophiolites from the Mediterranean and the Pacific belts have been studied through Pb sbnd Pb systematics. The ophiolites studied show both isotopic variations within one sequence and differences between the various complexes. The intra-sequence isotopic variations result principally from the in situ decay of uranium and thorium since the formation of the ophiolites. μ ratios ( 238U/ 204Pb ) higher than 50 in the effusive part of ophiolites are required to explain the 206Pb/ 204Pb spread within the sequences, and such values are notably higher than those presently measured in the oceanic crust. This uranium enrichment with respect to lead is due to the combined effect of the magmatic fractionations and of chemical exchanges during marine alteration. Pb loss must be an important factor for the U/Pb increase. Since the 207Pb/ 204Pb ratio is not affected by recent radioactive decay, it represents a very useful tracer for the discussion of the genetic environment of the ophiolites. Three main types of Pb isotopic characteristics may be distinguished among ophiolite complexes, on the basis of their 207Pb/ 204Pb : - The ophiolite complexes of In Zecca (Corsica), Semail (Oman) and Toba (Japan) show 207Pb/ 204Pb similar to the least radiogenic present-day MORB. These complexes probably originated in regions geochemically comparable to the present-day depleted mantle. However, the Semail ophiolite has a higher 208Pb/ 204Pb ratio than MORB, which may be compatible with an origin in an interarc basin or premature arc. - The circum-Pacific ophiolites of Papua New Guinea, New Caledonia and Zambales (Philippines) have 207Pb/ 204Pb comparable to the present-day "transitional" portions of the ridges. - Finally the circum-Mediterranean ophiolites of Troodos, Vourinos, and Antalya, display 207Pb/ 204Pb ratios clearly higher than those of the present accretion zones. Thus, their genesis must have involved a significant continental component, and an origin in an

  9. Discovery of the thallium, lead, bismuth, and polonium isotopes

    NASA Astrophysics Data System (ADS)

    Fry, C.; Thoennessen, M.

    2013-05-01

    Forty-two thallium, forty-two lead, forty-one bismuth, and forty-two polonium isotopes have so far been observed; the discovery of these isotopes is described. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  10. Identification of gasoline lead in children's blood using isotopic analysis.

    PubMed

    Tera, O; Schwartzman, D W; Watkins, T R

    1985-01-01

    The isotopic composition and concentrations of lead were measured, using mass spectrometric analysis, in blood drawn from 14 young children who lived in Washington, D.C. The isotopic composition of lead in ambient air, which reflects the changing sources of gasoline lead, was also determined for the period of sampling. Blood lead concentrations ranged from 4.38 to 24.7 micrograms/100 g blood. Based on linear patterns that involved ratios of all four isotopes consistent with two component mixing, we estimate a minimum contribution of recent gasoline lead ranging from 0 to 57% of the blood lead burden.

  11. Lead isotopes as a supplementary tool in the routine evaluation of household lead hazards.

    PubMed Central

    Gwiazda, R H; Smith, D R

    2000-01-01

    The advent of magnetic sector inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid, accurate, and precise measurement of lead isotopes in environmental and biological samples at a lower cost than traditional methods. This may increase the feasibility of including lead isotope measurements as a routine tool to identify household sources of lead exposure to children. Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental specialist could be supplemented with routine lead isotope analyses of potential lead sources and blood. Sampling for lead isotopes was undertaken following the U.S. Department of Housing and Urban Development regulatory guidelines for the evaluation of lead hazards in housing, and with the consideration of minimizing the additional costs associated with lead isotope measurements. The range of isotopic ratios within a single residence was large enough to allow the characterization of different lead sources, particularly when both major (e.g., (207)Pb/(206)Pb) and minor (e.g., (206)Pb/(204)Pb) isotope ratios were considered. These cases illustrate the utility of the lead isotope method to identify main source(s) of lead exposure to the child; discard unlikely sources of exposure to the child; point to sources of lead to dust; and substantiate or refine the environmental assessment based exclusively on lead concentrations and loadings. Thus, a more effective evaluation of household lead hazards would likely benefit from considering a) lead concentrations and loadings in and around the household environment; b) all isotopic ratios of potential lead sources within that environment; and c) information about behavioral habits, as well as an evaluation of viable pathways of exposure to the child. PMID:11102302

  12. Lead isotopes as a supplementary tool in the routine evaluation of household lead hazards.

    PubMed

    Gwiazda, R H; Smith, D R

    2000-11-01

    The advent of magnetic sector inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid, accurate, and precise measurement of lead isotopes in environmental and biological samples at a lower cost than traditional methods. This may increase the feasibility of including lead isotope measurements as a routine tool to identify household sources of lead exposure to children. Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental specialist could be supplemented with routine lead isotope analyses of potential lead sources and blood. Sampling for lead isotopes was undertaken following the U.S. Department of Housing and Urban Development regulatory guidelines for the evaluation of lead hazards in housing, and with the consideration of minimizing the additional costs associated with lead isotope measurements. The range of isotopic ratios within a single residence was large enough to allow the characterization of different lead sources, particularly when both major (e.g., (207)Pb/(206)Pb) and minor (e.g., (206)Pb/(204)Pb) isotope ratios were considered. These cases illustrate the utility of the lead isotope method to identify main source(s) of lead exposure to the child; discard unlikely sources of exposure to the child; point to sources of lead to dust; and substantiate or refine the environmental assessment based exclusively on lead concentrations and loadings. Thus, a more effective evaluation of household lead hazards would likely benefit from considering a) lead concentrations and loadings in and around the household environment; b) all isotopic ratios of potential lead sources within that environment; and c) information about behavioral habits, as well as an evaluation of viable pathways of exposure to the child.

  13. Tables for determining lead, uranium, and thorium isotope ages

    NASA Technical Reports Server (NTRS)

    Schonfeld, E.

    1974-01-01

    Tables for determining lead, uranium, and thorium isotope ages are presented in the form of computer printouts. Decay constants, analytical expressions for the functions evaluated, and the precision of the calculations are briefly discussed.

  14. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    USGS Publications Warehouse

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  15. Use of endogeneous, stable lead isotopes to determine release of lead from the skeleton

    SciTech Connect

    Smith, D. |; Flegal, R.; Osterioh, J.D.

    1996-01-01

    The stable lead isotope methodology can be used to study the release of lead from bone into the circulation because of its potential to distinguish circulatory lead form {open_quotes}older{close_quotes} and isotopically different skeletal lead that may have been accumulated years or decades earlier. Here we report the initial results from a larger ongoing study that evaluates the skeleton as a source of lead to the circulation in environmentally exposed human subjects. Lead concentrations and stable lead isotopic compositions were measured in blood and trabecular bone samples obtained from five patients who underwent total hip or knee joint replacement. All subjects contained low blood (1-6 {mu}g/dl) and bone (0.6-7 {mu}g/g dry weight) lead concentrations typical of environmentally exposed individuals. There were relatively large differences in the lead isotopic compositions between the paired blood and bone samples from each subject. These isotopic differences are attributed to differences in the lead isotopic compositions of past versus current lead exposures and to the long elimination half-life of lead in the skeleton compared to lead in the circulation. Based on these data, we determined that the skeleton contributed 40-70% of the lead in the blood of these subjects. This initial study demonstrates the utility of the stable lead isotope methodology for investigating the release of lead from the skeleton. It also shows that the skeleton can be an important endogenous source of lead exposure in environmentally exposed humans. 54 refs., 3 figs., 1 tab.

  16. Use of endogenous, stable lead isotopes to determine release of lead from the skeleton.

    PubMed Central

    Smith, D R; Osterloh, J D; Flegal, A R

    1996-01-01

    The stable lead isotope methodology can be used to study the release of lead from bone into the circulation because of its potential to distinguish circulatory lead from "older" and isotopically different skeletal lead that may have been accumulated years or decades earlier. Here we report the initial results from a larger ongoing study that evaluates the skeleton as a source of lead to the circulation in environmentally exposed human subjects. Lead concentrations and stable lead isotopic compositions were measured in blood and trabecular bone samples obtained from five patients who underwent total hip or knee joint replacement. All subjects contained low blood (1-6 micrograms/dl) and bone (0.6-7 micrograms/g dry weight) lead concentrations typical of environmentally exposed individuals. There were relatively large differences in the lead isotopic compositions between the paired blood and bone samples from each subject. These isotopic differences are attributed to differences in the lead isotopic compositions of past versus current lead exposures and to the long elimination half-life of lead in the skeleton compared to lead in the circulation. Based on these data, we determined that the skeleton contributed 40-70% of the lead in the blood of these subjects. This initial study demonstrates the utility of the stable lead isotope methodology for investigating the release of lead from the skeleton. It also shows that the skeleton can be an important endogenous source of lead exposure in environmentally exposed humans. Images Figure 1. Figure 2. A Figure 2. B Figure 3. PMID:8834863

  17. A lead isotope study of mineralization in the Saudi Arabian Shield

    USGS Publications Warehouse

    Stacey, J.S.; Doe, B.R.; Roberts, R.J.; Delevaux, M.H.; Gramlich, J.W.

    1980-01-01

    New lead isotope data are presented for some late Precambrian and early Paleozoic vein and massive sulfide deposits in the Arabian Shield. Using the Stacey Kramers (1975) model for lead isotope evolution, isochron model ages range between 720 m.y. and 420 m.y. Most of the massive sulfide deposits in the region formed before 680 m.y. ago, during evolution of the shield. Vein type mineralization of higher lead content occurred during the Pan African event about 550 m.y. ago and continued through the Najd period of extensive faulting in the shield that ended about 530 m.y. ago. Late post-tectonic metamorphism may have been responsible for vein deposits that have model ages less than 500 m.y. Alternatively some of these younger model ages may be too low due to the mineralizing fluids acquiring radiogenic lead from appreciably older local crustal rocks at the time of ore formation. The low207Pb/204Pb ratios found for the deposits in the main part of the shield and for those in north-eastern Egypt, indicate that the Arabian craton was formed in an oceanic crustal environment during the late Precambrian. Involvement of older, upper-crustal material in the formation of the ore deposits in this part of the shield is precluded by their low207Pb/204Pb and208Pb/204Pb characteristics. In the eastern part of the shield, east of longitude 44??20???E towards the Al Amar-Idsas fault region, lead data are quite different. They exhibit a linear207Pb/204Pb-206Pb/204Pb relationship together with distinctly higher208Pb/204Pb characteristics. These data imply the existence of lower crustal rocks of early Proterozoic age that apparently have underthrust the shield rocks from the east. If most of the samples we have analyzed from this easterly region were mineralized 530 m.y. ago, then the age of the older continental rocks is 2,100??300 m.y. (2??). The presence of upper crustal rocks, possibly also of early Proterozoic age, is indicated by galena data from Hailan in South Yemen and also

  18. The identification of lead ammunition as a source of lead exposure in First Nations: the use of lead isotope ratios.

    PubMed

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-04-15

    The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of (206)Pb/(204)Pb and (206)Pb/(207)Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (p<0.05) positive correlations for (206)Pb/(204)Pb and (206)Pb/(207)Pb, and a significant negative correlation for (208)Pb/(206)Pb, as predicted if leaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden.

  19. Galena Electric Power A Situational Analysis

    SciTech Connect

    Robert E. Chaney; Stephen G. Colt; Ronald A. Johnson; Richard W. Wiles; Gregory J. White

    2008-12-31

    The purpose of the investigation is to compare the economics of various electrical power generation options for the City of Galena. Options were assessed over a 30-year project period, beginning in 2010, and the final results were compared on the basis of residential customer electric rates ($/kWh). Galena's electric utility currently generates power using internal combustion diesel engines and generator sets. Nearby, there is an exposed coal seam, which might provide fuel for a power plant. Contributions to the energy mix might come from solar, municipal solid waste, or wood. The City has also been approached by Toshiba, Inc., as a demonstration site for a small (Model 4S) nuclear reactor power plant. The Yukon River is possibly a site for in-river turbines for hydroelectric power. This report summarizes the comparative economics of various energy supply options. This report covers: (1) thermal and electric load profiles for Galena; (2) technologies and resources available to meet or exceed those loads; (3) uses for any extra power produced by these options; (4) environmental and permitting issues and then; and (5) the overall economics of each of the primary energy options.

  20. Lead isotopic compositions of soil and near-surface till profiles from a watershed containing arsenic-enriched groundwater in coastal Maine

    USGS Publications Warehouse

    Ayuso, Robert; Foley, Nora; Wandless, Gregory; Dillingham, Jeremy; Colvin, Anna

    2005-01-01

    Lead isotope compositions of soils and near-surface tills from an area of coastal Maine known to have groundwater with anomalously high arsenic contents were measured in order to determine the source of the lead and, by inference, possible sources of arsenic. Five soil and till sites were selected for detailed chemical and isotopic analysis. To construct profiles of the soil and till horizons, five samples were collected at 10-cm intervals from the surface to the base of each horizon. Total lead and arsenic concentrations and lead isotopic compositions were measured for 48 leaches and bulk residues. The soils and tills are underlain by sulfidic schists of the Penobscot Formation. Several generations of minerals containing arsenic and lead exist in the regional bedrock, including rock-forming silicates (feldspar and micas), sulfide minerals formed during diagenesis (for example, arsenic-rich pyrite), and sulfide and oxide minerals that formed as a result of Silurian metamorphic and igneous events (for example, arsenopyrite, galena, iron-oxides, and arsenic-sulfides). A young group of secondary minerals (for example, iron-hydroxides, arsenic-hydroxides, lead-sulfate, and arsenic-jarosite) formed from recent weathering and pedogenic processes.

  1. Lead (Pb) isotopic fingerprinting and its applications in lead pollution studies in China: a review.

    PubMed

    Cheng, Hefa; Hu, Yuanan

    2010-05-01

    As the most widely scattered toxic metal in the world, the sources of lead (Pb) observed in contamination investigation are often difficult to identify. This review presents an overview of the principles, analysis, and applications of Pb isotopic fingerprinting in tracing the origins and transport pathways of Pb in the environment. It also summarizes the history and current status of lead pollution in China, and illustrates the power of Pb isotopic fingerprinting with examples of its recent applications in investigating the effectiveness of leaded gasoline phase-out on atmospheric lead pollution, and the sources of Pb found in various environmental media (plants, sediments, and aquatic organisms) in China. The limitations of Pb isotopic fingerprinting technique are discussed and a perspective on its development is also presented. Further methodological developments and more widespread instrument availability are expected to make isotopic fingerprinting one of the key tools in lead pollution investigation.

  2. Stable lead isotopes evidence anthropogenic contamination in Alaskan sea otters

    SciTech Connect

    Smith, D.R.; Estes, J.A.; Flegal, A.R. ); Niemeyer, S. )

    1990-10-01

    Lead concentrations and stable isotopic compositions were measured in teeth of preindustrial and contemporary sea otters (Enhydra lutris) from Amchitka Island, AK, to determine if changes had occurred in the magnitude and source of assimilated lead. Although there was no significant difference in lead concentrations between the two groups of otters ({bar x} {plus minus} {sigma}Pb/Ca atomic = 3.6 {plus minus} 2.9 {times} 10{sup {minus}8}), differences in stable lead isotopic compositions revealed a pronounced change in the source of accumulated lead. Lead {bar x} {plus minus} 2{sigma}{sub {bar x}} in the preindustrial otters ({sup 207}Pb/{sup 206}Pb = 0.828 {plus minus} 0.006) was derived from natural deposits in the Aleutian arc, while lead in the contemporary animals ({sup 207}Pb/{sup 206}Pb = 0.856 {plus minus} 0.003) was primarily industrial lead from Asia and western Canada. The isotopic ratios demonstrate anthropogenic perturbations of the lead cycle in present-day coastal food webs and indicate that lead concentration measurements alone are inadequate in assessing the introduction and transport of contaminant lead in the environment.

  3. A novel surfactant S-benzoyl-N,N-diethyldithiocarbamate synthesis and its flotation performance to galena

    NASA Astrophysics Data System (ADS)

    Ma, Xin; Hu, Yuan; Zhong, Hong; Wang, Shuai; Liu, Guangyi; Zhao, Gang

    2016-03-01

    In this paper, a novel dithiocarbamate compound, S-benzoyl-N,N-diethyldithiocarbamate (BEDTC), was synthesized via one-pot reaction of diethylamine, carbon disulfide, sodium hydroxide and benzoyl chloride using abundant carbon disulfide as a solvent. Its flotation performance and adsorption mechanism on the galena was first investigated by flotation tests, adsorption quantity measurements, FTIR spectra, X-ray photoelectron spectra (XPS) and density functional theory (DFT) calculation. The flotation results illustrated that BEDTC exhibited stronger collecting power than the conventional sulphide collectors such as sodium diethyl dithiocarbamate (SEDTC) and sodium isobutyl xanthate (SIBX) and superior selectivity for galena against sphalerite. The adsorption data demonstrated that the adsorption affinity of BEDTC to galena was stronger than that of SEDTC and SIBX, and the preferable pH range for BEDTC adsorption on galena surfaces was 6-10. The results of FTIR spectra and XPS indicated that the interaction of BEDTC with galena may be dominated by the chemical adsorption, which was further confirmed by DFT calculation. BEDTC probably acted as a bidentate ligand, bonding with lead through the thiol sulfur and carbonyl oxygen atoms to form two distinct adsorption geometries, one with the same Pb atom to form a six-membered ring complex, and the other with two different Pb atoms to form a "bullet" shape complex.

  4. Genetic relations of oceanic basalts as indicated by lead isotopes

    USGS Publications Warehouse

    Tatsumoto, M.

    1966-01-01

    The isotopic compositions of lead and the concentrations of lead, uranium, and thorium in samples of oceanic tholeiite and alkali suites are determined, and the genetic relations of the oceanic basalts are discussed. Lead of the oceanic tholeiites has a varying lead-206 : lead-204 ratio between 17.8 and 18.8, while leads of the alkali basalt suites from Easter Island and Guadalupe Island are very radiogenic with lead-206 : lead-204 ratios between 19.3 and 20.4. It is concluded that (i) the isotopic composition of lead in oceanic tholeiite suggests that the upper mantle source region of the tholeiite was differentiated from an original mantle material more than 1 billion years ago and that the upper mantle is not homogeneous at the present time, (ii) less than 20 million years was required for the crystal differentiation within the alkali suite from Easter Island, (iii) no crustal contamination was involved in the course of differentiation of rocks from Easter Island; however, some crustal contamination may have affected Guadalupe Island rocks, and (iv) alkali basalt may be produced from the tholeiite in the oceanic region by crystal differentiation. Alternatively the difference in the isotopic composition of lead in oceanic basalts may be produced by partial melting at different depths of a differentiated upper mantle.

  5. [Investigation of the enrichment and separation of lead and lead isotopes in simulated blood matrix].

    PubMed

    Wu, Jing; Ouyang, Li; Tang, Xiao-ping; Liu, Tie-bing; Liu, Duo-jian; Wang, Jing-yu

    2012-03-01

    The enrichment and separation method was used in the present paper to overcome the influence of matrix effect on the determination of lead concentration and isotope ratios. The patented method was used to enrich and separate the lead in simulated blood matrix; the lead concentrations and isotope ratios were determined by ICP-MS before and after enrichment and separation. The recovery rate of Pb is more than 99% through this method while the removal rate of major impurity ions such as Na, K is about 80%. The concentrations of each lead isotope decrease with the matrix concentration increasing (p < 0.001), and lead isotope ratios show no significant differences in the matrix of different concentrations. When the matrix concentration is more than 62.5 microg x mL(-1), the strength will decrease with the determination times increasing. It was concluded that the characteristics of this method are of high recovery rate (> 99%), fast, simple and convenient, and it can raise the accuracy and precision of the concentration determination of lead isotopes and has no significant influence on the accuracy of lead isotope ratios determination.

  6. Tracing source pollution in soils using cadmium and lead isotopes.

    PubMed

    Cloquet, C; Carignan, J; Libourel, G; Sterckeman, T; Perdrix, E

    2006-04-15

    Tracing the source of heavy metals in the environment is of key importance for our understanding of their pollution and natural cycles in the surface Earth reservoirs. Up to now, most exclusively Pb isotopes were used to effectively trace metal pollution sources in the environment. Here we report systematic variations of Cd isotope ratios measured in polluted topsoils surrounding a Pb-Zn refinery plant in northern France. Fractionated Cd was measured in soil samples surrounding the refinery, and this fractionation can be attributed to the refining processes. Despite the Cd isotopic ratios being precisely measured, the obtained uncertainties are still large compared to the total isotopic variation. Nevertheless, for the first time, Cd isotopically fractionated by industrial processes may be traced in the environment. On the same samples, Pb isotope systematics suggested that materials actually used by the refinery were not the major source of Pb in soils, probably because refined ore origins changed over the 100 years of operation. On the other hand, Cd isotopes and concentrations measured in topsoils allowed identification of three main origins (industrial dust and slag and agriculture), assuming that all Cd ores are not fractionated, as suggested by terrestrial rocks so far analyzed, and calculation of their relative contributions for each sampling point. Understanding that this refinery context was an ideal situation for such a study, our results lead to the possibility of tracing sources of anthropogenic Cd and better constrain mixing processes, fluxes, transport, and phasing out of industrial input in nature.

  7. Stable lead isotopes reveal a natural source of high lead concentrations to gasoline-contaminated groundwater

    USGS Publications Warehouse

    Landmeyer, J.E.; Bradley, P.M.; Bullen, T.D.

    2003-01-01

    Concentrations of total lead as high as 1,600 ??g/L were detected in gasoline-contaminated and uncontaminated groundwater at three gasoline-release sites in South Carolina. Total lead concentrations were highest in turbid groundwater samples from gasoline-contaminated and uncontaminated wells, whereas lower turbidity groundwater samples (collected using low-flow methods) had lower total lead concentrations. Dissolved lead concentrations in all wells sampled, however, were less than 15 ??g total lead/L, the current United States Environmental Protection Agency (US EPA) maximum contaminant level (MCL). Because many total lead concentrations exceeded the MCL, the source of lead to the groundwater system at two of the three sites was investigated using a stable lead isotope ratio approach. Plots of the stable isotope ratios of lead (Pb) in groundwater as 207Pb/206Pb versus 208Pb/206Pb, and 208Pb/204Pb versus 206Pb/204Pb were similar to ratios characteristic of lead-based minerals in local rocks of the southeastern US, and were not similar to the stable lead isotopes ratios characteristic of distant lead ore deposits such as Broken Hill, Australia, used to produce tetraethyl lead in gasoline products prior to its phase-out and ban in the United States. Moreover, the isotopic composition of dissolved lead was equivalent to the isotopic composition of total lead in turbid samples collected from the same well, suggesting that the majority of the lead detected in the groundwater samples was associated with sediment particulates of indigenous aquifer material, rather than lead associated with spilled leaded gasoline. The results of this investigation indicate that (1) lead detected at some gasoline-release sites may be derived from the local aquifer material, rather than the gasoline release, and consequently may affect site-specific remediation goals; (2) non-low flow groundwater sampling methods, such as a disposable bailer, may result in turbid groundwater samples and

  8. A list of references on lead isotope geochemistry through 1966

    USGS Publications Warehouse

    Doe, Bruce R.

    1968-01-01

    This bibliography was constructed to be as complete as possible for terminal papetrs containing new data relative to the geochmical applications of Common lead U-Th-Pb isotopic dating Pb-α Pb210, Pb212, Pb214 No effort was made for completeness of: Annual report, Yearbooks, etc. Review papers although many are included. Abstract and these are omitted.

  9. Lead isotopes in the western North Atlantic: Transient tracers of pollutant lead inputs

    SciTech Connect

    Veron, A.J. |; Church, T.M.; Flegal, A.R.

    1998-08-01

    In the early 1980s, Patterson and colleagues demonstrated that most lead in oceanic surface waters had an anthropogenic origin. Their discovery occurred during the phasing out of leaded gasoline in North America initiated in the previous decade. The corresponding decrease in anthropogenic lead emissions, verified by Pb/{sup 210}Pb ratios, accounted for the systematic decline in lead concentrations in surface waters of the western Sargasso Sea. Subsequent changes in anthropogenic lead inputs to the western Sargasso Sea surface waters have been documented by measurements of lead concentrations, isotopic compositions ({sup 206}Pb/{sup 207}Pb, {sup 208}Pb/{sup 206}Pb), and Pb/{sup 210}Pb ratios in precipitation and seawater for the period of 1981 to 1994. These data indicate the easterly trade winds are now the primary source of atmospheric lead in Bermuda, and they confirm that the decline of lead concentrations in the North Atlantic is associated with the phasing out of leaded gasoline in North America and western Europe over the past decade. Moreover, temporal variations in the relative contribution of industrial lead inputs from the two sides of the North Atlantic over that period can be quantified based on differences in their isotopic composition. The transient character of those isotopic signatures also allows calculations of pollutant lead penetration rates into the mixed layer and upper thermocline of the western Sargasso Sea.

  10. Lead isotopes in marine surface sediments reveal historical use of leaded fuel.

    PubMed

    Larsen, Martin M; Blusztajn, Jerzy S; Andersen, Ole; Dahllöf, Ingela

    2012-11-01

    Analyses of lead (Pb) isotopes have been performed in terrestrial and fresh water environments to estimate historical uses of leaded fuel, but so far this method has not been employed in studies of world-wide marine surface sediments. We analyzed Pb and its isotopes in 23 surface sediments from four continents collected during the Galathea 3 expedition in 2006-2007. To enhance the anthropogenic signal, a partial digestion using nitric acid was performed. The concentrations of Pb, Th, U and Al were determined with an ICP-Quadrupole MS, and Pb-isotope ratios with an ICP-multi-collector MS. The samples could be divided into three groups: Harbor areas in larger cities with concentrations of 150 to 265 mg kg(-1) dry weight, smaller towns with concentrations between 20 and 40 mg kg(-1) dry weight, and remotely located sites with concentrations below 15 mg kg(-1) dry weight. Pb-isotope ratios were compared to literature values for gasoline and local or geological background values, and the contribution of leaded-gasoline to total concentrations was calculated for contaminated sites using both a one-dimensional and a novel two-dimensional (vector) method. The North American sites had Pb-isotope ratios corresponding to the US leaded gasoline, with 24-88% of the Pb from leaded gasoline. Samples from Oceania showed Pb-isotope ratios corresponding to Australian gasoline, with 60% attributed to leaded gasoline in Sydney and 21% in Christchurch. Outside Cape Town, 15 to 46% of Pb in sediments was from leaded gasoline.

  11. Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine.

    PubMed

    Kristensen, Louise Jane; Taylor, Mark Patrick; Evans, Andrew James

    2016-07-01

    Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data.

  12. Tracing changes in atmospheric sources of lead contamination using lead isotopic compositions in Australian red wine.

    PubMed

    Kristensen, Louise Jane; Taylor, Mark Patrick; Evans, Andrew James

    2016-07-01

    Air quality data detailing changes to atmospheric composition from Australia's leaded petrol consumption is spatially and temporally limited. In order to address this data gap, wine was investigated as a potential proxy for atmospheric lead conditions. Wine spanning sixty years was collected from two wine regions proximal to the South Australian capital city, Adelaide, and analysed for lead concentration and lead and strontium isotopic composition for source apportionment. Maximum wine lead concentrations (328 μg/L) occur prior to the lead-in-air monitoring in South Australia in the later 1970s. Wine lead concentrations mirror available lead-in-air measurements and show a declining trend reflecting parallel reductions in leaded petrol emissions. Lead from petrol dominated the lead in wine ((206)Pb/(207)Pb: 1.086; (208)Pb/(207)Pb: 2.360) until the introduction of unleaded petrol, which resulted in a shift in the wine lead isotopic composition closer to vineyard soil ((206)Pb/(207)Pb: 1.137; (208)Pb/(207)Pb: 2.421). Current mining activities or vinification processes appear to have no impact with recent wine samples containing less than 4 μg/L of lead. This study demonstrates wine can be used to chronicle changes in environmental lead emissions and is an effective proxy for atmospherically sourced depositions of lead in the absence of air quality data. PMID:27037773

  13. Lead isotope characterization of petroleum fuels in Taipei, Taiwan.

    PubMed

    Yao, Pei-Hsuan; Shyu, Guey-Shin; Chang, Ying-Fang; Chou, Yu-Chen; Shen, Chuan-Chou; Chou, Chi-Su; Chang, Tsun-Kuo

    2015-04-24

    Leaded gasoline in Taiwan was gradually phased out from 1983 to 2000. However, it is unclear whether unleaded gasoline still contributes to atmospheric lead (Pb) exposure in urban areas. In this study, Pb isotopic compositions of unleaded gasolines, with octane numbers of 92, 95, 98, and diesel from two local suppliers in Taipei were determined by multi-collector inductively coupled plasma mass spectrometry with a two-sigma uncertainty of ± 0.02 %. Lead isotopic ratios of vehicle exhaust (²⁰⁸Pb/²⁰⁷Pb: 2.427, ²⁰⁶Pb/²⁰⁷Pb: 1.148, as estimated from petroleum fuels) overlap with the reported aerosol data. This agreement indicates that local unleaded petroleum fuels, containing 10-45 ng·Pb·g⁻¹, are merely one contributor among various sources to urban aerosol Pb. Additionally, the distinction between the products of the two companies is statistically significant in their individual ²⁰⁸Pb/²⁰⁶Pb ratios (p-value < 0.001, t test). Lead isotopic characterization appears to be applicable as a "fingerprinting" tool for tracing the sources of Pb pollution.

  14. Lead Isotope Characterization of Petroleum Fuels in Taipei, Taiwan

    PubMed Central

    Yao, Pei-Hsuan; Shyu, Guey-Shin; Chang, Ying-Fang; Chou, Yu-Chen; Shen, Chuan-Chou; Chou, Chi-Su; Chang, Tsun-Kuo

    2015-01-01

    Leaded gasoline in Taiwan was gradually phased out from 1983 to 2000. However, it is unclear whether unleaded gasoline still contributes to atmospheric lead (Pb) exposure in urban areas. In this study, Pb isotopic compositions of unleaded gasolines, with octane numbers of 92, 95, 98, and diesel from two local suppliers in Taipei were determined by multi-collector inductively coupled plasma mass spectrometry with a two-sigma uncertainty of ± 0.02 %. Lead isotopic ratios of vehicle exhaust (208Pb/207Pb: 2.427, 206Pb/207Pb: 1.148, as estimated from petroleum fuels) overlap with the reported aerosol data. This agreement indicates that local unleaded petroleum fuels, containing 10–45 ng·Pb·g−1, are merely one contributor among various sources to urban aerosol Pb. Additionally, the distinction between the products of the two companies is statistically significant in their individual 208Pb/206Pb ratios (p-value < 0.001, t test). Lead isotopic characterization appears to be applicable as a “fingerprinting” tool for tracing the sources of Pb pollution. PMID:25918913

  15. Lead isotope characterization of petroleum fuels in Taipei, Taiwan.

    PubMed

    Yao, Pei-Hsuan; Shyu, Guey-Shin; Chang, Ying-Fang; Chou, Yu-Chen; Shen, Chuan-Chou; Chou, Chi-Su; Chang, Tsun-Kuo

    2015-05-01

    Leaded gasoline in Taiwan was gradually phased out from 1983 to 2000. However, it is unclear whether unleaded gasoline still contributes to atmospheric lead (Pb) exposure in urban areas. In this study, Pb isotopic compositions of unleaded gasolines, with octane numbers of 92, 95, 98, and diesel from two local suppliers in Taipei were determined by multi-collector inductively coupled plasma mass spectrometry with a two-sigma uncertainty of ± 0.02 %. Lead isotopic ratios of vehicle exhaust (²⁰⁸Pb/²⁰⁷Pb: 2.427, ²⁰⁶Pb/²⁰⁷Pb: 1.148, as estimated from petroleum fuels) overlap with the reported aerosol data. This agreement indicates that local unleaded petroleum fuels, containing 10-45 ng·Pb·g⁻¹, are merely one contributor among various sources to urban aerosol Pb. Additionally, the distinction between the products of the two companies is statistically significant in their individual ²⁰⁸Pb/²⁰⁶Pb ratios (p-value < 0.001, t test). Lead isotopic characterization appears to be applicable as a "fingerprinting" tool for tracing the sources of Pb pollution. PMID:25918913

  16. Lead isotopes reveal different sources of lead in balsamic and other vinegars.

    PubMed

    Ndung'u, Kuria; Hibdon, Sharon; Véron, Alain; Flegal, A Russell

    2011-06-15

    Fifty-eight brands of balsamic vinegars were analyzed for lead concentrations and isotopic compositions ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) to test the findings of a previous study indicating relatively high levels of lead contamination in some of those vinegars--more than two thirds (70%) of them exceeded California's State Maximum Level (34 μg/L) based on consumption rates ≥0.5 μg Pb per day. The lead isotopic fingerprints of all those vinegars with high lead concentrations were then found to be primarily anthropogenic. This isotopic analysis unquestionably reveals multiple contamination sources including atmospheric pollutant Pb and an unidentified contamination source, likely occurring after grape harvest. Organically grown grape vinegars display the same Pb content and isotopic signatures as other vinegars. This implies that pesticides might not be a significant source of pollutant Pb in vinegars. A significant post-harvest contamination would be inherited from chemicals added during production and/or material used during transport, processing or storage of these vinegars. This is consistent with the highest Pb levels being found in aged vinegars (112±112 μg/L) in contrast to other vinegars (41.6±28.9 μg/L) suggesting contamination during storage. It is, therefore, projected that lead levels in most vinegars, especially aged balsamic and wine vinegars, will decrease with improvements in their manufacture and storage processes consequential to recent concerns of elevated levels of lead in some vinegars.

  17. Lead isotope systematics of three Apollo 17 mare basalts

    NASA Technical Reports Server (NTRS)

    Tilton, G. R.; Chen, J. H.

    1979-01-01

    The paper deals with new and more accurate determinations of uranium, thorium, and isotopic lead data for five bulk samples and separate pyroxene, ilmenite, and plagioclase from basalt 71055. In a concordia diagram, the samples suggest a postcrystallization disturbance of the U-Pb systems of the rock. There is no compelling reason, from U-Pb data, to believe that the moon is younger than 4.55 AE.

  18. Radiohalos: some unique lead isotope ratios and unknown alpha radioactivity.

    PubMed

    Gentry, R V

    1971-08-20

    Previously unreported lead isotope ratios, that is, values for the lead-206/lead-207 ratio ranging from about 20 to 60, primarily radiogenic in origin but unsupported by uranium decay, have been determined in the inclusions of certain polonium halos by means of ion microprobe techniques. Evidence for radiogenic lead-208 unsupported by thorium decay may also be inferred from the existence of a composite polonium halo type with rings from the radioactive precursors of lead-208. Several new dwarf halo sizes, seem to indicate the existence of unknown, very low-energy alpha-emitters. Furthermore, the three-ring "X halo" also provides evidence for an unknown series of genetically related alpha-emitters with energies in the range from 3 to 7 million electron volts.

  19. Hyperfine structure and isotope shift study in singly ionized lead

    NASA Astrophysics Data System (ADS)

    Wąsowicz, T. J.; Drozdowski, R.; Kwela, J.

    2005-12-01

    Hyperfine structure and isotope shifts in five optical transitions: 424.5 nm (6s^25f ^2textrm{F}_{7/2} 6s^26d^2 textrm{D}_{5/2}), 537.2 nm (6s^25f ^2textrm{F}_{7/2} 6s6p^2 ^4textrm{P}_{5/2}), 554.5 nm (6s^27d ^2textrm{D}_{5/2} 6s^27p ^2textrm{P}_{3/2}), 560.9 nm (6s^27p^2 textrm{P}_{3/2} 6s^27s ^2textrm{S}_{1/2}) and 666.0 nm (6s^27p ^2textrm{P}_{1/2} 6s^27s ^2textrm{S}_{1/2}) of Pb II have been measured. As a light source the discharge tube was used. The hyperfine structure measurements were performed using metallic isotope 207Pb. For isotope shifts measurements natural lead was used. The high resolution spectral apparatus consisted of a silver coated Fabry-Perot etalon and a grating spectrograph combined with a CCD camera used as a detector. In the analysis of the spectra a computer simulation technique was used. The hyperfine structure observations yielded the splitting constants A for seven levels of Pb II. The isotope shift studies enabled to separate the mass and the field shifts and to determine values of changes of the mean square nuclear charge radii.

  20. Lead isotopes and trace metals in dust at Yucca Mountain

    USGS Publications Warehouse

    Kwak, Loretta; Neymark, Leonid A.; Peterman, Zell E.

    2008-01-01

    Lead (Pb)-isotope compositions and trace-metal concentrations were determined for samples of dust collected from underground and surface locations at and near the proposed radioactive waste repository at Yucca Mountain, Nevada. Rare earth element concentrations in the dust samples from the underground tunnels are similar to those in wholerock samples of the repository host rocks (Miocene Tiva Canyon Tuff and Topopah Spring Tuff), supporting interpretation that the subsurface dust is mainly composed of rock comminuted during tunnel construction. Other trace metals (arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead, antimony, thallium, and zinc) are variably enriched in the subsurface dust samples relative to the average concentrations in the host rocks. Average concentrations of arsenic and lead in dust samples, high concentrations of which can cause corrosion of waste canisters, have enrichment factors from 1.2 to 1.6 and are insignificant relative to the range of concentrations for these metals observed in the host rock samples. Most dust samples from surface sites also are enriched in many of these trace metals relative to average repository host rocks. At least some of these enrichments may be artifacts of sampling. Plotted on a 208Pb/206Pb-207Pb/206Pb graph, Pb-isotope compositions of dust samples from underground sites form a mixing line extending from host-rock Pb-isotope compositions towards compositions of many of the dust samples from surface sites; however, combined Pb concentration and isotope data indicate the presence of a Pbenriched component in the subsurface dust that is not derived from host rock or surface dust and may derive from anthropogenic materials introduced into the underground environment.

  1. Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi.

    PubMed

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K; Wu, Michael

    2016-01-01

    Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead contents were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the use of leaded petrol for automobiles in Australia from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in (206)Pb/(207)Pb values from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi (206)Pb/(207)Pb values increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region.

  2. Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi.

    PubMed

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K; Wu, Michael

    2016-01-01

    Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead contents were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the use of leaded petrol for automobiles in Australia from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in (206)Pb/(207)Pb values from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi (206)Pb/(207)Pb values increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region. PMID:26608874

  3. Mineralogic, fluid inclusion, and sulfur isotope evidence for the genesis of Sechangi lead-zinc (-copper) deposit, Eastern Iran

    NASA Astrophysics Data System (ADS)

    Malekzadeh Shafaroudi, Azadeh; Karimpour, Mohammad Hassan

    2015-07-01

    The Sechangi lead-zinc (-copper) deposit lies in the Lut block metallogenic province of Eastern Iran. This deposit consists of ore-bearing vein emplaced along fault zone and hosted by Late Eocene monzonite porphyry. Hydrothermal alteration minerals developed in the wall rock include quartz, kaolinite, illite, and calcite. Microscopic studies reveal that the vein contains galena and sphalerite with minor chalcopyrite and pyrite as hypogene minerals and cerussite, anglesite, covellite, malachite, hematite, and goethite as secondary minerals. Fluorite and quartz are the dominant gangue minerals and show a close relationship with sulfide mineralization. Calculated δ34S values for the ore fluid vary between -9.9‰ and -5.9‰. Sulfur isotopic compositions suggest that the ore-forming aqueous solutions were derived from magmatic source and mixed with isotopically light sulfur, probably leached from the volcanic and plutonic country rocks. Microthermometric study of fluid inclusions indicates homogenization temperatures of 151-352 °C. Salinities of ore-forming fluids ranged from 0.2 to 16.5 wt.% NaCl equivalent. The ore-forming fluids of the Sechangi deposit are medium- to low-temperature and salinity. Fluid mixing may have played an important role during Pb-Zn (-Cu) mineralization. The key factors allowing for metal transport and precipitation during ore formation include the sourcing of magmatic fluids with high contents of metallogenic elements and the mixing of these hydrothermal fluids with meteoric waters resulting in the formation of deposit. In terms of the genetic type of deposit, the Sechangi is classified as a volcanic-subvolcanic hydrothermal-related vein deposit.

  4. A new method for stable lead isotope extraction from seawater.

    PubMed

    Zurbrick, Cheryl M; Gallon, Céline; Flegal, A Russell

    2013-10-24

    A new technique for stable lead (Pb) isotope extraction from seawater is established using Toyopearl AF-Chelate 650M(®) resin (Tosoh Bioscience LLC). This new method is advantageous because it is semi-automated and relatively fast; in addition it introduces a relatively low blank by minimizing the volume of chemicals used in the extraction. Subsequent analyses by HR ICP-MS have a good relative external precision (2σ) of 3.5‰ for (206)Pb/(207)Pb, while analyses by MC-ICP-MS have a better relative external precision of 0.6‰. However, Pb sample concentrations limit MC-ICP-MS analyses to (206)Pb, (207)Pb, and (208)Pb. The method was validated by processing the common Pb isotope reference material NIST SRM-981 and several GEOTRACES intercalibration samples, followed by analyses by HR ICP-MS, all of which showed good agreement with previously reported values.

  5. Laser photochemical lead isotopes separation for harmless nuclear power engineering

    NASA Astrophysics Data System (ADS)

    Bokhan, P. A.; Fateev, N. V.; Kim, V. A.; Zakrevsky, D. E.

    2016-09-01

    The collisional quenching of the metastable 3 P 1,2 and 1 D 2 lead atoms is studied experimentally in the gas flow of the lead atoms, reagent-molecules and a carrier gas Ar. The experimental parameters were similar to the conditions that are required in the operation of the experimental setup for photochemical isotope separation. Excited atoms are generated under electron impact conditions created by a gas glow discharge through the mixture of gases and monitored photoelectrically by attenuation of atomic resonance radiation from hollow cathode 208Pb lamp. The decay of the excited atoms has been studied in the presence various molecules and total cross section data are reported. The flow tube measurements has allowed to separate the physical and chemical quenching channels and measure the rates of the chemical reaction excited lead with N2O, CH2Cl2, SF6 and CuBr molecules. These results are discussed in the prospects of the obtaining isotopically modified lead as a promising coolant in the reactors on the fast-neutron.

  6. Isotopic generator for bismuth-212 and lead-212 from radium

    DOEpatents

    Atcher, Robert W.; Friedman, Arnold M.; Hines, John

    1987-01-01

    A method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

  7. Potential uses of lead isotope ratios in gunshot cases.

    PubMed

    Keisch, B; Callahan, R C

    1978-05-01

    The determination of lead isotope ratios in 14 bullets, and in material taken from 9 hand swabs and 5 primers shows that there are potentially valuable forensic uses for such a method. While a more complete study is required, this method could possibly be used to prove (or disprove) relatiohships between bullets and manufacturers, weapons, or persons firing the weapons. Sample size requirements (1 microgram or less) are such that damaged or fragmented bullets, or minute particles therefrom, may be used for the required analyses. An experiment showed that gunshot residue from a test-fired weapon was detectable even after washing the hands.

  8. Lead concentrations and isotopes in aerosols from Xiamen, China.

    PubMed

    Zhu, Laimin; Tang, Jianwu; Lee, Ben; Zhang, Yu; Zhang, Feifei

    2010-11-01

    To investigate the magnitude and origin of lead (Pb) pollution in the atmosphere of Xiamen, China, 40 aerosol samples were collected from the coast of Xiamen from January to December 2003. All these samples were measured for Pb isotopic compositions ((208)Pb/(206)Pb=2.10897 ± 0.00297, (207)Pb/(206)Pb=0.85767 ± 0.00159, n=40) using a Multi-collector-Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS). Thirty-five out of forty samples were also measured for Pb concentrations (79.1 ± 38.3 ng/m(3), n=35) by Atomic Absorption Spectroscopy (AAS). The results indicate that the Pb concentrations display significant seasonal variations while Pb isotopic ratios remain relatively constant. The Pb concentrations were high in January and February, abruptly decreased in March, remained relatively constant (but low) from April to August, and then gradually increased from September to December. This corresponds to the rainless climate in winter and rain scavenging in summer. The higher Pb concentration of Xiamen aerosols in winter and spring may be also caused by long-range transferred anthropogenic Pb during the northeastern monsoon seasons. Although the use of leaded gasoline in Xiamen was banned in 2000, our new data indicate that the Pb annual concentrations of aerosols in Xiamen increased about 12% when compared to the data measured between 1991 and 1993. Thus, Pb pollution in the atmosphere of Xiamen has not receded even after the phase-out of leaded gasoline. Our results further confirm the previous studies' conclusion that the primary source of atmospheric Pb in China, especially in South China, is the vast combustion of lead-containing coal, not leaded gasoline.

  9. Childhood lead exposure in an industrial town in China: coupling stable isotope ratios with bioaccessible lead.

    PubMed

    Li, Hong-Bo; Chen, Kai; Juhasz, Albert L; Huang, Lei; Ma, Lena Q

    2015-04-21

    Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 μg dL(-1), averaging 6.1 ± 3.2 μg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 μg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations.

  10. Childhood lead exposure in an industrial town in China: coupling stable isotope ratios with bioaccessible lead.

    PubMed

    Li, Hong-Bo; Chen, Kai; Juhasz, Albert L; Huang, Lei; Ma, Lena Q

    2015-04-21

    Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 μg dL(-1), averaging 6.1 ± 3.2 μg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 μg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations. PMID:25803404

  11. Uranium-thorium-lead isotope relations in lunar materials.

    PubMed

    Silver, L T

    1970-01-30

    The lead isotopic compositions and uranium, thorium, and lead concentrations have been measured on six samples of material from the Sea of Tranquillity. The leads are moderately to very radiogenic; the initial lead concentrations are very low; the uranium and thorium levels are 0.26 to 0.88 and 0.87 to 3.35 parts per million, respectively. The Th/U ratios cluster about a 3.6 value. Apparent ages calculated for four rocks are 4.1 to 4.2 x 10(9) years. Dust and breccia yield apparent ages of 4.60 to 4.63 x 10(9) years. The uranium-lead ages are concordant, or nearly so, in all cases. The lunar surface is an ancient region with an extended record of events in the early history of the solar system. discrepancy between the rock ages and dust ages poses a fundamental qusestion about rock genesis on the moon.

  12. Identifying sources of lead exposure for children, with lead concentrations and isotope ratios.

    PubMed

    Glorennec, P; Peyr, C; Poupon, J; Oulhote, Y; Le Bot, B

    2010-05-01

    Despite a dramatic decrease in children's blood lead levels (BLL), lead exposure remains a public health concern because increasing evidence shows effects at very low doses. Lowering BLL still further requires the identification of lead sources and, therefore, new tools to investigate and thus prevent exposure. We describe a procedure that uses both lead concentrations and isotope ratios (IRs) to identify sources of overexposure in homes. Water, dust, and paint chips were sampled from the homes of 21 children with elevated BLL from Aubervilliers (Paris metropolitan area). Lead concentrations of concern were calculated from reverse physiologically based pharmacokinetic modeling for water and dust. Isotope ratio matching of blood and environmental samples (with a lead content above the concentration of concern) was performed by computation of the distance between their IRs. When the IR of the source did not match that of the blood, the source was eliminated as a source of lead intoxication. The number of sources eliminated (per child) due to lead concentration ranged from 14% to 86% (mean 66%) for dust, and 100% for water samples. The number of remaining potential sources eliminated by IR interpretation varied from 0% to 100% for both dust and paint chips (mean 63% and 58%, respectively). IRs made it possible to eliminate at least one source in 20 of 21 cases and identified a single source in 11 of 21. The number of dust and paint sources not eliminated by concentration or IR varied from 8% to 45% (median 18%). The pilot study supports the usefulness of these procedures and the added value of IRs for identifying sources of lead poisoning. However, systematic use should be supported by cost-effectiveness analysis on a larger and more representative population of elevated BLL.

  13. Lead contamination and transfer in urban environmental compartments analyzed by lead levels and isotopic compositions.

    PubMed

    Hu, Xin; Sun, Yuanyuan; Ding, Zhuhong; Zhang, Yun; Wu, Jichun; Lian, Hongzhen; Wang, Tijian

    2014-04-01

    Lead levels and isotopic compositions in atmospheric particles (TSP and PM2.5), street dust and surface soil collected from Nanjing, a mega city in China, were analyzed to investigate the contamination and the transfer of lead in urban environmental compartments. The lead contents in TSP and PM2.5 are significantly higher than them in the surface soil and street dust (p < 0.05). The enrichment factor using the mass ratio of lead to the major crustal elements (Al, Sr, Ti and Fe) indicates significant lead enrichment in atmospheric particles. The plots of (206)Pb/(207)Pb vs.(208)Pb/(206)Pb and (206)Pb/(207)Pb vs. 1/Pb imply that the street dust and atmospheric particles (TSP and PM2.5) have very similar lead sources. Coal emissions and smelting activities may be the important lead sources for street dust and atmospheric particles (TSP and PM2.5), while the deposition of airborne lead is an important lead source for urban surface soil.

  14. Variations in lead isotopic abundances in Sprague-Dawley rat tissues: possible reason of formation.

    PubMed

    Liu, Duojian; Wu, Jing; Ouyang, Li; Wang, Jingyu

    2014-01-01

    It has been reported in previous research that the lead isotopic composition of blood, urine and feces samples statistically differed from the given lead sources in Sprague-Dawley (SD) rats. However, the reason for this phenomenon is still unclear. An animal experiment was performed to investigate the lead isotope fractionation in diverse biological samples (i.e., lungs, liver, kidneys, bone) and to explore the possible reasons. SD rats were intratracheally instilled with lead acetate at the concentrations of 0, 0.02, 0.2, and 2 mg/kg body weight. Biological samples were collected for lead isotope analysis using an inductively coupled plasma mass spectrometry (ICP-MS). Significant differences are observed in lead isotope abundances among the diverse biological samples. The lead isotope abundances ((206)Pb, (207)Pb and (208)Pb) in diverse biological samples show different degrees and directions of departure from the given lead source. The results suggest that differences in enrichment or depletion capacity for each lead isotope in the various tissues might lead to the variation in lead isotopic abundances in tissues. Moreover, a nonlinear relationship between the blood lead level and the lead isotope abundances in liver and bone is observed. When the whole-blood level is higher than 50 ng/mL, the lead isotopic compositions of biological samples tend to be the same. Thus, the data support the speculation of a fractionation functional threshold.

  15. Variations in Lead Isotopic Abundances in Sprague-Dawley Rat Tissues: Possible Reason of Formation

    PubMed Central

    Liu, Duojian; Wu, Jing; Ouyang, Li; Wang, Jingyu

    2014-01-01

    It has been reported in previous research that the lead isotopic composition of blood, urine and feces samples statistically differed from the given lead sources in Sprague-Dawley (SD) rats. However, the reason for this phenomenon is still unclear. An animal experiment was performed to investigate the lead isotope fractionation in diverse biological samples (i.e., lungs, liver, kidneys, bone) and to explore the possible reasons. SD rats were intratracheally instilled with lead acetate at the concentrations of 0, 0.02, 0.2, and 2 mg/kg body weight. Biological samples were collected for lead isotope analysis using an inductively coupled plasma mass spectrometry (ICP-MS). Significant differences are observed in lead isotope abundances among the diverse biological samples. The lead isotope abundances (206Pb, 207Pb and 208Pb) in diverse biological samples show different degrees and directions of departure from the given lead source. The results suggest that differences in enrichment or depletion capacity for each lead isotope in the various tissues might lead to the variation in lead isotopic abundances in tissues. Moreover, a nonlinear relationship between the blood lead level and the lead isotope abundances in liver and bone is observed. When the whole-blood level is higher than 50 ng/mL, the lead isotopic compositions of biological samples tend to be the same. Thus, the data support the speculation of a fractionation functional threshold. PMID:24587048

  16. A lead isotope perspective on urban development in ancient Naples.

    PubMed

    Delile, Hugo; Keenan-Jones, Duncan; Blichert-Toft, Janne; Goiran, Jean-Philippe; Arnaud-Godet, Florent; Romano, Paola; Albarède, Francis

    2016-05-31

    The influence of a sophisticated water distribution system on urban development in Roman times is tested against the impact of Vesuvius volcanic activity, in particular the great eruption of AD 79, on all of the ancient cities of the Bay of Naples (Neapolis). Written accounts on urbanization outside of Rome are scarce and the archaeological record sketchy, especially during the tumultuous fifth and sixth centuries AD when Neapolis became the dominant city in the region. Here we show that isotopic ratios of lead measured on a well-dated sedimentary sequence from Neapolis' harbor covering the first six centuries CE have recorded how the AD 79 eruption was followed by a complete overhaul of Neapolis' water supply network. The Pb isotopic signatures of the sediments further reveal that the previously steady growth of Neapolis' water distribution system ceased during the collapse of the fifth century AD, although vital repairs to this critical infrastructure were still carried out in the aftermath of invasions and volcanic eruptions.

  17. A lead isotope perspective on urban development in ancient Naples.

    PubMed

    Delile, Hugo; Keenan-Jones, Duncan; Blichert-Toft, Janne; Goiran, Jean-Philippe; Arnaud-Godet, Florent; Romano, Paola; Albarède, Francis

    2016-05-31

    The influence of a sophisticated water distribution system on urban development in Roman times is tested against the impact of Vesuvius volcanic activity, in particular the great eruption of AD 79, on all of the ancient cities of the Bay of Naples (Neapolis). Written accounts on urbanization outside of Rome are scarce and the archaeological record sketchy, especially during the tumultuous fifth and sixth centuries AD when Neapolis became the dominant city in the region. Here we show that isotopic ratios of lead measured on a well-dated sedimentary sequence from Neapolis' harbor covering the first six centuries CE have recorded how the AD 79 eruption was followed by a complete overhaul of Neapolis' water supply network. The Pb isotopic signatures of the sediments further reveal that the previously steady growth of Neapolis' water distribution system ceased during the collapse of the fifth century AD, although vital repairs to this critical infrastructure were still carried out in the aftermath of invasions and volcanic eruptions. PMID:27185923

  18. Bioavailability of soilborne lead in adults, by stable isotope dilution.

    PubMed Central

    Maddaloni, M; Lolacono, N; Manton, W; Blum, C; Drexler, J; Graziano, J

    1998-01-01

    Using stable isotope dilution, we determined the bioavailability of soilborne lead (Pb) in human adult volunteers. Soil from a residential yard at a mining-impacted federal Superfund site that had negligible amounts of other priority pollutants was dried and screened through a 25-micron mesh sieve. The < 250-micron fraction, which likely represents that ingested via hand-to-mouth activity, was then sterilized by exposure to radiation. Ten replicate samples yielded a mean (SD) soil Pb concentration of 2924 +/- 36 ppm, and a mean 206Pb/207Pb ratio of 1.1083 +/- 0.0002, indicating remarkable soil homogeneity. Six adults with 206Pb/207Pb ratios of > 1.190 were admitted to the clinical research center and fasted overnight prior to dosing with 250 micrograms Pb/70 kg bw (i.e., 85.5 mg soil/70 kg) in a gelatin capsule. Blood for Pb and 206Pb/207Pb ratios was obtained at 14 time points through 30 hr. Results of the isotopic analyses from these subjects indicate that on average 26.2% +/- 8.1 of the administered dose was absorbed. Six additional subjects were subsequently studied but ingested soil immediately after a standardized breakfast. Bioavailability in this group was only 2.52% +/- 1.7. Collectively, this study provides the first experimental estimates of soil Pb absorption in humans, and should allow for more precise estimates of health risks due to Pb-contaminated soil. Images Figure 1 Figure 2 Figure 3 PMID:9860919

  19. [Laser-induced isotopic discrimination effect in laser resonance ionization process of lead atom].

    PubMed

    Wang, Xin-Shun; Li, Ying; Dai, Lin; Zheng, Rong-Er

    2008-07-01

    Isotope ratio measurements have been increasingly used in geochemistry, geochronology, cosmos chemistry and environmental science. Precise and accurate isotope ratio measurements are an important task in many applications such as the determination of isotope variations in geological and cosmic samples. Due to its high sensitivity, high ionization efficiency and high element selectivity, laser resonance ionization spectroscopy has nowadays become one of the key techniques, including isotope ratio measurements and trace amount analyses. Because of the isotope shifts and hyperfine structure, there is laser-induced isotopic discrimination effect in the process of laser resonance ionization. The different isotope ionization efficiency can affect precise and accurate measurement of isotope ratios. In the present paper, the dependences of the laser-induced isotopic discrimination effect on some of the laser parameters were studied by theoretical methods. Based on the numerical simulation of the population rate equations, laser-induced isotopic discrimination effect of lead isotopes was studied, by calculating laser resonance ionization transition "6s2 6p23 P0-6s2 6p7 s3 P1(0) --> ionization". The population rate equations was approximated considering some factors which affect the probability of laser resonance transition such as spectral lines width of laser and atom, isotope shifts and hyperfine structure. According to the approximated population rate equations, "1+1" laser resonant ionization process was employed to calculate the ionization probability of lead isotopes by means of computer simulation. The dependences of laser-induced isotopic discrimination effect on the laser parameters, such as laser central wavelength, bandwidth and intensity were investigated. The calculated results show that the laser-induced isotopic discrimination effect of lead isotopes could be almost eliminated by operating at optimized wavelength and could be lessened by using wide band laser

  20. Asian anthropogenic lead contamination in the North Pacific Ocean as evidenced by stable lead isotopic compositions

    NASA Astrophysics Data System (ADS)

    Zurbrick, Cheryl M.

    This dissertation work determined the changing scope of lead (Pb) contamination in the North Pacific Ocean since the phase-out of leaded gasoline in most of the world. Chapters 1 and 2 consisted of validating our method for determining Pb concentrations and isotopic compositions in seawater. Chapter 3 established a baseline of Pb isotopic compositions (PbICs) in the western and central North Pacific in 2002. This was an ideal time to establish such a baseline because China had recently (mid-2000) ceased their use of leaded gasoline and simultaneously began consuming increasingly large amounts of coal, known to have relatively high Pb concentrations. We found subsurface waters were contaminated with Asian industrial Pb, predominantly Chinese coal emissions. In contrast, the abyssal waters were a mix of Asian industrial Pb and background (i.e., natural) Pb. Chapter 4 revisited the western and central North Pacific in 2009 -- 2011 to determine what, if any, changes had occurred in this short time period. We found that Pb in subsurface and abyssal waters of the western North Pacific were similar to Chinese aerosols. Such a large change in the PbICs of abyssal water in 9 years was unanticipated and attributed to the relatively large flux of particle-bound Pb from the euphotic zone to the deep ocean, which was in isotopic equilibrium with the reservoir of dissolved Pb. In contrast, the central North Pacific abyssal water PbICs were similar to values previously reported because of the relatively lower particulate export. Based on comparisons to baseline PbIC data, we determined that abyssal waters in the western and central North Pacific would be isotopically indistinguishable from surface waters in the next three decades. Sources of Pb to coastal California waters were reevaluated in Chapter 5. Prior studies had found that surface waters of the California Current System (CCS) were isotopically consistent with both Asian industrial Pb and US leaded gasoline, still in use

  1. Metallogeny and lead isotope data from the Oslo Paleorift

    NASA Astrophysics Data System (ADS)

    Bjørlykke, A.; Ihlen, P. M.; Olerud, S.

    1990-06-01

    The Permian Oslo Paleorift, situated at the southwestern margin of the Baltic shield, includes the Oslo Region and its southward extension under Skagerak. The exposed part of the paleorift comprises two half-grabens (Vestfold and Akershus graben segments) filled with Permian sediments, volcanics and intrusive rocks as well as Cambrc-Silurian sedimentary rocks. The evolution of the Oslo Rift can be divided into a rifting stage, a caldera stage and a batholith stage. The rifting stage is characterized by weak mineralization of native copper in basalts. The caldera stage includes Fe-Ti cumulates in subvolcanic layered alkali gabbros, Nb-REE disseminations in aphyric trachytes, and epigenetic Mo-mineralizations. The batholith stage includes porphyry and intraplutonic vein deposits of Mo and contact metasomatic deposits of Fe, W, Mo, Be, Zn, Pb, Cu, Bi, As and F. Along the rift margin in Precambrian gneisses and amphibolites there are vein deposits of Fe-oxides, base metals and native silver. The relationship between the rift margin deposits and the evolution of the rift is still unclear, but many deposits are spatially related to Permian dolerite dykes. Lead isotope data from hydrothermal deposits in the Oslo Rift fall into two main groups. The first group comprises the rift margin deposits. They are very radiogenic and reflect an upper crustal source for the metals. The source of the silver deposits generally has a lower μ-value and a higher w- value than the base metal deposits. The rift margin deposits are therefore not a product of metal zonation from a single hydrothermal solution. The second group comprises deposits associated with granitic intrusions in the Oslo Graben and reflects a lower to intermediate crustal source for the metals. Deposits in the Vestfold graben segment are generally more radiogenic than deposits in the Akershus graben segment and this difference may be explained by a small contribution of highly radiogenic lead from underlying Precambrian

  2. Overview of environmental and hydrogeologic conditions at Galena, Alaska

    USGS Publications Warehouse

    Nakanishi, Allan S.; Dorava, Joseph M.

    1994-01-01

    The remote Native village of Galena along the Yukon River in west-central Alaska has long cold winters and short summers that affects the hydrology of the area. The Federal Aviation Administration owns or operates airport support facilities in Galena and wishes to consider the subsistence lifestyle of the residents and the quality of the current environment when evaluating options for remediation of environmental contamination at these facilities. Galena is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available but at significantly greater cost than existing supplies.

  3. Spectroscopic study of galena surface oxidation in aqueous solutions I. Identification of surface species by XPS and ATR/FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Chernyshova, I. V.; Andreev, S. I.

    1997-02-01

    The measurements by ATR/FTIR and X-ray photoelectron spectroscopy were performed in order to identify galena surface compounds formed in air-saturated solutions under different experimental conditions. Wet polishing under distilled water was found to produce lead- or sulphur-rich galena surface depending on the semiconducting nature of the sample. The probable mechanisms of this phenomenon are discussed. After cathodic polarization at -0.5 V (SHE) in borate buffer (pH 9.2), the surface appears to be lead-rich regardless of the origin of galena. Bulk lead hydroxide Pb(OH) 2 was established to be the major product of the galena oxidation at +0.4 V in the air-saturated buffer. The assignment of IR bands and XPS peaks of bulk lead hydroxide was made. It was shown with the ATR/FTIR spectroscopy that galena, when being oxidized with hydrogen peroxide, is covered by lead hydroxide, lead thiosulphate and adsorbed oxygen in addition to elemental sulphur and basic lead sulphate (detected earlier by XPS). The relative quantity of each compound as well as the outermost layer composition was found to depend strongly on the oxidation kinetics.

  4. Source of lead in Central American and Caribbean mineralization, II. Lead isotope provinces

    NASA Astrophysics Data System (ADS)

    Cumming, George L.; Kesler, Stephen E.; Krstic, Dragan

    1981-12-01

    In an earlier study of Mesozoic and Cenozoic mineralization in Central America and the Caribbean region, we found that lead isotopic compositions of deposits in northern Central America, which is underlain by a pre-Mesozoic craton, ranged to higher 206Pb/ 204Pb and 207Pb/ 204Pb compositions than did deposits from elsewhere in the region, where the basement is Mesozoic oceanic material. Using 16 analyses for 12 new deposits, as well as new analyses for 11 of the samples studied previously, we have found that lead isotopic compositions correlate closely with crustal type but show little or no correlation with depth to the M-discontinuity. The deposits are divisible into three main groups including (in order of increasing 207Pb/ 204Pb and 208Pb/ 204Pb ratio): (1) deposits in southern Central America and all deposits in the Greater Antilles except Cuba; (2) all deposits in northern Central America; and (3) the Cuban deposits. Southern Central American and Caribbean lead is higher in 207Pb/ 204Pb and 208Pb/ 204Pb than most mid-ocean ridge basalts but could have been derived directly or indirectly from undepleted mantle. Northern Central America can be divided into the Maya block, which belongs to the Americas plate, and the Chortis block, which belongs to the Caribbean plate. Maya block deposits fall along a linear array whereas those of the Chortis block (except the Monte Cristo deposit) form a cluster. These results suggest that the Maya block is underlain by crust or mantle with a large range of U/Pb and Th/U ratios, whereas the Chortis block basement is more homogeneous. Two-stage model calculations indicate an age of about 2280±310 m.y. for the Maya block basement, although no such rocks are known in the region. Comparison of the Chortis block data to our recently published lead isotopic analyses of Mexican deposits shows considerable similarities suggesting that the Chortis block could have been derived from Mexico.

  5. Stable isotope identification of lead sources in preschool children--the Omaha Study.

    PubMed

    Angle, C R; Manton, W I; Stanek, K L

    1995-01-01

    The objective was to determine, from analysis of the naturally occurring stable isotopes of lead, the relative contribution of food, handdust, housedust, soil and air lead to the absorbed (urinary) lead and the blood lead of children living in a former smelter city. A longitudinal 12 month study was conducted of 21 children, 2 - 3 years of age, living in central Omaha, balanced for race, gender and socioeconomic status. Field clean samples were collected monthly of 24 hour duplicate diet, handwipe and urine, with quarterly blood lead, annual environmental lead, weekly air for total lead and 206Pb, 207Pb and 208Pb by thermal ionization/mass spectrometry with a 205Pb spike in a Class II laboratory. Despite residence in a smelter city each child had a unique isotopic ratio of handwipe, blood and urine lead, the latter being identical. There was no correlation of handwipe isotopic ratio with proximity to a lead emission source or to the decade of the housing stock. The isotopic ratio of the annual mean handwipe lead predicted 43% of the variance of the annual mean blood and urine lead ratio (r2 = .43; p = .001). Handwipe lead ratios correlated (p < or = .05) with those of the windowsills and air ducts. The mean isotopic ratios of blood and urine lead were lower than those of handwipe and food, consistent with a contribution by endogenous bone lead. Clean catch urine provides a noninvasive index of blood lead isotopic ratio in children, as in adults.

  6. Discrimination of bullet types using analysis of lead isotopes deposited in gunshot entry wounds.

    PubMed

    Wunnapuk, Klintean; Minami, Takeshi; Durongkadech, Piya; Tohno, Setsuko; Ruangyuttikarn, Werawan; Moriwake, Yumi; Vichairat, Karnda; Sribanditmongkol, Pongruk; Tohno, Yoshiyuki

    2009-01-01

    In order to discriminate bullet types used in firearms, of which the victims died, the authors investigated lead isotope ratios in gunshot entry wounds from nine lead (unjacketed) bullets, 15 semi-jacketed bullets, and 14 full-jacketed bullets by inductively coupled plasma-mass spectrometry. It was found that the lead isotope ratio of 207/206 in gunshot entry wounds was the highest with lead bullets, and it decreased in order from full-jacketed to semi-jacketed bullets. Lead isotope ratios of 208/206 or 208/207 to 207/206 at the gunshot entry wound were able to discriminate semi-jacketed bullets from lead and full-jacketed ones, but it was difficult to discriminate between lead and full-jacketed bullets. However, a combination of element and lead isotope ratio analyses in gunshot entry wounds enabled discrimination between lead, semi-jacketed, and full-jacketed bullets.

  7. Use of stable lead isotopes to characterize the sources of anthropogenic lead in North Atlantic surface waters

    SciTech Connect

    Veron, A.J. Univ. of Delaware, Newark, DE ); Church, T.M. ); Patterson, C.C. ); Flegal, A.R. Univ. of California, Santa Cruz, CA )

    1994-08-01

    Stable lead isotopes are used to illustrate the impact of surface water circulation on dissolved lead distribution in North Atlantic surface waters during oligotrophic conditions. Using stable lead isotopic signatures from (1) the Sargasso Sea and (2) direct tropospheric deposition to the North Atlantic, the authors estimate that 10-40% of the lead accumulated in surface waters of the European Basin is transported from the western North Atlantic by the North Atlantic Current. South of 50[degrees]N, lead appears to be primarily distributed by the Subtropical North Atlantic Gyre that extends well beyond the western basins to 30[degrees]W in the North African Basin (at 30-40[degrees]N). There are different lead isotopic signatures between the subtropical gyre of the Guiana and western Guinea Basins, which suggests that the Inter Tropical Convergence Zone acts as an efficient barrier limiting chemical exchanges between the gyre and the equatorial currents.

  8. Tracing the transport of anthropogenic lead in the atmosphere and in soils using isotopic ratios

    NASA Astrophysics Data System (ADS)

    Erel, Yigal; Veron, Alain; Halicz, Ludwik

    1997-11-01

    The isotopic composition of lead in aerosols and soils in Israel is used to characterize the sources of anthropogenic lead in the region, to ascertain the isotopic composition of natural, rock-derived lead in specific areas, and to determine rates of anthropogenic lead migration in soils. The isotopic composition of lead currently emitted from cars in Israel ( 206Pb /207Pb = 1.115 ± 2 ) is controlled by alkyl-lead produced in France and Germany. In addition to petrol-lead, two more sources of anthropogenic lead can be detected in sampled aerosols: the first one has low concentrations of lead (˜4 ng/m 3) and 206Pb /207Pb ˜ 1.157 , and is most likely lead, emitted in Turkey, that traveled across the eastern Mediterranean basin; the second type of aerosols contains a mixture of lead emitted in several countries including Turkey, Greece, and Ukraine ( 206Pb /207Pb value of 1.155-1.160; [Pb] ˜ 20-30 ng/m 3). Anthropogenic lead is more accessible for acid leaching than natural lead, therefore, it is more labile in the soil. The isotopic composition of lead in the acid-leached fraction of near-road soil profiles record the histor of alkyl-lead emission in the country. Based on changes in the isotopic composition of lead with soil depth, it is estimated that anthropogenic lead migrates into the soil at approximately 0.5 cm/y. A soil profile from a relatively remote area is less contaminated by anthropogenic lead and displays a different distribution of lead isotopic values with depth. The isotopic composition of lead suggests that natural lead in soils developed on carbonate bedrock is derived from clays, either from the rock-esidue (the clay fraction in the carbonate bedrock), or from airborne clay, but not from lead released from the carbonate fraction in the rock.

  9. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis

    SciTech Connect

    Finkelstein, Myra E.; Kuspa, Zeka E.; Welch, Alacia; Eng, Curtis; Clark, Michael; Burnett, Joseph; Smith, Donald R.

    2014-10-15

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ∼20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events. - Highlights: • We conducted a case-based analysis of illegal shootings of California condors. • Blood and feather Pb isotopes were used to reconstruct the illegal shooting events. • Embedded birdshot from the three condors had the same Pb isotope ratios. • Feather and blood Pb isotopes indicated that the condors were shot in a common event. • Ingested shot causes substantially greater lead exposure compared to embedded shot.

  10. 75 FR 33165 - Revision of Class E Airspace; Galena, AK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-11

    ... FR 9565, 3 CFR, 1959-1963 Comp., p. 389. Sec. 71.1 0 2. The incorporation by reference in 14 CFR 71.1... airspace at Galena, AK (75 FR 17892). Interested parties were invited to participate in this rulemaking... Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant preparation of a regulatory...

  11. Base- and precious-metal deposits in the Basin and Range of Southern California and Southern Nevada - Metallogenic implications of lead isotope studies

    USGS Publications Warehouse

    Church, S.E.; Cox, D.P.; Wooden, J.L.; Tingley, J.V.; Vaughn, R.B.

    2005-01-01

    Southern California and southern Nevada contain abundant lead-zinc deposits with strikingly different characteristics. On the west, the Darwin Terrane contains abundant Jurassic and Cretaceous intrusions surrounded by lead-zinc skarn and replacement deposits rich in pyrite and manganese minerals. The Tecopa Terrane is east of the Darwin Terrane and contains some lead deposits that are hosted by the Proterozoic Noonday Dolomite. These lead deposits have no consistent relation to igneous rocks; they contain mainly galena, and are devoid of pyrite and manganese minerals. Other skarn and vein deposits in the Ivanpah and Tecopa districts are more closely associated with igneous rocks. Mississippi Valley type lead-zinc deposits are present still farther to the east in the Goodsprings Terrane in Nevada. These deposits are hosted by breccias formed below the Mississippian-Pennsylvanian unconformity and are unrelated to igneous rocks. Deposits in the Darwin Terrane have lead isotopic signatures that lie along a mantle-sediment mixing line indicating that they formed in a continental arc setting analogous to that for the plutons in the Sierra Nevada batholith [Chen, J.H. and Tilton, G.R., 1991. Application of lead and strontium isotopic relationships to the petrogenesis of granitoid rocks, central Sierra Nevada batholith, California. Geological Society of America Bulletin 103, 439-447]. Encroachment of this continental arc on the North American continent in the eastern part of the Darwin Terrane resulted in a lead isotopic signature that is like that of the strongly contaminated plutons [Chen, J.H. and Tilton, G.R., 1991. Application of lead and strontium isotopic relationships to the petrogenesis of granitoid rocks, central Sierra Nevada batholith, California. Geological Society of America Bulletin 103, 439-447]. Many deposits from the Inyo Mountains on east side of the Owens Valley have lead isotopic signatures that reflect this encroachment. To the east in the Tecopa

  12. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis.

    PubMed

    Finkelstein, Myra E; Kuspa, Zeka E; Welch, Alacia; Eng, Curtis; Clark, Michael; Burnett, Joseph; Smith, Donald R

    2014-10-01

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events.

  13. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis.

    PubMed

    Finkelstein, Myra E; Kuspa, Zeka E; Welch, Alacia; Eng, Curtis; Clark, Michael; Burnett, Joseph; Smith, Donald R

    2014-10-01

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ~20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events. PMID:25173094

  14. Lead-isotopic compositions of diverse igneous rocks and ore deposits from southwestern New Mexico and their implications for early Proterozoic crustal evolution in the western United States.

    USGS Publications Warehouse

    Stacey, J.S.; Hedlund, D.C.

    1983-01-01

    Basement rocks in this area are 1750 m.y. old and extend northward through Colorado to Utah. Galena data show that the fraction of older sialic lead in these rocks increases toward the the Archaean craton in Wyoming. The crust apparently developed southward from Wyoming in stages at 2400 m.y. ago or before, 2100 m.y. ago and 1750 m.y. ago. The Laramide alkali to calc-alkaline rocks and their associated porphyry Cu and massive replacement deposits have similar 206Pb/204Pb ratios and are the least radiogenic in the region; their 206Pb/204Pb ratios are all 18.0. Pb isotopes in this region offer some criteria for prospecting purposes. The 206Pb/204Pb values for the larger ore deposits related to Laramide activity are all <18.0, particularly for the larger ones. Within the mid- Tertiary group, the same criteria apply - i.e. the largest deposits have the lowest 206Pb/204Pb ratios. -L.C.H.

  15. Mesozoic vein-type Pb-Zn mineralization in the Pyrenees: Lead isotopic and fluid inclusion evidence from the Les Argentières and Lacore deposits

    NASA Astrophysics Data System (ADS)

    Munoz, Marguerite; Baron, Sandrine; Boucher, Adrien; Béziat, Didier; Salvi, Stefano

    2016-03-01

    The Axial Zone of the Pyrenees contains numerous sedimentary-exhalative Pb-Zn deposits formed during the Early Palaeozoic, which have been the subject of several studies. In addition to these, base-metal vein-type mineralizations are also exposed within the Axial Zone metasediments. These deposits, however, have not been investigated in depth and the timing and geodynamic context of their formation has not been specifically addressed. The vein-type Pb-Zn deposits of Les Argentières and Lacore are located in Devonian terranes of the eastern Pyrenees, south of the Mesozoic Aulus basin. They are interpreted as having been emplaced under an extensional setting. They are characterized by silver-rich tetrahedrite that occurs with Pb-Zn sulphides deposited by low-temperature NaCl-CaCl2 brines. Lead isotopic 208Pb/204Pb and 206Pb/204Pb ratios acquired on galena show more radiogenic values compared to those from the Palaeozoic sedimentary-exhalative mineralization, thus indicating younger ages. According to the model ages, the formation of the two deposits may be narrowed down to middle Late Triassic and Late Jurassic periods, respectively, which allows us to argue in favour of the role of pre-Alpine rifting phases in hydrothermal fluids circulation and mineralization deposition in a vein system bounding the Mesozoic Aulus basin.

  16. Historical record of lead accumulation and source in the tidal flat of Haizhou Bay, Yellow Sea: Insights from lead isotopes.

    PubMed

    Zhang, Rui; Guan, Minglei; Shu, Yujie; Shen, Liya; Chen, Xixi; Zhang, Fan; Li, Tiegang

    2016-05-15

    In order to investigate the historical records of lead contamination and source in coastal region of Haizhou Bay, Yellow Sea, a sediment core was collected from tidal flat, dated by (210)Pb and (137)Cs. Lead and its stable isotopic ratios were determined. The profiles of enrichment factor (EF) and Pb isotope ratios showed increasing trend upward throughout the core, correlating closely with the experience of a rapid economic and industrial development of the catchment. According to Pb isotopic ratios, coal combustion emission mainly contributed to the Pb burden in sediments. Based on end-member model, coal combustion emission dominated anthropogenic Pb sources in recent decades contributing from 48% to 67% in sediment. And the contribution of leaded gasoline was lower than 20%. A stable increase of coal combustion source was found in sediment core, while the contribution of leaded gasoline had declined recently, with the phase-out of leaded gasoline in China.

  17. Lead isotope compositions as guides to early gold mineralization: The North Amethyst vein system, Creede district, Colorado

    USGS Publications Warehouse

    Foley, Nora K.; Ayuso, Robert A.

    1994-01-01

    Pb isotope compositions from the late stage of the North Amethyst vein system and from the Bondholder and central and southern Creede mining districts are more radiogenic than the host volcanic rocks of the central cluster of the San Juan volcanic field. Our Pb isotope results indicate that early Au mineralization of the North Amethyst area may represent the product of an older and relatively local hydrothermal system distinct from that of the younger base metal and Ag mineralization found throughout the region. Fluids that deposited Au minerals may have derived their Pb isotope composition by a greater degree of interaction with shallow, relatively less radiogenic volcanic wall rocks. The younger, base metal and Ag-rich mineralization that overprints the Au mineralization in the North Amethyst area clearly has a more radiogenic isotopic signature, which implies that the later mineralization derived a greater component of its Pb from Proterozoic source rocks, or sediments derived from them.Paragenetically early sulfide-rich vein assemblages have the least radiogenic galenas and generally also have the highest Au contents. Thus, identification of paragenetically early vein assemblages with relatively unradiogenic Pb isotope compositions similar to those of the North Amethyst area provides an additional exploration tool for Au in the central San Juan Mountains area.

  18. Lead concentrations and isotopic signatures in vintages of French wine between 1950 and 1991

    SciTech Connect

    Rosman, K.J.R.; Chisholm, W.; Jimi, S.; Candelone, J.P. |; Boutron, C.F. |; Teissedre, P.L.; Adams, F.C.

    1998-08-01

    Vintages of French wine from 1950 to 1991 were analyzed for lead isotopes and concentration to investigate whether they might be used to archive the isotopic composition of the anthropogenic lead in aerosols to which the vineyard was exposed. Early vintages (1950--1980) contained 78--227 ng/g of lead with {sup 206}Pb/{sup 207}Pb ratios between 1.152 and 1.173, while the later vintages displayed significantly lower concentrations and a smaller range of isotopic ratios. The concentration of trimethyl lead, which is associated with automobile emissions, was found to be poorly correlated with total lead in the wines, suggesting that automobile aerosols were not a significant source of the lead. This result was supported by lead isotope data which showed a poor correlation with the available petrol and aerosol data. To identify its origin lead isotopes were measured in vineyard aerosols, soil particles, bottle caps, corks, and brass components used to dispense the wine. Although a dominant source could not be identified there was some evidence to suggest that brass which had a high lead concentration was a significant contributor. Because the lead contribution from the processing of wine was probably relatively high in the past it is unlikely that old vintages of wine will be a suitable archive for lead isotopes in aerosols.

  19. Lead concentrations and isotopic signatures in vintages of French wine between 1950 and 1991.

    PubMed

    Rosman, K J; Chisholm, W; Jimi, S; Candelone, J P; Boutron, C F; Teissedre, P L; Adams, F C

    1998-08-01

    Vintages of French wine from 1950 to 1991 were analyzed for lead isotopes and concentrations to investigate whether they might be used to archive the isotopic composition of the anthropogenic lead in aerosols to which the vineyard was exposed. Early vintages (1950-1980) contained 78-227 ng/g of lead with 206Pb/207Pb ratios between 1.152 and 1.173, while the later vintages displayed significantly lower concentrations and a smaller range of isotopic ratios. The concentration of trimethyl lead, which is associated with automobile emissions, was found to be poorly correlated with total lead in the wines, suggesting that automobile aerosols were not a significant source of the lead. This result was supported by lead isotope data which showed a poor correlation with the available petrol and aerosol data. To identify its origin lead isotopes were measured in vineyard aerosols, soil particles, bottle caps, corks, and brass components used to dispense the wine. Although a dominant source could not be identified there was some evidence to suggest that brass which had a high lead concentration was a significant contributor. Because the lead contribution from the processing of wine was probably relatively high in the past it is unlikely that old vintages of wine will be a suitable archive for lead isotopes in aerosols.

  20. The lead isotopic age of the Earth can be explained by core formation alone.

    PubMed

    Wood, Bernard J; Halliday, Alex N

    2010-06-10

    The meaning of the age of the Earth defined by lead isotopes has long been unclear. Recently it has been proposed that the age of the Earth deduced from lead isotopes reflects volatile loss to space at the time of the Moon-forming giant impact rather than partitioning into metallic liquids during protracted core formation. Here we show that lead partitioning into liquid iron depends strongly on carbon content and that, given a content of approximately 0.2% carbon, experimental and isotopic data both provide evidence of strong partitioning of lead into the core throughout the Earth's accretion. Earlier conclusions that lead is weakly partitioned into iron arose from the use of carbon-saturated (about 5% C) iron alloys. The lead isotopic age of the Earth is therefore consistent with partitioning into the core and with no significant late losses of moderately volatile elements to space during the giant impact.

  1. Origin of the mysterious Yin-Shang bronzes in China indicated by lead isotopes.

    PubMed

    Sun, Wei-dong; Zhang, Li-peng; Guo, Jia; Li, Cong-ying; Jiang, Yu-hang; Zartman, Robert E; Zhang, Zhao-feng

    2016-01-01

    Fine Yin-Shang bronzes containing lead with puzzlingly highly radiogenic isotopic compositions appeared suddenly in the alluvial plain of the Yellow River around 1400 BC. The Tongkuangyu copper deposit in central China is known to have lead isotopic compositions even more radiogenic and scattered than those of the Yin-Shang bronzes. Most of the Yin-Shang bronzes are tin-copper alloys with high lead contents. The low lead and tin concentrations, together with the less radiogenic lead isotopes of bronzes in an ancient smelting site nearby, however, exclude Tongkuangyu as the sole supplier of the Yin-Shang bronzes. Interestingly, tin ingots/prills and bronzes found in Africa also have highly radiogenic lead isotopes, but it remains mysterious as to how such African bronzes may have been transported to China. Nevertheless, these African bronzes are the only bronzes outside China so far reported that have lead isotopes similar to those of the Yin-Shang bronzes. All these radiogenic lead isotopes plot along ~2.0-2.5 Ga isochron lines, implying that deposits around Archean cratons are the most likely candidates for the sources. African cratons along the Nile and even micro-cratons in the Sahara desert may have similar lead signatures. These places were probably accessible by ancient civilizations, and thus are the most favorable suppliers of the bronzes. PMID:26988425

  2. Origin of the mysterious Yin-Shang bronzes in China indicated by lead isotopes

    NASA Astrophysics Data System (ADS)

    Sun, Wei-Dong; Zhang, Li-Peng; Guo, Jia; Li, Cong-Ying; Jiang, Yu-Hang; Zartman, Robert E.; Zhang, Zhao-Feng

    2016-03-01

    Fine Yin-Shang bronzes containing lead with puzzlingly highly radiogenic isotopic compositions appeared suddenly in the alluvial plain of the Yellow River around 1400 BC. The Tongkuangyu copper deposit in central China is known to have lead isotopic compositions even more radiogenic and scattered than those of the Yin-Shang bronzes. Most of the Yin-Shang bronzes are tin-copper alloys with high lead contents. The low lead and tin concentrations, together with the less radiogenic lead isotopes of bronzes in an ancient smelting site nearby, however, exclude Tongkuangyu as the sole supplier of the Yin-Shang bronzes. Interestingly, tin ingots/prills and bronzes found in Africa also have highly radiogenic lead isotopes, but it remains mysterious as to how such African bronzes may have been transported to China. Nevertheless, these African bronzes are the only bronzes outside China so far reported that have lead isotopes similar to those of the Yin-Shang bronzes. All these radiogenic lead isotopes plot along ~2.0-2.5 Ga isochron lines, implying that deposits around Archean cratons are the most likely candidates for the sources. African cratons along the Nile and even micro-cratons in the Sahara desert may have similar lead signatures. These places were probably accessible by ancient civilizations, and thus are the most favorable suppliers of the bronzes.

  3. Origin of the mysterious Yin-Shang bronzes in China indicated by lead isotopes

    PubMed Central

    Sun, Wei-dong; Zhang, Li-peng; Guo, Jia; Li, Cong-ying; Jiang, Yu-hang; Zartman, Robert E.; Zhang, Zhao-feng

    2016-01-01

    Fine Yin-Shang bronzes containing lead with puzzlingly highly radiogenic isotopic compositions appeared suddenly in the alluvial plain of the Yellow River around 1400 BC. The Tongkuangyu copper deposit in central China is known to have lead isotopic compositions even more radiogenic and scattered than those of the Yin-Shang bronzes. Most of the Yin-Shang bronzes are tin-copper alloys with high lead contents. The low lead and tin concentrations, together with the less radiogenic lead isotopes of bronzes in an ancient smelting site nearby, however, exclude Tongkuangyu as the sole supplier of the Yin-Shang bronzes. Interestingly, tin ingots/prills and bronzes found in Africa also have highly radiogenic lead isotopes, but it remains mysterious as to how such African bronzes may have been transported to China. Nevertheless, these African bronzes are the only bronzes outside China so far reported that have lead isotopes similar to those of the Yin-Shang bronzes. All these radiogenic lead isotopes plot along ~2.0–2.5 Ga isochron lines, implying that deposits around Archean cratons are the most likely candidates for the sources. African cratons along the Nile and even micro-cratons in the Sahara desert may have similar lead signatures. These places were probably accessible by ancient civilizations, and thus are the most favorable suppliers of the bronzes. PMID:26988425

  4. Origin of the mysterious Yin-Shang bronzes in China indicated by lead isotopes.

    PubMed

    Sun, Wei-dong; Zhang, Li-peng; Guo, Jia; Li, Cong-ying; Jiang, Yu-hang; Zartman, Robert E; Zhang, Zhao-feng

    2016-03-18

    Fine Yin-Shang bronzes containing lead with puzzlingly highly radiogenic isotopic compositions appeared suddenly in the alluvial plain of the Yellow River around 1400 BC. The Tongkuangyu copper deposit in central China is known to have lead isotopic compositions even more radiogenic and scattered than those of the Yin-Shang bronzes. Most of the Yin-Shang bronzes are tin-copper alloys with high lead contents. The low lead and tin concentrations, together with the less radiogenic lead isotopes of bronzes in an ancient smelting site nearby, however, exclude Tongkuangyu as the sole supplier of the Yin-Shang bronzes. Interestingly, tin ingots/prills and bronzes found in Africa also have highly radiogenic lead isotopes, but it remains mysterious as to how such African bronzes may have been transported to China. Nevertheless, these African bronzes are the only bronzes outside China so far reported that have lead isotopes similar to those of the Yin-Shang bronzes. All these radiogenic lead isotopes plot along ~2.0-2.5 Ga isochron lines, implying that deposits around Archean cratons are the most likely candidates for the sources. African cratons along the Nile and even micro-cratons in the Sahara desert may have similar lead signatures. These places were probably accessible by ancient civilizations, and thus are the most favorable suppliers of the bronzes.

  5. Lead isotopes tracing weathering and atmospheric deposition in a small volcanic catchment

    NASA Astrophysics Data System (ADS)

    Négrel, Philippe; Petelet-Giraud, Emmanuelle; Guerrot, Catherine; Millot, Romain

    2015-09-01

    Lead isotopes were studied in soil and sediments of the small volcanic catchment in the Massif Central (France), a large area of Tertiary to Recent continental alkaline volcanism. The comparison of Pb and K (normalized to Zr) shows a linear evolution of weathering processes, whereby lead enrichment from atmospheric deposition is a major contributor explaining the deviation of several points from this line. A box model simulates the lead evolution in sediments from soil production on the hillslopes due to bedrock weathering and from anthropogenic input through atmospheric deposition and constrains the dynamics of sediment transfer. Lead isotope ratios decrease from bedrock to sediment and soil without any clear relationship when compared to lead contents. Pb isotopic compositions showed that most of the lead budget in sediment and soil results from bedrock weathering with influence of gasoline-additive-lead and past mining activities derived inputs, but no lead input from agricultural activity.

  6. Lead content and isotopic composition in submound and recent soils of the Volga Upland

    NASA Astrophysics Data System (ADS)

    Pampura, T. V.; Probst, A.; Ladonin, D. V.; Demkin, V. A.

    2013-11-01

    Literature data on the historical reconstructions of the atmospheric lead deposition in Europe and the isotopic composition of the ores that are potential sources of the anthropogenic lead in the atmospheric deposition in the lower Volga steppes during different time periods have been compiled. The effect of the increasing anthropogenic lead deposition recorded since the Bronze Age on the level of soil contamination has been investigated. For the first time paleosol buried under a burial mound of the Bronze Age has been used as a reference point to assess of the current contamination level. The contents and isotopic compositions of the mobile and total lead have been determined in submound paleosols of different ages and their recent remote and roadside analogues. An increase in the content and fraction of the mobile lead and a shift of its isotopic composition toward less radiogenic values (typical for lead from the recent anthropogenic sources) has been revealed when going from a Bronze-Age paleosol to a recent soil. In the Bronze-Age soil, the isotopic composition of the mobile lead is inherited from the parent rock to a greater extent than in the modern soils, where the lead is enriched with the less radiogenic component. The effect of the anthropogenic component is traced in the analysis of the mobile lead, but it is barely visible for the total lead. An exception is provided by the recent roadside soils characterized by increased contents and the significantly less radiogenic isotopic composition of the mobile and total lead.

  7. Lead isotope systematics in Polytrichum formosum: An example from a biomonitoring field study with mosses

    SciTech Connect

    Kunert, M.; Friese, K.; Weckert, V.; Markert, B.

    1999-10-15

    With the aid of inductively coupled plasma mass spectrometry (ICP-MS), {sup 206/207}Pb isotope ratios were determined in 34 moss samples (Polytrichum formosum) taken from the Hoerner Bruch area near Osnabrueck (FRG) in the years 1987--1996. The goal was to distinguish different sources of atmospheric lead pollution by the investigation of lead isotope ratios. Reproducibility tests were carried out to ensure the reliability of analyzing Pb isotope ratios in moss samples by means of quadrupole ICP-MS. The reproducibility of the isotope ratios for one digested sample and the day-to-day reproducibility were determined. In all the moss samples analyzed, relative standard deviations of < 0.26% for five replicate measurements of one digested sample were achieved for the {sup 206/207}Pb isotope ratios. On the basis of the {sup 206/207}Pb isotope ratio, it was possible to establish that the sources of man-made atmospheric inputs of lead have changed over the 10-year period investigated. In the moss samples analyzed, the {sup 206/207}Pb isotope ratio was found to have risen significantly from 1.131 in 1987 to 1.154 in 1996. This increase in the {sup 206/207}Pb isotope ratio can be attributed to a reduction of atmospheric inputs of lead from petrol.

  8. Lead isotopic studies of the Samail ophiolite, Oman

    NASA Technical Reports Server (NTRS)

    Chen, J. H.; Pallister, J. S.

    1981-01-01

    The isotopic composition of Pb and the concentrations of U, Th, and Pb are determined for samples from massive sulfides and lithologic units of the Samail ophiolite. It is shown that the magma that formed the ophiolite was probably derived from a depleted mantle, similar in Pb isotopic composition to the source area of mid-ocean ridge basalt. The gross geochemical characteristics of the mantle sources have remained almost unchanged for the last 100 million years. It is also shown that the U-Th-Pb systematics of the Samail formation indicate that local vertical heterogeneity in the oceanic crust can result from crystal fractionation and metasomatism at, and near, an oceanic spreading center.

  9. A lead isotopic study of the human bioaccessibility of lead in urban soils from Glasgow, Scotland.

    PubMed

    Farmer, John G; Broadway, Andrew; Cave, Mark R; Wragg, Joanna; Fordyce, Fiona M; Graham, Margaret C; Ngwenya, Bryne T; Bewley, Richard J F

    2011-11-01

    The human bioaccessibility of lead (Pb) in Pb-contaminated soils from the Glasgow area was determined by the Unified Bioaccessibility Research Group of Europe (BARGE) Method (UBM), an in vitro physiologically based extraction scheme that mimics the chemical environment of the human gastrointestinal system and contains both stomach and intestine compartments. For 27 soils ranging in total Pb concentration from 126 to 2160 mg kg(-1) (median 539 mg kg(-1)), bioaccessibility as determined by the 'stomach' simulation (pH ~1.5) was 46-1580 mg kg(-1), equivalent to 23-77% (mean 52%) of soil total Pb concentration. The corresponding bioaccessibility data for the 'stomach+intestine' simulation (pH ~6.3) were 6-623 mg kg(-1) and 2-42% (mean 22%) of soil Pb concentration. The soil (206)Pb/(207)Pb ratios ranged from 1.057 to 1.175. Three-isotope plots of (208)Pb/(206)Pb against (206)Pb/(207)Pb demonstrated that (206)Pb/(207)Pb ratios were intermediate between values for source end-member extremes of imported Australian Pb ore (1.04)--used in the manufacture of alkyl Pb compounds (1.06-1.10) formerly added to petrol--and indigenous Pb ores/coal (1.17-1.19). The (206)Pb/(207)Pb ratios of the UBM 'stomach' extracts were similar (<0.01 difference) to those of the soil for 26 of the 27 samples (r=0.993, p<0.001) and lower in 24 of them. A slight preference for lower (206)Pb/(207)Pb ratio was discernible in the UBM. However, the source of Pb appeared to be less important in determining the extent of UBM-bioaccessible Pb than the overall soil total Pb concentration and the soil phases with which the Pb was associated. The significant phases identified in a subset of samples were carbonates, manganese oxides, iron-aluminium oxyhydroxides and clays.

  10. Lead isotopes and the origin of granulite and eclogite inclusions in deep-seated pipes

    USGS Publications Warehouse

    Lovering, J.F.; Tatsumoto, M.

    1968-01-01

    The isotopic composition of lead and the concentrations of lead, uranium, and thorium in Delegate basic pipes from Australia and in South African kimberlite pipes have been determined. The observed 238U/204Pb and observed 232Th/238U of eclogite inclusions in the pipes range from 2.9 to 18.7 and from 3.5 to 5.9, respectively. This result as well as the isotopic composition of lead suggests that the upper mantle is chemically heterogeneous with regard to the trace elements. Pyrochemically extracted leads from eclogite inclusions in the Delegate basic pipes and in a South African kimberlite pipe appear to be different in isotopic compositions from leads extracted from the host rock (matrix). These data are consistent with the hypothesis that the eclogitic inclusions in deep-seated pipes are of "accidental" origin and represent upper mantle materials caught up in the host materials during their intrusion. Lead extracted from a two-pyroxene granulite inclusion in one of the Delegate pipes has an isotopic composition indistinguishable from lead in the host rock. This observation is consistent either with a "cognate" origin for the granulite inclusion or with a modified "accidental" origin in which the isotopic composition of the original lead in the inclusion has been contaminated by lead from the host magma. Other evidence would indicate that an "accidental" origin be preferred. ?? 1968.

  11. Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring

    SciTech Connect

    Gulson, Brian; Korsch, Michael; Winchester, Wayne; Devenish, Matthew; Hobbs, Thad; Main, Cleve; Smith, Gerard; Rosman, Kevin; Howearth, Lynette; Burn-Nunes, Laurie; Seow, Jimmy; Oxford, Cameron; Yun, Gracie; Gillam, Lindsay; Crisp, Michelle

    2012-01-15

    In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments, air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty. - Highlights: Black-Right-Pointing-Triangle Lead carbonate concentrate. Black-Right-Pointing-Triangle Successful use of Pb isotopes in identifying sources of Pb arising from transport and shipping. Black-Right-Pointing-Triangle Use of Pb isotopes in legal proceedings and their use in cleanup of residences. Black

  12. Variations of lead isotopes and airborne particulate concentrations from the Kozani basin, West Macedonia, Greece.

    PubMed

    Charalampides, G; Manoliadis, O; Triantafyllou, A

    2002-03-01

    The spread and variation in 206Pb/207Pb ratios make Pb isotopes a powerful tool when it comes to detecting trends in airborne particulates originating mainly from power plants. This study was conducted to determine the source of pollution in Kozani area, an affected industrial area. Lead isotopic ratios of air filters under certain meteorological conditions were compared to Pb isotope analyses sampled from lignite mines, but also to Pb isotope analyses of cultivations in soil originating from the reclamation of old abandoned lignite-mines. The particles taken into consideration have an aerodynamic diameter less than 10 microm (PM10). The measurements were carried out in a central part of the town of Kozani, West Macedonia, for one year observation period. The lead isotope values of air filters and of wheat in the Kozani area are between the values of lignite Pb and of Greek gasoline.

  13. Isotopic and fluid-inclusion constraints on the formation of polymetallic vein deposits in the central Argentinian Patagonia

    NASA Astrophysics Data System (ADS)

    Dejonghe, Léon; Darras, Benoît; Hughes, Guillermo; Muchez, Philippe; Scoates, James S.; Weis, Dominique

    2002-03-01

    The lead isotope compositions of galena and the fluid-inclusion systematics of nine barite-bearing polymetallic (Au, Ag, Pb, Zn) deposits of the central Argentinian Patagonia (Chubut and Rio Negro provinces) have been investigated to constrain the compositions and sources of the mineralizing fluids. Most of the deposits occur as veins, with less common wall-rock disseminations and/or stockworks, and are low-sulfidation epithermal deposits hosted in Jurassic volcanic rocks. Fluid-inclusion homogenization temperatures (Th) from quartz and sphalerite from the deposits fall within the range of 100-300 °C, with the highest measured average temperatures for the most eastern deposits (Mina Angela - 298 °C; Cañadón Bagual - 343 °C). The salinities of the hydrothermal fluids at all deposits were low to moderate (≤10.4 equiv. wt% NaCl). Three groups of ore deposits can be defined on the basis of 206Pb/204Pb ratios for galena and these show a general decrease from west to east (from 18.506 to 18.000). The central Argentinian Patagonia deposits have distinctly less radiogenic lead isotope compositions than similar deposits from Peru and Chile, except for the porphyry copper deposits of central and southern Peru. Galena from the Mina Angela deposit is characterized by very low radiogenic lead isotope compositions (18.000<206Pb/204Pb<18.037 and 38.03<208Pb/204Pb<38.09) and reflects interaction with Precambrian basement. The geographic trend in lead isotope compositions of both galena and whole rocks indicates a crustal contribution which increases eastwards, also reflected in the strontium-neodymium isotope systematics of the host lavas. Finally, due to the lack of precise age determinations for the central Patagonian polymetallic deposits, a potential link with Andean porphyry copper systems remains an open question.

  14. Stable lead isotopes in environmental health with emphasis on human investigations.

    PubMed

    Gulson, Brian

    2008-08-01

    There has been widespread use of stable lead isotopes in the earth sciences for more than 40 years focussed on the origin and age of rocks and minerals with lesser application in environmental investigations where the emphasis has been directed typically to the source of lead in environmental media such as air, water and soils. In contrast, the number of environmental health investigations focussed on humans (and primates) is limited in spite of the demonstrated utility of the approach in pioneering studies in the early 1970's. This paper reviews the status of lead isotopes in human investigations especially over the past 2 decades, the period over which most activity has taken place. Following a brief introduction to the method, examples are provided illustrating the use of lead isotopes in a wide spectrum of activities including sources and pathways of lead in diverse environments from urban to mining communities, various applications associated with pregnancy, the contribution of bone lead to blood lead including in the elderly, the half-life of lead in blood, and lead in bones and other media. A brief outline of critical research on non-human primates is also given. The lead isotope method is a powerful technique for tracing lead and could be employed more widely in human investigations.

  15. Provenance of dust to Antarctica: A lead isotopic perspective

    NASA Astrophysics Data System (ADS)

    Gili, Stefania; Gaiero, Diego M.; Goldstein, Steven L.; Chemale, Farid, Jr.; Koester, Edinei; Jweda, Jason; Vallelonga, Paul; Kaplan, Michael R.

    2016-03-01

    Antarctic ice preserves an ~800 kyr record of dust activity in the Southern Hemisphere. Major efforts have been dedicated to elucidate the origin of this material in order to gain greater insight into the atmospheric dust cycle. On the basis of Pb isotopes in Antarctic dust samples and potential sources, this contribution demonstrates for the first time that Patagonia is the main contributor of dust to Antarctica during interglacial periods as well as glacials, although the potential importance of Tierra del Fuego remains unclear because of its geochemical similarities to Patagonia. An important new finding is that the Puna-Altiplano sector of the continent is a second important dust source to eastern Antarctica during both glacials and interglacials, being more prominent during interglacials. The data indicate South America is the primary dust source to Antarctica during both glacials and interglacials.

  16. Isotopic source signatures for atmospheric lead: the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Bollhöfer, A.; Rosman, K. J. R.

    2000-10-01

    Aerosols collected between 1994 and 1999 at more than 70 different sites affecting the Southern Hemisphere have been measured for their 206Pb/ 207Pb, 208Pb/ 207Pb and 206Pb/ 204Pb ratios and Pb concentrations. Lower ratios are found at the southern tips of Africa, Australia and South America probably due to the supply of alkyllead from a common supplier such as Associated Octel. The ratios increase in a northerly direction probably due to a changing market share in alkyllead or an increasing industrial Pb contribution. The geographical variations in isotopic signatures made it possible to broadly characterize the different regions that influence the Southern Hemisphere. Brazil and Argentina exhibited 206Pb/ 207Pb, 208Pb/ 207Pb and 206Pb/ 204Pb ratios in aerosols of 1.141-1.184, 2.416-2.442 and 17.77-18.57, respectively. Mexican aerosols had values of 1.188-1.197, 2.452-2.463 and 18.46-18.73. Aerosols sampled in Chile had low ratios in the South of 1.063-1.094, 2.337-2.373 and 16.46-17.13 which increased in a northerly direction. Emissions from South Africa were characterized by ratios 1.067-1.090, 2.340-2.358 and 16.53-16.99. In 1994-1995 Australia and New Zealand had ratios of 1.060-1.193, 2.324-2.445 and 16.08-18.54. In 1997 however, the range was narrower: 1.072-1.112, 2.342-2.398 and 16.55-17.36, respectively. These isotopic signatures are potentially useful for tracing sources of pollution and the movement of air-masses on a global scale.

  17. Fluid-inclusion gases in sphalerite, galena, and dolomite from the Silesian-Cracow Zn-Pb district, Poland

    USGS Publications Warehouse

    Leach, D.L.; Apodaca, L.E.; Kozlowski, A.; Landis, G.P.; Hofstra, A.H.

    1996-01-01

    The gases in fluid inclusions from samples of sphalerite, galena, and sparry dolomite from ore deposits in the Silesian-Cracow zinc-lead district were determined by mass spectrometry. The results show that CO2 is the major gas in the fluid inclusions with lesser amounts of CH4. Samples of galena and sphalerite also commonly contain H2S and short-chain hydrocarbon gases. Gases in sphalerite and galena appear to contain two end-member compositions, CO2-CH4 and CO2-H2S bearing fluid inclusions. The apparent end member compositions could represent chemically distinct generations of fluid inclusions trapped at different times or at least two distinct fluids present during ore formation. The presence of distinct fluid inclusion gas compositions is consistent with previous fluid inclusion studies that show the presence of multiple fluids during ore deposition. The presence of multiple fluids in the ore-forming environment could lead to ore precipitation through processes of fluid mixing.

  18. Asian industrial lead inputs to the North Pacific evidenced by lead concentrations and isotopic compositions in surface waters and aerosols.

    PubMed

    Gallon, Céline; Ranville, Mara A; Conaway, Christopher H; Landing, William M; Buck, Clifton S; Morton, Peter L; Flegal, A Russell

    2011-12-01

    Recent trends of atmospheric lead deposition to the North Pacific were investigated with analyses of lead in aerosols and surface waters collected on the fourth Intergovernmental Oceanographic Commission Contaminant Baseline Survey from May to June, 2002. Lead concentrations of the aerosols varied by 2 orders of magnitude (0.1-26.4 pmol/m(3)) due in part to variations in dust deposition during the cruise. The ranges in lead aerosol enrichment factors relative to iron (1-119) and aluminum (3-168) were similar, evidencing the transport of Asian industrial lead aerosols across the North Pacific. The oceanic deposition of some of those aerosols was substantiated by the gradient of lead concentrations of North Pacific waters, which varied 3-fold (32.7-103.5 pmol/kg), were highest along with the Asian margin of the basin, and decreased eastward. The hypothesized predominance of Asian industrial lead inputs to the North Pacific was further corroborated by the lead isotopic composition of ocean surface waters ((206)Pb/(207)Pb = 1.157-1.169; (208)Pb/(206)Pb = 2.093-2.118), which fell within the range of isotopic ratios reported in Asian aerosols that are primarily attributed to Chinese industrial lead emissions.

  19. Lead isotopic fingerprinting of aerosols to characterize the sources of atmospheric lead in an industrial city of India

    NASA Astrophysics Data System (ADS)

    Sen, Indra S.; Bizimis, Michael; Tripathi, Sachchida Nand; Paul, Debajyoti

    2016-03-01

    Anthropogenic Pb in the environment is primarily sourced from combustion of fossil fuel and high-temperature industries such as smelters. Identifying the sources and pathways of anthropogenic Pb in the environment is important because Pb toxicity is known to have adverse effects on human health. Pb pollution sources for America, Europe, and China are well documented. However, sources of atmospheric Pb are unknown in India, particularly after leaded gasoline was phased out in 2000. India has a developing economy with a rapidly emerging automobile and high temperature industry, and anthropogenic Pb emission is expected to rise in the next decade. In this study, we report on the Pb-isotope compositions and trace metal ratios of airborne particulates collected in Kanpur, a large city in northern part of India. The study shows that the PM10 aerosols had elevated concentration of Cd, Pb, Zn, As, and Cu in the Kanpur area, however their concentrations are well below the United States Environmental Protection Agency chronic exposure limit. Lead isotopic and trace metal data reveal industrial emission as the plausible source of anthropogenic Pb in the atmosphere in Kanpur. However, Pb isotopic compositions of potential source end-members are required to fully evaluate Pb contamination in India over time. This is the first study that characterizes the isotopic composition of atmospheric Pb in an Indian city after leaded gasoline was phased out by 2000.

  20. Tracing the anthropogenic lead sources in coastal sediments of SE-pacific (36 degrees Lat. S) using stable lead isotopes.

    PubMed

    Muñoz, Práxedes N V; Garbe-Schönberg, Carl-Dieter; Salamanca, Marco A

    2004-04-01

    This study evaluates the main sources of antropogenic Pb in one of the most industrialized centers of the southern Chilean coast (36 degrees S). Stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(207)Pb) were used to trace main Pb sources to coastal sediments, considering the suspended particulate matter (SPM) from marine (traps), continental (rivers) and industrial effluents, sediments and leaded gasoline samples. The atmospheric input was evaluated through natural collectors; i.e. Raqui-Tubul salt marsh. Results show that marine samples lie on a trend between industrial effluents ( approximately 1.16, 2.44) and natural sources (1.20, 2.50), not related to gasoline consumption. Salt marsh sediments show comparable isotopic composition to marine samples, suggesting the importance of the atmospheric input in the coastal sediments, not related to the leaded gasoline composition either. The continental input (1.18, 2.48) is highly influenced by precipitation, being difficult to separate both sources (atmosphere and continental runoff), showing also similar isotopic ratio to marine sediments. The signal of industrial emissions is masked with the introduction of Pb with higher isotopic ratios, compared to the values observed in the material collected from traps (SPM approximately 1.19, 2.48). The contribution of more radiogenic Pb by the upwelling is suggested.

  1. Lead isotope determinations from sulfide mineral occurrences--Russian Far East

    USGS Publications Warehouse

    Church, Stanley E.; Goryachev, Nikolai A.; Shpikerman, Vladimir I.

    2013-01-01

    The lead isotope database for sulfide deposits and occurrences in the Russian Far East was funded by the Mineral Resources Program, U.S. Geological Survey (USGS) in conjunction with the collaborative studies of mineral resources by the Russian Academy of Sciences and the U. S. Geological Survey (Nokleberg and others, 1996). Comparisons of these data with similar lead isotope data from Alaska published in Church, Delevaux, and others (1987) and Gaccetta and Church (1989) provide a basis for the following three-fold project objectives: 1. To utilize lead isotope signatures, in conjunction with regional mapping, to assess the relative ages and to categorize the types of mineral deposits studied, 2. To relate the lead isotope and trace-element geochemical signatures of specific deposits and occurrences to ore-forming processes, and 3. To use the lead isotope data to correlate lithotectonic terranes within the northern Cordillera (Alaska, Yukon Territories and British Columbia in Canada, and the western Cordillera of the United States). The report by Church, Gray, and others (1987) shows how this fingerprinting methodology can be applied to trace the offset of lithotectonic (or lithostratigraphic as labeled by some authors) terranes.The lead isotope data presented in table 1 represent the work completed on sulfide mineral deposits located in the Russian Far East from 1993 to 1995, when this study was terminated due to lack of funding. The lead isotope data are reported here for use by investigators who may find them of value in mineral exploration. No attempt is made to summarize the voluminous literature on these mineral deposits.

  2. A modified lead-matrix separation procedure shown for lead isotope analysis in Trojan silver artefacts as an example.

    PubMed

    Vogl, Jochen; Paz, Boaz; Koenig, Maren; Pritzkow, Wolfgang

    2013-03-01

    A modified Pb-matrix separation procedure using NH4HCO3 solution as eluent has been developed and validated for determination of Pb isotope amount ratios by thermal ionization mass spectrometry. The procedure is based on chromatographic separation using the Pb·Spec resin and an in-house-prepared NH4HCO3 solution serving as eluent. The advantages of this eluent are low Pb blanks (<40 pg mL(-1)) and the property that NH4HCO3 can be easily removed by use of a heating step (>60 °C). Pb recovery is >95 % for water samples. For archaeological silver samples, however, the Pb recovery is reduced to approximately 50 %, but causes no bias in the determination of Pb isotope amount ratios. The validated procedure was used to determine lead isotope amount ratios in Trojan silver artefacts with expanded uncertainties (k = 2) <0.09 %.

  3. Lead isotope mapping of crustal reservoirs within the Grenville Superterrane: I. Central and southern Appalachians

    NASA Astrophysics Data System (ADS)

    Sinha, A. K.; Hogan, J. P.; Parks, J.

    New whole rock Pb isotope data are presented from basement rocks of Grenville age. Samples from nine major basement rocks, extending from Pennsylvania to Georgia have been utilized to delineate isotopic crustal reservoirs. Utilizing Pb isotope correlation diagrams, three distinct isotopic reservoirs can be recognized. The three groups are subdivided on the basis of inferred μ (238U/204Pb) of the Grenville age rocks, as well as evidence of an Archean component in two of the blocks. On the basis of only 94 analyses, the three groups are: (i) Carvers Gap Gneiss and Stage Road Layered Gneiss; (ii) Blue Ridge, Baltimore Gneiss, State Farm Gneiss, and Pine Mountain Gneiss; and (iii) Tallulah Falls, Sauratown Mountain, Corbin and Honeybrook Uplands. It is suggested that Grenville age tectonic processes juxtaposed these isotopic reservoirs, leading to the development of the Grenville Superterrane.

  4. Isotopic composition of lead and strontium from Ascension and Gough Islands

    USGS Publications Warehouse

    Gast, P.W.; Tilton, G.R.; Hedge, C.

    1964-01-01

    Isotopic composition of lead and strontium has been determined in a series of rock samples from two islands on the Mid-Atlantic Ridge. Both inter-and intra-island variations exist in the abundance of radiogenic isotopes of both elements. Lead from basalt of Ascension Island has a Pb206-Pb 204 ratio of 19.5, while the corresponding ratio at Gough Island is only 18.4. The Pb208-Pb204 ratios from the two islands do not differ. Conversely, strontium from basalt of Ascension Island is less radiogenic than that from Gough Island basalts. The trachytes of both islands have lead and strontium that is more radiogenic than that found in the basalts. The inter-island differences indicate the existence of regional variations in the uranium-lead and rubidium-strontium ratios of the upper mantle source of these rocks and show that isotope compositions are a means for investigating chemical heterogeneities in the mantle.

  5. Effectiveness of leaded petrol phase-out in Tianjin, China based on the aerosol lead concentration and isotope abundance ratio.

    PubMed

    Wang, Wan; Liu, Xiande; Zhao, Liwei; Guo, Dongfa; Tian, Xiaodan; Adams, Freddy

    2006-07-01

    The phase-out of leaded petrol has been a measure widely used to reduce atmospheric lead pollution. Since the 1980s, China began to promote unleaded petrol. In order to assess the effectiveness of the measure an isotope fingerprint technique was applied for aerosol samples in the city of Tianjin. After dilute acid leaching, the lead concentration and isotope abundance ratios were determined for 123 samples collected in Tianjin during eight years (1994-2001). The 206Pb/207Pb ratio was lower in summer, when coal combustion emission was low and vehicle exhaust became more important, indicating that the 206Pb/207Pb ratio of leaded petrol in Tianjin is lower than that of aerosol samples. The 206Pb/207Pb ratio gradually increased from 1994 to 2001, a trend that suggests that the contribution from vehicle exhaust was diminishing. Overall, the measurements matched well with national statistical data of leaded and unleaded petrol production. After the nationwide switch to unleaded gasoline, comprehensive control measures are urgently needed to reduce air lead pollution in China, as aerosol lead reduced slightly but remains at a relatively high level.

  6. Identification of the sources of metal (lead) contamination in drinking waters in north-eastern Tasmania using lead isotopic compositions.

    PubMed

    Harvey, P J; Handley, H K; Taylor, M P

    2015-08-01

    This study utilises a range of scientific approaches, including lead isotopic compositions, to differentiate unknown sources of ongoing lead contamination of a drinking water supply in north-eastern Tasmania, Australia. Drinking water lead concentrations are elevated above the Australian Drinking Water Guideline (10 μg/L), reaching 540 μg/L in the supply network. Water lead isotopic compositions from the town of Pioneer ((208)Pb/(207)Pb 2.406, (206)Pb/(207)Pb 1.144 to (208)Pb/(207)Pb 2.360, (206)Pb/(207)Pb 1.094) and Ringarooma ((208)Pb/(207)Pb 2.398, (206)Pb/(207)Pb 1.117) are markedly different from the local bedrock ((208)Pb/(207)Pb 2.496, (206)Pb/(207)Pb 1.237). The data show that the lead in the local waters is sourced from a combination of dilapidated drinking water infrastructure, including lead jointed pipelines, end-of-life polyvinyl chloride pipes and household plumbing. Drinking water is being inadvertently contaminated by aging infrastructure, and it is an issue that warrants investigation to limit the burden of disease from lead exposure.

  7. Rubidium isotopes in primitive chondrites: Constraints on Earth's volatile element depletion and lead isotope evolution

    NASA Astrophysics Data System (ADS)

    Nebel, O.; Mezger, K.; van Westrenen, W.

    2011-05-01

    The bulk silicate Earth (BSE) shows substantial deficits in volatile elements compared to CI-chondrites and solar abundances. These deficits could be caused by pre-accretionary depletion in the solar nebula during condensation of solids, or by later heat-driven evaporation during collision of small bodies that later accreted to form the Earth. The latter is considered to result in isotope fractionation for elements with low condensation temperatures that correlates with the degree of depletion. Here, we report first high-precision isotope ratio measurements of the moderately volatile and lithophile trace element Rb. Data from seventeen chondrite meteorites show that their Rb isotope abundances are nearly indistinguishable from Earth, not deviating more than 1 per mil in their 87Rb/85Rb. The almost uniform solar system Rb isotope pool suggests incomplete condensation or evaporation in a single stage is unlikely to be the cause of the volatile element deficit of the Earth. As Rb and Pb have similar condensation temperatures, we use their different degrees of depletion in the BSE to address the mechanisms and timing of terrestrial volatile depletion. The Rb isotope data are consistent with a scenario in which the volatile budget of the Earth was generated by a mixture of a highly volatile-element depleted early Proto-Earth with undepleted material in the course of terrestrial accretion. Observed Pb and Rb abundances and U-Pb and Rb-Sr isotope systematics suggest that volatile addition occurred at approximately the same time at which last core-mantle equilibration was achieved. In line with previous suggestions, this last equilibration involved a second stage of Pb (but not Rb) depletion from the BSE. The timing of this second Pb loss event can be constrained to ~ 110 Ma after the start of the solar system. This model supports a scenario with core storage of Pb in the aftermath of a putative Moon forming giant impact that also delivered the bulk of the volatile

  8. Contaminated lead environments of man: reviewing the lead isotopic evidence in sediments, peat, and soils for the temporal and spatial patterns of atmospheric lead pollution in Sweden.

    PubMed

    Bindler, Richard

    2011-08-01

    Clair Patterson and colleagues demonstrated already four decades ago that the lead cycle was greatly altered on a global scale by humans. Moreover, this change occurred long before the implementation of monitoring programs designed to study lead and other trace metals. Patterson and colleagues also developed stable lead isotope analyses as a tool to differentiate between natural and pollution-derived lead. Since then, stable isotope analyses of sediment, peat, herbaria collections, soils, and forest plants have given us new insights into lead biogeochemical cycling in space and time. Three important conclusions from our studies of lead in the Swedish environment conducted over the past 15 years, which are well supported by extensive results from elsewhere in Europe and in North America, are: (1) lead deposition rates at sites removed from major point sources during the twentieth century were about 1,000 times higher than natural background deposition rates a few thousand years ago (~10 mg Pb m(-2) year(-1) vs. 0.01 mg Pb m(-2) year(-1)), and even today (~1 mg Pb m(-2) year(-1)) are still almost 100 times greater than natural rates. This increase from natural background to maximum fluxes is similar to estimated changes in body burdens of lead from ancient times to the twentieth century. (2) Stable lead isotopes ((206)Pb/(207)Pb ratios shown in this paper) are an effective tool to distinguish anthropogenic lead from the natural lead present in sediments, peat, and soils for both the majority of sites receiving diffuse inputs from long range and regional sources and for sites in close proximity to point sources. In sediments >3,500 years and in the parent soil material of the C-horizon, (206)Pb/(207)Pb ratios are higher, 1.3 to >2.0, whereas pollution sources and surface soils and peat have lower ratios that have been in the range 1.14-1.18. (3) Using stable lead isotopes, we have estimated that in southern Sweden the cumulative anthropogenic burden of

  9. Lead and sulfur isotopes of Guarn Halfaya and Bou Grine deposits associated to salt dome cap rocks (Diapirs zone, Northern Tunisia): sources of metals and genetic model

    NASA Astrophysics Data System (ADS)

    Jemmali, N.; Souissi, F.; Carranza, E. J. M.; Vennemann, T. W.

    2012-04-01

    The Pb-Zn ores districts at Guarn Halfaya and Bou Grine are hosted mainly by the dolostones in the contact breccias between Triassic and Upper Cretaceous and by Upper Cretaceous limestones. The mineralization occurs as lenticular, impregnations, substitutions, replacements, stratiform, vein, dissemination, and stockwork. A complex polymetallic sulfide assemblage typifies the main ore stage, dominated by sphalerite and galena, pyrite with minor chalcopyrite, arsenopyrite, and sulfosalt (grey copper). Limestone, barite and celestite dominate the gangue, with lesser calcite. Barite and celestite intergrown with main ore-stage sulfides of Oum Edeboua has δ34S values of 12.7 to 15.0 ‰, consistent with the derivation of sulfate from Triassic evaporites form the study area (12.8<δ34S<14.0 ‰). The δ34S values for sulfides of the both study area range from 2.6 to 9.5 ‰. These positive δ34S values are likely due to abiotic thermally-driven abiotic sulfate reduction (TSR) of Triassic sulfates at depth. However, the presence of bacterial relics suggests involvement of bacterially-mediated sulfate reduction (BSR). The lead isotope composition is homogeneous with 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratio ranging between from 18.723 to 18.783, 15.667 to 15.685, and 38.806 to 38.889, respectively, and plot between the upper crust and orogene curves of Zartman and Doe (1981) which imply involvement of a well-mixed multi-source reservoir of Pb at depth. The syn-diagenetic mineralization in the Bahloul Formation and the calculate of model age suggest a Late Cretaceous age, correspond to a NE-SW to ENE-WSS regional extensional tectonic events, which likely favored migration of mineralizing fluids and eventual deposition at Guarn Halfaya and Bou Grine.

  10. The Rosetta Stone of isotope science and the uranium/lead system.

    PubMed

    De Laeter, John

    2011-01-01

    The nucleosynthetic characteristics of U and Pb, together with the interconnectivity between these elements by two radioactive decay chains, are the foundation on which the U/Pb system was able to make a unique contribution to isotope science. The Rosetta Stone is an ancient Egyptian tablet that enabled previously indecipherable hieroglyphics to be translated. In a similar manner, the isotopic investigation of the U/Pb system, by a variety of mass spectrometric instrumentation, has led to our knowledge of the age of the Earth and contributed to thermochronology. In a similar manner, climate change information has been garnered by utilizing the U-Disequilibrium Series to measure the ages of marine archives. The impact of Pb in the environment has been demonstrated in human health, particularly at the peak of leaded petrol consumption in motor vehicles in the 1970s. Variations in the isotopic composition of lead in samples enable the source of the lead to be "fingerprinted" so as to trace the history of the Pb in ice cores and aerosols. The discovery of nuclear fission of (235)U led to the development of nuclear reactors and the isotopic investigation of the Oklo natural reactors. The mass spectrometer is the modern Rosetta Stone of isotope science, which has enabled the isotopic hieroglyphics of the U/Pb system to be investigated to reveal new horizons in our understanding of nature, and to address a number of societal and environmental problems.

  11. Regional lead isotope study of a polluted river catchment: River Wear, Northern England, UK.

    PubMed

    Shepherd, Thomas J; Chenery, Simon R N; Pashley, Vanessa; Lord, Richard A; Ander, Louise E; Breward, Neil; Hobbs, Susan F; Horstwood, Matthew; Klinck, Benjamin A; Worrall, Fred

    2009-08-15

    High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally controlled and dominated by large lead discharges from historic mining centres in the North Pennine Orefield ((208)Pb/(206)Pb, (207)Pb/(206)Pb ratios range from 2.0744-2.0954 and 0.8413-0.8554 respectively). In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in the upper catchment ((208)Pb/(206)Pb, (207)Pb/(206)Pb ratios range from 2.0856-2.1397 and 0.8554-0.8896 respectively) and far exceed values determined for the geogenic regional background. Here, the pollution is characterised by the atmospheric deposition of industrial lead and petrol lead. Lead derived from the combustion of coal, although present, is masked by the other two sources. Recent sediments from the main channel of the River Wear are isotopically indistinguishable from older, low order stream sediments of the North Pennine Orefield, indicating that contamination of the river by lead mining waste (up to several 1000 mg/kg Pb at some locations) continues to pose an environmental problem; a pattern that can be traced all the way to the tidal reach. Using within-catchment isotope variation and sediment lead concentrations, estimates can be made of the discharges from discrete mines or groups of mines to the overall level of lead pollution in the River Wear. As well as providing information pertinent to source apportionment and on-going catchment remediation measures, the database is a valuable resource for epidemiologists concerned with the health risks posed by environmental lead.

  12. Glacial recharge and paleohydrologic flow systems in the Illinois basin: Evidence from chemistry of Ordovician carbonate (Galena) formation waters

    SciTech Connect

    Stueber, A.M. ); Walter, L.M. )

    1994-11-01

    The Illinois basin provides an opportune setting for elucidating the roles of remnant evaporite brines and meteoric waters in the evolution of formation waters in an intracratonic sedimentary basin. Formation waters from carbonate reservoirs in the Upper Ordovician Galena Group have been analyzed geochemically to study the origin of their salinity, their chemical and isotopic evolution, and their relationship to paleohydrologic flow systems. Chloride/bromide ratios and Cl/Br-Na/Br relations indicate that initial brine salinity resulted from subaerial evaporation of seawater rather than from halite dissolution. Subsequent subsurface dilution of the brines by meteoric waters is disclosed by [delta]D-[delta][sup 18]O covariance; however, the remnant evaporite brine has not been completely expelled from these Ordovician strata. Galena formation waters have [sup 87]Sr/[sup 86]Sr ratios that range from 0.708 17 (a value nearly equal to that of coeval seawater) to 0.710 43. This is the greatest range of Sr isotopic ratios found in waters from any stratigraphic unit in the basin. Two fluid mixing events are revealed in plots of [sup 87]Sr/[sup 86]Sr vs. 1/Sr. 41 refs., 11 figs., 1 tab.

  13. Lead isotope studies of the Guerrero composite terrane, west-central Mexico: implications for ore genesis

    NASA Astrophysics Data System (ADS)

    Potra, Adriana; Macfarlane, Andrew W.

    2014-01-01

    New thermal ionization mass spectrometry and multi-collector inductively coupled plasma mass spectrometry Pb isotope analyses of three Cenozoic ores from the La Verde porphyry copper deposit located in the Zihuatanejo-Huetamo subterrane of the Guerrero composite terrane are presented and the metal sources are evaluated. Lead isotope ratios of 3 Cenozoic ores from the El Malacate and La Esmeralda porphyry copper deposits located in the Zihuatanejo-Huetamo subterrane and of 14 ores from the Zimapan and La Negra skarn deposits from the adjoining Sierra Madre terrane are also presented to look for systematic differences in the lead isotope trends and ore metal sources among the proposed exotic tectonostratigraphic terranes of southern Mexico. Comparison among the isotopic signatures of ores from the Sierra Madre terrane and distinct subterranes of the Guerrero terrane supports the idea that there is no direct correlation between the distinct suspect terranes of Mexico and the isotopic signatures of the associated Cenozoic ores. Rather, these Pb isotope patterns are interpreted to reflect increasing crustal contribution to mantle-derived magmas as the arc advanced eastward onto a progressively thicker continental crust. The lead isotope trend observed in Cenozoic ores is not recognized in the ores from Mesozoic volcanogenic massive sulfide and sedimentary exhalative deposits. The Mesozoic ores formed prior to the amalgamation of the Guerrero composite terrane to the continental margin, which took place during the Late Cretaceous, in intraoceanic island arc and intracontinental marginal basin settings, while the Tertiary deposits formed after this event in a continental arc setting. Lead isotope ratios of the Mesozoic and Cenozoic ores appear to reflect these differences in tectonic setting of ore formation. Most Pb isotope values of ores from the La Verde deposit (206Pb/204Pb = 18.674-18.719) are less radiogenic than those of the host igneous rocks, but plot within the

  14. Use of Lead Isotopes to Assess Sources and Mobility of Contaminants from Barber's Orchard, North Carolina

    NASA Astrophysics Data System (ADS)

    Kondrad, S.; Miller, J. R.; Lechler, P. J.

    2001-12-01

    Pb-isotopes were used to identify and analyze the off-site migration of lead arsenate, a pesticide used on Barber's Orchard, western North Carolina. The orchard, heavily contaminated by Pb, As, and DDT, is being considered for the EPA's National Priorities List of hazardous waste sites. ICP-MS was used to analyze concentration and isotopic composition of Pb in sediment, fish, and water samples of Richland Creek, which drains the orchard. Isotopic ratios of contaminated sediment were compared to ratios of sediment, water, and fish collected up and downstream of the orchard. The data suggest that off-site migration of contaminants has occurred. Contaminated sediment from Barber's Orchard and older (historic) floodplain sediment downstream of the orchard fall along a well-defined mixing line, indicating a mixing of Pb from the underlying bedrock and from lead arsenate. Sediment not contaminated by lead arsenate, including samples upstream of the orchard, have a significantly different isotopic composition than contaminated terrace sediments. The composition of modern channel sediment also differs from contaminated materials, and may reflect the recent influx of upland sediments eroded during development activities. Whole fish samples of rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), and longnose dace (Rhinichythys cataractae) were analyzed from three sites located downstream of the orchard. At each site, no differences were seen in isotopic composition among species. However, isotopic fractionation and differential accumulation does occur within the fish. Total Pb in bone was significantly greater than in liver or muscle. Isotopic composition of bone was similar to contaminated sediment. Conversely, the Pb isotopic signature of liver and muscle was found to be similar to water samples. Waters sampled during low-flow conditions show a unique signature, differing from both contaminated and non-contaminated sediment. It is hypothesized that this

  15. Lead and strontium isotopes in rocks of the Absaroka volcanic field, Wyoming

    USGS Publications Warehouse

    Peterman, Z.E.; Doe, B.R.; Prostka, H.J.

    1970-01-01

    The Absaroka volcanic field is comprised of predominant andesitic volcaniclastic rocks and less abundant potassium-rich mafic lavas (shoshonites and absarokites). Strontium and lead isotopic variations preclude a simple derivation from an isotopically uniform source: Sr87/Sr86, 0.7042 to 0.7090; Pb206/Pb204, 16.31 to 17.30; Pb208/Pb204, 36.82 to 37.64. We postulate that these rocks were derived from a lower crust or upper mantle which underwent a preferential loss of uranium relative to lead approximately 2800??200 m.y. ago. Variations in lead and strontium isotopic compositions are thought to reflect small inhomogeneities in U/Pb and Rb/Sr ratios in the source. ?? 1970 Springer-Verlag.

  16. Lead shot contribution to blood lead of First Nations people: the use of lead isotopes to identify the source of exposure.

    PubMed

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-11-01

    Although lead isotope ratios have been used to identify lead ammunition (lead shotshell pellets and bullets) as a source of exposure for First Nations people of Canada, the actual source of lead exposure needs to be further clarified. Whole blood samples for First Nations people of Ontario, Canada, were collected from participants prior to the traditional spring harvest of water birds, as well as post-harvest. Blood-lead levels and stable lead isotope ratios prior to, and after the harvest were determined by ICP-MS. Data were analyzed by paired t-tests and Wilcoxon Signed-Ranks tests. All participants consumed water birds harvested with lead shotshell during the period of study. For the group excluding six males who were potentially exposed to other sources of lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (p<0.05) increases in blood-lead concentrations and blood levels of (206)Pb/(204)Pb and (206)Pb/(207)Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in (208)Pb/(206)Pb values towards the mean for lead shotshell pellets. However, when we categorized the group further into a group that did not use firearms and did not eat any other traditional foods harvested with lead ammunition other than waterfowl, our predictions for (206)Pb/(204)Pb, (206)Pb/(207)Pb and (208)Pb/(206)Pb hold true, but there was not a significant increase in blood-lead level after the hunt. It appears that the activity of hunting (i.e., use of a shotgun) was also an important route of lead exposure. The banning of lead shotshell for all game hunting would eliminate a source of environmental lead for all people who use firearms and/or eat wild game.

  17. Lead isotopic compositions of common arsenical pesticides used in New England

    USGS Publications Warehouse

    Ayuso, Robert; Foley, Nora; Robinson, Gilpin; Wandless, Gregory; Dillingham, Jeremy

    2004-01-01

    The three most important arsenical pesticides and herbicides that were extensively used on apple, blueberry, and potato crops in New England from mid-1800s to recent times are lead arsenate, calcium arsenate, and sodium arsenate. Lead arsenate was probably the most heavily used of the arsenical pesticides until it was banned in 1988. Other metal-arsenic pesticides were also used but in lesser amounts. A recent report identified areas in New England where arsenical pesticides were used extensively (Robinson and Ayuso, 2004). On the basis of factor analysis of metal concentrations in stream sediment samples, a positive correlation with pesticide use was shown in regions having stream sediment sample populations that contained concentrations of high arsenic and lead. Lead isotope compositions of stream sediments from areas with heavy use of the pesticides could not be entirely explained by lead originating from rock sulfides and their weathering products. An industrial lead contribution (mostly from atmospheric deposition of lead) was suggested in general to explain the lead isotopic distributions of the stream sediments that could not be accounted for by the natural lead in the environment. We concluded that when agricultural land previously contaminated with arsenical pesticides is urbanized, pesticide residues in the soils and stream sediments could be released into the groundwater. No lead isotopic data characterizing the compositions of pesticides were available for comparison. We have determined the lead isotopic compositions of commonly used pesticides in New England, such as lead arsenate, sodium metaarsenite, and calcium arsenate, in order to assist in future isotopic comparisons and to better establish anthropogenic sources of Pb and As. New data are also presented for copper acetoarsenite (or Paris green), methyl arsonic acid and methane arsonic acid, as well as for arsanilic acid, all of which are used as feed additives to promote swine and poultry growth

  18. Isotopic ratio based source apportionment of children's blood lead around coking plant area.

    PubMed

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2014-12-01

    Lead exposure in the environment is a major hazard affecting human health, particularly for children. The blood lead levels in the local children living around the largest coking area in China were measured, and the source of blood lead and the main pathways of lead exposure were investigated based on lead isotopic ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) in blood and in a variety of media, including food, airborne particulate matter, soil, dust and drinking water. The children's blood lead level was 5.25 (1.59 to 34.36 as range) μg dL(-1), lower than the threshold in the current criteria of China defined by the US Centers for Disease Control (10 μg dL(-1)). The isotopic ratios in the blood were 2.111±0.018 for (208)Pb/(206)Pb and 0.864±0.005 for (207)Pb/(206)Pb, similar to those of vegetables, wheat, drinking water, airborne particulate matter, but different from those of vehicle emission and soil/dust, suggesting that the formers were the main pathway of lead exposure among the children. The exposure pathway analysis based on the isotopic ratios and the human health risk assessment showed that dietary intake of food and drinking water contributed 93.67% of total exposed lead. The study further indicated that the coal used in the coking plant is the dominant pollution source of lead in children's blood.

  19. Effects of reduced lead deposition on pied flycatcher (Ficedula hypoleuca) nestlings: tracing exposure routes using stable lead isotopes.

    PubMed

    Berglund, Asa M M; Klaminder, Jonatan; Nyholm, N Erik I

    2009-01-01

    To what extent the lead burden of birds living in strongly contaminated ecosystems is responding to decreased atmospheric lead deposition is not well known. In this study, we measured lead concentrations and stable lead isotope ratios (206pb/207Pb and 208Pb/207Pb) in liver and feces from pied flycatcher nestlings (Ficedula hypoleuca) along a 90 km pollution gradient from the Rönnskär smelter in northern Sweden. Changes in lead concentration in the birds from 1984 to 2006 were used for assessing the recovery of the environment following reduced lead emissions at the smelter. The 206Pb/207Pb and 208Pb/207Pb ratios were used to identify lead sources to the birds. Lead concentrations in liver and feces have decreased since the 1980s, typically by 9-15% (liver) and 18-40% (feces) as a result of a 98% emission reduction. This relatively weak recovery is explained by a transfer of old lead contaminants accumulated in soil to the birds via their prey, which was evident by a 206Pb/207Pb ratio in liver tissue (1.15 +/- 0.01) that overlapped with the ratio in ants (1.16 +/- 0.01) and organic soil horizon (1.17 +/- 0.01) rather than the current atmospheric lead pollution (1.11 +/- 0.01). Our findings suggest that insectivorous birds living around smelters may remain contaminated decades after ceased emissions.

  20. Lead isotope systematics of some igneous rocks from the Egyptian Shield

    NASA Technical Reports Server (NTRS)

    Gillespie, J. G.; Dixon, T. H.

    1983-01-01

    Lead isotope data on whole-rock samples and two feldspar separates for a variety of Pan-African (late Precambrian) igneous rocks for the Egyptian Shield are presented. It is pointed out that the eastern desert of Egypt is a Late Precambrian shield characterized by the widespread occurrence of granitic plutons. The lead isotope ratios may be used to delineate boundaries between Late Precambrian oceanic and continental environments in northeastern Africa. The samples belong to three groups. These groups are related to a younger plutonic sequence of granites and adamellites, a plutonic group consisting of older tonalites to granodiorites, and the Dokhan volcanic suite.

  1. Lead isotope ratios for bullets, a descriptive approach for investigative purposes and a new method for sampling of bullet lead.

    PubMed

    Sjåstad, Knut-Endre; Simonsen, Siri Lene; Andersen, Tom H

    2014-11-01

    To establish a link between a bullet fired from a suspected firearm, investigation of striation marks are one of the corner stones in the forensic laboratory. Nevertheless, on some occasions, the bullet may be deformed to such extent that traditional investigation of striation marks will be impossible. Fragments of lead can be investigated by lead isotope ratio determination in order to distinguish between bullets with different origin. This approach initially seems reasonable, since the abundance of lead isotopes varies significantly in nature. To make a method valid for forensic purposes, it is important to have a fundamental understanding of the variation within a box of lead bullets and the expected variation between boxes. Studies of variability within and between boxes of ammunition are imperative to perform any type of forensic interpretation, both in an investigative and evaluative context. This work presents an extensive study of variability within and between boxes of ammunition by use of multicollector inductive coupled mass spectrometry. As a first approximation to classify bullets to any given source, a simple and robust graphical method is presented. In addition, an easy-to-use sampling procedure of lead is presented.

  2. Successful application of lead isotopes in source apportionment, legal proceedings, remediation and monitoring.

    PubMed

    Gulson, Brian; Korsch, Michael; Winchester, Wayne; Devenish, Matthew; Hobbs, Thad; Main, Cleve; Smith, Gerard; Rosman, Kevin; Howearth, Lynette; Burn-Nunes, Laurie; Seow, Jimmy; Oxford, Cameron; Yun, Gracie; Gillam, Lindsay; Crisp, Michelle

    2012-01-01

    In late 2006, the seaside community in Esperance Western Australia was alerted to thousands of native bird species dying. The source of the lead (Pb) was determined by Pb isotopes to derive from the handling of Pb carbonate concentrate through the Port, which began in July 2005. Concern was expressed for the impact of this on the community. Our objectives were to employ Pb isotope ratios to evaluate the source of Pb in environmental samples for use in legal proceedings, and for use in remediation and monitoring. Isotope measurements were undertaken of bird livers, plants, drinking water, soil, harbour sediments, air, bulk ceiling dust, gutter sludge, surface swabs and blood. The unique lead isotopic signature of the contaminating Pb carbonate enabled diagnostic apportionment of lead in samples. Apart from some soil and water samples, the proportion of contaminating Pb was >95% in the environmental samples. Lead isotopes were critical in resolving legal proceedings, are being used in the remediation of premises, were used in monitoring of workers involved in the decontamination of the storage facility, and monitoring transport of the concentrate through another port facility. Air samples show the continued presence of contaminant Pb, more than one year after shipping of concentrate ceased, probably arising from dust resuspension. Brief details of the comprehensive testing and cleanup of the Esperance community are provided along with the role of the Community. Lead isotopic analyses can provide significant benefits to regulatory agencies, interested parties, and the community where the signature is able to be characterised with a high degree of certainty.

  3. The Pb isotopic record of historical to modern human lead exposure.

    PubMed

    Kamenov, George D; Gulson, Brian L

    2014-08-15

    Human teeth and bones incorporate trace amounts of lead (Pb) from the local environment during growth and remodeling. Anthropogenic activities have caused changes in the natural Pb isotopic background since historical times and this is reflected in the Pb isotopes of historical European teeth. Lead mining and use increased exponentially during the last century and the isotopic compositions of modern human teeth reflect the modern anthropogenic Pb. USA teeth show the most radiogenic Pb and Australian teeth show the least radiogenic Pb, a result of different Pb ores used in the two regions. During the last century the Australian Pb was exported to Europe, Asia, South America, and Africa, resulting in swamping of the local environmental Pb signal by the imported Pb. As a result, the modern human teeth in Europe show a significant drop to lower isotopic values compared with historical times. Similarly, modern human teeth in other regions of the world show similar Pb isotopic ratios to modern European teeth reflecting the Pb imports. The specific pattern of human Pb exposure allows us to use the Pb isotopic signal recorded in the skeleton as a geo-referencing tool. As historical European teeth show a distinct Pb signal, we can identify early European skeletal remains in the New World and likely elsewhere. In modern forensic investigations we can discriminate to some extent Eastern Europeans from Western and Northern Europeans. Australians can be identified to some extent in any region in the world, although there is some overlap with Western European individuals. Lead isotopes can be used to easily identify foreigners in the USA, as modern USA teeth are distinct from any other region of the world. By analogy, USA individuals can be identified virtually in any other region of the world.

  4. Identification of historical lead sources in roof dusts and recent lake sediments from an industrialized area: indications from lead isotopes.

    PubMed

    Chiaradia, M; Chenhall, B E; Depers, A M; Gulson, B L; Jones, B G

    1997-10-20

    X-ray fluorescence and stable lead (Pb) isotopic analyses have been undertaken on dusts, known from microscopic investigation to contain significant quantities of industrially- and urban-derived particulate matter, present in the roof cavities of houses in the Illawarra region (N.S.W., Australia), with the objective of examining the historic record of Pb pollution. All investigated houses contained in excess of 250 micrograms g-1 Pb, with dwellings close to a copper smelter, in a large industrial complex including a major steelworks, containing higher (> 2500 micrograms g-1) Pb concentrations. The isotopic composition in the dusts, expressed here as 206Pb/204Pb, is relatively constant at 17.0, irrespective of dwelling age or distance from the industrial complex. Contamination of the dusts by Pb sourced from paint cannot explain the isotopic uniformity of the dust samples. Isotopic modelling indicates that the dusts contain Pb derived from the copper smelter, gasoline-air Pb and a minor contribution from coal-utilising sources. Lead loading was also investigated in the adjacent lagoon, which acts as a natural sink for particulate matter in the Illawarra region. Isotopic data and modelling indicate that one natural and four anthropogenic sources contribute to the Pb burden of this lagoon. The natural source consists of Permian rocks cropping out in the catchment area which have a 206Pb/204Pb of approximately 18.7. The suggested anthropogenic sources are an old disbanded base-metal (Pb) smelter (206Pb/204Pb approximately 16.2-16.3), the copper smelter (206Pb/204Pb approximately 17.9), gasoline-air derived Pb (206Pb/204Pb approximately 16.4-16.5) and industries utilising coal, for example the recently closed thermal coal-fired power station (206Pb/204Pb approximately 18.9). The relative contributions of the base-metal (mainly lead) smelter and gasoline-air Pb in the sediment can only be partly assessed due to the isotopic similarity of these sources. Likewise the

  5. The graphical presentation of lead isotope data for environmental source apportionment.

    PubMed

    Ellam, R M

    2010-07-15

    Lead isotope ratios are widely used to identify original sources of Pb in the environment. Such source apportionment depends on the ability to distinguish potential sources on the basis of their isotopic composition. However, almost all terrestrial Pb is co-linear in some of the plots i.e. (206)Pb/(208)Pb versus (206)Pb/(207)Pb and (206)Pb/(204)Pb versus (206)Pb/(207)Pb commonly presented in the literature. These diagrams are unable to distinguish more than two sources of environmental Pb. Linear trends in such plots are an inevitable consequence of the co-linearity of terrestrial leads and should not be taken necessarily to indicate simple binary mixing of sources. A more reliable test for multiple source mixing can be obtained from plots involving (206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb and therefore requires measurements of the minor (204)Pb isotope.

  6. Tracing lead pollution sources in abandoned mine areas using stable Pb isotope ratios.

    PubMed

    Yoo, Eun-Jin; Lee, Jung-A; Park, Jae-Seon; Lee, Khanghyun; Lee, Won-Seok; Han, Jin-Seok; Choi, Jong-Woo

    2014-02-01

    This study focused on Pb isotope ratios of sediments in areas around an abandoned mine to determine if the ratios can be used as a source tracer. For pretreatment, sediment samples were dissolved with mixed acids, and a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, Nu plasma II) was used to investigate the Pb isotopic composition of the samples. The measured isotope ratios were then corrected for instrumental mass fractionation by measuring the (203)Tl/(205)Tl ratio. Repeated measurements with the NIST SRM 981 reference material showed that the precision of all ratios was below 104 ppm (±2σ) for 50 ng/g. The isotope ratios ((207)Pb/(206)Pb) found were 0.85073 ± 0.0004~0.85373 ± 0.0003 for the main stream, while they were 0.83736 ± 0.0010 for the tributary and 0.84393 ± 0.0002 for the confluence. A binary mixing equation for isotope ratios showed that the contributions of mine lead to neighboring areas were up to 60%. Therefore, Pb isotope ratios can be a good source tracer for areas around abandoned mines.

  7. Electronic and nuclear properties from the analysis of the isotope shifts in the spectral lines of lead

    NASA Astrophysics Data System (ADS)

    Wasowicz, T. J.

    2009-06-01

    Isotope shifts in the 623.7 nm line of Pb I have been measured. Then, in a spectral range of 280div730 nm the optical isotope shifts in 24 lines of neutral and singly ionized lead have been analyzed using a combined model-independent method. From the combination of the optical isotope shifts data with elastic electron scattering, muonic X-ray and electronic Kα X-ray data, we were able to determine the two contributions to the total isotope shift, namely the mass and the field shifts, and to obtain the values of several nuclear factors for a long chain of lead isotopes.

  8. Insights into past atmospheric lead emissions using lead concentrations and isotopic compositions in historic lichens and fungi (1852-2008) from central and southern Victoria, Australia

    NASA Astrophysics Data System (ADS)

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K.; Gulson, Brian L.

    2016-08-01

    Lead concentrations and lead isotopic compositions were determined in historic central and southern Victoria, Australia lichen (Cladonia and Usnea) and fungi (Trametes) samples collected between 1852 and 2008 to evaluate long-term atmospheric lead contamination sources. The data are grouped into four time intervals of 1850-1931, 1932-1984, 1985-2001 and 2002-2008 corresponding to the history of leaded petrol use in Australia. Elevated lichen and fungi lead concentrations and relatively high isotopic compositions from the period 1850-1931 are attributed to lithogenic sources, gold mining activities and early industrialisation. Significant increases in lichen and fungi lead concentrations and concomitant lower lead isotopic compositions correspond to the marked increase in lead emissions from leaded petrol use after 1932. Following the end of leaded petrol use in 2002 lead isotopic composition values 'recover' toward more lithogenic values. However, the lead isotopic composition data indicate that the environmental impact from leaded petrol emissions persists in contemporary samples dated to 2002-2008. Overall, the data reveal that herbarium lichens and fungi from central and southern Victoria can be used as proxies for environmental lead emissions over the past 150 years.

  9. A Chinese imprint in insoluble pollutants recently deposited in central Greenland as indicated by lead isotopes.

    PubMed

    Bory, Aloys J-M; Abouchami, Wafa; Galer, Stephen J G; Svensson, Anders; Christensen, John N; Biscaye, Pierre E

    2014-01-01

    A unique ∼ 10 year record of the lead isotopic composition of airborne insoluble particulate matter deposited in central Greenland was extracted from recent snow layers at NorthGRIP (75.1°N, 042.3°W; elevation 2,959 m), spanning the years 1989-2001. Comparison with lead isotopic signatures of both natural and anthropogenic northern hemisphere (NH) aerosol sources shows that human activities must have accounted for most of the insoluble lead deposited on Greenland during the late 1990 s, exceeding by far the natural contribution from large Asian mineral dust inputs. Lead isotopes imply predominance with time of European/Canadian sources over U.S.-derived lead, with an admixed signature typical of Chinese anthropogenic lead sources. The relative contribution of the latter shows a marked seasonal increase during spring. Our record also suggests that China's weight in the overall supply of insoluble pollutants deposited on Greenland was growing over the past decade of the 20th century.

  10. Lead isotopes in Southern Ocean marine sediments: implications for paleoclimatic provenance and seawater studies

    NASA Astrophysics Data System (ADS)

    Cook, C. P.; Martin, E. E.

    2014-12-01

    Lead (Pb) isotopes in detrital marine sediments and authigenic oxide coatings have proven useful in reconstructing past changes in continental weathering of glaciated continents and ocean circulation. This approach is under-utilised in the Southern Ocean, despite uncertainties about the evolution of Antarctica's ice sheets and oceanographic changes in this region throughout the Cenozoic. Lead isotopes in sediments are controlled by the mineralogy and age of their bedrock sources, making them an ideal tool to trace changes in Southern Ocean sediment provenance associated with onland erosion patterns (and ice sheet variability), and ocean circulation. However, core-top mapping of Pb isotope signatures of detrital marine sediments in this region is non-existent. We present new Pb isotope data for acid-digested <63µm and bulk Late Holocene sediments from 40 cores located in the East Antarctic sector of Southern Ocean. Results demonstrate that, similar to existing Nd and Sr core-top surveys, distinct provenance sectors can be seen in sediments proximal to the continent, due to the geological characteristics of bedrock sources along the margin. A striking N-S trend is also evident, with distal sediments characterised by less radiogenic isotopic signatures, likely associated with a decrease in radiogenic Pb-bearing minerals with increasing distance from the continental margin. This pattern suggests that Pb isotopes in marine sediments may be useful in reconstructing past provenance trends associated with ice sheet change, and migrations of Southern Ocean frontal positions. In addition, we will present new seawater Pb isotope data from reductive leaching of authigenic coatings of these same sediments, permitting for Late Holocene Pb isotope seawater mapping of the Southern Ocean. To ensure we measured the true seawater signal, we adapted established sequential leaching procedures to minimise detrital contamination, and monitored leachate compositions with Nd isotopes, and

  11. Anthropogenic lead concentrations and sources in Baltic Sea sediments based on lead isotopic composition.

    PubMed

    Zaborska, Agata

    2014-08-15

    The Gulf of Gdańsk is influenced by heavy metals of anthropogenic origin. In this study, temporal concentration changes of Pb, Zn, Cd, and Cu were studied in six, 50 cm long sediment cores. The main aim of the study was to concentrate on the history of Pb fluxes and Pb isotopic composition ((206)Pb/(207)Pb and (208)Pb/(206)Pb) to trace Pb sources. The lowest Pb concentrations (19 μg g(-1)) were measured in sediments deposited circa 1860, while the highest Pb concentrations (63-147 μg g(-1)) were measured in sediments deposited between 1960s and 70s. Pre-industrial Pb fluxes were 7 Pb m(2)year(-1), while after WWII they reached 199 Pb m(2)year(-1). Highest (206)Pb/(207)Pb ratios (∼1.22) were measured in the oldest sediment layers, and the lowest (206)Pb/(207)Pb ratios (∼1.165) were measured in the sediments deposited in 1970s-90s. During the period of highest Pb contamination, the anthropogenic Pb fraction reached up to 93%. A general discussion of the Pb sources, emissions, and loads for Poland is included.

  12. Lead Isotopic Composition and Trace Metals in Aerosols for Source Apportionment

    NASA Astrophysics Data System (ADS)

    Chien, C. T.; Paytan, A.

    2014-12-01

    Transported thousands of miles away from their source, aerosols can be dispersed and deposition throughout the Earth's surface. Aerosols from natural and industrial sources have different characteristics and health impacts thus it is important to identify their sources. The lead isotopic composition and trace metals in aerosol samples collected in different regions and periods around the world can help us better understand spatial and seasonal variation of aerosol sources. Aerosol samples collected in California, Bermuda, China and the Red Sea have been analyzed. The trace metal and Pb isotopes in these samples provide information regarding the various sources of aerosols to these sites.

  13. Lead concentration and isotopic composition in five peridotite inclusions of probable mantle origin

    USGS Publications Warehouse

    Zartman, R.E.; Tera, F.

    1973-01-01

    The lead content of five whole-rock peridotite inclusions (four lherzolites and one harzburgite) in alkali basalt ranges from 82 to 570 ppb (parts per billion). Approximately 30-60 ppb of this amount can be accounted for by analyzed major silicate minerals (olivine ??? 10 ppb; enstatite 5-28 ppb; chrome diopside ???400 ppb). Through a series of acid leaching experiments, the remainder of the lead is shown to be quite labile and to reside in either glassy or microcrystalline veinlets or accessory mineral phases, such as apatite and mica. The lead isotopic composition of the peridotites (206Pb/204Pb = 18.01-18.90; 207Pb/204Pb = 15.52-15.61; 208Pb/204Pb = 37.80-38.86) lies within the range of values defined by many modern volcanic rocks and, in particular, is essentially coextensive with the abyssal tholeiite field. In all but one instance, isotopic differences were found between the peridotite and its host alkali basalt. Two of the peridotites clearly demonstrated internal isotopic heterogeneity between leachable and residual fractions that could not simply be due to contamination by the host basalt. However, there is no evidence that these ultramafic rocks form some layer in the mantle with isotopic characteristics fundamentally different from those of the magma sources of volcanic rocks. ?? 1973.

  14. The isotopic composition of silver and lead in two iron meteorites - Cape York and Grant

    NASA Technical Reports Server (NTRS)

    Chen, J. H.; Wasserburg, G. J.

    1983-01-01

    Anomalies in silver isotope composition in the metal phases of the Cape York (IIIA) and Grant (IIIB) iron meteorites are studied together with the lead isotopic composition of both the metal and sulfide phases of Cape York. Following extensive surface cleaning, the Ag-107/Ag-109 ratio in the metal phases of the meteorites is found to be in excess of the terrestrial ratio, and of that found in the sulfide phases. A definite correlation between the Ag-107/Ag-109 and Pd-108/Ag-109 ratios is observed for these meteorites, indicating the in situ decay of Pd-107 and supporting the widespread presence of Pd in the early universe. Lead, determined after cleaning and with chemical separations using low blank levels, is found to exist in variable proportions in the metal and sulfide phases. The sulfides appear to be dominated by radiogenic modern lead, which may be explained by terrestrial contamination or by late metamorphism in the meteorite parent body.

  15. Isotopic tracing of landfill leachates and pollutant lead mobility in soil and groundwater.

    PubMed

    Vilomet, J D; Veron, A; Ambrosi, J P; Moustier, S; Bottero, J Y; Chatelet-Snidaro, L

    2003-10-15

    Here we provide evidence of the capability of stable lead isotopes to trace landfill leachate in a shallow groundwater. The municipal landfill we have investigated is located in southeastern France. It has no bottom liner, and wastes are placed directly on the ground. Stable lead isotopes allow the characterization of this landfill leachate signature (206Pb/207Pb = 1.189 +/- 0.004) that is clearly different from that of the local atmosphere (206Pb/207Pb = 1.150 +/- 0.006) and crustal lead (206Pb/207Pb = 1.200 +/- 0.005). Piezometers located in the direct vicinity of the landfill generally display this contaminant imprint. The landfill plume is monitored up to 1000 m downgradient of the landfill, in very good agreement with evaluation from chloride concentration. Meanwhile, 206Pb/207Pb ratios measured at a piezometer located 4600 m downgradient of the landfill suggest a contamination by the landfill plume. This result shows that the complexity of a pollutant plume dispersion in this shallow groundwater system requires several independent tracers to clearly resolve origin and transport pathways for contaminants. Furthermore, seasonal rainfall variation for this Mediterranean mixed Quaternary alluvion reservoir and the use of KCl fertilizers might favor an efficient remobilization of atmospheric lead in plowed soils and its transfer into groundwater as shown by lead isotope systematics.

  16. Tracking mobility using human hair: What can we learn from lead and strontium isotopes?

    PubMed

    Vautour, Geneviève; Poirier, André; Widory, David

    2015-01-01

    The isotope ratios of strontium (Sr) and lead (Pb) in water derive from local geology and their isotopic signature can be linked to the age and type of underlying bedrocks and soils (if applicable), and are transferred up the food-chain. Both elements are transferred to human blood through diet and water, and some of it will ultimately be incorporated into the hair structure, making Sr and Pb isotopes interesting tools for tracing human mobility. In this study, we analyzed both the elemental concentration and isotope ratios of Sr and Pb from four different women of different ages to monitor their permanent relocation from central France to Eastern Canada during the summer 2012. For comparison, we also characterized bulk hair samples of sedentary individuals and local tap waters from their regions of origin and of settlement. Our results indicate that the 87Sr/86Sr and 206Pb/204Pb ratios are significantly modified by the change of environment, but also confirm that human hair compositions are impacted by other external factors (such as dust). Sr and Pb isotope systematics demonstrate their added value for detecting human mobility, but require further studies to better constrain the main sources and processes controlling their respective budgets in human hair for provenancing purposes.

  17. Phosphorite-hosted zinc and lead mineralization in the Sekarna deposit (Central Tunisia)

    USGS Publications Warehouse

    Garnit, Hechmi; Bouhel, Salah; Barca, Donatella; Johnson, Craig A.; Chtara, Chaker

    2012-01-01

    The Sekarna Zn–Pb deposit is located in Central Tunisia at the northeastern edge of the Cenozoic Rohia graben. Mineralization comprises two major ore types: (1) disseminated Zn–Pb sulfides that occur as lenses in sedimentary phosphorite layers and (2) cavity-filling zinc oxides (calamine-type ores) that crosscut Late Cretaceous and Early Eocene limestone. We studied Zn sulfide mineralization in the Saint Pierre ore body, which is hosted in a 5-m-thick sedimentary phosphorite unit of Early Eocene age. The sulfide mineralization occurs as replacements of carbonate cement in phosphorite. The ores comprise stratiform lenses rich in sphalerite with minor galena, Fe sulfides, and earlier diagenetic barite. Laser ablation–inductively coupled plasma mass spectrometry analyses of sphalerite and galena show a wide range of minor element contents with significant enrichment of cadmium in both sphalerite (6,000–20,000 ppm) and galena (12–189 ppm). The minor element enrichments likely reflect the influence of the immediate organic-rich host rocks. Fluid inclusions in sphalerite give homogenization temperatures of 80–130°C. The final ice melting temperatures range from −22°C to −11°C, which correspond to salinities of 15–24 wt.% NaCl eq. and suggest a basinal brine origin for the fluids. Sulfur isotope analyses show uniformly negative values for sphalerite (−11.2‰ to −9.3‰) and galena (−16‰ to −12.3‰). The δ34S of barite, which averages 25.1‰, is 4‰ higher than the value for Eocene seawater sulfate. The sulfur isotopic compositions are inferred to reflect sulfur derivation through bacterial reduction of contemporaneous seawater sulfate, possibly in restricted basins where organic matter was abundant. The Pb isotopes suggest an upper crustal lead source.

  18. Lead isotope ratio measurements by ICP-QMS to identify metal accumulation in vegetation specimens growing in mining environments.

    PubMed

    Marguí, E; Iglesias, M; Queralt, I; Hidalgo, M

    2006-08-31

    The use of variations in stable Pb isotope ratios has become a well-established diagnostic technique for characterising sources of lead contamination. In this work, lead isotope ratios in mining wastes (lead content 320-130,000 mg kg-1) and vegetation specimens (lead concentration 7-650 mg kg-1) have been determined by inductively coupled plasma quadrupole-based mass spectrometry (ICP-QMS) in order to investigate lead bioaccumulation in Buddleia davidii growing on wastes from two abandoned Pb/Zn mining areas in Spain. The accuracy of the isotope ratio measurements was evaluated by analysing a certified isotopic standard NIST SRM 981. Good agreements were obtained between the lead isotope ratios measured and the certified values (deviations within 0.01-0.2%). The results indicate that the lead isotopic ratios in vegetation samples collected in the mining areas differed from those of a specimen from an uncontaminated site (control sample). However, close lead isotope ratio values were found between vegetation specimens and mining tailings. Therefore, the results suggest that lead in the collected vegetation specimens is most likely related to the influence of mining activities rather than to other sources like past leaded-petrol emissions.

  19. Ulexite-galena intermediate-weight concrete as a novel design for overcoming space and weight limitations in the construction of efficient shields against neutrons and photons.

    PubMed

    Aghamiri, S M R; Mortazavi, S M J; Razi, Z; Mosleh-Shirazi, M A; Baradaran-Ghahfarokhi, M; Rahmani, F; Faeghi, F

    2013-01-01

    Recently, due to space and weight limitations, scientists have tried to design and produce concrete shields with increased attenuation of radiation but not increased mass density. Over the past years, the authors' had focused on the production of heavy concrete for radiation shielding, but this is the first experience of producing intermediate-weight concrete. In this study, ulexite (hydrated sodium calcium borate hydroxide) and galena (lead ore) have been used for the production of a special intermediate-weight concrete. Shielding properties of this intermediate-weight concrete against photons have been investigated by exposing the samples to narrow and broad beams of gamma rays emitted from a ⁶⁰Co radiotherapy unit. Densities of the intermediate-weight concrete samples ranged 3.64-3.90 g cm⁻³, based on the proportion of the ulexite in the mix design. The narrow-beam half-value layer (HVL) of the ulexite-galena concrete samples for 1.25 MeV ⁶⁰Co gamma rays was 2.84 cm, much less than that of ordinary concrete (6.0 cm). The Monte Carlo (MC) code MCNP4C was also used to model the attenuation of ⁶⁰Co gamma-ray photons and Am-Be neutrons of the ulexite-galena concrete with different thicknesses. The ⁶⁰Co HVL calculated by MCNP simulation was 2.87 cm, indicating a good agreement between experimental measurements and MC simulation. Furthermore, MC-calculated results showed that thick ulexite-galena concrete shields (60-cm thickness) had a 7.22 times (722 %) greater neutron attenuation compared with ordinary concrete. The intermediate-weight ulexite-galena concrete manufactured in this study may have many important applications in the construction of radiation shields with weight limitations such as the swing or sliding doors that are currently used for radiotherapy treatment rooms.

  20. Ulexite-galena intermediate-weight concrete as a novel design for overcoming space and weight limitations in the construction of efficient shields against neutrons and photons.

    PubMed

    Aghamiri, S M R; Mortazavi, S M J; Razi, Z; Mosleh-Shirazi, M A; Baradaran-Ghahfarokhi, M; Rahmani, F; Faeghi, F

    2013-01-01

    Recently, due to space and weight limitations, scientists have tried to design and produce concrete shields with increased attenuation of radiation but not increased mass density. Over the past years, the authors' had focused on the production of heavy concrete for radiation shielding, but this is the first experience of producing intermediate-weight concrete. In this study, ulexite (hydrated sodium calcium borate hydroxide) and galena (lead ore) have been used for the production of a special intermediate-weight concrete. Shielding properties of this intermediate-weight concrete against photons have been investigated by exposing the samples to narrow and broad beams of gamma rays emitted from a ⁶⁰Co radiotherapy unit. Densities of the intermediate-weight concrete samples ranged 3.64-3.90 g cm⁻³, based on the proportion of the ulexite in the mix design. The narrow-beam half-value layer (HVL) of the ulexite-galena concrete samples for 1.25 MeV ⁶⁰Co gamma rays was 2.84 cm, much less than that of ordinary concrete (6.0 cm). The Monte Carlo (MC) code MCNP4C was also used to model the attenuation of ⁶⁰Co gamma-ray photons and Am-Be neutrons of the ulexite-galena concrete with different thicknesses. The ⁶⁰Co HVL calculated by MCNP simulation was 2.87 cm, indicating a good agreement between experimental measurements and MC simulation. Furthermore, MC-calculated results showed that thick ulexite-galena concrete shields (60-cm thickness) had a 7.22 times (722 %) greater neutron attenuation compared with ordinary concrete. The intermediate-weight ulexite-galena concrete manufactured in this study may have many important applications in the construction of radiation shields with weight limitations such as the swing or sliding doors that are currently used for radiotherapy treatment rooms. PMID:23019599

  1. Lead concentration and isotope chronology in two coastal environments in Western and South East Asia

    NASA Astrophysics Data System (ADS)

    Carrasco, G. G.; Chen, M.; Boyle, E. A.; Zhao, N.; Nurhati, I. S.; Gevao, B.; al Ghadban, A.; Switzer, A.; Lee, J. M.

    2014-12-01

    Lead is a trace metal that is closely related to anthropogenic activity, mainly via leaded gasoline and coal combustion. The study of lead concentrations and isotopes in seawater, sediments, corals and aerosols allows for a systematic look at its sources and their time evolution in a natural environment. We will discuss results from two projects in Western and South East Asia, regions that have seen dramatic socio-economical changes over the past half-century that may have left environmental signals. These results highlight the usefulness of the method, indicate the degree of complexity of these systems, and point to the need for a continuous monitoring of anthropogenic trace metals in the small-medium coastal scale to be able to asses the larger scale effects of human activity. On the one hand, coastal Kuwait is heavily influenced by the Shat al-Arab river and shows a clear anthropogenic signature from Kuwait city. A mix of two sources can be tracked through the coral and sediment chronological records, with Pb206/Pb207 ratios (1.202 and 1.151) that approach the suspected source values (1.21 and 1.12) and eliminate the possibility of other sources. Through a wide sediment geographic distribution, the strength of the anthropogenic signature is modulated. On the other hand, Singapore offers a more complex system, where an apparent mix of two sources (extreme isotope ratios 1.215 and ~1.14) occurs also, but where either an unresolved potentially important third source (isotope ratio ~1.18), or an isotope exchange process should be invoked. The sediment and coral records allows us to track the changes through time; however, there seems to be incongruence with the aerosol isotope record. Further potential sources are being explored currently and will be discussed.

  2. Lead-isotopic data from sulfide minerals from the Cascade Range, Oregon and Washington

    USGS Publications Warehouse

    Church, S.E.; LeHuray, A.P.; Grant, A.R.; Delevaux, M.H.; Gray, J.E.

    1986-01-01

    Lead-isotopic studies of mineral deposits associated with Tertiary plutons found in the Cascade Range of Oregon and Washington demonstrate a rather uniform isotopic composition in various sulfide minerals ( 206Pb 204Pb = 18.84 to 19.05; 207Pb 204Pb = 15.57 to 15.62; 208Pb 204Pb = 38.49 to 38.74), show less variation than data from the volcanic rocks of the Cascade Range and fall within the mixing array defined by the MORB regression line and continental sediments. An evaluation of the role of crustal assimilation by hydrothermal convection during emplacement was made on five sulfide deposits associated with a single composite batholith, the Cloudy Pass pluton. The Pb-isotopic data and mass balance calculations suggest that only minor amounts of the lead were derived from the overlying Precambrian (?) Swakane Biotite Gneiss during emplacement. The bulk of the metal that occurs in sulfide deposits in the Cascade mineral belt appears to have been derived from subducted continental detritus. The variation of the Pb-isotopic signature of Sulfides from specific districts or deposits suggests that there is a correlation with age and structure of the crust. 206Pb 204Pb is greater than 18.92 in northern Washington and southern Oregon where deposits have intruded Mesozoic or older crust. However, the ore deposits between the northern Oregon border and central Oregon, south of Eugene, have intruded younger crust composed largely of mafic and andesitic volcanic rocks and 206Pb 204Pb lies between 18.84 and 18.92. This region, previously called the Columbia embayment, appears to be underlain by Tertiary volcanic rocks. Lead-isotopic data may be used to define the boundaries between discontinuous blocks of Mesozoic crust and Tertiary volcanic cover. ?? 1986.

  3. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits.

    PubMed

    Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

    2016-04-28

    Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ(114/110)Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ(114/110)Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits.

  4. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits.

    PubMed

    Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

    2016-01-01

    Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ(114/110)Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ(114/110)Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits. PMID:27121538

  5. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits

    PubMed Central

    Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

    2016-01-01

    Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ114/110Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ114/110Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits. PMID:27121538

  6. Lead isotope and trace element composition of urban soils in Mongolia

    NASA Astrophysics Data System (ADS)

    Tserenpil, Sh.; Sapkota, A.; Liu, C.-Q.; Peng, J.-H.; Liu, B.; Segebade, P. Chr.

    2016-08-01

    Lead (Pb) pollution in and around Ulaanbaatar is of national concern, given that the Mongolian capital is home to nearly half of the country's entire population. By comparison, Mongolian countryside is a pristine environment because of its sparse population and low industrial activity. The concentration of Pb in urban soils (average of 39.1 mg kg-1) was twice the values found (average 18.6 mg kg-1) in background territories (i.e., Mongolian rural sites). Furthermore, Pb contamination was examined by using Pb stable isotopic composition, and covariance of Pb isotopic ratios showed two groups between rural and urban soils as pristine and disturbed sites. The 206Pb/207Pb ratio, the most prominent fingerprint for Pb pollution, was 1.163-1.185 for the urban whereas values for rural soils (1.186-1.207) were analogue to the regional Pb isotopic signatures. Local coal sources and their combustion products, one of the potential Pb pollution sources in Ulaanbaatar, have significant radiogenic properties in terms of Pb isotopic composition and revealed an average of 1.25 for 206Pb/207Pb and 19.551 for 206Pb/204Pb ratios. Thus, contributions from coal firing activity to Pb pollution lower than it was assumed, and smaller range of these values measured in urban soils may be attributed to the mixing of less radiogenic Pb as a constituent of the leaded gasolines.

  7. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits

    NASA Astrophysics Data System (ADS)

    Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

    2016-04-01

    Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ114/110Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ114/110Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits.

  8. The isotopic composition of ore lead of the Creede mining district and vicinity, San Juan Mountains, Colorado: Text of a talk presented at the San Juan Mountains symposium to honor Thomas A. Steven; Rocky Mountain Section meeting of the Geological Society of America, May 2, 1987, Boulder, Colorado

    USGS Publications Warehouse

    Foley, N.K.; Barton, P.B.; Bethke, P.M.; Doe, B.R.

    1988-01-01

    Recent work allows us to extend the results of Doe et al. and to consider alternative processes to explain the widespread homogeneity and radiogenic nature of the ore lead: 1) David Matty (pers. commun., 1986) has shown that some minor volcanic units in the area have unusually radiogneic lead values; magmas comparable in composition to the units are a possible, though improbable, source of the ore lead. 2) The uniformity of the isotopic values of galenas may have resulted from homogenization during an extensive potassium-metasomatic event that predated the ores; this possibility is being tested in an on-going study of feldspars from metasomatized and unmetasomatized rocks. 3) Recent regional studies suggest the possibility of a prevolcanic, NNW-trending graben system filled by clastic sediments derived from the Precambrian basement, a process that would have an homogenizing effect on the lead isotopes. This interpretation implies importation, deep within the Creede hydrologic system, of fluids from remote sources. These alternatives show that the Pbisotope systematics may have a profound impact on the interpretation of the Creede hydrothermal system, and that further study is warranted.

  9. Metal leachability and anthropogenic signal in roadside soils estimated from sequential extraction and stable lead isotopes.

    PubMed

    Bäckström, Mattias; Karlsson, Stefan; Allard, Bert

    2004-01-01

    Several roadside soil samples were collected at two field sites in Sweden. They were analysed for total elemental content (using both ICP-MS and XRF) and stable lead isotopes. Extraction with deicing salt solution and sequential extraction were performed in order to elucidate the potential mobility due to the use of deicing agents. The total concentrations of elements, especially lead, have decreased and lead is presently almost at background concentrations (15-51 ppm for surface samples). However, the isotopic signature indicates that old gasoline lead still is left at the site constructed prior to 1975. The field site constructed in 1992 showed, however, no 206Pb/207Pb ratio below 1.14. Only minor amounts were leached using deicing salt solutions; for lead only 0.29%, on average, was extracted indicating that the mobile fraction already was released. Sequential extraction indicated that lead mainly was associated with reducible (34.4%) and oxidisable (35.4%) fractions. Exchangable and acid soluble fractions contained 20.3% while 10.0% was found in the residual fraction. The salt extraction released, however, very low concentrations indicating that most in fraction 1 is acid soluble (e.g. carbonates). Tungsten was also found at high concentrations indicating a possible impact from studded tires. For tungsten the following composition was obtained: residual (48.0%) > oxidisable (47.6%) > reducible (3.3%) > exchangeable/acid soluble (1.1%). From the isotopic studies it was also suggested that the order for incorporating anthropogenic lead into soils is exchangeable/carbonates > (hydr)oxides > organic matter > residual. The multivariate technique principal component analysis (PCA) seems promising for evaluating large sequential extraction datasets. PMID:15887369

  10. Lead isotope data bank; 2,624 samples and analyses cited

    USGS Publications Warehouse

    Doe, Bruce R.

    1976-01-01

    The Lead Isotope Data Bank (LIDB) was initiated to facilitate plotting data. Therefore, the Bank reflects data most often used in plotting rather than comprises a comprehensive tabulation of lead isotope data. Up until now, plotting was done using card decks processed by computer with tapes plotted by a Gerber plotter and more recently a CRT using a batch mode. Lack of a uniform format for sample identification was not a great impediment. With increase in the size of the bank, hand sorting is becoming prohibitive and ·plans are underway to put the bank into a uniform format on DISK with a card backup so that it may be accessed by use of IRIS on the DECK 10 computer at the U.S.G.S. facility in Denver. Plots will be constructed on a CRT. Entry of the bank into the IRIS accessing program is scheduled for completion in FY 1976

  11. Sources and Evolution of Anthropogenic Lead in Northwestern Pacific Seawater: High Resolution Coral Pb Isotope Record

    NASA Astrophysics Data System (ADS)

    Wang, B.; You, C.; Nohda, S.

    2008-12-01

    Lattice-bound Lead in scleractinian coral skeletons provides a potential tracer to investigate the historical anthropogenic disturbance in the surface ocean. In this study, a Porites coral core collected from an islet offshore southeastern Taiwan was used to reconstruct decadal lead variation in surface seawater at northwestern Pacific. Seasonal Pb/Ca peaks are in accordance with rainfall episodes, while the long-term trend shows high lead input before 1970s. This can be attributed to extensively use of alkyl-lead in the region. Moreover, temporal variations of lead isotope display a significant change of lead sources in mid-20 th, coinciding with the Australian Pb imported period. These isotopic signatures also indicate contribution from China/Japan pollutant through atmospheric circulation during 1962-1998. This preliminary study infers that Pb in surface seawater is dominantly transported by ocean current and aeolian deposition from adjacent urban area, while Pb concentration may not reflect entirely the source flux due to potential loss during transportation.

  12. Determination of lead in rocks by radiometric isotope dilution and substoichiometric extraction

    USGS Publications Warehouse

    Aruscavage, P.

    1976-01-01

    A rapid procedure is described for the determination of lead in rocks by an isotope-dilution substoichiometric method. After the sample has been digested with acid in the presence of 210Pb tracer, the lead is separated by dithizone extractions. After the lead has been back-extracted into aqueous solution, it is reacted with a substoichiometric amount of EDTA. Excess of unreacted lead is removed by extraction with dithizone in carbon tetrachloride, and the specific activity of the aqueous complex is determined by counting 210Pb. The standard deviation of the method is less than 10 % for replicate determinations of lead in several U.S. Geological Survey standard rocks. The agreement with literature values indicates that the method is accurate. ?? 1976.

  13. Lead Isotopic Tracing of Coal-Based Anthropogenic Pollution in Agricultural Soils in Jianghan Plain, China

    NASA Astrophysics Data System (ADS)

    Daniel, J. N.; Ying, S.; Zhao, R.; Bu, J.; Gan, Y.; Wang, Y.; Weiss, D. J.; Fendorf, S. E.

    2014-12-01

    The Chinese demand for energy is one of the greatest in the world, and the vast majority of it is generated through coal combustion - a process by which diverse pollutants are released into the atmosphere. Due to the relative proximity of croplands to power plants in much of China, these pollutants can be deposited onto agricultural soils via atmospheric transport. Relative amounts of lead (Pb) isotopes in airborne anthropogenic coal-based contaminants (fly ash) are currently understood. However, contaminants' effects on agricultural soil composition are less clear. We investigate the prevalence of anthropogenic contaminants in cropland soils using lead (Pb) isotope ratios as a tracer. Surface soil samples and deep core samples, taken from Chinese field sites in proximity to a coal combustion plant, undergo an acid extraction process and lead (Pb) isotope concentrations are measured. The results of this study illustrate the extent to which airborne contaminants have entered cropland soils and integrated themselves into the chemical processes at work. They further expand our understanding of the impacts of human coal combustion activities on the biogeochemistry of agricultural soils.

  14. Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth.

    PubMed

    Shepherd, Thomas J; Dirks, Wendy; Roberts, Nick M W; Patel, Jaiminkumar G; Hodgson, Susan; Pless-Mulloli, Tanja; Walton, Pamela; Parrish, Randall R

    2016-04-01

    We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and (208)Pb/(206)Pb, (207)Pb/(206)Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5-8 years, living in NE England. By integrating the isotope data with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2-3 years for molars, first 1-2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2µgPb/g) with (208)Pb/(206)Pb (mean ±2σ: 2.126-2.079) (208)Pb/(206)Pb (mean ±2σ: 0.879-0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM10, PM2.5) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4µgPb/g) with (208)Pb/(206)Pb (mean ±2σ: 2.145-2.117) (208)Pb/(206)Pb (mean ±2σ: 0.898-0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1-2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot study confirms that

  15. Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth.

    PubMed

    Shepherd, Thomas J; Dirks, Wendy; Roberts, Nick M W; Patel, Jaiminkumar G; Hodgson, Susan; Pless-Mulloli, Tanja; Walton, Pamela; Parrish, Randall R

    2016-04-01

    We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and (208)Pb/(206)Pb, (207)Pb/(206)Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5-8 years, living in NE England. By integrating the isotope data with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2-3 years for molars, first 1-2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2µgPb/g) with (208)Pb/(206)Pb (mean ±2σ: 2.126-2.079) (208)Pb/(206)Pb (mean ±2σ: 0.879-0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM10, PM2.5) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4µgPb/g) with (208)Pb/(206)Pb (mean ±2σ: 2.145-2.117) (208)Pb/(206)Pb (mean ±2σ: 0.898-0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1-2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot study confirms that

  16. A two century record of lead isotopes in high altitude Alpine snow and ice

    NASA Astrophysics Data System (ADS)

    Rosman, K. J. R.; Ly, C.; Van de Velde, K.; Boutron, C. F.

    2000-03-01

    A 140 m snow/ice core drilled at Mont Blanc, France, has been analysed for Pb isotopes, Pb and Ba concentrations. The 206Pb/ 207Pb ratio, which was measured by thermal ionisation mass spectrometry, decreased steadily from ˜1.18 about two centuries ago to ˜1.17 in 1960, then fell rapidly to ˜1.15 by 1968. Evidence of the Italian (Turin) isotopic lead experiment (IILE) was found in samples dated ˜1977 where the ratio dipped to 1.117. By the early 1990s it had returned to mid 1960s values. Large seasonal variations were found in Pb and Ba concentrations. Summer samples were associated with smooth changes in the 206Pb/ 207Pb ratio while larger fluctuations were encountered in winter which is consistent with a low altitude inversion near Mont Blanc in the winter and free transfer of pollutants from lower to higher altitudes at other times. A plot of 208Pb/ 207Pb versus 206Pb/ 207Pb ratios reveals three isotopic groupings, associated with the periods pre-1923, 1923-1968 and 1969-1991. In the first group, the isotopic composition is consistent with local mining, smelting and coal burning, while in the second, motor vehicle exhaust emissions dominate. In the third group, motor vehicle emissions also dominate but the Pb is even less radiogenic. During this period the IILE occurred and there was a reduction in the use of leaded gasoline in Europe. A comparison of the Mont Blanc and Summit (central Greenland) records shows they contain similar 206Pb/ 207Pb ratios between 1960 and 1968, although small differences in isotopic composition can be detected by also considering the 208Pb/ 207Pb ratio. However, after 1969 the two records diverge markedly, with the Greenland ratios being dominated by the highly radiogenic Mississippi valley-type Pb from the USA and with the Mont Blanc ratios moving to lower values particularly about the time of the IILE.

  17. Neodymium and lead isotope evidence for enriched early Archean crust in North America

    NASA Technical Reports Server (NTRS)

    Bowring, Samuel A.; Housh, Todd B.; Isachsen, Clark E.; Podosek, Frank A.; King, Janet E.

    1989-01-01

    Neodymium and lead isotope measurements and uranium-lead zircon geochronology from Archaean gneisses of the Slave Province in the Northwest Territories of Canada are reported. The gneisses contain zircons with cores older than 3.842 Gyr and an epsilon(Nd) (3.7 Gyr) of - 4.8. This is the oldest reported chondritic model age for a terrestrial sample and provides evidence for strongly enriched pre-3.8-Gyr crust, a reservoir complementary to the depleted mantle already in existence by 3.8 Gyr before the present.

  18. The Use of Lead Isotope and Rare Earth Element Geochemistry for Forensic Geographic Provenancing

    NASA Astrophysics Data System (ADS)

    Carey, A.; Darrah, T.; Harrold, Z.; Prutsman-Pfeiffer, J.; Poreda, R.

    2008-12-01

    Lead isotope and rare earth element composition of modern human bones are analyzed to explore their utility for geographical provenancing. DNA analysis is the standard for identification of individuals. DNA analysis requires a DNA match for comparison. Thus, DNA analysis is of limited use in cases involving unknown remains. Trace elements are incorporated into bones and teeth during biomineralization, recording the characteristics of an individual's geochemical environment. Teeth form during adolescence, recording the geochemical environment of an individual's youth. Bones remodel throughout an individual's lifetime. Bones consist of two types of bone tissue (cortical and trabecular) that remodel at different rates, recording the geochemical environment at the time of biomineralization. Cortical bone tissue, forming the outer surface of bones, is dense, hard tissue that remodels in 25-30 yrs. Conversely, trabecular bone tissue, the inner cavity of bones, is low density, porous and remodels in 2-5 years. Thus, analyzing teeth and both bone tissues allows for the development of a geographical time line capable of tracking immigration patterns through time instead of only an individual's youth. Geochemical isotopic techniques (Sr, O, C, N) have been used for geographical provenancing in physical anthropology. The isotopic values of Sr, C, O, N are predominantly a function of soil compositions in areas where food is grown or water is consumed. Application of these provenancing techniques has become difficult as an individual's diet may reflect the isotopic composition of foods obtained at the local grocer as opposed to local soil compositions. Thus, we explore the use of REEs and Pb isotopes for geographical provenancing. Pb and REEs are likely more reliable indicators of modern geographical location as their composition are high in bio-available sources such as local soils, atmospheric aerosols, and dust as opposed to Sr, C, O, N that are controlled by food and

  19. Copper and lead isotopic and metallic pollution record in soils from the Kombat mining area, Namibia

    NASA Astrophysics Data System (ADS)

    Mihaljevic, Martin; Ettler, Vojtech; Vanek, Ales; Chrastny, Vladislav; Kribek, Bohdan; Penizek, Vit; Sracek, Ondrej

    2013-04-01

    Copper (Cu) and lead (Pb) concentration, isotopic composition (206Pb/207Pb, 65Cu/63Cu) and speciation were studied in soils from the Kombat mining area. The Cu and Pb concentrations in the studied soils ranged between 21 mg/kg - 757 mg/kg, and 19 mg/kg - 815 mg/kg respectively. In the sequential extractions, the largest part of soil Cu appeared in the residual and reducible fractions and Pb was predominantly bound in reducible and residual fractions and was more mobile compared to Cu. Copper and Pb concentration are higher in soils close to the slime deposit. Concentration of both metals increased with increasing soil depth in irrigated and cultivated soils. In soils not contaminated by dust eroded from the slime deposit, Cu and Pb contents are not dependent on the soil depth. The Pb isotopic signatures (206Pb/207Pb) ranged between 1.15 - 1.21 in soils from the Kombat area. In most of soil samples, surface horizons exhibited lower 206Pb/207Pb ratio, which originates from the slime dust pollution (206Pb/207Pb ~ 1.15) compared to deeper soil horizons, with lithogenic Pb signatures (206Pb/207Pb > 1.2). Isotopic composition of Cu differs on contaminated and uncontaminated sites and cultivated and non-cultivated sites. The δ65Cu in the studied soil horizon ranged between -0.373 ‰ and 0.561 ‰. The most pronounced variations occurred in contaminated non cultivated and non-irrigated soils (0.529 ‰). The contaminated top horizons are enriched in isotopically heavier Cu (tailing materials), and δ65Cu decreased with depth. Irrigated (cultivated) and contaminated soils exhibited heavier Cu in the surface horizons (originated from tailing dust δ65Cu = 0.260), decrease of δ65Cu in Bt horizons (biological uptake of light isotope by crop, and their incorporation in this horizons) and increase of δ65Cu in Bc horizons. The Bc horizons of cultivated and irrigated Phaeozems are enriched in Mn nodules (0.2 - 1.5 cm diameter, prevailing Mn phase pyrochroite Mn(OH)2) which

  20. Lead isotopes reveal bilateral asymmetry and vertical continuity in the Hawaiian mantle plume.

    PubMed

    Abouchami, W; Hofmann, A W; Galer, S J G; Frey, F A; Eisele, J; Feigenson, M

    2005-04-14

    The two parallel chains of Hawaiian volcanoes ('Loa' and 'Kea') are known to have statistically different but overlapping radiogenic isotope characteristics. This has been explained by a model of a concentrically zoned mantle plume, where the Kea chain preferentially samples a more peripheral portion of the plume. Using high-precision lead isotope data for both centrally and peripherally located volcanoes, we show here that the two trends have very little compositional overlap and instead reveal bilateral, non-concentric plume zones, probably derived from the plume source in the mantle. On a smaller scale, along the Kea chain, there are isotopic differences between the youngest lavas from the Mauna Kea and Kilauea volcanoes, but the 550-thousand-year-old Mauna Kea lavas are isotopically identical to Kilauea lavas, consistent with Mauna Kea's position relative to the plume, which was then similar to that of present-day Kilauea. We therefore conclude that narrow (less than 50 kilometres wide) compositional streaks, as well as the larger-scale bilateral zonation, are vertically continuous over tens to hundreds of kilometres within the plume.

  1. Lead isotopes reveal bilateral asymmetry and vertical continuity in the Hawaiian mantle plume.

    PubMed

    Abouchami, W; Hofmann, A W; Galer, S J G; Frey, F A; Eisele, J; Feigenson, M

    2005-04-14

    The two parallel chains of Hawaiian volcanoes ('Loa' and 'Kea') are known to have statistically different but overlapping radiogenic isotope characteristics. This has been explained by a model of a concentrically zoned mantle plume, where the Kea chain preferentially samples a more peripheral portion of the plume. Using high-precision lead isotope data for both centrally and peripherally located volcanoes, we show here that the two trends have very little compositional overlap and instead reveal bilateral, non-concentric plume zones, probably derived from the plume source in the mantle. On a smaller scale, along the Kea chain, there are isotopic differences between the youngest lavas from the Mauna Kea and Kilauea volcanoes, but the 550-thousand-year-old Mauna Kea lavas are isotopically identical to Kilauea lavas, consistent with Mauna Kea's position relative to the plume, which was then similar to that of present-day Kilauea. We therefore conclude that narrow (less than 50 kilometres wide) compositional streaks, as well as the larger-scale bilateral zonation, are vertically continuous over tens to hundreds of kilometres within the plume. PMID:15829954

  2. Ancient bronze coins from Mediterranean basin: LAMQS potentiality for lead isotopes comparative analysis with former mineral

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Italiano, A.; Torrisi, A.

    2016-11-01

    Bronze coins coming from the area of the Mediterranean basin, dated back the II-X Cent. A.D., were analyzed using different physical analytical techniques. Characteristic X-ray fluorescence was used with electrons and photons, in order to investigate the elemental composition of both the surface layers and bulk. Moreover, the quadrupole mass spectrometry coupled to laser ablation (LAMQS technique) in high vacuum was used to analyse typical material compounds from surface contamination. Mass spectrometry, at high resolution and sensitivity, extended up to 300 amu, allowed measuring the 208Pb/206Pb and 207Pb/206Pb isotopic ratios into the coins. Quantitative relative analyses of these isotopic ratios identify the coin composition such as a "fingerprint" depending on the mineral used to extract the lead. Isotopic ratios in coins can be compared to those of the possible minerals used to produce the bronze alloy. A comparison between the measured isotope ratios in the analyzed coins and the literature database, related to the mineral containing Pb as a function of its geological and geophysical extraction mine, is presented. The analysis, restricted to old coins and the mines of the Mediterranean basin, indicates a possible correlation between the coin compositions and the possible geological sites of the extracted mineral.

  3. Understanding the partitioning processes of mobile lead in soakaway sediments using sequential extraction and isotope analysis.

    PubMed

    Kumar, Manish; Furumai, Hiroaki; Kurisu, Futoshi; Kasuga, Ikuro

    2009-01-01

    Lead (Pb) isotopic data were used in this study to first distinguish the partitioning of anthropogenic and natural lead in different fractions, obtained by BCR sequential extraction, and then to anticipate their mixing process in the soakaway sediment of artificial infiltration facilities (AIF). Total metal content was found higher in soakaway sediment samples than that of soil. The lowest (206)Pb/(207)Pb ratios were mostly observed in exchangeable fractions of soil and sediment samples, while residual fractions mostly showed the highest (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios than those of other fractions. In general, both ratios were higher in the soil than those of sediments. Further among soil samples, residual fraction of bottom soil exhibited higher ratios than surface soil indicating higher contribution of natural lead with depth. In addition, the difference in Pb content, partitioning and its isotope signature among four sediment samples were also investigated considering their sampling locations. The plot of (206)Pb/(207)Pb versus (208)Pb/(207)Pb showed two well demarcated cluster formations by soil and sediments samples that describe the partitioning between anthropogenic and natural lead; and some points falling in between soil and sediment samples pertinently illustrated the mixing processes between these two different pools of lead.

  4. A lead isotope distribution study in swine tissue using ICP-MS

    USGS Publications Warehouse

    May, T.W.; Wiedmeyer, Ray H.; Brown, L.D.; Casteel, S.W.

    1999-01-01

    In the United States lead is an ubiquitous environmental pollutant that is a serious human health hazard, especially for women of childbearing age, developing fetuses, and young children. Information concerning the uptake and distribution of lead to maternal and fetal tissues during pregnancy is poorly documented. A study was designed using domestic swine and lead isotope enrichment methodology to focus on maternal absorption and distribution of lead into bone and soft tissues, including the fetal compartment, under varying conditions of oral lead exposure and during altered physiological states (pregnant vs unbred). Total lead levels and Pb207/Pb206 ratios in bone (femur and vertebra), blood, and soft tissues (liver, kidney, brain) were determined by ICP-MS. Lead in fetal tissues derived from maternal bone could be differentiated from that derived from exogenous dosing. Unbred swine absorbed much less lead than pregnant females receiving the same dose. The accuracy and precision of ICP-MS at the instrumental level and for the entire method (sample collection, digestion, and analysis) were evaluated for both Pb207/Pb206 ratios and total lead. Several changes were suggested in method design to improve both instrumental and total method precision.

  5. One hundred fifty-year record of lead isotopes in Antarctic snow from Coats Land

    NASA Astrophysics Data System (ADS)

    Planchon, F. A. M.; van de Velde, K.; Rosman, K. J. R.; Wolff, E. W.; Ferrari, C. P.; Boutron, C. F.

    A record of the concentrations of Pb and Ba and the isotopic composition of Pb has been established for a remote, low accumulation site in the Atlantic sector of Antarctica (Coats Land) by means of thermal ionization mass spectrometry. The snow samples cover the period ˜1840 to 1990. They were taken from the walls of a pit to a depth of 7.8 m and as a core to 16 m; ultraclean procedures were used. Detailed laboratory subsampling provided both long-term (secular scale) and short-term (intra-annual) Pb, Ba, and Pb isotope variations. The results show that there have been significant variations in Pb concentrations (range, 0.1 to 9.3 pg/g) and isotopic composition (range, 1.096 to 1.208 for 206Pb/ 207Pb ratio) since the 1840s. The data show evidence of pollution for this metal in Antarctica as early as the 1880s. Several Pb maxima were observed: the first at the beginning of the 20th century and the last in the 1970s to 1980s, with a clear decrease during recent years. Although the last maximum is clearly linked to the rise and fall in the use of leaded gasoline in the Southern Hemisphere, especially in South America, the reason for the first remains uncertain. The pattern of changing isotopic composition of Pb reveals the changing origin and character of the anthropogenic inputs to Antarctica. An interesting feature in this pattern is the relatively large contribution of unradiogenic Pb in the ˜1890s, possibly originating from Australia. Another interesting feature is the pronounced intra-annual variation in the isotopic composition of Pb, which illustrates the complexity of the changing inputs of Pb to Antarctica.

  6. The isotopic composition of uranium and lead in Allende inclusions and meteoritic phosphates

    NASA Technical Reports Server (NTRS)

    Chen, J. H.; Wasserburg, G. J.

    1981-01-01

    The isotopic compositions of uranium and lead in Ca-Al-rich inclusions from the Allende chondrite and in whitlockite from the St. Severin chondrite and the Angra dos Reis achondrite are reported. Isoptopic analysis of acid soluble fractions of the Allende inclusions and the meteoritic whitlockite, which show isotopic anomalies in other elements, reveals U-235/U-238 ratios from 1/137.6 to 1/138.3, within 20 per mil of normal terrestrial U abundances. The Pb isotopic compositions of five coarse-grained Allende inclusions give a mean Pb-207/Pb-206 model age of 4.559 + or - 0.015 AE, in agreement with the U results. Pb isotope ratios of two fine-grained inclusions and a coarse-grained inclusion with strong mass fractionation and some nonlinear isotopic anomalies indicate that the U-Pb systems of these inclusions have evolved differently from the rest of Allende. Th/U abundance ratios in the Allende inclusions and meteoritic phosphate are found to range from 3.8 to 96, presumably indicating an optimal case for Cm/U fractionation, although the normal U concentrations do not support claims of abundant live Cm-247 or Cm-247/U-238 fractionation at the time of meteorite formation, in contrast to previous results. A limiting Cm-247/U-235 ratio of 0.004 at the time of meteorite formation is calculated which implies that the last major r process contribution at the protosolar nebula was approximately 100 million years prior to Al-26 formation and injection.

  7. Metals and metalloids in atmospheric dust: Use of lead isotopic analysis for source apportionment

    NASA Astrophysics Data System (ADS)

    Felix Villar, Omar I.

    Mining activities generate aerosol in a wide range of sizes. Smelting activities produce mainly fine particles (<1 microm). On the other hand, milling, crushing and refining processes, as well tailings management, are significant sources of coarse particles (> 1 microm). The adverse effects of aerosols on human health depend mainly on two key characteristics: size and chemical composition. One of the main objectives of this research is to analyze the size distribution of contaminants in aerosol produced by mining operations. For this purpose, a Micro-Orifice Uniform Deposit Impactor (MOUDI) was utilized. Results from the MOUDI samples show higher concentrations of the toxic elements like lead and arsenic in the fine fraction (<1 microm). Fine particles are more likely to be deposited in the deeper zones of the respiratory system; therefore, they are more dangerous than coarse particles that can be filtered out in the upper respiratory system. Unfortunately, knowing the total concentration of contaminants does not give us enough information to identify the source of contamination. For this reason, lead isotopes have been introduced as fingerprints for source apportionment. Each source of lead has specific isotopic ratios; by knowing these ratios sources can be identified. During this research, lead isotopic ratios were analyzed at different sites and for different aerosol sizes. From these analyses it can be concluded that lead isotopes are a powerful tool to identify sources of lead. Mitigation strategies could be developed if the source of contamination is well defined. Environmental conditions as wind speed, wind direction, relative humidity and precipitation have an important role in the concentration of atmospheric dust. Dry environments with low relative humidity are ideal for the transport of aerosols. Results obtained from this research show the relationship between dust concentrations and meteorological parameters. Dust concentrations are highly correlated

  8. Lead Isotopes and Temporal Records of Atmospheric Aerosol and Pollutants in Lichens

    NASA Astrophysics Data System (ADS)

    Getty, S. R.; Nash, T.; Asmerom, Y.

    2001-05-01

    Lichens are useful receptors of atmospheric particulate matter (PM) and pollutants due to their retention of body parts (unlike plants), slow growth rates, fairly uniform morphologies, lack of a vascular system, and sessile character over decades to centuries. Lichen biomonitoring has been used widely to map patterns of aerosol deposition, yet few studies have tested whether lichens can preserve a temporal record of airborne PM and pollutants. We show with U-Pb data that epilithic lichens (rock as host) can retain in their porous structure an integrated, decadal-scale history of changing aerosol inputs to desert ecosystems. Three lichens resided along an 80-km transect from a copper smelter (Douglas, AZ) closed in early 1987, to the ENE into adjacent New Mexico. For the radially growing lichen (Xanthoparmelia sp.), U-Pb data were obtained along cm-scale transects in the growth direction on a single thallus. Profiles from lichen rim to interior show increasing [Pb] and [U], or net accumulation with thallus age. Total lead contents are highest near the smelter. In contrast, each lead isotope profile (206Pb/207Pb) is flat during smelter operation, showing low ratios near the smelter (1.152) and high ratios (1.175) 80 km away. This suggests comparable mixtures of crust and smelter lead per locality over decades. Since smelter closure, lichens 80 km from the smelter show a sharp upturn in lead ratio in the recently grown lichen rim, indicating that smelter lead is either dispersed by aeolian recycling, or suppressed in desert soils. The amplitude and position of the isotope signal suggests a soil recovery "half-life" of about 13 yrs, a radial growth rate of 0.57+/-0.1 mm/yr, and a total lichen age of 105+/-18 yrs. Lichens near the smelter have no upturn in isotope ratio, indicating continued aeolian recylcing of lead from soils about 11 yrs after closure. Results at a far-removed desert site (c. New Mexico) also argue that isotope profiles reflect aerosol deposition

  9. Potential of Opuntia ficus-indica for air pollution biomonitoring: a lead isotopic study.

    PubMed

    El Hayek, Eliane; El Samrani, Antoine; Lartiges, Bruno; Kazpard, Veronique; Benoit, Mathieu; Munoz, Marguerite

    2015-11-01

    Opuntia ficus-indica (Ofi) is a long-domesticated cactus that is widespread throughout arid and semiarid regions. Ofi is grown for both its fruits and edible cladodes, which are flattened photosynthetic stems. Young cladodes develop from mother cladodes, thus forming series of cladodes of different ages. Therefore, successive cladodes may hold some potential for biomonitoring over several years the local atmospheric pollution. In this study, cladodes, roots, dust deposited onto the cladodes, and soil samples were collected in the vicinity of three heavily polluted sites, i.e., a fertilizer industry, the road side of a highway, and mine tailings. The lead content was analyzed using atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS). Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) was used to characterize the cladode surfaces and the nature of dust deposit, and the lead isotopes were analyzed to identify the origin of Pb. The results show that (i) Ofi readily bioaccumulates Pb, (ii) the lead isotopic composition of cladodes evidences a foliar pathway of lead into Ofi and identifies the relative contributions of local Pb sources, and (iii) an evolution of air quality is recorded with successive cladodes, which makes Ofi a potential biomonitor to be used in environmental and health studies.

  10. INTERLABORATORY COMPARISON OF MASS SPECTROMETRIC METHODS FOR LEAD ISOTOPES AND TRACE ELEMENTS IN NIST SRM 1400 BONE ASH

    EPA Science Inventory

    The results of an interlaboratory comparison are reported for he lead isotope composition and for trace element concentrations in NIST SRM 1400 Bone Ash obtained using quadrupole and magnetic-sector inductively coupled plasma mass spectrometry (ICP-MS) and (for the Pb isotopes on...

  11. Tracing geogenic and anthropogenic sources in urban dusts: Insights from lead isotopes

    NASA Astrophysics Data System (ADS)

    Del Rio-Salas, R.; Ruiz, J.; De la O-Villanueva, M.; Valencia-Moreno, M.; Moreno-Rodríguez, V.; Gómez-Alvarez, A.; Grijalva, T.; Mendivil, H.; Paz-Moreno, F.; Meza-Figueroa, D.

    2012-12-01

    Tracing the source of metals in the environment is critical to understanding their pollution level and fate. Geologic materials are an important source of airborne particulate matter, but the contribution of contaminated soil to concentrations of Pb in airborne dust is not yet widely documented. To examine the potential significance of this mechanism, surface soil samples were collected, as well as wind-transported dust trapped at 1 and 2 m height at seven different locations including residential, industrial, high-traffic and rural sites. Samples of dust deposited on roofs from 24 schools were also obtained and analyzed for Pb isotope ratios. Spatial distribution of Pb of airborne and sedimented dust suggests a process dominated by re-suspension/sedimentation, which was controlled by erosion, traffic and topography of the urban area. Anthropogenic lead input in the city grades outward the urban zone toward geogenic values. Our results shows that Pb-isotopic signatures of leaded gasoline are imprinted in dust sedimented on roofs. Considering that leaded-gasoline has not been in use in Mexico since two decades ago, this signature shows not only a Pb-legacy in soil, but also a re-suspension process affecting air column below 3 m in height. The combination of the 207Pb/206Pb data of the surrounding rocks and urban dust, reveal three well-defined zones with remarkable anthropogenic influence, which correspond to the oldest urban sectors. This work highlights the importance of spatial characterization of metals in particles suspended below a height of 3 m of the airborne column, a fact that should be considered to identify exposure paths to humans and the potential risks. Lead isotope signatures allowed the identification of geogenic and anthropogenic emission sources for dust, a matter that deserves consideration in the efforts to control airborne metal emissions.

  12. Strontium, Lead, and Oxygen Isotopic Signatures of Mid-Miocene Silicic Volcanism in Eastern Oregon

    NASA Astrophysics Data System (ADS)

    Hess, Emily Nancy

    Widespread, mid-Miocene rhyolite volcanism of eastern Oregon that are coeval or slightly postdate flood basalts of the Columbia River Basalt Province allows for mapping crustal domains using radiogenic and stable isotopes. Rhyolites are thought to be derived in large part by partial melting of the crust and thus yield direct information on the composition of the crust. Silicic volcanism is expressed in the form of numerous domes and tuffs exposed over a wide area (~300 km in N-S dimension and ~200 km in E-W dimension) west of the presumed craton boundary, which runs parallel but mostly east of the Oregon-Idaho state border as delineated by geophysical characteristics and isotopic transitions, including the 87Sr/86Sri =0.7060 line (MSL) and 87Sr/86Sri =0.7040 line (CSL). 87Sr/86Sri of twenty-seven silicic units are variable and some are high. Sr isotopic ratios are inconsistent with the location of the traditional MSL and CSL boundaries. A primary control on the 87Sr/86Sri isotope variations may reflect changes in the crustal make-up of Paleozoic accreted terranes of a particular area rather than arising from a westward-dipping decollement that moved cratonic lithosphere below accreted terranes in eastern Oregon. A secondary control on observed isotopic ratios may be related to the amount and composition of basalt involved in the generation of rhyolites. This could lead to higher or lower 87Sr/86Sri relative to the surrounding crust because de facto coeval mafic magmas of the Columbia River Basalt Group have a wide range of Sr isotopic signatures. While Pb isotope data is incomplete for all samples of this study, the available data indicate a significant range in Pb isotopes. Yet, data of individual regions tend to plot close to one another relative to the entire data distribution. Comparison of samples from this study in a more regional view indicates the samples generally fall within the previously defined lead isotope boundaries of the main-phase Columbia River

  13. [Regional effect research of blood lead concentrations and isotopic fingerprints in four cities by ICP-MS].

    PubMed

    Zeng, Jing; Wang, Jing-Yu; Liu, Ya-Qiong; Xie, Qing; Ouyang, Li

    2011-11-01

    Blood lead is a reflection of environment lead in vivo, its concentration could be used to assess lead exposure of environment quantitatively, and its isotopic ratio could be used to fingerprint environment source qualitatively. In the present study, concentrations and isotopic ratios of blood lead (BPb) of four cities in China were measured by ICP-MS for the first time. The regional effects of BPb in four Chinese cities were observed in our study. The BPb levels of industrial cities (Taiyuan and Chengdu) are higher than that of non-industrial cities (Suzhou and Beijing), indicating that industrial pollution remains primary lead contamination factor. The BPb isotopic ratios are diverse with the different character of environment the individuals live in. Food-borne lead probably has replaced the air-borne lead to be the major source of BPb in Beijing. Besides, regional effect of BPb in some developed cities is partly weakened by diversity of vast majority of imported resources.

  14. Isotopic generator for bismuth-212 and lead-212 based on radium

    DOEpatents

    Hines, J.J.; Atcher, R.W.; Friedman, A.M.

    1985-01-30

    Disclosed are method and apparatus for providing radionuclides of bismuth-212 and lead-212. Thorium-228 and carrier solution starting material is input to a radiologically contained portion of an isotopic generator system, and radium-224 is separated from thorium-228 which is retained by a strongly basic anion exchange column. The separated radium-224 is transferred to an accessible, strongly acidic cationic exchange column. The cationic column retains the radium-224, and natural radioactive decay generates bismuth-212 and lead-212. The cationic exchange column can also be separated from the contained portion of the system and utilized without the extraordinary safety measures necessary in the contained portion. Furthermore, the cationic exchange column provides over a relatively long time period the short lived lead-212 and bismuth-212 radionuclides which are useful for a variety of medical therapies.

  15. Element distribution patterns in the ordovician Galena group, Southeastern Minnesota: Indicators of fluid flow and provenance of terrigenous material

    USGS Publications Warehouse

    Lively, R.S.; Morey, G.B.; Mossler, J.H.

    1997-01-01

    As part of a regional geochemical investigation of lower Paleozoic strata in the Hollandale embayment of southeastern Minnesota, elemental concentrations in acid-insoluble residues were determined for carbonate rock in the Middle Ordovician Galena Group. Elemental distribution patterns within the insoluble residues, particularly those of Ti, Al, and Zr, show that the Wisconsin dome and the Wisconsin arch, which contributed sediment to the embayment prior to Galena time, continued as weak sources of sediment during this period. In contrast, trace metals commonly associated with Mississippi Valley-type lead-zinc mineralization, including Pb, Zn, Cu, Ag, Ni, Co, As, and Mo, show dispersal patterns that are independent of those associated with primary depositional phenomena. These trace metals are concentrated in southern Minnesota in carbonate rocks near the interface between limestone- and dolostone-dominated strata. Dispersal patterns imply that the metals were carried by a north-flowing regional ground-water system. The results show that the geochemical attributes of insoluble residues can be used to distinguish provenance and transport directions of primary sediments within a depositional basin from effects of subsequent regional ground-water flow systems.

  16. Using trace element content and lead isotopic composition to assess sources of PM in Tijuana, Mexico

    NASA Astrophysics Data System (ADS)

    Salcedo, D.; Castro, T.; Bernal, J. P.; Almanza-Veloz, V.; Zavala, M.; González-Castillo, E.; Saavedra, M. I.; Perez-Arvízu, O.; Díaz-Trujillo, G. C.; Molina, L. T.

    2016-05-01

    PM2.5 samples were collected at two urban sites (Parque Morelos (PQM) and CECyTE (CEC)) in Tijuana during the Cal-Mex campaign from May 24 to June 5, 2010. Concentration of trace elements (Mg, Al, Ti, V, Mn, Fe, Co, Ni, Zn, Cu, Ga, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Ba, La, Ce, and Pb), and Pb isotopic composition were determined in order to study the sources of PM impacting each site. Other chemical analysis (gravimetric, elemental and organic carbon (EC/OC), and polycyclic aromatic hydrocarbons (PAHs)), were also performed. Finally, back-trajectories were calculated to facilitate the interpretation of the chemical data. Trace elements results show that CEC is a receptor site affected by mixed regional sources: sea salt, mineral, urban, and industrial. On the other hand, PQM seems to be impacted mainly by local sources. In particular, Pb at CEC is of anthropogenic, as well as crustal origin. This conclusion is supported by the lead isotopic composition, whose values are consistent with a combination of lead extracted from US mines, and lead from bedrocks in the Mexican Sierras. Some of the time variability observed can be explained using the back-trajectories.

  17. Laser isotope purification of lead for use in semiconductor chip interconnects

    SciTech Connect

    Scheibner, K.; Haynam, C.; Worden, E.; Esser, B.

    1996-03-19

    Lead, used throughout the electronics industries, typically contains small amounts of radioactive {sup 210}Pb (a daughter product of the planets ubiquitous {sup 238}U) whose {sup 210}Po daughter emits an {alpha}-particle that is known to cause soft errors in electronic circuits. The {sup 210}Pb is not separable by chemical means. This paper describes the generic Atomic Vapor Laser Isotope Separation (AVLIS) process developed at the Lawrence Livermore National Laboratory (LLNL) over the last 20 years, with particular emphasis on recent efforts to develop the process physics and component technologies required to remove the offending {sup 210}Pb using lasers. We have constructed a developmental facility that includes a process laser development area and a test bed for the vaporizer and ion and product collectors. We will be testing much of the equipment and demonstrating pilot scale AVLIS on a surrogate material later this year. Detection of the very low alpha emission even from commercially available low-alpha lead is challenging. LLNL`s detection capabilities will be described. The goal of the development of lead purification technology is to demonstrate the capability in FY97, and to deploy a production machine capable of up to several MT/y of isotopically purified material, possible beginning in FY98.

  18. Laser isotope purification of lead for use in semiconductor chip interconnects

    SciTech Connect

    Scheibner, K.; Haynam, C.; Worden, E.; Esser, B.

    1996-02-01

    Lead, used throughout the electronics industries, typically contains small amounts of radioactive {sup 210}Pb (a daughter product of the planet`s ubiquitous {sup 210}U) whose {sup 210}Po daughter emits and {alpha}-particle that is known to cause soft errors in electronic circuits. The {sup 210}Pb is not easily separable by chemical means. This paper describes the generic Atomic Vapor Laser Isotope Separation (AVLIS) process developed at the Lawrence Livermore National Laboratory (LLNL) over the last 20 years, with particular emphasis on recent efforts to develop the process physics and component technologies required to remove the offending {sup 210}Pb using lasers. We have constructed a developmental facility that includes a process laser development area and a test bed for the vaporizer and ion and product collectors. We will be testing much of the equipment and demonstrating pilot-scale AVLIS on a surrogate material later this year. Detection of the very low alpha emission even from commercially available low-alpha lead is challenging. LLNL`s detection capabilities will be described. The goal of the development of lead purification technology is to demonstrate the capability in FY97, and to begin filling orders of up to several MT/y of isotopically purified material in FY98.

  19. Lead (Pb) fluxes and Pb isotopic compositions from Masaya Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Vallelonga, P.; Mather, T. A.

    We report Pb concentrations and isotopic compositions measured in plume aerosol and Pele's hair (lava) samples collected from Masaya volcano, Nicaragua, to provide the first data pertaining to Pb emissions from the Central American volcanic arc. Lead isotopic compositions, determined by Thermal Ionisation Mass Spectrometry, in the Pele's hair samples were found to be 206Pb/ 207Pb˜1.196, 208Pb/ 207Pb˜2.46 and 206Pb/ 204Pb˜18.6. Mean Pb fluxes from Masaya were calculated to be 1.0 ton Pb yr -1 with a mean plume Pb/S (gas) ratio of 1.3×10 -5. Also, it was found that the majority of Pb emitted was present in the fine aerosol (<2.5 μm diameter) fraction but that the percentage of Pb in the fine aerosol fraction decreased from 96% in the dry daytime plume to 61% in the condensed night-time plume. The contribution from the filter blank was usually a substantial fraction of the total amount of Pb measured, requiring the data to be corrected for blank contributions using Pb isotopic systematics.

  20. New isotopic evidence of lead contamination in wheat grain from atmospheric fallout.

    PubMed

    Yang, Jun; Chen, Tongbin; Lei, Mei; Zhou, Xiaoyong; Huang, Qifei; Ma, Chuang; Gu, Runyao; Guo, Guanghui

    2015-10-01

    Crops could accumulate trace metals by soil-root transfer and foliar uptake from atmospheric fallout, and an accurate assessment of pollution sources is a prerequisite for preventing heavy metal pollution in agricultural products. In this study, we examined Pb isotope rates to trace the sources of Pb in wheat grain grown in suburbs. Results showed that, even in zones with scarcely any air pollution spots, atmospheric fallout was still a considerable source of Pb accumulation in wheat. The concentration of Pb in wheat grain has poor correlation with that in farm soil. The Pb concentration in wheat grains with dust in bran coat was significantly higher than that in wheat grains, which indicates that Pb may accumulate by foliar uptake. The Pb isotope rate has obvious differences between the soil and atmospheric fallout, and scatter ratio is significantly closer between the wheat grain and atmospheric fallout. Atmospheric fallout is a more significant source of Pb concentration in wheat grains than in soil. As far as we know, this is the first study on the main sources of lead in grain crop (wheat) samples with isotope. This study aims to improve our understanding of the translocation of foliar-absorbed metals to nonexposed parts of plants.

  1. Lead isotopes and lead shot ingestion in the globally threatened marbled teal (Marmaronetta angustirostris) and white-headed duck (Oxyura leucocephala).

    PubMed

    Svanberg, Fredrik; Mateo, Rafael; Hillström, Lars; Green, Andy J; Taggart, Mark A; Raab, Andrea; Meharg, Andy A

    2006-11-01

    Lead isotope ratios ((206)Pb/(207)Pb and (208)Pb/(207)Pb) and concentrations in the livers and bones of marbled teal and white-headed duck found dead or moribund were determined in order to establish the main lead source in these waterfowl species. Lead concentrations in bone (dry weight) and liver (wet weight) were found to be very high in many of the white-headed ducks (bone: geometric mean=88.9 ppm, maximum=419 ppm; liver: geometric mean=16.8 ppm, maximum=57.0 ppm). Some of the marbled teal had high lead levels in the bones but liver lead levels were all low (bone: geometric mean=6.13 ppm, maximum=112 ppm; liver: geometric mean=0.581 ppm, maximum=4.77 ppm). Ingested lead shot were found in 71% of the white-headed duck and 20% of the marbled teal. The (206)Pb/(207)Pb ratio in livers and bones of white-headed ducks and marbled teals showed no significant differences compared to the ratios obtained from lead shot. The (206)Pb/(207)Pb ratio in bones of marbled teal ducklings with the highest lead concentrations tended to resemble the ratios of lead shot, which supports our hypothesis that the lead was derived from the hens. We also found that the lead ratios of lead shot and lead ratios described for soils in the area overlapped, but also that the isotopic ratio (206)Pb/(207)Pb in lead shot used in Spain has a narrow range compared with those used in North America. The principal source of lead in many of these birds was, however, most likely lead shot, as supported by the similar isotopic ratios, high lead concentrations in tissues and evidence of ingested shot.

  2. {ital E}3 transition probabilities in the platinum, mercury, and lead isotopes

    SciTech Connect

    Egido, J.L.; Martin, V.; Robledo, L.M.; Sun, Y. |||

    1996-06-01

    Spectroscopical properties of the platinum, mercury, and lead isotopes are studied within the Hartree-Fock plus BCS framework with the finite range density-dependent Gogny force. These properties are also studied beyond mean-field theory by combining the use of generator-coordinate-method-like wave functions with the angular momentum projection technique as to generate many-body correlated wave functions that are at the same time eigenstates of the angular momentum operator. We apply this formalism to the calculation of reduced transition probabilities {ital B}({ital E}3) from the lowest-lying octupole collective state to the ground state of several isotopes of the platinum, mercury, and lead nuclei whose experimental {ital B}({ital E}3) values present a peculiar behavior. The projected calculations show a large improvement over the unprojected ones when compared with the experimental data. The unprojected calculations are unable to predict any structure in the {ital B}({ital E}3). {copyright} {ital 1996 The American Physical Society.}

  3. Spatial and temporal variation in isotopic composition of atmospheric lead in Norwegian moss

    SciTech Connect

    Rosman, K.J.R.; Ly, C.; Steinnes, E.

    1998-09-01

    Earlier studies using moss as a biomonitor of pollution have shown that long-range transport is a major source of pollution in Norway. Until now, the origin of these pollutants has been inferred from concentration measurements of various elements in moss and the climatology at each sampling site. Lead isotopes provide an opportunity to identify the sources and to quantify the contribution of each. This preliminary study reports measurements of lead isotopes in moss from selected sites along the full extent of Norway that reveal significant spatial and temporal variations. There are significant north-south trends that differ at coastal and inland sites and differ between sampling periods (1974--1994). These variations reflect the changing contributions from the different source regions as the regulation of pollution from automobiles and industry takes effect. Identifiable sources are the U.K. and possibly France, which is noticeable at coastal sites; western Europe at the southern end; and eastern Europe and Russia influencing the inland and northernmost sites.

  4. Impact on the environment from steel bridge paint deterioration using lead isotopic tracing, paint compositions and soil deconstruction.

    PubMed

    Gulson, Brian; Chiaradia, Massimo; Davis, Jeffrey; O'Connor, Gary

    2016-04-15

    Deterioration and repair of lead paint on steel structures can result in contamination of the ambient environment but other sources of lead such as from past use of leaded paint and gasoline and industrial activities can also contribute to the contamination. Using a combination of high precision lead isotopic tracing, detailed paint examination, including with scanning electron microscopy, and soil deconstruction we have compared paint on a steel bridge and bulk soil and lead-rich particles separated from soil. The majority of Pb found in the paint derives from Australian sources but some also has a probable US origin. The isotopic data for the bulk soils and selected particles lie on a mixing line with end members the geologically ancient Broken Hill lead and possible European lead which is suggested to be derived from old lead paint and industrial activities. Data for gasoline-derived particulates lie on this array and probably contribute to soil Pb. Although paint from the bridge can be a source of lead in the soils, isotopic tracing, paint morphology and mineralogical identification indicate that other sources, including from paint, gasoline and industrial activities, are contributing factors to the lead burden. Even though physical characteristics and elemental composition are the same in some particles, the isotopic signatures demonstrate that the sources are different. Plots using (206)Pb/(208)Pb vs (206)Pb/(207)Pb ratios, the common representation these days, do not allow for source discrimination in this investigation.

  5. Comparison of lead isotopes with source apportionment models, including SOM, for air particulates.

    PubMed

    Gulson, Brian; Korsch, Michael; Dickson, Bruce; Cohen, David; Mizon, Karen; Davis, J Michael

    2007-08-01

    We have measured high precision lead isotopes in PM(2.5) particulates from a highly-trafficked site (Mascot) and rural site (Richmond) in the Sydney Basin, New South Wales, Australia to compare with isotopic data from total suspended particulates (TSP) from other sites in the Sydney Basin and evaluate relationships with source fingerprints obtained from multi-element PM(2.5) data. The isotopic data for the period 1998 to 2004 show seasonal peaks and troughs that are more pronounced in the rural site for the PM(2.5).samples but are consistent with the TSP. The Self Organising Map (SOM) method has been applied to the multi-element PM(2.5) data to evaluate its use in obtaining fingerprints for comparison with standard statistical procedures (ANSTO model). As seasonal effects are also significant for the multi-element data, the SOM modelling is reported as site and season dependent. At the Mascot site, the ANSTO model exhibits decreasing (206)Pb/(204)Pb ratios with increasing contributions of fingerprints for "secondary smoke" (industry), "soil", "smoke" and "seaspray". Similar patterns were shown by SOM winter fingerprints for both sites. At the rural site, there are large isotopic variations but for the majority of samples these are not associated with increased contributions from the main sources with the ANSTO model. For two winter sampling times, there are increased contributions from "secondary industry", "smoke", "soil" and seaspray with one time having a source or sources of Pb similar to that of Mascot. The only positive relationship between increasing (206)Pb/(204)Pb ratio and source contributions is found at the rural site using the SOM summer fingerprints, both of which show a significant contribution from sulphur. Several of the fingerprints using either model have significant contributions from black carbon (BC) and/or sulphur (S) that probably derive from diesel fuels and industrial sources. Increased contributions from sources with the SOM summer

  6. Lead concentrations and isotope ratios in street dust in major cities in Greece in relation to the use of lead in petrol.

    PubMed

    Anagnostopoulou, Maria A; Day, J Philip

    2006-08-31

    Until recently, the most important source of environmental lead pollution in cities was thought to come from the combustion of leaded petrol. A simple way to monitor the extent of this phenomenon, used in a number of studies in the past, has been to measure lead levels in street dust. Nowadays, it would be expected that lead concentrations in urban dust would have decreased from earlier values, following the progressive reduction of lead in petrol over the past few years, and this hypothesis has recently been confirmed in Manchester, UK. The object of the present work is to determine levels of lead pollution in cities in Greece on 1997 and, if possible, to discover whether similar reductions in lead concentrations have occurred there also. Surveys have been conducted in Thessaloniki, Athens and Piraeus. Samples of roadside dust were collected from streets (categorised by traffic density), national gardens and school playgrounds, and lead was extracted by digestion with concentrated nitric acid. Lead concentrations were determined by graphite furnace atomic absorption spectrometry and lead isotope ratios measured by inductively coupled plasma mass spectrometry. Results for Thessaloniki showed that mean lead concentrations in all categories of location are similar to present levels in Manchester. Further, lead concentrations in dust in the busiest streets in Thessaloniki have fallen by about 55% since a previous study 17 years ago. In Athens and Piraeus, the lead levels in street dust are much higher and significant differences were observed between the various types of street. In particular, it was observed that lead levels in school playgrounds in these two cities were much higher than in similar locations in Thessaloniki and Manchester, with a possible hazard to children. Isotope ratio measurements showed that Thessaloniki's lead is isotopically distinct from that found in Athens and Piraeus, which presumably reflects differences in sources of supply.

  7. Use and abuse of Pb-isotope fingerprinting technique and GIS mapping data to assess lead in environmental studies.

    PubMed

    Duzgoren-Aydn, N S; Weiss, A L

    2008-12-01

    The danger to health, especially of young children, from lead-bearing particulates in the surface environment is still a valid concern. Given the multifaceted uses of lead today as well as historically, the sources of lead must be investigated to distinguish the etiology of lead contamination on the environment. The lead isotope finger printing technique based on isotopic ratio analyses (IRA) is one of the methods used commonly for provenancing lead sources in environmental studies throughout the world. This technique, however, has some inherited shortcomings. Therefore, caution must be used in the interpretation of the results, as this technique can lead to overestimations as well as underestimations of the true source etiology/apportionment of lead in specific environments. This paper illustrates this with some examples. Data on geographical information systems (GIS) mapping in urban regions are also presented in this paper.

  8. Lead concentrations and isotope ratios in street dust determined by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

    PubMed

    Nageotte, S M; Day, J P

    1998-01-01

    A major source of environmental lead, particularly in urban areas, has been from the combustion of leaded petrol. Street dust has previously been used to assess urban lead contamination, and the dust itself can also be a potential source of lead ingestion, particularly to children. The progressive reduction of lead in petrol, in recent years, would be expected to have been reflected in a reduction of lead in urban dust. We have tested this hypothesis by repeating an earlier survey of Manchester street dust and carrying out a comparable survey in Paris. Samples were collected from streets and parks, lead was extracted by digestion with concentrated nitric acid and determined by electrothermal atomic absorption spectrometry. Lead isotope ratios were measured by inductively coupled plasma mass spectrometry. Results for Manchester show that lead concentrations have fallen by about 40% (street dust averages, 941 micrograms g-1 (ppm) in 1975 down to 569 ppm in 1997). In Paris, the lead levels in street dust are much higher and significant differences were observed between types of street (not seen in Manchester). Additionally, lead levels in parks were much lower than in Manchester. Samples collected under the Eiffel Tower had very high concentrations and lead isotope ratios showed that this was unlikely to be fallout from motor vehicles but could be due to the paint used on the tower. Isotope ratios measurements also revealed that lead additives used in France and the UK come from different sources.

  9. Trace Metals and Lead Isotopes in modern Sediments Near Rio de Janeiro, Brazil

    NASA Astrophysics Data System (ADS)

    Boyle, E. A.; Lazzari, L.; Wagener, A. L.; Carreira, R.; Godoy, J. M.; Noble, A.; Carrasco, G. G.; Moos, S. B.

    2014-12-01

    This work focuses on the export of trace metals and combustion residues from land to ocean and on the Southeast continental margin of Brazil and its historical variability using stable lead isotopes. Two sediment cores were collected, one in highly impacted Guanabara Bay and the other on the Southeast continental shelf. Continental shelf samples were analyzed for trace element concentrations [Mn (117±50 ppm), Ni (6.5±2.3 ppm), Zn (5.0±1.5), (233±46 ppm), ], Pb (5.4±2.4 ppm), as well as Cu, Ag, Cd, Sr, Ba, Tl, U and Pb isotope ratios & Pb-210. Most of the elements show higher concentrations on the upper part of the core compared to the bottom. Downcore changes of the concentrations of these elements were similar. The sediments of adjacent rivers and bays around the upper section of the southeast continental shelf of Brazil are considered highly enriched with Pb, Zn, Cu and Cr such as Guanabara Bay, Sepetiba Bay and Paraíba do Sul River compared with the natural concentrations and other regions in the world. A [Pb] maximum is seen between samples from 24 to 43 cm (~8 ppm). Utilization of tetraethyl lead (TEL) gasoline in Brazil was phased out beginning in 1983 and was largely completed by 1988. Continental shelf Pb-206/Pb-207 varies between 1.174 near the core top to 1.190 at 100 cm, with a sharp difference between samples at 6 and 8 cm. Higher core top Pb, Zn, and Ni corroborate the recent anthropogenic influence on the southeast continental shelf of Brazil. For Guanabara Bay sediment samples [Pb] varies between 90 ppm near the top to 1 ppm at the bottom. Pb-206/Pb-207 varies between 1.161 near the core top to 1.165 near the bottom. Using triple isotope plots we can discern different sources of lead to the region and how these vary with time.

  10. Distribution and sources of pre-anthropogenic lead isotopes in deep ocean water from Fe-Mn crusts

    USGS Publications Warehouse

    Von Blanckenburg, F.; O'Nions, R. K.; Hein, J.R.

    1996-01-01

    The lead isotope composition of ocean water is not well constrained due to contamination by anthropogenic lead. Here the global distribution of lead isotopes in deep ocean water is presented as derived from dated (ca. 100 ka) surface layers of hydrogenetic Fe-Mn crusts. The results indicate that the radiogenic lead in North Atlantic deep water is probably supplied from the continents by river particulates, and that lead in Pacific deep water is similar to that characteristic of island and continental volcanic arcs. Despite a short residence time in deep water (80-100 a), the isotopes of lead appear to be exceedingly well mixed in the Pacific basin. There is no evidence for the import of North Atlantic deep water-derived lead into the Pacific ocean, nor into the North Indian Ocean. This implies that the short residence time of lead in deep water prohibits advection over such long distances. Consequently, any climate-induced changes in deep-water flow are not expected to result in major changes in the seawater Pb-isotope record of the Pacific Ocean.

  11. Bone remodeling during pregnancy and post-partum assessed by metal lead levels and isotopic concentrations.

    PubMed

    Gulson, Brian; Taylor, Alan; Eisman, John

    2016-08-01

    Bone remodeling is normally evaluated using bone turnover markers/indices as indicators of bone resorption and formation. However, during pregnancy and post-partum, there have been inconsistent results between and within biomarkers for bone formation and resorption. These differences may relate to pregnancy-related changes in metabolism and/or hemodilution altering measured marker levels. An alternative approach to evaluating bone remodeling is to use the metal lead (Pb) concentrations and Pb isotopic compositions in blood. These measurements can also provide information on the amount of Pb that is mobilized from the maternal skeleton. Despite some similarities with accepted bone turnover markers, the Pb data demonstrate increased bone resorption throughout pregnancy that further continues post-partum independent of length of breast-feeding, dietary intake and resumption of menses. Furthermore the isotopic measurements are not affected by hemodilution. These data confirm calcium balance studies that indicate increased bone resorption throughout pregnancy and lactation. They also indicate potentially major public health implications of the transfer of maternal Pb burden to the fetus and new born. PMID:27233973

  12. Lead Isotope Constraints on the Sources of Ore Metals in SW Mexican Deposits

    NASA Astrophysics Data System (ADS)

    Potra, A.; Macfarlane, A. W.

    2007-12-01

    Lead isotope ratios from mineral deposits in southern Mexico increase with distance from the trench from 206Pb/204Pb values between 18.597 and 18.650 in the coastal area to values between 18.712 and 19.069 approximately 800 km east from the trench. This variation has been attributed to increasing assimilation of radiogenic lead from the crust with increasing distance from the trench. New sampling was undertaken in this area to provide a clearer picture of the potential sources of ore metals in this arc system, and also, if possible, to examine whether ore metal sources differ among the proposed tectonostratigraphic exotic terranes of southern Mexico. New TIMS lead isotope analyses are presented for samples from the metamorphic basement rocks of the Guerrero Terrane, the Late Cretaceous clastic sedimentary rocks from the Upper Mesozoic Assemblage, and for mid-Cretaceous igneous rocks, as well as for samples from the Oligocene La Verde, Esmeralda, and El Malacate copper prospects. Whole rock samples of schist from the Jurassic-Cretaceous Arteaga Complex and phyllite and slate from the Tierra Caliente Complex contain radiogenic lead relative to bulk earth models, with 206Pb/204Pb ranging from 18.981-19.256. These values are substantially more radiogenic than published values of analyses of metagabbro and charnockite from the Grenvillian-age Oaxaca Terrane. Sedimentary rocks (sandstones, siltstones, and marls) belonging to the Huetamo Sequence have 206Pb/204Pb values ranging between 18.630 to 18.998, close to the published data for the sediments from IPOD-DSDP Sites 487 and 488, Cocos Plate. Whole rock analyses of igneous rocks (granodiorite) collected from La Verde and El Malacate have 206Pb/204Pb ranging from 18.764 to 18.989, clustering between the fields represented by the sedimentary and the metamorphic rocks, suggesting assimilation of lead from these components. Ore samples from La Verde and Esmeralda have 206Pb/204Pb between 18.685 and 18.731 and plot within

  13. A Qualitative Reactivity and Isotopic Assessment of Fuels for Lead-Alloy Cooled Fast Reactors

    SciTech Connect

    Kevan Weaver; Phil MacDonald

    2004-09-01

    Various methods have been proposed to transmute and thus consume the current inventory of transuranic waste from spent light water reactor (LWR) fuel and plutonium from weapons. We discuss the neutronics performance of nonfertile, fertile metallic, and fertile nitride fuels loaded with 20 to 30 wt% LWR-grade plutonium plus minor actinides and burned in an open-lattice lead-alloy-cooled fast reactor, with an emphasis on the fuel cycle life and spent fuel isotopic content. As a comparison, similar fuel was also studied in a sodium-cooled fast reactor. Our calculations show that the average actinide burn rate for fertile-free fuel is similar for both the sodium- and lead-bismuth-cooled cases, ranging from 1.02 to 1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. In addition, our calculations show that the effective full-power days (EFPDs) of operation (or equivalent reactivity-limited burnup) using fertile fuel can extend beyond 20 yr, and the average actinide burn rate is similar for both the sodium- and lead-bismuth-cooled cases, ranging from 0.5 to 0.9 g/MWd. Using the same parameters (i.e., a large pitch-to-diameter ratio, same linear power, and fissile/fertile loading, etc.), the lead-alloy-cooled cases had an EFPD that was 18% to several times greater than their sodium-cooled counterparts. However, tight sodium-cooled lattices are equivalent to the looser lead-alloy lattices in terms of beginning-of-life excess reactivity.

  14. A Qualitative Reactivity and Isotopic Assessment of Fuels for Lead-Alloy-Cooled Fast Reactors

    SciTech Connect

    Weaver, Kevan D.; MacDonald, Philip E.

    2004-09-15

    Various methods have been proposed to transmute and thus consume the current inventory of transuranic waste from spent light water reactor (LWR) fuel and plutonium from weapons. We discuss the neutronics performance of nonfertile, fertile metallic, and fertile nitride fuels loaded with 20 to 30 wt% LWR-grade plutonium plus minor actinides and burned in an open-lattice lead-alloy-cooled fast reactor, with an emphasis on the fuel cycle life and spent fuel isotopic content. As a comparison, similar fuel was also studied in a sodium-cooled fast reactor. Our calculations show that the average actinide burn rate for fertile-free fuel is similar for both the sodium- and lead-bismuth-cooled cases, ranging from 1.02 to 1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. In addition, our calculations show that the effective full-power days (EFPDs) of operation (or equivalent reactivity-limited burnup) using fertile fuel can extend beyond 20 yr, and the average actinide burn rate is similar for both the sodium- and lead-bismuth-cooled cases, ranging from 0.5 to 0.9 g/MWd. Using the same parameters (i.e., a large pitch-to-diameter ratio, same linear power, and fissile/fertile loading, etc.), the lead-alloy-cooled cases had an EFPD that was 18% to several times greater than their sodium-cooled counterparts. However, tight sodium-cooled lattices are equivalent to the looser lead-alloy lattices in terms of beginning-of-life excess reactivity.

  15. Flow-Meter and Passive Diffusion Bag Tests and Potential Influences on the Vertical Distribution of Contaminants in Wells at Galena Airport, Galena, Alaska, August to October 2002

    USGS Publications Warehouse

    Vroblesky, Don A.; Peterson, J.E.

    2004-01-01

    Past activities at Galena Airport, a U.S. Air Force Base in Galena, Alaska, have resulted in ground-water contamination by volatile organic compounds. The primary contaminants are petroleum hydrocarbons and chlorinated aliphatic hydrocarbons. The U.S. Geological Survey and Earth Tech, in cooperation with the Air Force Center for Environmental Excellence, conducted investigations at Galena Airport from August to October 2002 using polyethylene diffusion bag samplers and borehole flow-meter testing to examine the vertical distribution of ground-water contamination in selected wells. This investigation was limited to the vicinity of building 1845 and to the area between building 1845 and the Yukon River. In addition, the U.S. Geological Survey was asked to determine whether additional wells are needed to more clearly define the nature and extent of the ground-water contamination at the Air Force Base. Little or no vertical water movement occurred under ambient conditions in the wells tested at Galena Airport, Alaska, in August 2002. All of the ambient vertical flows detected in wells were at rates less than the quantitative limit of the borehole flow meter (0.03 gallons per minute). In wells 06-MW-07 and 10-MW-01, no vertical flow was detected. In wells where ambient flow was detected, the direction of flow was downward. In general, concentrations of volatile organic compounds detected in the low-flow samples from wells at Galena Airport were approximately the same concentrations detected in the closest polyethylene diffusion bag sample for a wide variety of volatile organic compounds. The data indicate that the polyethylene diffusion bag sample results are consistent with the low-flow sample results. Vertical profiling of selected wells using polyethylene diffusion bag samplers at Galena Airport showed that from September 30 to October 1, 2002, little vertical change occurred in volatile organic compound concentrations along the screen length despite the fact that

  16. Old Masters' lead white pigments: investigations of paintings from the 16th to the 17th century using high precision lead isotope abundance ratios.

    PubMed

    Fortunato, G; Ritter, A; Fabian, D

    2005-06-01

    White lead (2PbCO(3).Pb(OH)(2)), a common component in 17c. artists' painting materials, was singled out to investigate the potential of lead isotope abundance ratios in the field of authentication and origin assignment. Paintings by Peter Paul Rubens, Anthony van Dyck and other Old Masters of the Northern and Southern schools were chosen for this study. An interdisciplinary approach was chosen using both analytical instrumental methods, art technological and art historical knowledge. Minute samples taken from paintings from selected art collections worldwide were investigated using mass spectrometry, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The high precision lead isotope abundance ratios were measured by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The determination of the calcium matrix influence with respect to possible bias effects to the isotope ratios gave clear decision support, to whether a result lies within the stated combined measurement uncertainty of the result, to eliminate time-consuming matrix separations. The scatter plots of the measured isotope abundance ratios for the painting pigments from P. P. Rubens, A. van Dyck and other Flemish painters exhibit a very narrow distribution forming a cluster. The range of the measured ratio (206)Pb/(204)Pb amounts to 0.55% and for the ratio (207)Pb/(204)Pb to 0.2%. The comparison of the data to cis-alpine (Italian) sample pigments from paintings from the same time period reveals a clear distinction between the two fields. With respect to the lead isotope data originating from the ores it is assumed that the pigment isotope ratio distribution can be explained by very distinct origin of raw materials. Presumably, no mixing of different lead ores from Europe took place. The comparison of the measured white lead isotope ratio values (Flemish paintings) and the data from ore samples led to the unexpected conclusion that local ores were not

  17. 75 FR 17892 - Proposed Revision of Class E Airspace; Galena, AK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-08

    ... Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant preparation of... follows: Authority: 49 U.S.C. 106(g), 40103, 40113, 40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959-1963 Comp... Federal Aviation Administration 14 CFR Part 71 Proposed Revision of Class E Airspace; Galena, AK...

  18. Lead/cadmium contamination and lead isotopic ratios in vegetables grown in peri-urban and mining/smelting contaminated sites in Nanjing, China.

    PubMed

    Hu, Xin; Ding, Zhuhong

    2009-01-01

    Lead/cadmium contamination in vegetables grown in peri-urban area of Nanjing, China was assessed and the route for metals entering into plants was investigated through lead isotopic tracing. Results show that agricultural soils have been polluted with Cd. Contents of Pb (22.1-37.5 mg kg(-1 )dw) and Cd (2.53-4.19 mg kg(-1) dw) in vegetables' edible parts nearby a lead/zinc mining/smelting plant were beyond their maximum allowable limit prescribed in the (EC) No 1881/2006. Pb isotope ratios in plants differed from those in the corresponding soils, suggesting that soils were not the only contamination source of Pb and Cd in plants.

  19. Containing arsenic-enriched groundwater tracing lead isotopic compositions of common arsenical pesticides in a coastal Maine watershed

    USGS Publications Warehouse

    Ayuso, Robert A.; Foley, Nora K.; Robinson, Glipin R.; Colvin, A.S.; Lipfert, G.; Reeve, A.S.

    2006-01-01

    Arsenical pesticides and herbicides were extensively used on apple, blueberry, and potato crops in New England during the first half of the twentieth century. Lead arsenate was the most heavily used arsenical pesticide until it was officially banned. Lead arsenate, calcium arsenate, and sodium arsenate have similar Pb isotope compositions: 208Pb207Pb = 2.3839-2.4722, and 206Pb207Pb = 1.1035-1.2010. Other arsenical pesticides such as copper acetoarsenite (Paris green), methyl arsonic acid and methane arsonic acid, as well as arsanilic acid are widely variable in isotope composition. Although a complete understanding of the effects of historical use of arsenical pesticides is not available, initial studies indicate that arsenic and lead concentrations in stream sediments in New England are higher in agricultural areas that intensely used arsenical pesticides than in other areas. The Pb isotope compositions of pesticides partially overlap values of stream sediments from areas with the most extensive agricultural use. The lingering effects of arsenical pesticide use were tested in a detailed geochemical and isotopic study of soil profiles from a watershed containing arsenic-enriched ground water in coastal Maine. Acid-leach compositions of the soils represent lead adsorbed to mineral surfaces or held in soluble minerals (Fe- and Mn-hydroxides, carbonate, and some micaceous minerals), whereas residue compositions likely reflect bedrock compositions. The soil profiles contain labile Pb (acid-leach) showing a moderate range in 206Pb 207Pb (1.1870-1.2069), and 208Pb207Pb (2.4519-2.4876). Isotope values vary as a function of depth: the lowest Pb isotope ratios (e.g.,208Pb206Pb) representing labile lead are in the uppermost soil horizons. Lead contents decrease with depth in the soil profiles. Arsenic contents show no clear trend with depth. A multi-component mixing scheme that included lead from the local parent rock (Penobscot Formation), lead derived from combustion of

  20. Uranium-lead isotope systematics of Mars inferred from the basaltic shergottite QUE 94201

    SciTech Connect

    Gaffney, A M; Borg, L E; Connelly, J N

    2006-12-22

    Uranium-lead ratios (commonly represented as {sup 238}U/{sup 204}Pb = {mu}) calculated for the sources of martian basalts preserve a record of petrogenetic processes that operated during early planetary differentiation and formation of martian geochemical reservoirs. To better define the range of {mu} values represented by the source regions of martian basalts, we completed U-Pb elemental and isotopic analyses on whole rock, mineral and leachate fractions from the martian meteorite Queen Alexandra Range 94201 (QUE 94201). The whole rock and silicate mineral fractions have unradiogenic Pb isotopic compositions that define a narrow range ({sup 206}Pb/{sup 204}Pb = 11.16-11.61). In contrast, the Pb isotopic compositions of weak HCl leachates are more variable and radiogenic. The intersection of the QUE 94201 data array with terrestrial Pb in {sup 206}Pb/{sup 204}Pb-{sup 207}Pb/{sup 204}Pb-{sup 208}Pb/{sup 204}Pb compositional space is consistent with varying amounts of terrestrial contamination in these fractions. We calculate that only 1-7% contamination is present in the purified silicate mineral and whole rock fractions, whereas the HCl leachates contain up to 86% terrestrial contamination. Despite the contamination, we are able to use the U-Pb data to determine the initial {sup 206}Pb/{sup 204}Pb of QUE 94201 (11.086 {+-} 0.008) and calculate the {mu} value of the QUE 94201 mantle source to be 1.823 {+-} 0.008. This is the lowest {mu} value calculated for any martian basalt source, and, when compared to the highest values determined for martian basalt sources, indicates that {mu} values in martian source reservoirs vary by at least 100%. The range of source {mu} values further indicates that the {mu} value of bulk silicate Mars is approximately three. The amount of variation in the {mu} values of the mantle sources ({mu} {approx} 2-4) is greater than can be explained by igneous processes involving silicate phases alone. We suggest the possibility that a small

  1. Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district.

    PubMed

    Witt, Emitt C; Pribil, Michael J; Hogan, John P; Wronkiewicz, David J

    2016-09-01

    The isotopic composition of lead (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 (207)Pb/(206)Pb 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 (207)Pb/(206)Pb 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 conditions. Aqua regia total concentrations and (207)Pb/(206)Pb of mining area dust suggest that 35.4-84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1-52.7% is associated with the smelter mixture, and 0-21.6% is associated with background materials. Isotope ratios varied minimally within the operational phases of sequential extraction suggesting that mixing of all three Pb mixtures occurs throughout. Labile forms of Pb were attributed to all three end members. The extractable carbonate phase had as much as 96.6% of the total concentration associated with mine tailings, 51.8% associated with smelter deposition, and 34.2% with background. The next most labile geochemical phase (Fe + Mn Oxides) showed similar results with as much as 85.3% associated with mine tailings, 56.8% associated with smelter deposition, and 4.2% associated with the background soil.

  2. Isotopic compositions of gangue versus ore minerals in the Upper Mississippi Valley zinc-lead district

    SciTech Connect

    Brannon, J.C.; Podosek, F.A. . Dept. of Earth Planetary Sciences); McLimans, R.K. . Jackson Research Lab.)

    1993-03-01

    Four successive stages of gangue calcite occur after sulfide mineralization in the Upper Mississippi Valley zinc-lead district. These are commonly interpreted to represent the waning stage of MTV mineralization, because of spatial association and a smooth transition of decreasing fluid inclusion temperatures from late stage sphalerite through calcites 2 to 4. U-Pb systematics in two calcite 2 crystals suggests an age of 162 Ma, with [mu] values sufficiently great (1,175 and 1,611) that the indicated age is insensitive to initial [sup 206]Pb/[sup 204]Pb. This age for calcite formation is [approx] 100 Ma after that of sulfide mineralization and thus represents recurrent fluid activity along fracture zones. Initial [sup 87]Sr/[sup 86]Sr isotopic composition for three calcite 2 crystals range from 0.70956--0.70961, consist with initial [sup 87]Sr/[sup 86]Sr in the 270 Ma sphalerites. The initial [sup 87]Sr/[sup 86]Sr for two calcite 3 crystals and one calcite 4 crystal range from 0.70845--0.70875, consistent with mid-Ordovician seawater and the host carbonates of that age. The authors propose a hypothesis which is consistent with the Sr and U-Pb isotopic data. 162 Ma ago fluids flushed the existing pore fluids (left over from 270 Ma MVT event) from carbonate strata and deposited calcite 2. Subsequently, additional fluids containing [sup 87]Sr/[sup 86]Sr consistent with that derived from mid-Ordovician carbonates deposited calcite 3 and 4. If this hypothesis is correct the paragenetic connection between ore and gangue mineralization at UMV is weak and geochemical study of the gangue minerals may provide only limited information about the fluid which formed the ores.

  3. Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district

    USGS Publications Warehouse

    Witt, Emitt C.; Pribil, Michael; Hogan, John P; Wronkiewicz, David

    2016-01-01

    The isotopic composition of lead (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 conditions. 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, 9.1–52.7% is associated with the smelter mixture, and 0–21.6% is associated with background materials. Isotope ratios varied minimally within the operational phases of sequential extraction suggesting that mixing of all three Pb mixtures occurs throughout. Labile forms of Pb were attributed to all three end members. The extractable carbonate phase had as much as 96.6% of the total concentration associated with mine tailings, 51.8% associated with smelter deposition, and 34.2% with background. The next most labile geochemical phase (Fe + Mn Oxides) showed similar results with as much as 85.3% associated with mine tailings, 56.8% associated with smelter deposition, and 4.2% associated with the background soil.

  4. Source of lead and mineralizing brines for rossie-type Pb-Zn veins in the Frontenac axis area, New York ( USA).

    USGS Publications Warehouse

    Ayuso, Robert; Foley, Nora K.; Brown, C. Erwin

    1987-01-01

    The present study of fluid inclusions and lead isotopes was done to understand better the nature and possible source of the mineralizing solutions for both vertical and gash veins and the possible origin of the lead and zinc mineralization. Large deposits of essentially syngenetic sphalerite with minor to trace galena occur in the Proterozoic rocks of this region (e.g., Balmat-Edwards, New York). Although none of these deposits are known in the immediate vicinity of Rossie veins, the possibility that Rossie veins contain remobilized metals from these older deposits was considered.

  5. Stable lead isotope compositions in selected coals from around the world and implications for present day aerosol source tracing

    SciTech Connect

    M. Diaz-Somoano; M.E. Kylander; M.A. Lopez-Anton; I. Suarez-Ruiz; M.R. Martinez-Tarazona; M. Ferrat; B. Kober; D.J. Weiss

    2009-02-15

    The phasing out of leaded gasoline in many countries around the world at the end of the last millennium has resulted in a complex mixture of lead sources in the atmosphere. Recent studies suggest that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Lead concentration and isotopic composition is reported for 59 coal samples representing major coal deposits worldwide in an attempt to characterize this potential source. The average concentration in these coals is 35 {mu}g Pb g{sup -1}, with the highest values in coals from Spain and Peru and the lowest in coals from Australia and North America. The {sup 206}Pb/{sup 207}Pb isotope ratios range between 1.15 and 1.24, with less radiogenic Pb in coals from Europe and Asia compared to South and North America. Comparing the Pb isotopic signatures of coals from this and previous studies with those published for Northern and Southern Hemisphere aerosols, we hypothesize that coal combustion might now be an important Pb source in China, the eastern U.S., and to some extent, in Europe but not as yet in other regions including South Africa, South America, and western U.S. This supports the notion that 'old Pb pollution' from leaded gasoline reemitted into the atmosphere or long-range transport (i.e., from China to the western U.S.) is important. Comparing the isotope ratios of the coals, the age of the deposits, and Pb isotope evolution models for the major geochemical reservoirs suggests that the lead isotope ratios (PbIC) in coals is strongly influenced by the depositional coal forming environment. 47 refs., 3 figs., 1 tab.

  6. Use of lead isotopes to identify sources of metal and metalloid contaminants in atmospheric aerosol from mining operations.

    PubMed

    Félix, Omar I; Csavina, Janae; Field, Jason; Rine, Kyle P; Sáez, A Eduardo; Betterton, Eric A

    2015-03-01

    Mining operations are a potential source of metal and metalloid contamination by atmospheric particulate generated from smelting activities, as well as from erosion of mine tailings. In this work, we show how lead isotopes can be used for source apportionment of metal and metalloid contaminants from the site of an active copper mine. Analysis of atmospheric aerosol shows two distinct isotopic signatures: one prevalent in fine particles (<1μm aerodynamic diameter) while the other corresponds to coarse particles as well as particles in all size ranges from a nearby urban environment. The lead isotopic ratios found in the fine particles are equal to those of the mine that provides the ore to the smelter. Topsoil samples at the mining site show concentrations of Pb and As decreasing with distance from the smelter. Isotopic ratios for the sample closest to the smelter (650m) and from topsoil at all sample locations, extending to more than 1km from the smelter, were similar to those found in fine particles in atmospheric dust. The results validate the use of lead isotope signatures for source apportionment of metal and metalloid contaminants transported by atmospheric particulate. PMID:25496740

  7. Use of lead isotopes to identify sources of metal and metalloid contaminants in atmospheric aerosol from mining operations.

    PubMed

    Félix, Omar I; Csavina, Janae; Field, Jason; Rine, Kyle P; Sáez, A Eduardo; Betterton, Eric A

    2015-03-01

    Mining operations are a potential source of metal and metalloid contamination by atmospheric particulate generated from smelting activities, as well as from erosion of mine tailings. In this work, we show how lead isotopes can be used for source apportionment of metal and metalloid contaminants from the site of an active copper mine. Analysis of atmospheric aerosol shows two distinct isotopic signatures: one prevalent in fine particles (<1μm aerodynamic diameter) while the other corresponds to coarse particles as well as particles in all size ranges from a nearby urban environment. The lead isotopic ratios found in the fine particles are equal to those of the mine that provides the ore to the smelter. Topsoil samples at the mining site show concentrations of Pb and As decreasing with distance from the smelter. Isotopic ratios for the sample closest to the smelter (650m) and from topsoil at all sample locations, extending to more than 1km from the smelter, were similar to those found in fine particles in atmospheric dust. The results validate the use of lead isotope signatures for source apportionment of metal and metalloid contaminants transported by atmospheric particulate.

  8. Isotopic composition of epiphytic lichens as a tracer of the sources of atmospheric lead emissions in southern Quebec, Canada

    SciTech Connect

    Carignan, J.; Gariepy, C.

    1995-11-01

    Lead isotopic data are reported for epiphytic lichens, vegetation samples, and lacustrine sediments collected in the boreal forest of Quebec between 47{degrees} and 55{degrees}N, and along the St. Lawrence Valley between 45{degrees} to 48{degrees}N. Lichens located up to 500 km north of Noranda (48{degrees}N) record a significant input is not apparent beyond 53{degrees}N where only the isotopic signal typical of Canadian aerosols is recorded. Lichens along the St. Lawrence Valley show evidences for a dominant input from U.S. sources. The lead isotopic composition of lichens allow quantitative monitoring of the sources of atmospheric Pb. However, their slow metabolism and their unknown age detract from recording the Pb signal on short and precise timescales. Spruce needles have isotopic compositions undistinguishable from that of lichens; this reflects integration of the atmospheric Pb signal over a comparable time span, a result confirmed by the lead isotopic record in lacustrine sediments. Vegetation samples such as spruce bark, spruce wood, and decidous tree leaves are more radiogenic than lichens from the same site. This may reflect mixing of radiogenic Pb metabolized from soil solutions through the root system with atmospheric Pb. 37 refs., 4 figs.

  9. Use of Lead Isotopes to Identify Sources of Metal and Metalloid Contaminants in Atmospheric Aerosol from Mining Operations

    PubMed Central

    Félix, Omar I.; Csavina, Janae; Field, Jason; Rine, Kyle P.; Sáez, A. Eduardo; Betterton, Eric A.

    2014-01-01

    Mining operations are a potential source of metal and metalloid contamination by atmospheric particulate generated from smelting activities, as well as from erosion of mine tailings. In this work, we show how lead isotopes can be used for source apportionment of metal and metalloid contaminants from the site of an active copper mine. Analysis of atmospheric aerosol shows two distinct isotopic signatures: one prevalent in fine particles (< 1 μm aerodynamic diameter) while the other corresponds to coarse particles as well as particles in all size ranges from a nearby urban environment. The lead isotopic ratios found in the fine particles are equal to those of the mine that provides the ore to the smelter. Topsoil samples at the mining site show concentrations of Pb and As decreasing with distance from the smelter. Isotopic ratios for the sample closest to the smelter (650 m) and from topsoil at all sample locations, extending to more than 1 km from the smelter, were similar to those found in fine particles in atmospheric dust. The results validate the use of lead isotope signatures for source apportionment of metal and metalloid contaminants transported by atmospheric particulate. PMID:25496740

  10. Lead isotopic composition of insoluble particles from widespread mountain glaciers in western China: Natural vs. anthropogenic sources

    NASA Astrophysics Data System (ADS)

    Yu, Guangming; Xu, Jianzhong; Kang, Shichang; Zhang, Qianggong; Huang, Jie; Ren, Qian; Ren, Jiawen; Qin, Dahe

    2013-08-01

    Stable lead (Pb) isotopic fingerprints provide opportunities to trace natural and anthropogenic Pb sources in the environment. In order to evaluate Pb deposition from different sources over mountainous areas of western China, Pb isotopic compositions were characterized from modern aeolian dust in 15 snowpit samples collected from 13 typical mountain glaciers between 2008 and 2010. Most of the snowpits sampled cover more than a whole year of accumulation and overlap with each other on deposition date. Pb isotopic variability among all the samples is small, varying in the range of 18.1399-18.9199 for 206Pb/204Pb, 15.5979-15.8743 for 207Pb/204Pb, 38.2272-39.9453 for 208Pb/204Pb, 1.1605-1.2009 for 206Pb/207Pb and 2.4433-2.5182 for 208Pb/207Pb. Three isotopic plots of the different Pb isotope ratios (207Pb/204Pb vs. 206Pb/204Pb, 208Pb/204Pb vs. 206Pb/204Pb, and 208Pb/207Pb vs. 206Pb/207Pb) in all the samples show identical geographic trends, with more radiogenic in the south and less in the north. This trend is consistent with the distribution of natural dust sources and supports the interpretation of a regional/local source for insoluble particles (IP) to snow/glaciers in this region. Comparison with the Pb isotope results from potential dust sources, however, it shows that the Pb isotopic compositions of IP samples in snow samples are relatively less radiogenic. Parts of these less-radiogenic Pb isotopes are comparable with the ice core results during recent decades, which are shown to be influenced by anthropogenic sources. At sites located along the periphery of western China, the Pb isotopic compositions are much closer to anthropogenic results. Natural and anthropogenic Pb sources are roughly assessed using a simple binary model. The sites with a high anthropogenic fraction are at lower elevations and are relatively close to population centers.

  11. Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios.

    PubMed

    Camizuli, E; Monna, F; Bermond, A; Manouchehri, N; Besançon, S; Losno, R; van Oort, F; Labanowski, J; Perreira, A; Chateau, C; Alibert, P

    2014-02-15

    The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km(2) zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the "labile" and "less labile" pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the "labile" and "less labile" lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota.

  12. Origin of the Red Dog Zn-Pb-Ag deposits, Brooks Range, Alaska: Evidence from regional Pb and Sr isotope sources

    USGS Publications Warehouse

    Ayuso, R.A.; Kelley, K.D.; Leach, D.L.; Young, L.E.; Slack, J.F.; Wandless, G.; Lyon, A.M.; Dillingham, J.L.

    2004-01-01

    Pb and Sr isotope data were obtained on the shale-hosted Zn-Pb-Ag Red Dog deposits (Qanaiyaq, Main, Aqqaluk, and Paalaaq), other shale-hosted deposits near Red Dog, and Zn-Pb-Ag sulfide and barite deposits in the western and central Brooks Range. The Red Dog deposits and other shale-hosted Zn-Pb-Ag deposits near Red Dog are hosted in the Mississippian Kuna Formation, which is underlain by a sequence of marine-deltaic clastic rocks of the Upper Devonian to Lower Mississippian Endicott Group. Ag-Pb-Zn vein-breccias are found in the Endicott Group. Galena formed during the main mineralization stages in the Red Dog deposits and from the Anarraaq and Wulik deposits have overlapping Pb isotope compositions in the range 206Pb/204Pb = 18.364 to 18.428, 207Pb/204Pb = 15.553 to 15.621, and 208Pb/204Pb = 38.083 to 38.323. Galena and sphalerite formed during the main ore-forming stages in the Red Dog deposits define a narrow field on standard uranogenic and thorogenic Pb isotope diagrams. Lead in sulfides of the Red Dog district is less radiogenic (238U/204Pb: ?? = 9.51-9.77) than is indicated by the average crustal lead evolution model (?? = 9.74), a difference consistent with a long history of evolution at low ratios of ?? before the Carboniferous. The homogeneous regional isotopic reservoir of Pb may indicate large-scale transport and leaching of minerals with various ?? ratios and Th/Pb ratios. Younger and genetically unrelated fluids did not significantly disturb the isotopic compositions of galena and sphalerite after the main mineralization event in the Red Dog district. Some pyrite shows evidence of minor Pb remobilization. The overall lead isotope homogeneity in the shale-hosted massive sulfide deposits is consistent with three types of control: a homogeneous regional source, mixing of lead during leaching of a thick sedimentary section and fluid transport, or mixing at the site of deposition. Isotopic variability of the hydrothermal fluids, as represented by galena

  13. Lead isotope and Pb-Pb model age determinations of ores from Central Europe and their metallogenetic interpretation

    NASA Astrophysics Data System (ADS)

    Bielicki, K.-H.; Tischendorf, G.

    1991-02-01

    The paper presents lead isotope data from 211 samples from Phanerozoic lead-bearing ore occurrences in Central Europe, particularly from the Southern part of the former German Democratic Republic. The data are interpreted in terms of Amov's dynamic model of continuous lead isotope evolution. The relationships between thoro-genic and urano-genic model ages and the source of lead in different regional units are discussed. We observed differences in lead isotope evolution in the Hercynian internides and externides. Within the Moldanubian and Saxothuringian zones we distinguish five main lead-bearing ore associations: (1) Cambrian, stratiform base metal (Hermsdorf-Waldsassen; 206Pb/ 204Pb=17.50 17.70), (2) Devonian, vein type Sb-bearing, metamorphogene (neumühle-Hartmannsdorf; 17.80 18.00), (3) Upper Carboniferous-Permian, polymetallic, including tin, vein type (Kutna hora-Freiberg-Altenberg; 18.00 18.20), (4) Triassic (-Jurassic), Pb-Ba, vein type (Střibro-Halsbrücke; 18.20 18.60), (5) Cenozoic, polymetallic, vein type, riftogene (Roztoky-Banska Štiavnica; 18.80 19.10). Pb isotope characteristics from ores of the Montagne Noire and the Brioude-Massiac district correspond to this subdivision. Ore associations from the Rheno-Hercynian zone display higher 207Pb/204Pb ratios which can be explained by more evolved and less metamorphosed source rocks. Mineralizations of the eastern Harz (Straßberg-Neudorf) belong to the Permian association, those from the western Harz (Clausthal-Bad Grund) to the Triassic-Jurassic. Because of Pb isotope agreement the stratabound Rammelsberg and the vein bound Ramsbeck-I mineralization are presumed to be isogenetic. Pb isotope identity of distinct mineralizations in the basement zone (Halsbrücke-Bad Grund) and in the Triassic sediments (Gorny Slask-Mechernich-Bleiglanzbänke) suggests a strong genetic coherence. Pb isotope conformity between the Upper Carboniferous-Permian-Triassic ore associations and Hercynian postkinematic

  14. Isotopic equilibration between dissolved and suspended particulate lead in the Atlantic Ocean - Evidence from Pb-210 and stable Pb isotopes

    NASA Technical Reports Server (NTRS)

    Sherrell, Robert M.; Boyle, Edward A.; Hamelin, Bruno

    1992-01-01

    Vertical profiles of, on one hand, the stable Pb isotopic composition, and on the other, the ratio of total Pb to Pb-210 in suspended particles, are noted to closely track contemporaneous depth variations in these ratios for dissolved Pb throughout the upper 2 km of the Sargasso Sea near Bermuda. A simple flux model suggests that the effect of deep ocean scavenging processes on the flux and isotopic composition of Pb sinking on large particles was minor throughout the preanthropogenic, and most of the anthropogenic era: but it has become more important as surface inputs decrease to preleaded gasoline levels, perhaps exceeding the contribution of surface-derived Pb flux in the next decade.

  15. The lead (Pb) isotope signature, behaviour and fate of traffic-related lead pollution in roadside soils in The Netherlands.

    PubMed

    Walraven, N; van Os, B J H; Klaver, G Th; Middelburg, J J; Davies, G R

    2014-02-15

    In this study the origin, behaviour and fate of anthropogenic Pb in sandy roadside soils were assessed by measuring soil characteristics, Pb isotope composition and content. In 1991 and 2003 samples were taken at different depth intervals at approximately 8 and 75 m from two highways in The Netherlands. The Pb isotope composition of the litter layer ((206)Pb/(207)Pb=1.12-1.14) differs from the deeper soil samples ((206)Pb/(207)Pb=1.20-1.21). Based on a mixing model it is concluded that the samples contain two Pb sources: natural Pb and anthropogenic Pb, the latter mainly derived from gasoline. (206)Pb/(207)Pb ratios demonstrate that the roadside soils were polluted to a depth of ~15 cm. Within this depth interval, anthropogenic Pb content is associated with organic matter. Although Pb pollution only reached a depth of ~15 cm, this does not mean that the topsoils retain all anthropogenic Pb. Due to the low pH and negligible binding capacity of soils at depths >15 cm, anthropogenic Pb migrated towards groundwater after reaching depths of >15 cm. The Pb isotope composition of the groundwater ((206)Pb/(207)Pb=1.135-1.185) establishes that groundwater is polluted with anthropogenic Pb. The contribution of anthropogenic Pb to the groundwater varies between ~30 and 100%. Based on the difference in soil Pb content and Pb isotope compositions over a period of 12 years, downward Pb migration is calculated to vary from 72 ± 95 to 324 ± 279 mg m(-2)y(-1). Assuming that the downward Pb flux is constant over time, it is calculated that 35-90% of the atmospherically delivered Pb has migrated to the groundwater.

  16. The lead (Pb) isotope signature, behaviour and fate of traffic-related lead pollution in roadside soils in The Netherlands.

    PubMed

    Walraven, N; van Os, B J H; Klaver, G Th; Middelburg, J J; Davies, G R

    2014-02-15

    In this study the origin, behaviour and fate of anthropogenic Pb in sandy roadside soils were assessed by measuring soil characteristics, Pb isotope composition and content. In 1991 and 2003 samples were taken at different depth intervals at approximately 8 and 75 m from two highways in The Netherlands. The Pb isotope composition of the litter layer ((206)Pb/(207)Pb=1.12-1.14) differs from the deeper soil samples ((206)Pb/(207)Pb=1.20-1.21). Based on a mixing model it is concluded that the samples contain two Pb sources: natural Pb and anthropogenic Pb, the latter mainly derived from gasoline. (206)Pb/(207)Pb ratios demonstrate that the roadside soils were polluted to a depth of ~15 cm. Within this depth interval, anthropogenic Pb content is associated with organic matter. Although Pb pollution only reached a depth of ~15 cm, this does not mean that the topsoils retain all anthropogenic Pb. Due to the low pH and negligible binding capacity of soils at depths >15 cm, anthropogenic Pb migrated towards groundwater after reaching depths of >15 cm. The Pb isotope composition of the groundwater ((206)Pb/(207)Pb=1.135-1.185) establishes that groundwater is polluted with anthropogenic Pb. The contribution of anthropogenic Pb to the groundwater varies between ~30 and 100%. Based on the difference in soil Pb content and Pb isotope compositions over a period of 12 years, downward Pb migration is calculated to vary from 72 ± 95 to 324 ± 279 mg m(-2)y(-1). Assuming that the downward Pb flux is constant over time, it is calculated that 35-90% of the atmospherically delivered Pb has migrated to the groundwater. PMID:24342096

  17. A list of references on lead isotope geochemistry, 1967-1969 (with an addendum to the list through 1966)

    USGS Publications Warehouse

    Doe, Bruce R.

    1971-01-01

    This bibliography was constructed to be as complete as possible for terminal papers containing new data relative to the geochemical applications of: Common lead U-The-Pb isotopic dating Pb-α Pb210, Pb212, Pb214 No effort was made for completeness of: Annual reports, Yearbooks, etc. Review papers although many are included. Abstracts and theses are omitted.

  18. Electron-Rotor Interaction in Organic-Inorganic Lead Iodide Perovskites Discovered by Isotope Effects.

    PubMed

    Gong, Jue; Yang, Mengjin; Ma, Xiangchao; Schaller, Richard D; Liu, Gang; Kong, Lingping; Yang, Ye; Beard, Matthew C; Lesslie, Michael; Dai, Ying; Huang, Baibiao; Zhu, Kai; Xu, Tao

    2016-08-01

    We report on the carrier-rotor coupling effect in perovskite organic-inorganic hybrid lead iodide (CH3NH3PbI3) compounds discovered by isotope effects. Deuterated organic-inorganic perovskite compounds including CH3ND3PbI3, CD3NH3PbI3, and CD3ND3PbI3 were synthesized. Devices made from regular CH3NH3PbI3 and deuterated CH3ND3PbI3 exhibit comparable performance in band gap, current-voltage, carrier mobility, and power conversion efficiency. However, a time-resolved photoluminescence (TRPL) study reveals that CH3NH3PbI3 exhibits notably longer carrier lifetime than that of CH3ND3PbI3, in both thin-film and single-crystal formats. Furthermore, the comparison in carrier lifetime between CD3NH3PbI3 and CH3ND3PbI3 single crystals suggests that vibrational modes in methylammonium (MA(+)) have little impact on carrier lifetime. In contrast, the fully deuterated compound CD3ND3PbI3 reconfirmed the trend of decreasing carrier lifetime upon the increasing moment of inertia of cationic MA(+). Polaron model elucidates the electron-rotor interaction. PMID:27396858

  19. Lead isotopes decipher multiple origins within single PM10 samples in the atmosphere of Paris.

    PubMed

    Widory, David

    2006-03-01

    The atmospheric concentration of lead (Pb) in France has strongly decreased since its legal reduction in gasoline in 2000. Pb-isotope ratios are effective tracers of its origin. Pb in atmospheric particulate matter with a diameter <10 microm (PM10) in Paris is shown to have a dual origin: (1) an intrinsic fraction (leached by hydrofluoric acid) forms the cores of particles and (2) a labile fraction (complexation with hydrobromic acid) represents generally >90 % (mass) of the bulk Pb and aggregates on pre-existing particles in the atmosphere. Characterisation of the emissions from different pollution sources, however, indicates that Pb is entirely contained in the labile fraction. Our results show that, in air, the intrinsic fraction is consistently more radiogenic (the degree of enrichment being greater in summer), hinting at different origins. The labile fraction clearly identifies industrial activity as its main source, but the intrinsic fraction may result from either a different industrial-pollution source or, more likely, from a natural end-member (i.e. pre-industrial sediment).

  20. Changes in the lead isotopic composition of blood, diet and air in Australia over a decade: Globalization and implications for future isotopic studies

    SciTech Connect

    Gulson, Brian . E-mail: bgulson@gse.mq.edu.au; Mizon, Karen; Korsch, Michael; Taylor, Alan

    2006-01-15

    Source apportionment in biological or environmental samples using the lead isotope method, where there are diverse sources of lead, relies on a significant difference between the isotopic composition in the target media and the sources. Because of the unique isotopic composition of Australian lead, source apportionment has been relatively successful in the past. Over the period of a decade, the {sup 206}Pb/{sup 204}Pb ratio for Australian (mainly female) adults has shown an increase from a geometric mean of 16.8-17.3. Associated with this increase, there has been a decrease in mean blood lead concentration from 4.7 to 2.3 {mu}g/dL, or about 5% per year, similar to that observed in other countries. Lead in air, which up until 2000 was derived largely from the continued use of leaded gasoline, showed an overall increase in the {sup 206}Pb/{sup 204}Pb ratio during 1993-2000 from 16.5 to 17.2. Since 1998 the levels of lead in air were less than 0.2 {mu}g/m{sup 3} and would contribute negligibly to blood lead. Over the 10-year period, the {sup 206}Pb/{sup 204}Pb ratio in diet, based mainly on quarterly 6-day duplicate diets, increased from 16.9 to 18.3. The lead concentration in diet showed a small decrease from 8.7 to 6.4 {mu}g Pb/kg although the daily intake increased markedly from 7.4 to 13.9 {mu}g Pb/day during the latter part of the decade probably reflecting differences in demographics. The changes in blood lead from sources such as lead in bone or soil or dust is not dominant because of the low {sup 206}Pb/{sup 204}Pb ratios in these media. Unless there are other sources not identified and analysed for these adults, it would appear that in spite of our earlier conclusions to the contrary, diet does make an overall contribution to blood lead, and this is certainly the case for specific individuals. Certain population groups from south Asia, south-east Asia, the Middle East and Europe (e.g. UK) are unsuitable for some studies as their isotopic ratios in blood are

  1. High-precision lead isotopes and stripy plumes: Revisiting the Society chain in French Polynesia

    NASA Astrophysics Data System (ADS)

    Cordier, Carole; Chauvel, Catherine; Hémond, Christophe

    2016-09-01

    An increasing number of geochemical studies looked for spatial organization of the isotopic variations along Pacific volcanic island chains (e.g., Hawaii, Marquesas, Samoa and Society Islands) in order to discuss the possible zoning of the plume conduits. Here, we reexamine the occurrence of isotopic stripes in the Society archipelago in French Polynesia, using new Sr-Nd-Hf-Pb isotope ratios of sixty-six lavas from six islands (Mehetia, Moorea, Maupiti, Huahine, Raiatea, Bora-Bora). We demonstrate that the Pb isotope variability observed using literature data is an analytical artifact related to the poor control of mass fractionation during Pb measurements by conventional TIMS technique. New MC-ICP-MS Pb data demonstrate that the isotopic stripes as previously defined disappear. They rather show that individual islands cover a significant part of the entire isotopic range of the chain. We suggest, therefore, that the dominant characteristic of the Society plume is small-scale heterogeneities, evenly distributed within the plume conduit. At a global scale, we show that some ocean island chains with similar geochemical and isotopic characteristics, such as Samoa and Society Islands, define different arrays when variations of Nd with high-precision Pb isotopes are considered. We proposed that this puzzling observation might record differences in recycling age of the basalt + sediment mixture subducted into the mantle and sampled by mantle plume.

  2. Lead isotope database of unpublished results from sulfide mineral occurrences-California, Idaho, Oregon, and Washington

    USGS Publications Warehouse

    Church, S.E.

    2010-01-01

    The Pb isotope database for sulfide deposits and occurrences in the Western United States was funded by the Mineral Resources Program, U.S. Geological Survey (USGS). Reports on Pb isotope data from Alaska were published in Church and others (1987a) and Gaccetta and Church (1989). The primary objectives of the project were three-fold: * To utilize Pb isotope signatures, in conjunction with the regional mapping, to assess the relative ages and to categorize the types of deposits studied, * To relate the Pb isotope and trace-element geochemical signatures of specific deposits and occurrences to ore-forming processes, and * To use the Pb isotope data to correlate lithotectonic terranes within the northern Cordillera. The report by Church and others (1987b) shows how this fingerprinting methodology can be applied to trace the offset of lithostratigraphic terranes

  3. Lead isotope ratios in tree bark pockets: an indicator of past air pollution in the Czech Republic.

    PubMed

    Conkova, M; Kubiznakova, J

    2008-10-15

    Tree bark pockets were collected at four sites in the Czech Republic with differing levels of lead (Pb) pollution. The samples, spanning 1923-2005, were separated from beech (Fagus sylvatica) and spruce (Picea abies). Elevated Pb content (0.1-42.4 microg g(-1)) reflected air pollution in the city of Prague. The lowest Pb content (0.3-2.6 microg g(-1)) was found at the Kosetice EMEP "background pollution" site. Changes in (206)Pb/(207)Pb and (208)Pb/(206)Pb isotope ratios were in agreement with operation times of the Czech main anthropogenic Pb sources. Shortly after the Second World War, the (206)Pb/(207)Pb isotope ratio in bark pockets decreased from 1.17 to 1.14 and the (208)Pb/(206)Pb isotope ratio increased from 2.12 to 2.16. Two dominant emission sources responsible for these changes, lignite and leaded petrol combustion, contributed to the shifts in Pb isotope ratios. Low-radiogenic petrol Pb ((206)Pb/(207)Pb of 1.11) lead to lower (206)Pb/(207)Pb in bark pockets over time. High-radiogenic lignite-derived Pb ((206)Pb/(207)Pb of 1.18 to 1.19) was detected in areas affected by coal combustion rather than by traffic.

  4. Stable lead isotope compositions in selected coals from around the world and implications for present day aerosol source tracing.

    PubMed

    Díaz-Somoano, M; Kylander, M E; López-Antón, M A; Suárez-Ruiz, I; Martínez-Tarazona, M R; Ferrat, M; Kober, B; Weiss, D J

    2009-02-15

    The phasing out of leaded gasoline in many countries around the world at the end of the last millennium has resulted in a complex mixture of lead sources in the atmosphere. Recent studies suggest that coal combustion has become an important source of Pb in aerosols in urban and remote areas. Here, we report lead concentration and isotopic composition for 59 coal samples representing major coal deposits worldwide in an attempt to characterize this potential source. The average concentration in these coals is 35 microg Pb g(-1), with the highest values in coals from Spain and Peru and the lowest in coals from Australia and North America. The 206Pb/207Pb isotope ratios range between 1.15 and 1.24, with less radiogenic Pb in coals from Europe and Asia compared to South and North America. Comparing the Pb isotopic signatures of coals from this and previous studies with those published for Northern and Southern Hemisphere aerosols, we hypothesize that coal combustion might now be an important Pb source in China, the eastern U.S., and to some extent, in Europe but not as yet in other regions including South Africa, South America, and western U.S. This supports the notion that "old Pb pollution" from leaded gasoline reemitted into the atmosphere or long-range transport (i.e., from China to the western U.S.) is important. Comparing the isotope ratios of the coals, the age of the deposits, and Pb isotope evolution models for the major geochemical reservoirs suggests that the PbIC in coals is strongly influenced by the depositional coal forming environment.

  5. Lead contamination of small cetaceans in European waters--the use of stable isotopes for identifying the sources of lead exposure.

    PubMed

    Caurant, F; Aubail, A; Lahaye, V; Van Canneyt, O; Rogan, E; López, A; Addink, M; Churlaud, C; Robert, M; Bustamante, P

    2006-08-01

    Lead concentrations and isotopic composition have been measured in bone and teeth of small cetaceans belonging to three species (Delphinus delphis, Phocoena phocoena and Stenella coeruleoalba), to evaluate the toxicological risk and to determine sources of lead in the European waters. Lead concentrations, far lower than threshold value inducing toxic effects in human, were higher in teeth than in bones, but highly correlated between the two tissues (r=0.92, p<0.001). Large variations of 206Pb/207Pb values in bone tissue showed that cetaceans must be submitted to various atmospheric influences. No geographical differences appeared which is consistent with studies on their distribution indicating seasonal movements between Brittany waters and the Bay of Biscay. The negative correlation between 206Pb/207Pb ratios and age of the individuals reflected the decrease in the production of alkyl lead in Europe, i.e., the increasing use of unleaded gasoline.

  6. Lead isotopes in iron and manganese oxide coatings and their use as an exploration guide for concealed mineralization

    USGS Publications Warehouse

    Gulson, B.L.; Church, S.E.; Mizon, K.J.; Meier, A.L.

    1992-01-01

    Lead isotopes from Fe and Mn oxides that coat stream pebbles from around the Mount Emmons porphyry molybdenum deposit in Colorado were studied to assess the feasibility of using Pb isotopes to detect concealed mineral deposits. The Fe/Mn oxide coatings were analyzed to determine their elemental concentrations using ICP-AES. The Pb isotope compositions of solutions from a selected suite of samples were measured, using both thermal ionization and ICP mass spectrometry, to compare results determined by the two analytical methods. Heavy mineral concentrates from the same sites were also analyzed to compare the Pb isotope compositions of the Fe/Mn coatings with those found in panned concentrates. The Fe/Mn and 206Pb/204Pb ratios of the oxide coatings are related to the lithology of the host rocks; Fe/Mn oxide coatings on pebbles of black shale have higher Fe/Mn values than do the coatings on either sandstone or igneous rocks. The shale host rocks have a more radiogenic signature (e.g. higher 206Pb/ 204Pb) than the sandstone or igneous host rocks. The Pb isotope data from sandstone and igneous hosts can detect concealed mineralized rock on both a regional and local scale, even though there are contributions from: (1) metals from the main-stage molybdenite ore deposit; (2) metals from the phyllic alteration zone which has a more radiogenic Pb isotope signature reflecting hydrothermal leaching of Pb from the Mancos Shale; (3) Pb-rich base metal veins with a highly variable Pb isotope signature; and (4) sedimentary country rocks which have a more radiogenic Pb isotope signature. An investigation of within-stream variation shows that the Pb isotope signature of the molybdenite ore zone is retained in the Fe/Mn oxide coatings and is not camouflaged by contributions from Pb-rich base-metal veins that crop out upstream. In another traverse, the Pb isotope data from Fe/Mn oxide coatings reflect a complex mixing of Pb from the molybdenite ore zone and its hornfels margin, Pb

  7. Spatial and temporal evolution of lead isotope ratios in the North Atlantic Ocean between 1981 and 1989

    NASA Astrophysics Data System (ADS)

    Weiss, Dominik; Boyle, Edward A.; Wu, Jingfeng; Chavagnac, ValéRie; Michel, Anna; Reuer, Matthew K.

    2003-10-01

    Lead concentrations and isotope ratios were measured in North Atlantic surface water samples collected in 1981 (29°-79°N, 6°E-49°W) and in 1989 (23°-39°N, 29°-68°W). In the early 1980s, 206Pb/207Pb ratios in the North African Basin averaged 1.193 ± 0.005 (1 σ). Similar radiogenic ratios within the level of analytical precision (average 0.29%) were found in the Labrador and Iceland Basins (1.198 ± 0.006) and in the Norwegian Sea (1.196 ± 0.008). These radiogenic mixed layer signatures along with atmospheric global lead emission patterns suggest that most North Atlantic lead in the early 1980s was derived from North American leaded gasoline. Samples in the East Iberian Basin near Portugal and France showed lower 206Pb/207Pb ratios, between 1.167 and 1.182, indicating a significant influence of less radiogenic atmospheric lead transported from Europe and possibly the influence of the Rio Tinto acid mine drainage very close to shore in the Gulf of Cadiz. [Pb] across the entire North Atlantic Basin ranged between 54 and 145 pmol/kg, with the lowest values (54-74 pmol/kg) found at high latitudes (>65°N). In the late 1980s, surface waters in the western subtropical North Atlantic (North American Basin/Sargasso Sea, >47°W) and in the eastern subtropical North Atlantic (North African Basin/Central Iberian Basin, <45°W) showed very similar 206Pb/207Pb signatures with little zonal variation, ranging from 1.177 to 1.192. Lead concentrations ranged between 47 and 137 pmol/kg, increasing slightly from west to east. South of 25°N in the equatorial North Atlantic, crossing the subtropical/tropical surface water boundary, the 206Pb/207Pb seawater signatures were significantly less radiogenic (1.170-1.175) and concentrations were lower (≤51 pmol/kg). This difference suggests a relative increase in the atmospheric lead supply from the western Mediterranean/North African continent via Trade Easterlies and illustrates the effective barrier between the subtropical

  8. Pb isotopes in anorthositic breccias 67075 and 62237 - A search for primitive lunar lead

    NASA Technical Reports Server (NTRS)

    Premo, W. R.; Tatsumoto, M.; Wang, J.-W.

    1989-01-01

    The lunar Pb isotopic evolution is explored based on an investigation of the U-Th-Pb systematics of the primitive Apollo 16 anorthositic breccias 76075 and 62237. The isotope data for acid-leached residues from 67075 lie within or on a triangle formed by plagioclase, opaques, and a pyroxen-olivine mixture, and the isotope data for 62237 lie within or on a triangle formed by plagioclase, olivine, and pyroxene. The results suggest that the moon had high first-stage values for the Pb evolution equations from the onset.

  9. The Schwartzwalder uranium deposit, II: Age of uranium mineralization and lead isotope constraints on genesis.

    USGS Publications Warehouse

    Ludwig, K. R.; Wallace, A.R.; Simmons, K.R.

    1985-01-01

    Schwartzwalder ores have high amounts of initial (common) Pb that was both variable and relatively radiogenic in its isotope ratios. Assuming the common Pb in these ores to have sources of similar age and similar Th/U, samples with initial Pb isotope ratios are identified - and others with variable initial ratios are normalized - to obtain U-Pb isochrons yielding an early Laramide age of 69.3 + or - 1.1 m.y. for the ores. The initial Pb-isotope systematics indicate local sources of U, dispersed in concentrations <100 ppm, in rocks of 1730 + or - 130 m.y. age. -G.J.N.

  10. Contrasting origins of the upper mantle revealed by hafnium and lead isotopes from the Southeast Indian Ridge.

    PubMed

    Hanan, Barry B; Blichert-Toft, Janne; Pyle, Douglas G; Christie, David M

    2004-11-01

    The origin of the isotopic signature of Indian mid-ocean ridge basalts has remained enigmatic, because the geochemical composition of these basalts is consistent either with pollution from recycled, ancient altered oceanic crust and sediments, or with ancient continental crust or lithosphere. The radiogenic isotopic signature may therefore be the result of contamination of the upper mantle by plumes containing recycled altered ancient oceanic crust and sediments, detachment and dispersal of continental material into the shallow mantle during rifting and breakup of Gondwana, or contamination of the upper mantle by ancient subduction processes. The identification of a process operating on a scale large enough to affect major portions of the Indian mid-ocean ridge basalt source region has been a long-standing problem. Here we present hafnium and lead isotope data from across the Indian-Pacific mantle boundary at the Australian-Antarctic discordance region of the Southeast Indian Ridge, which demonstrate that the Pacific and Indian upper mantle basalt source domains were each affected by different mechanisms. We infer that the Indian upper-mantle isotope signature in this region is affected mainly by lower continental crust entrained during Gondwana rifting, whereas the isotope signature of the Pacific upper mantle is influenced predominantly by ocean floor subduction-related processes.

  11. A stable lead isotopic investigation of the use of sycamore tree rings as a historical biomonitor of environmental lead contamination.

    PubMed

    Patrick, Gavin J; Farmer, John G

    2006-06-01

    The validity of the use of sycamore (Acer pseudoplatanus) tree-rings for the reconstruction of atmospheric lead pollution histories was investigated. Tree cores spanning 1892-2003 were collected from several sycamores from the eastern shore of Loch Lomond, Scotland, an area with no local point sources of lead emission. The lead concentration and 206Pb/207Pb profiles of the Loch Lomond region cores were compared with corresponding data for the 210Pb-dated loch sediment, and also with data for moss of known age from a Scottish herbarium collection. Two of the seven sycamore cores showed the same lead concentration trend as the lead flux to the loch, the rest having no similarity to either each other or the loch sediment record. Two further sycamore cores showed some similarity in their temporal 206Pb/207Pb trends to those seen in the sediment and moss records, but only in part of their profiles, whilst the 206Pb/207Pb ratios of the other sycamore cores remained relatively unchanged for the majority of the time covered, or exhibited an opposite trend. The 206Pb/207Pb ratios of the tree cores were also mostly higher than those of the previously established records for any given time period. Tree cores covering 1878-2002 were also collected along transects from Wanlockhead and Tyndrum, two areas of former lead mining and smelting associated with distinct 206Pb/207Pb ratios of 1.170 and 1.144, respectively. The Wanlockhead tree cores exhibited a generally decreasing trend in lead concentration with both time and distance from the lead mine. The characteristic 206Pb/207Pb ratio of 1.170 was observed in samples close to the mine but a decrease in the influence of the mine-derived lead was observed in more distant samples. The tree sampled at Tyndrum showed elevated lead concentrations, which decreased with time, and a fairly constant 206Pb/207Pb ratio of 1.15 reflecting input from the mine, features not observed in any other trees along the transect. Overall the data

  12. Isotope ratio analysis of lead in blood and environmental samples by multi-collector inductively coupled plasma mass spectrometry.

    PubMed

    Takagi, Mai; Yoshinaga, Jun; Tanaka, Atsushi; Seyama, Haruhiko

    2011-01-01

    It is widely recognized that lead (Pb) affects children's cognitive function, even at relatively low blood lead levels (<10 µg dL(-1)). The determination of the source of Pb in children is essential for effective risk management. The use of multi-collector ICPMS (MC-ICPMS) for isotope ratio measurements of Pb in environmental and biological samples was examined for this purpose. MC-ICPMS with an instrumental mass fractionation correction by Tl allowed accurate isotope ratio measurements of the Pb isotopic reference material NIST SRM 981. However, the presence of matrix elements (Al, Ca, Fe and Na) at more than 10 mg kg(-1) in the sample solution significantly deteriorated the accuracy. The separation of Pb from the matrix is necessary for accurate measurements of the isotope ratio of Pb in environmental and biological samples. Bromide-complexation, followed by anion exchange was found to be satisfactory in terms of the recovery of Pb (90 to 104%) and the efficiency of matrix separation. The procedure was applied to a preliminary source analysis of Pb in the blood of Japanese children, and a significant contribution of indoor dust was demonstrated.

  13. Tracing the origin of pollution in French Alpine snow and aerosols using lead isotopic ratios.

    PubMed

    Veysseyre, A M; Bollhöfer, A F; Rosman, K J; Ferrari, C P; Boutron, C F

    2001-11-15

    Fresh snow samples collected at 15 remote locations and aerosols collected at one location in the French Alps between November 1998 and April 1999 have been analyzed for Pb concentration and isotopic composition by thermal ionization mass spectrometry. The snow samples contained 19-1300 pg/g of Pb with isotopic ratios 206Pb/207Pb (208Pb/207Pb) of 1.1279-1.1607 (2.3983-2.4302). Airborne Pb concentrations at one sampling site ranged from 0.42 to 6.0 ng/m3 with isotopic ratios of 1.1321-1.1427 (2.4029-2.4160). Air mass trajectory analysis combined with isotopic compositions of potential source regions did not show discernible evidence of the long-range atmospheric transport of pollutants. Isotopic ratios in the Alpine snow samples and thus the free troposphere were generally higher than airborne Pb isotopic ratios in urban France, which coupled with the relatively high Pb concentrations suggested a regional anthropogenic Pb source, probably Italy but possibly Eastern Europe.

  14. The effects of succimer on the absorption of lead in adults determined by using the stable isotope [sup 204]Pb

    SciTech Connect

    Smith, D.R. Univ. of California, Santa Cruz, CA ); Markowitz, M.E.; Rosen, J.F. ); Crick, J.; Flegal, A.R. )

    1994-10-01

    The chelating agent succimer (meso-2,3-dimercaptosuccine acid) is orally effective at inducing a urinary lead diuresis and a decrease in blood lead levels in lead poisoned children and adults. However, there are concerns that succimer may increase the absorption of lead from the gastrointestinal (GI) tract during treatment, particularly in cases of continuing lead exposure, which would compromise its effectiveness in reducing whole body lead stores. This preliminary study investigated the effects of succimer on the absorption of lead in adults using a stable lead isotopic tracer ([sup 204]Pb). Twelve male subjects were divided into control (no succimer), 10, and 30 mg succimer/kg body wt treatment groups of 4 individuals each. All subjects ingested a single tracer dose (200 [mu]g) of [sup 204]Pb, followed by a single oral dose of placebo (control) or succimer. Whole blood was collected at intervals of 0, 2, 4, and [approx] 26 hr following ingestion of the [sup 204]Pb tracer, and composite urine and feces samples were collected over the duration of the study ([approx] 26 hr). Mean intestinal excretion of [sup 204]Pb was reduced in the succimer-treated groups compared to the control (placebo), whereas urinary diuresis of [sup 204]Pb was higher in the succimer groups. The amount of lead [sup 204]Pb tracer accounted for at the end of the study was lower in the succimer-treated groups. These results suggest that GI lead absorption was enhanced by succimer and that succimer mediated the redistribution of lead from the circulation to other tissues. However, none of the differences between treatment groups were statistically significant (P < 0.05, t test) because of the relatively large within-group variability. This study demonstrates the utility of microgram doses of a stable lead isotopic tracer to assess the efficacy of clinical chelating agents in humans. 39 refs., 1 fig., 2 tabs.

  15. Concentrations, isotopic compositions, and sources of lead in the surface waters of the Eastern Tropical South Pacific

    NASA Astrophysics Data System (ADS)

    Till, R.; Zurbrick, C. M.; Flegal, A. R., Jr.

    2014-12-01

    Lead concentrations and isotopic compositions were measured in surface and subsurface waters across the Eastern Tropical South Pacific as part of the 2013 US GEOTRACES Zonal Transect from Peru to Tahiti. Surface waters were collected throughout the transect, and subsurface waters were collected to a depth of 1,000 m at 36 vertical profile stations. Aliquots of some of those samples, as well as samples from greater depths, were used in intercalibrations with Ed Boyle's group, which focused on lead fluxes from hydrothermal vents and at the benthic boundary layer. In contrast, our group focused on aeolian lead fluxes to surface waters from natural and industrial sources. Preliminary data indicate that lead concentrations in those South Pacific surface waters are low compared to the more contaminated North Pacific. Moreover, complementary lead isotopic compositions indicate distinguishing between natural and industrial lead fluxes in the South Pacific will be more difficult now that the use of gasoline with lead alkyls from Australia have been eliminated.

  16. A lead isotopic study of the Stillwater Complex, Montana: constraints on crustal contamination and source regions

    USGS Publications Warehouse

    Wooden, J.L.; Czamanske, G.K.; Zientek, M.L.

    1991-01-01

    Analyses of the Pb isotopic compositions of plagioclase from 23 samples covering the stratigraphic thickness of the Stillwater Complex indicate a narrow range of apparent initial isotopic compositions (206Pb/ 204Pb=13.95; 207Pb/204Pb=14.95-15.01; 208Pb/204Pb=33.6). The uniformity of our data is in contrast to, but not necessarily contradictory to, other recent investigations which give indications that the complex formed by repeated injection of magmas with at least two distinct compositions that were presumably derived from different source regions. Samples from the Basal series of the complex have consistently higher 207Pb/204Pb ratios, suggesting either minor contamination from adjacent country rocks or a slight distinction between parental magmas. Apparent initial Pb isotopic compositions of the complex are very radiogenic compared to Late Archean model-mantle values, but are nearly identical to initial Pb isotopic compositions found for the the adjacent, slightly older (2.73-2.79 Ga), Late Archean crustal suite in the Beartooth Mountains. Contamination of magmas parental to the Stillwater Complex by the Late Archean crustal suite is rejected for two reasons: (1) Th and U concentrations in Stillwater rocks and plagioclase are very low (about 0.08 and 0.02 ppm respectively), yet Th/U ratios are uniform at about 4, in contrast to the highly variable (2-26) but often high Th/U ratios found for the Late Archean crustal complex; (2) it seems improbable that any contamination process would have adjusted the isotopic compositions of the diverse magmas entering the Stillwater chamber to near-identical values. The preferred hypothesis to explain the Pb isotopic data for the Stillwater Complex and the associated Late Archean crustal suite involves a major Late Archean crust-forming event that resulted in a compositionally complex crust/mantle system with relatively homogeneous and unusual Pb isotopic compositions. The parental magmas of the Stillwater Complex were

  17. A "Tail" Of Two Mines: Determining The Sources Of Lead In Mine Waters Using Pb Isotopes

    NASA Astrophysics Data System (ADS)

    Cousens, B. L.; Allen, D. M.; Lepitre, M. E.; Mortensen, J. K.; Gabites, J. E.; Nugent, M.; Fortin, D.

    2004-12-01

    Acid mine drainage can be a significant environmental problem in regions where mine tailings are exposed to surface water and shallow groundwater flow. Whereas high metal concentrations in surface waters and groundwaters indicate that metals are being mobilized, these data do not uniquely identify the source of the contamination. The isotopic composition of Pb in mine waters is a superb tracer of Pb sources, because the isotopic composition of ore Pb is usually significantly different from that of host rocks, other surficial deposits, and aerosols. We have investigated metal mobility at two abandoned Pb-Zn mines in different geological settings: the sediment-hosted Sullivan Mine in southeastern British Columbia, and the New Calumet Mine of western Quebec that is hosted in metamorphic rocks of the Grenville Province. Ores from both mines have homogeneous Pb isotopic compositions that are much less radiogenic than surrounding host rocks. At Sullivan, the Pb isotopic compositions of water samples define a mixing line between Sullivan ore and at least one other more radiogenic end-member. Water samples with high Pb concentrations (0.002 to 0.3 mg/L) generally are acidic and have Pb isotope ratios equal to Sullivan ore, whereas waters with low Pb contents have near-neutral pH and have variably more radiogenic Pb isotope ratios. Thus not all the waters collected in the study area originate from Sullivan ore or mining operations, as previously thought. The dominant source of ore Pb in mine waters are the waste rock dumps. Based on their isotopic compositions, host shales or aerosols from the local Pb smelter are potential sources of non-Sullivan ore Pb; local glacial tills are an unlikely source due to their heterogeneous Pb isotopic composition. Similarly, at the New Calumet mine, water samples collected in direct contact with either ore at the surface or tailings have high Pb concentrations (up to 0.02 mg/L) and Pb isotope ratios equal to New Calumet Pb-Zn ore. However

  18. Lead isotopes tracing the life cycle of a catchment: From source rock via weathering to human impact

    NASA Astrophysics Data System (ADS)

    Negrel, P. J.; Petelet-Giraud, E.; Guerrot, C.; Millot, R.

    2015-12-01

    Chemical weathering of rocks involves consumption of CO2, a greenhouse gas with a strong influence on climate. Among rocks exposed to weathering, basalt plays a major role in the carbon cycle as it is more easily weathered than other crystalline silicate rocks. This means that basalt weathering acts as a major atmospheric CO2 sink. The present study investigated the lead isotopes in rock, soil and sediment for constraining the life cycle of a catchment, covering source rocks, erosion processes and products, and anthropogenic activities. For this, we investigated the Allanche river drainage basin in the Massif Central, the largest volcanic areas in France, that offers opportunities for selected geochemical studies since it drains a single type of virtually unpolluted volcanic rock, with agricultural activity increasing downstream. Soil and sediment are derived exclusively from basalt weathering, and their chemistry, coupled to isotope tracing, should shed light on the behavior of chemical species during weathering from parental bedrock. Bedrock samples of the basin, compared to regional bedrock of the volcanic province, resulted from a complex history and multiple mantle reservoir sources and mixing. Regarding soils and sediments, comparison of Pb and Zr normalized to mobile K shows a linear evolution of weathering processes, whereby lead enrichment from atmospheric deposition is the other major contributor. Lead-isotope ratios showed that most of the lead budget in sediment and soil results from bedrock weathering with an influence of past mining and mineral processing of ores in the Massif Central, and deposition of lead-rich particles from gasoline combustion, but no lead input from agricultural activity. A classic box model was used to investigate the dynamics of sediment transfer at the catchment scale, the lead behavior in the continuum bedrock-soil-sediment and the historical evolution of anthropogenic aerosol emissions.

  19. Geogenic lead isotope signatures from meat products in Great Britain: Potential for use in food authentication and supply chain traceability.

    PubMed

    Evans, Jane A; Pashley, Vanessa; Richards, Gemma J; Brereton, Nicola; Knowles, Toby G

    2015-12-15

    This paper presents lead (Pb) isotope data from samples of farm livestock raised in three areas of Britain that have elevated natural Pb levels: Central Wales, the Mendips and the Derbyshire Peak District. This study highlights three important observations; that the Pb found in modern British meat from these three areas is geogenic and shows no clear evidence of modern tetraethyl anthropogenic Pb contribution; that the generally excellent match between the biological samples and the ore field data, particularly for the Mendip and Welsh data, suggests that this technique might be used to provenance biological products to specific ore sites, under favourable conditions; and that modern systems reflect the same process of biosphere averaging that is analogous to cultural focusing in human archaeological studies that is the process of biological averaging leading to an homogenised isotope signature with increasing Pb concentration.

  20. Nuclear volume effects in equilibrium stable isotope fractionations of mercury, thallium and lead.

    PubMed

    Yang, Sha; Liu, Yun

    2015-01-01

    The nuclear volume effects (NVEs) of Hg, Tl and Pb isotope systems are investigated with careful evaluation on quantum relativistic effects via the Dirac's formalism of full-electron wave function. Equilibrium (202)Hg/(198)Hg, (205)Tl/(203)Tl, (207)Pb/(206)Pb and (208)Pb/(206)Pb isotope fractionations are found can be up to 3.61‰, 2.54‰, 1.48‰ and 3.72‰ at room temperature, respectively, larger than fractionations predicted by classical mass-dependent isotope fractionations theory. Moreover, the NVE can cause mass-independent fractionations (MIF) for odd-mass isotopes and even-mass isotopes. The plot of [formula in text] for Hg-bearing species falls into a straight line with the slope of 1.66, which is close to previous experimental results. For the first time, Pb(4+)-bearing species are found can enrich heavier Pb isotopes than Pb(2+)-bearing species to a surprising extent, e.g., the enrichment can be up to 4.34‰ in terms of (208)Pb/(206)Pb at room temperature, due to their NVEs are in opposite directions. In contrast, fractionations among Pb(2+)-bearing species are trivial. Therefore, the large Pb fractionation changes provide a potential new tracer for redox conditions in young and closed geologic systems. The magnitudes of NVE-driven even-mass MIFs of Pb isotopes (i.e., [formula in text]) and odd-mass MIFs (i.e., [formula in text) are almost the same but with opposite signs. PMID:26224248

  1. Investigation of off-site airborne transport of lead from a superfund removal action site using lead isotope ratios and concentrations

    USGS Publications Warehouse

    Pribil, Michael J.; Maddaloni, Mark A.; Staiger, Kimberly; Wilson, Eric; Magriples, Nick; Ali, Mustafa; Santella, Dennis

    2014-01-01

    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.

  2. Helium and lead isotopes reveal the geochemical geometry of the Samoan plume.

    PubMed

    Jackson, M G; Hart, S R; Konter, J G; Kurz, M D; Blusztajn, J; Farley, K A

    2014-10-16

    Hotspot lavas erupted at ocean islands exhibit tremendous isotopic variability, indicating that there are numerous mantle components hosted in upwelling mantle plumes that generate volcanism at hotspots like Hawaii and Samoa. However, it is not known how the surface expression of the various geochemical components observed in hotspot volcanoes relates to their spatial distribution within the plume. Here we present a relationship between He and Pb isotopes in Samoan lavas that places severe constraints on the distribution of geochemical species within the plume. The Pb-isotopic compositions of the Samoan lavas reveal several distinct geochemical groups, each corresponding to a different geographic lineament of volcanoes. Each group has a signature associated with one of four mantle endmembers with low (3)He/(4)He: EMII (enriched mantle 2), EMI (enriched mantle 1), HIMU (high µ = (238)U/(204)Pb) and DM (depleted mantle). Critically, these four geochemical groups trend towards a common region of Pb-isotopic space with high (3)He/(4)He. This observation is consistent with several low-(3)He/(4)He components in the plume mixing with a common high-(3)He/(4)He component, but not mixing much with each other. The mixing relationships inferred from the new He and Pb isotopic data provide the clearest picture yet of the geochemical geometry of a mantle plume, and are best explained by a high-(3)He/(4)He plume matrix that hosts, and mixes with, several distinct low-(3)He/(4)He components. PMID:25318524

  3. Helium and lead isotopes reveal the geochemical geometry of the Samoan plume.

    PubMed

    Jackson, M G; Hart, S R; Konter, J G; Kurz, M D; Blusztajn, J; Farley, K A

    2014-10-16

    Hotspot lavas erupted at ocean islands exhibit tremendous isotopic variability, indicating that there are numerous mantle components hosted in upwelling mantle plumes that generate volcanism at hotspots like Hawaii and Samoa. However, it is not known how the surface expression of the various geochemical components observed in hotspot volcanoes relates to their spatial distribution within the plume. Here we present a relationship between He and Pb isotopes in Samoan lavas that places severe constraints on the distribution of geochemical species within the plume. The Pb-isotopic compositions of the Samoan lavas reveal several distinct geochemical groups, each corresponding to a different geographic lineament of volcanoes. Each group has a signature associated with one of four mantle endmembers with low (3)He/(4)He: EMII (enriched mantle 2), EMI (enriched mantle 1), HIMU (high µ = (238)U/(204)Pb) and DM (depleted mantle). Critically, these four geochemical groups trend towards a common region of Pb-isotopic space with high (3)He/(4)He. This observation is consistent with several low-(3)He/(4)He components in the plume mixing with a common high-(3)He/(4)He component, but not mixing much with each other. The mixing relationships inferred from the new He and Pb isotopic data provide the clearest picture yet of the geochemical geometry of a mantle plume, and are best explained by a high-(3)He/(4)He plume matrix that hosts, and mixes with, several distinct low-(3)He/(4)He components.

  4. Isotopic compositions of bismuth, lead, thallium, and mercury from mini r-processing

    SciTech Connect

    Heymann, D.; Liffman, K.

    1986-03-01

    The yields of stable isotopes of Bi, Pb, Tl and Hg as well as yields of Pb-205 are calculated with a parametrized model for mini r-processing in the Ne, O, C-rich zones of explosive burning in massive stars. The Pb isotopic compositions stand out by their comparatively low Pb-207 yields and by the fact that this r-process variant yields Pb-204 quite abundantly. The average Pb-205/Pb-204 yield ratio of 6.1 is the same order of magnitude as yield ratios deduced for s-processing. The Hg from this mini r-process looks like normal solar-system mercury, but with Hg-196 missing and the light s-isotopes A = 198, 199, 200 and 201 depleted (especially the odd-A species). 24 references

  5. Isotopic compositions of bismuth, lead, thallium, and mercury from mini r-processing

    NASA Technical Reports Server (NTRS)

    Heymann, D.; Liffman, K.

    1986-01-01

    The yields of stable isotopes of Bi, Pb, Tl and Hg as well as yields of Pb-205 are calculated with a parametrized model for 'mini r-processing' in the Ne, O, C-rich zones of explosive burning in massive stars. The Pb isotopic compositions stand out by their comparatively low Pb-207 yields and by the fact that this r-process variant yields Pb-204 quite abundantly. The average Pb-205/Pb-204 yield ratio of 6.1 is the same order of magnitude as yield ratios deduced for s-processing. The Hg from this mini r-process looks like normal solar-system mercury, but with Hg-196 missing and the light s-isotopes A = 198, 199, 200 and 201 depleted (especially the odd-A species).

  6. Lead and stable lead isotope ratios in soil, earthworms, and bones of American woodcock (Scolopax minor) from eastern Canada.

    PubMed

    Scheuhammer, Anton M; Bond, Della E; Burgess, Neil M; Rodrigue, Jean

    2003-11-01

    A study to discriminate among different possible sources of elevated Pb exposure for American woodcock (Scolopax minor) in eastern Canada is described. Undamaged wing bones excised from young-of-the-year woodcock collected from several locations in southern Ontario, southern Quebec, New Brunswick, and Nova Scotia, Canada, along with soil and earthworm (Aporrectodea tuberculata and Lumbricus rubellus) samples from the same sites, were analyzed for total Pb, and stable Pb isotopes. Ignoring six soil samples with high (> 60 microg/g) Pb concentration from the vicinity of Montreal (QC, Canada), the mean soil-Pb concentration for all sites combined was 19 microg/g (dry wt; n = 64), with a mean 206Pb:207Pb ratio of 1.19, values typical for uncontaminated rural soils in eastern North America. In earthworms, Pb concentrations ranged from 2.4 to 865 (microg/g [dry wt], mean = 24 microg/g). Concentrations of Pb in worms and soils were positively correlated (r = 0.71; p < 0.01), and 206Pb:207Pb ratios for worms and soils were also positively correlated (r = 0.54; p < 0.05). However, most young-of-the-year woodcock with high bone-Pb accumulation (> 20 microg/g) had 206Pb:207Pb ratios substantially different from worms and soils sampled from the same areas, even though woodcock feed extensively on soil invertebrates, especially earthworms. The range of 206Pb:207Pb ratios in wing bones of woodcock with elevated Pb exposure was not consistent with exposure to environmental Pb from past gasoline combustion nor Precambrian mining wastes but was consistent with ingestion of spent Pb shotgun pellets. PMID:14587896

  7. Lead and stable lead isotope ratios in soil, earthworms, and bones of American woodcock (Scolopax minor) from eastern Canada.

    PubMed

    Scheuhammer, Anton M; Bond, Della E; Burgess, Neil M; Rodrigue, Jean

    2003-11-01

    A study to discriminate among different possible sources of elevated Pb exposure for American woodcock (Scolopax minor) in eastern Canada is described. Undamaged wing bones excised from young-of-the-year woodcock collected from several locations in southern Ontario, southern Quebec, New Brunswick, and Nova Scotia, Canada, along with soil and earthworm (Aporrectodea tuberculata and Lumbricus rubellus) samples from the same sites, were analyzed for total Pb, and stable Pb isotopes. Ignoring six soil samples with high (> 60 microg/g) Pb concentration from the vicinity of Montreal (QC, Canada), the mean soil-Pb concentration for all sites combined was 19 microg/g (dry wt; n = 64), with a mean 206Pb:207Pb ratio of 1.19, values typical for uncontaminated rural soils in eastern North America. In earthworms, Pb concentrations ranged from 2.4 to 865 (microg/g [dry wt], mean = 24 microg/g). Concentrations of Pb in worms and soils were positively correlated (r = 0.71; p < 0.01), and 206Pb:207Pb ratios for worms and soils were also positively correlated (r = 0.54; p < 0.05). However, most young-of-the-year woodcock with high bone-Pb accumulation (> 20 microg/g) had 206Pb:207Pb ratios substantially different from worms and soils sampled from the same areas, even though woodcock feed extensively on soil invertebrates, especially earthworms. The range of 206Pb:207Pb ratios in wing bones of woodcock with elevated Pb exposure was not consistent with exposure to environmental Pb from past gasoline combustion nor Precambrian mining wastes but was consistent with ingestion of spent Pb shotgun pellets.

  8. Application of lead isotopic methods to the study of the anthropogenic lead provenance in Spanish overbank floodplain deposits.

    PubMed

    Adánez Sanjuán, Paula; Flem, Belinda; Llamas Borrajo, Juan F; Locutura Rupérez, Juan; Garcia Cortés, Angel

    2016-04-01

    Changes in the principal sources of Pb in overbank sediment profiles have been documented for two Spanish areas by using Pb isotopes and Pb concentrations. These locations (Madrid and Tinto-Odiel basin) represent two of the most contaminated regions in Spain. The Community of Madrid is characterized by heavy industrial and urban activity, focused mainly in Madrid City. The Tinto-Odiel basin drains the Iberian Pyrite Belt, which hosts many polymetallic massive sulphides and is heavily affected by mining activities in their headwaters. It has been proven that the influence of anthropogenic activity is reflected in these overbank deposits by variations in Pb concentrations that, in general, correlate with shifts in the (206)Pb/(207)Pb ratio. Rivas profile (downstream of Madrid) was found to be the most anthropogenically influenced site. The sediments within this profile which were recently deposited (170 ± 40 years BP) have the least radiogenic signatures. (206)Pb/(207)Pb ratios ranged between 1.1763 and 1.1876 indicating significant contributions of anthropogenic Pb. In contrast, profiles upstream of Madrid possess an average (206)Pb/(207)Pb ratio of 1.2272. It is difficult to clearly identify the most prominent source as the sediments appear to be characterized by an input from several sources. The floodplain profiles in the Tinto-Odiel basin exhibit uniform (206)Pb/(207)Pb ratios ranging from 1.1627 (Odiel river) to 1.1665 (Tinto river). These ratios are similar to the ones possessed by sulphide ores in the area and differ from the ratios of other nonmineralized formations in the basin, indicating that mining activities are the primary, if not sole, source of Pb to the sediments. PMID:26100323

  9. [Lead isotope signatures and source identification in urban soil of Baoshan district, Shanghai].

    PubMed

    Dong, Chen-Yin; Zhang, Wei-Guo; Wang, Guan; Ma, Hong-Lei; Liu, Yuan; Liu, Ying; Ye, Lei-Ping; Yu, Li-Zhong

    2012-03-01

    Two soil cores were collected from the Yuepu Park and a vegetable field near the Yunchuan Road in Baoshan district, Shanghai. Particle size, Pb content and Pb stable isotopic ratios were measured to examine Pb contamination status and its source. The results indicate that Pb concentration in the vegetable field soil and Yuepu park soil varies from 17.2 mg x kg(-1) to 34.8 mg x kg(-1) and 17.5 mg x kg(-1) to 36. 5 mg x kg(-1), respectively. The observed Pb isotopic ratios of vegetable field samples vary from 0.827 to 0.849 for 207Pb/206Pb, and 2.082 to 2.101 for 208Pb/206Pb, while those of Yuepu Park samples range from 0.839 to 0.848 and 2.089 to 2.097, respectively. Pb content, its enrichment factor (EF) and Pb stable isotopic ratios increase upward in both soil cores. EF values of surfacial (top 10 cm) vegetable field samples and park samples are mostly greater than 1.5, suggesting that higher Pb contents in topsoils are caused by anthropogenic activities. Compared with previous reports on Pb isotope signatures of different environmental materials in Shanghai, Pb isotopic ratios in the two soil cores are between those of Yangtze River intertidal sediments and the dust of coal combustion, and those of soil samples with EF > 1.5 are closer to the isotopic ratios of coal combustion dust. It indicates that topsoil in the Baoshan district is contaminated by dust derived from coal combustion.

  10. Monthly-resolved coral skeletal lead isotopic determination in picogram quantities by MC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Chou, Y.; Shen, C.; Lo, Y.; Chang, C.

    2011-12-01

    Pb concentrations and isotopic composition in coral skeletons have been applied to understanding annual-decadal trends of natural hydrological evolution, ocean circulation, and anthropogenic pollution. However, the low Pb contents of only 10s-100s ng/g has hindered measurements of monthly-resolved coral Pb isotopic records and limited its applications. We refined chemistry and improved instrumental methodology to develop a reliable procedure for picogram-quantity coral Pb isotopic determination (Pb-204, Pb-206, Pb-207, and Pb-208) on a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, Thermo Electron NEPTUNE). The overall procedural blank is <20 pg. Replicate measurements made on standard NIST SRM 981 shows that our method can achieve a precision of ± 300 ppm (2σ) for Pb-207/Pb-206 and Pb-208/Pb-206 with 100s-1000s pg of Pb. Monthly-resolution Pb isotopic and concentration records of a coral Porites collected by Son Tra Island, central Vietnam (16°12'59.4", 108°1'57.1") from 1978-2004 AD have been measured. Three features are exhibited as follows: (1) The high Pb/Ca background level of 0.652 μmol/mol after 1992, 1.5 times larger than value of 0.437 μmol/mol in 1978-1992, shows an impact of economic development on hydrological change. (2) Ratios of Pb-208/Pb-207, Pb-206/Pb-207, and Pb-206/Pb-204 are relatively low in winter and high in summer, reflecting different seasonal sources. (3) Significant Pb isotopic anomalies in 1991-1992 could result from the eruption of Mt. Pinatubo on June 15, 1991. Our results indicate that monthly-resolved coral Pb isotopic and concentration can be used as proxies of seasonal climate changes, volcanic impacts and humanity activities.

  11. Evaluation of zinc, cadmium and lead isotope fractionation during smelting and refining.

    PubMed

    Shiel, Alyssa E; Weis, Dominique; Orians, Kristin J

    2010-05-01

    To evaluate metallurgical processing as a source of Zn and Cd isotopic fractionation and to potentially trace their distribution in the environment, high-precision MC-ICP-MS Zn, Cd and Pb isotope ratio measurements were made for samples from the integrated Zn-Pb smelting and refining complex in Trail, B.C., Canada. Significant fractionation of Zn and Cd isotopes during processing of ZnS and PbS ore concentrates is demonstrated by the total variation in delta(66/64)Zn and delta(114/110)Cd values of 0.42 per thousand and 1.04 per thousand, respectively, among all smelter samples. No significant difference is observed between the isotopic compositions of the Zn ore concentrates (delta(66/64)Zn=0.09 to 0.17 per thousand; delta(114/110)Cd=-0.13 to 0.18 per thousand) and the roasting product, calcine (delta(66/64)Zn=0.17 per thousand; delta(114/110)Cd=0.05 per thousand), due to approximately 100% recovery from roasting. The overall Zn recovery from metallurgical processing is approximately 98%, thus the refined Zn metal (delta(66/64)Zn=0.22 per thousand) is not significantly fractionated relative to the starting materials despite significantly fractionated fume (delta(66/64)Zn=0.43 per thousand) and effluent (delta(66/64)Zn=0.41 to 0.51 per thousand). Calculated Cd recovery from metallurgical processing is 72-92%, with the majority of the unrecovered Cd lost during Pb operations (delta(114/110)Cd=-0.38 per thousand). The refined Cd metal is heavy (delta(114/110)Cd=0.39 to 0.52 per thousand) relative to the starting materials. In addition, significant fractionation of Cd isotopes is evidenced by the relatively light and heavy isotopic compositions of the fume (delta(114/110)Cd=-0.52 per thousand) and effluent (delta(114/110)Cd=0.31 to 0.46 per thousand). In contrast to Zn and Cd, Pb isotopes are homogenized by mixing during processing. The total variation observed in the Pb isotopic compositions of smelter samples is attributed to mixing of ore sources with different

  12. Lead

    MedlinePlus

    ... Lead Share Facebook Twitter Google+ Pinterest Contact Us Lead Poisoning is Preventable If your home was built before ... of the RRP rule. Read more . Learn about Lead Poisoning Prevention Week . Report Uncertified Contractors and Environmental Violations ...

  13. Lead isotope evidence for a young formation age of the Earth-Moon system

    NASA Astrophysics Data System (ADS)

    Connelly, J. N.; Bizzarro, M.

    2016-10-01

    A model of a giant impact between two planetary bodies is widely accepted to account for the Earth-Moon system. Despite the importance of this event for understanding early Earth evolution and the inventory of Earth's volatiles critical to life, the timing of the impact is poorly constrained. We explore a data-based, two-stage Pb isotope evolution model in which the timing of the loss of volatile Pb relative to refractory U in the aftermath of the giant impact is faithfully recorded in the Pb isotopes of bulk silicate Earth. Constraining the first stage Pb isotopic evolution permits calculating an age range of 4.426-4.417 Ga for the inflection in the U/Pb ratio related to the giant impact. This model is supported by Pb isotope data for angrite meteorites that we use to demonstrate volatility-driven, planetary-scale Pb loss was an efficient process during the early Solar System. The revised age is ∼100 Myr younger than most current estimates for the age of the Moon but fully consistent with recent ages for lunar ferroan anorthosite and the timing of Earth's first crust inferred from the terrestrial zircon record. The estimated loss of ∼98% of terrestrial Pb relative to the Solar System bulk composition by the end of the Moon-forming process implies that the current inventory of Earth's most volatile elements, including water, arrived during post-impact veneering by volatile-rich bodies.

  14. Sulfate-water isotope geothermometry and lead isotope data for the regional geothermal system in the Twin Falls Area, South-Central Idaho

    SciTech Connect

    Mariner, R.H.; Bullen, T.D.; Janik, C.J.; Young, H.W.

    1997-12-31

    Sulfate-water isotope geothermometry for the geothermal system at Twin Falls, Idaho indicates aquifer-temperatures of 90{degrees} to 106{degrees}C; most sites are between 90{degrees} and 93{degrees}C. {sup 206}Pb/{sup 204}Pb and {sup 208}Pb/{sup 204}Pb of individual thermal waters are principally a function of how much lead has been dissolved from the carbonate and silicate fractions of the Paleozoic limestone collected west of Grand View Peak. Although most thermal waters are recovered from Tertiary rhyolite, very little of the dissolved lead is from the rhyolite. Recharge to this system occurs in northern Nevada and the fluid moves northward in the Paleozoic limestones. The occurrence of thermal fluid in the Idavada Volcanics near and south of Twin Falls, Idaho is the result of upward movement of this fluid from the Paleozoic limestone.

  15. [Speciation analysis of lead and its isotopes in fine particulate matters in Beijing by ICP-MS].

    PubMed

    Chen, Xi; Wang, Xiao-Yan; Liu, Yang; Zhang, Jing-Hua; Liu, Jing-Xiu; Yan, Lai-Lai; Wang, Jing-Yu

    2009-02-01

    Fine particulate matters (PMZ2.5) collected in Beijing during a period from September 2005 to May 2006 were studied. Sequential extraction procedures were applied to divide the total lead into three fractions, i.e. water soluble, liposoluble and insoluble lead. Lead concentrations and their isotopes in each fraction were then determined by inductively coupled plasma mass spectrometry (ICP-MS). Lead standard reference GBW 09133 was used to investigate the accuracy of lead concentration determination and SRM 981 was used to correct the mass discrimination and instrumental drift. The obtained results showed that the analytical precision of lead isotope ratios for SRM 981 of seven repeat measurements at lead concentration of 10 ng x mL(-1) came to about 0.34, 0.27 and 0.24 percent for the 206 Pb/204 Pb, 206Pb/207 Pb and 206Pb/208 Pb ratios, respectively. In Beijing, the mass concentrations for PM2.5 and lead of ambient air were 125.556 and 0.5415 microg x m(-3) respectively for winter 2005, and 201.6 and 0.475 microg x m(-3) respectively for spring 2006 on average, resembling those published results. It was indicated that the lead in the PM2.5 existed mainly in insoluble form, which accounted for 78.99%, while water soluble lead and liposoluble lead amount were 20.69% and 0.32%, respectively. The mean values of 206Pb/207Pb ratio for water soluble species and insoluble species were 1.152 6 +/- 0.009 3 and 1.219 3 +/- 0.009 1 respectively, with a significant difference (Student's test; p < 0.01) statically. By comparing 206Pb/207Pb ratios between biological specimen and ambient air samples, the 206Pb/207Pb ratios in water soluble fraction coincided very well with those in adult blood, therefore, water soluble lead but not insoluble lead in PM2.5 may be the potential source of adults blood lead in Beijing. More attention should be paid to the effect of soluble lead in fine particle matters on human health.

  16. The application of lead isotope ratios in the Antarctic macroalga Iridaea cordata as a contaminant monitoring tool.

    PubMed

    Runcie, John W; Townsend, Ashley T; Seen, Andrew J

    2009-07-01

    Lead (Pb) isotope ratios were measured in the marine macroalga Iridaea cordata collected from four locations in the Windmill Islands, East Antarctica. Based on the masses of thalli collected, samples analysed in this study were likely to be a mixture of one and two year old thalli. For a sample of thalli of various ages (<12 months to 2 years old) from the same site there was no apparent variation in Pb concentration or Pb isotope ratio with thallus mass/age, indicating that contaminant sources had been constant over the lifetime of the thalli sampled. I.cordata samples close to the Thala Valley waste disposal site (Brown Bay Inner) near the Australian Station, Casey, displayed isotopic signatures ((208)Pb/(204)Pb 35.99; (206)Pb/(207)Pb 1.066; n=3; average values shown) trending towards that possessed by major Australian Pb sources (Broken Hill and Mt Isa, (208)Pb/(204)Pb 35.60; (206)Pb/(207)Pb 1.041) suggesting that these samples had been exposed to anthropogenic Pb originating from the Thala Valley waste disposal site. Material collected hundreds of metres from the tip location at Brown Bay Outer had isotopic values ((208)Pb/(204)Pb 36.32; (206)Pb/(207)Pb 1.088; n=10) intermediate between Brown Bay Inner and sites further from the contaminant source at Sparkes Bay and Wilkes ((208)Pb/(204)Pb 36.46; (206)Pb/(207)Pb 1.094; n=4) showing that contaminant transport was predominantly restricted to Brown Bay Inner. This study demonstrates that the isotope ratios of Pb in marine macroalgae can provide valuable information as to the origin and extent of heavy metal flux in a marine environment.

  17. Lead

    MedlinePlus

    ... obvious symptoms, it frequently goes unrecognized. CDC’s Childhood Lead Poisoning Prevention Program is committed to the Healthy People ... Lead Levels Information for Parents Tips for preventing lead poisoning About Us Overview of CDC’s Childhood Lead Poisoning ...

  18. Using stable lead isotopes to trace heavy metal contamination sources in sediments of Xiangjiang and Lishui Rivers in China.

    PubMed

    Sun, Guo-Xin; Wang, Xin-Jun; Hu, Qin-Hong

    2011-12-01

    Lead isotopes and heavy metal concentrations were measured in two sediment cores sampled in estuaries of Xiangjiang and Lishui Rivers in Hunan province, China. The presence of anthropogenic contribution was observed in both sediments, especially in Xiangjiang sediment. In the Xiangjiang sediment, the lower (206)Pb/(207)Pb and higher (208)Pb/(206)Pb ratio, than natural Pb isotope signature (1.198 and 2.075 for (206)Pb/(207)Pb and (208)Pb/(206)Pb, respectively), indicated a significant input of non-indigenous Pb with low (206)Pb/(207)Pb and high (208)Pb/(206)Pb. The corresponding concentrations of heavy metals (As, Cd, Zn, Mn and Pb) were much higher than natural values, suggesting the contaminations of heavy metals from extensive ore-mining activities in the region.

  19. [CAIS correction for blood matrix effect on determination of lead concentration and isotope ratio by ICP-MS].

    PubMed

    Zeng, Jing; Wang, Xiao-yan; Liu, Hu-sheng; Dun, Zhe; Zhai, Lei; Wang, Jing-yu

    2007-02-01

    The research studied the influence of matrix effect on the determination of lead concentration and isotope ratio through simulating blood matrix, and its correction by common analyte internal standardization (CAIS) method. The experiment results showed that CAIS method was suitable for the multi-element-matrix. The relative errors between the determined and the true concentration values are 20% (without correction), 8% (by conventional internal reference correction) and 2% (by CAIS correction), respectively. Otherwise, the influence of matrix effect and its correction for isotope ratio determination are not that obvious. Similarity of the mass number and properties between internal reference and analyte elements seems not important for CAIS correction, since very close correction results were obtained by using Tl and Dy as internal reference elements. Besides, correction results are not affected by different matrix dilution. Reliability and practicality of CAIS were proved by bovine blood standard material determination.

  20. Lead Isotopic Compositions of the Endeavour Sulfides, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Labonte, F.; Hannington, M. D.; Cousens, B. L.; Blenkinsop, J.; Gill, J. B.; Kelley, D. S.; Lilley, M. D.; Delaney, J. R.

    2006-12-01

    32 sulfide samples from the main structures of the Endeavour vent field, Juan de Fuca Ridge, were analyzed for their Pb isotope composition. The samples were collected from 6 main vent fields between 1985 and 2005 and encompass a strike length of more than 15 km along the ridge crest. The sulfides are typical of black smoker deposits on sediment-starved mid-ocean ridges. Pb isotope compositions of the massive sulfides within the six hydrothermal fields vary within narrow ranges, with 206Pb/204Pb = 18.58 18.75, 207Pb/204Pb = 15.45 15.53 and 208Pb/204Pb = 37.84 38.10. A geographic trend is observed, with the lower Pb ratios restricted mostly to the northern part of the segment (Salty Dawg, Sasquatch and High Rise fields), and the higher Pb ratios restricted mostly to the southern part of the segment (Main Endeavour, Clam Bed and Mothra fields). Variations within individual fields are much smaller than those between fields, and variation within individual sulfide structures is within the uncertainty of the measurements. Therefore, it is unlikely that the ranges of Pb isotope compositions along the length of the segment reflect remobilization, replacement, and recrystallization of sulfides, as suggested for the observed Pb isotope variability in some large seafloor sulfide deposits. Instead, the differences in isotopic compositions from north to south are interpreted to reflect differences in the source rocks exposed to hydrothermal circulation of fluids below the seafloor. Possible sources of the somewhat more radiogenic Pb may be small amounts of buried sediment, either from turbidites or from hemipelagic sediment. This possibility is supported by high concentrations of CH4 and NHC4 found in the high-temperature vent fluids at the Main Endeavour Field, which are interpreted to reflect subseafloor interaction between hydrothermal fluids and organic material in buried sediments. However, the majority of the samples fall below and are approximately parallel to the

  1. Lead and strontium isotopes in post-glacial basalts from Iceland

    NASA Technical Reports Server (NTRS)

    Sun, S.-S.; Jahn, B.-M.

    1975-01-01

    We report here our Pb and Sr isotopic study of some post-glacial basalts (less than 12,000 yr old) from the southern part of Iceland, and use our new data to evaluate various proposed models for the genesis of volcanic rocks on Iceland. The interpretation for Icelandic rocks is also extended to the genesis of volcanic rocks on other oceanic islands of the world.

  2. The persistence of lead from past gasoline emissions and mining drainage in a large riparian system: Evidence from lead isotopes in the Sacramento River, California

    USGS Publications Warehouse

    Dunlap, C.E.; Alpers, C.N.; Bouse, R.; Taylor, H.E.; Unruh, D.M.; Flegal, A.R.

    2008-01-01

    Lead concentrations and isotope ratios measured in river water colloids and streambed sediment samples along 426 km of the Sacramento River, California reveal that the influence of lead from the historical mining of massive sulfide deposits in the West Shasta Cu-mining district (at the headwaters of the Sacramento River) is confined to a 60 km stretch of river immediately downstream of that mining region, whereas inputs from past leaded gasoline emissions and historical hydraulic Au-mining in the Sierra Nevadan foothills are the dominant lead sources in the remaining 370 km of the river. Binary mixing calculations suggest that more than 50% of the lead in the Sacramento River outside of the region of influence of the West Shasta Cu-mining district is derived from past depositions of leaded gasoline emissions. This predominance is the first direct documentation of the geographic extent of gasoline lead persistence throughout a large riparian system (>160,000 km2) and corroborates previous observations based on samples taken at the mouth of the Sacramento River. In addition, new analyses of sediment samples from the hydraulic gold mines of the Sierra Nevada foothills confirm the present-day fluxes into the Sacramento River of contaminant metals derived from historical hydraulic Au-mining that occurred during the latter half of the 19th and early part of the 20th centuries. These fluxes occur predominantly during periods of elevated river discharge associated with heavy winter precipitation in northern California. In the broadest context, the study demonstrates the potential for altered precipitation patterns resulting from climate change to affect the mobility and transport of soil-bound contaminants in the surface environment. ?? 2008 Elsevier Ltd.

  3. The effect of exposure to employees from mining and milling operations in a uranium mine on lead isotopes--a pilot study.

    PubMed

    Gulson, Brian L; Mizon, Karen J; Dickson, Bruce L; Korsch, Michael J

    2005-03-01

    Potential exposure during mining and milling of uranium ore has resulted in the industry being highly regulated. Exposure can arise from inhalation of the daughter product radioactive gas radon (222Rn), inhalation of radioactive dust particles from mining and milling, direct irradiation from outside the body, and ingestion of radionuclides (e.g. uranium or radium) in food or water. Making use of the highly unusual lead isotopic signature for uranium ores (high 206Pb/204Pb from the high uranium content, low 208Pb/204Pb from the low Th/U ratio), we undertook a pilot study of nine male mine employees and three controls from the Ranger uranium mine in the Northern Territory Australia to determine if it was feasible to use lead isotopes in blood to identify exposure to uranium-derived materials. The lead isotopic data for the mine employees and controls plot in two distinct fields which are consistent with predicted isotopic patterns. Assuming retention of 10% of the ingested lead, then the increases seen in 206Pb represent intakes of between 0.9 and 15 mg, integrated over the years of exposure. The small amount of lead does not affect blood lead concentrations, but appears to be sufficient to be detectable with sensitive isotopic methods. Further studies, including those on urine, should be undertaken to confirm the veracity of the lead isotope method in monitoring exposure of uranium industry employees.

  4. Characteristics of trace elements and lead isotope ratios in PM(2.5) from four sites in Shanghai.

    PubMed

    Chen, Jianmin; Tan, Mingguang; Li, Yulan; Zheng, Jian; Zhang, Yuanmao; Shan, Zuci; Zhang, Guilin; Li, Yan

    2008-08-15

    PM(2.5) samples were collected in Shanghai at four sites with different typical land-uses. The sampling was done concurrently once per month from April 2004 to April 2005, and the ambient mass concentration, the elemental composition and the stable lead isotope ratios in these PM(2.5) samples were determined. The annual average concentrations of PM(2.5) samples at each site were 84+/-30, 65+/-20, 55+/-18, and 41+/-10 microg m(-3), respectively, indicating there were severe air pollution levels in Shanghai. The enrichment factor was calculated for each element and the comparison and discussion of elements with significant anthropogenic contributions between Shanghai and Tokyo suggested that the major source of PM(2.5) in Shanghai was not traffic-derived emissions, but the stationary industrial contribution emitted from coal use. Moreover, the analysis of stable lead isotope ratios revealed only a slight difference within the samples at the four sites which fell well within the scope of coal composition difference, further confirming that the contribution from stationary industrial emissions to atmospheric lead pollution of PM(2.5) was very substantial in Shanghai.

  5. Development of a particulate mass measurement system for tracing pollution sources using atmospheric mercury concentrations and lead isotopes

    NASA Astrophysics Data System (ADS)

    Pierce, A.; Gustin, M. S.; Christensen, J. N.

    2015-12-01

    The Teledyne Advanced Pollution Instrumentation Model 602 BetaPlus (TAPI) particulate measurement system is a unique platform for non-destructive analysis of PM2.5 mass concentration, and destructive analyses of particulate bound mercury (PBM), perhaps gaseous oxidized mercury (GOM), and lead isotopes. Samples were collected at a flow rate of 16.7 Lpm for 24 hours on 47 mm diameter cation exchange membranes (CEM) for mercury (Hg) and Teflon membranes for lead isotopes. We compared total mercury collected on CEM filters from the TAPI to that collected with the UNR active Hg membrane system and a Tekran 2537/1130/1135 system for gaseous Hg at a highway-impacted site (elev. 1370 m) from December 2013 to November 2015. The TAPI and UNR active system were also compared at a high elevation site (elev. 2515 m) adjacent to the highway-impacted site from December 2013 to October 2014. Data collection using the TAPI and UNR active system started in spring and summer of 2015 at Great Basin National Park (GBNP) in eastern Nevada. The UNR active system consists of three CEM and nylon filters (with backups in series to catch break through) sampling at a rate of 1 Lpm for 1-to-4 weeks. A Tekran total Hg system (Model 2600) was used for analyses of CEM filters from the two membrane systems after digestion. Lead isotope samples from the TAPI were analyzed on a multi-collector ICPMS (IsoProbe). Both the TAPI system and the UNR active system should collect reactive mercury (RM=GOM+PBM) on the CEM filters. TAPI measurements differed from those obtained using the Tekran system depending on season at the low elevation site and were lower than the UNR active system at the highway-impacted site and the high elevation site. We hypothesize that, due to the high flow rate and therefore short retention time, the TAPI captures mainly PBM. Lead isotopes and the chemical forms of GOM measured with the UNR active system can be used to track sources, which is important in rural areas such as GBNP.

  6. Determination of lead, uranium, thorium, and thallium in silicate glass standard materials by isotope dilution mass spectrometry

    USGS Publications Warehouse

    Barnes, I.L.; Garner, E.L.; Gramlich, J.W.; Moore, L.J.; Murphy, T.J.; Machlan, L.A.; Shields, W.R.; Tatsumoto, M.; Knight, R.J.

    1973-01-01

    A set of four standard glasses has been prepared which have been doped with 61 different elements at the 500-, 50-, 1-, and 0.02-ppm level. The concentrations of lead, uranium, thorium, and thallium have been determined by isotope dilution mass spectrometry at a number of points in each of the glasses. The results obtained from independent determinations in two laboratories demonstrate the homogeneity of the samples and that precision of the order of 0.5% (95% L.E.) may be obtained by the method even at the 20-ppb level for these elements. The chemical and mass spectrometric procedures necessary are presented.

  7. Genetic interpretation of lead-isotopic data from the Columbia River basalt group, Oregon, Washington, and Idaho.

    USGS Publications Warehouse

    Church, S.E.

    1985-01-01

    Lead-isotopic data for the high-alumina olivine plateau basalts and most of the Colombia River basalt group plot within the Cascade Range mixing array. The data for several of the formations form small, tight clusters and the Nd and Sr isotopic data show discrete variation between these basalt groups. The observed isotopic and trace-element data from most of the Columbia River basalt group can be accounted for by a model which calls for partial melting of the convecting oceanic-type mantle and contamination by fluids derived from continental sediments which were subducted along the trench. These sediments were transported in the low-velocity zone at least 400 km behind the active arc into a back-arc environment represented by the Columbia Plateau province. With time, the zone of melting moved up, resulting in the formation of the Saddle Mt basalt by partial melting of a 2600 m.y.-old sub-continental lithosphere characterized by high Th/U, Th/Pb, Rb/Sr and Nd/Sm ratios and LREE enrichment. Partial melting of old sub-continental lithosphere beneath the continental crust may be an important process in the formation of continental tholeiite flood basalt sequences world-wide. -L.di H.

  8. Historical lead isotope record of a sediment core from the Derwent River (Tasmania, Australia): a multiple source environment.

    PubMed

    Townsend, Ashley T; Seen, Andrew J

    2012-05-01

    A 105 cm sediment core from the Derwent River (Tasmania, Australia) was collected in 2004 and was characterised considering both physical (loss on ignition at 550 °C and grain size) and chemical (Fe, Cu, Zn, Cd and Pb concentrations, Pb isotope ratios and (210)Pb dating) properties. The core was analysed to (i) investigate the historical profiles of some important elements associated with the Risdon zinc refinery adjacent to the Derwent River, (ii) determine Pb isotopic signatures of sediment samples, and (iii) assess the veracity of Pb isotope ratios as indicators of contaminant Pb input. Extractable metal concentrations were (all values as mgkg(-1), non-normalised for grain size) Fe: 20,000-35,000, Zn: 42-4500, Pb: 5-1090, Cu: 13-141, and Cd: 1-31; with a close correlation between Cu, Zn, Cd and Pb. Metal enrichment factors (normalised to Al) were Pb: 0.9-144, Zn: 0.8-93, Cd: 0.8-30, Cu: 0.8-8.9 and Fe: 0.9-1.3, confirming anthropogenic contributions of Cu, Zn, Pb and Cd to the sediments. The onset of metal contamination above background levels occurred at a depth between 43 and 49 cm, with maximum concentrations noted near 20 cm for Cu, Zn, Cd and Pb. Lead isotope ratios were determined in sediments using sector field ICP-MS, and were found to be 36.5-38.8, 16.5-18.7 and 1.07-1.20 for (208)Pb/(204)Pb, (206)Pb/(204)Pb and (206)Pb/(207)Pb ratios, respectively. Major Australian ores processed at the refinery over the previous ~90 years include those from Broken Hill, Rosebery, Mt Isa, Elura, Hellyer and Century deposits. Anthropogenic impact by Pb with Broken Hill type isotopic ratio was initially evident in the core at 43-49 cm. The introduction of Rosebery and Elura ores to the refinery was also clearly noted. Pb isotope ratios further highlight that the Derwent River has been exposed to a greater impact by anthropogenic Pb in comparison to other major Tasmanian rivers, namely the Huon and Tamar.

  9. Spatial Distribution of Lead Isotope Ratios and Inorganic Element Concentrations in Epiphytic Lichens from the Athabasca Oil Sands Region

    NASA Astrophysics Data System (ADS)

    Graney, J. R.; Landis, M. S.; Puckett, K.; Edgerton, E.; Krupa, S.; Percy, K.

    2013-12-01

    Coupled studies of inorganic element concentrations and lead (Pb) isotope ratios have been conducted on Hypogymnia physodes samples collected in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada in 2002, 2008, and 2011. To investigate the spatial extent of air emissions, the lichens were collected from sites as far as 160 km from the mining and processing operations. 30 milligram sub-samples of the lichens were microwave digested, and the extracts were analyzed using DRC-ICPMS to determine elemental concentrations, and sector field ICPMS to measure Pb isotope ratios. Concentrations of elements in the lichens were found to reflect proximity to mining and oil processing sites as well as topography, ecosystem differences, and the metabolic biogeochemistry of the lichens. An exponential decrease in concentration of metals associated with fugitive dust (aluminum and others) versus distance from the mining sites, suggests elevated coarse particle emissions associated with mining operations. Near source concentrations of metals with an oil signature (vanadium and others) are less enhanced and more homogeneous than the metals in the fugitive dust, reflecting emission and deposition of smaller diameter particles at greater distances from oil processing sources. The mining and oil processing signatures are superimposed over elemental concentrations that reflect the nutrient needs of the lichens. These findings are being confirmed through ongoing studies using dichot samplers to collect coarse and fine particulate aerosol samples. The lichen samples collected beyond 50 km from the mining and processing sites cluster into a Pb isotope grouping with a 207Pb / 206Pb ratio of 0.8650 and a 208Pb / 206Pb ratio near 2.095. This grouping likely reflects the regional background Pb isotope ratio signature. 207Pb / 206Pb and 208Pb / 206Pb ratios decrease as one nears the mining and processing operations. This indicates that other Pb source(s), (e.g. Pb in the bitumen from the oil

  10. Lead isotopes as a tracer of Pb origin in the sediments from Beijiang River, South China.

    PubMed

    Gao, Bo; Liang, Xirong; Zhou, Huaidong; Tu, Xianglin

    2012-01-01

    Concentrations and enrichment of heavy metals were determined in sediments collected from Beijiang River, South China. The Pb isotopic compositions in these sediment samples were also employed to effectively identify metal pollution sources. According to the measured Pb concentrations, the total Pb concentrations in sediments varied from 62.1 to 1,152.5 μg/g, with an average concentration of 249.6 μg/g. The assessment by Geoaccumulation Index indicates that Pb is at the 'strongly contaminated' level, indicating that the Pb pollution was mainly due to anthropogenic inputs. The observed isotopic ratios varied from 1.174 to 1.204 for ²⁰⁶Pb/²⁰⁷Pb, 2.452 to 2.478 for ²⁰⁸Pb/²⁰⁷Pb, 18.404 to 18.937 for ²⁰⁶Pb/²⁰⁴Pb, 15.631 to 15.790 for ²⁰⁷Pb/²⁰⁴Pb, 38.455 to 39.121 for ²⁰⁸Pb/²⁰⁴Pb. The majority of these ratios are lower than those reported for natural geological sources, especially for sediments collected from a smelter. Significant correlation between Pb concentration and isotopic ratios suggested possible binary mixing of Pb. Combined with Pb concentration and enrichment levels, our results show that Pb pollution in the sediments of Beijiang River was mainly derived from anthropogenic sources. The mining activities and metal smelting processing was the main source of Pb pollution in this region.

  11. Lead isotopes and the sources of the Columbia River Basalt Group

    NASA Astrophysics Data System (ADS)

    Chamberlain, V. E.; Lambert, R. St. J.

    1994-06-01

    A detailed study of Pb-208/Pb-204, Pb-207/Pb-204, and Pb-206/Pb-204 ratios suggests that the number of Pb isotopic reservoirs required for the Columbia River Basalt Group (CRBG) (as currently defined) must be increased from the presently accepted four to at least six. The identities of the six reservoirs are two of mid-ocean ridge basalt (MORB) slightly contaminated with sediment (R1 and R2, R1 being 'Cascades' PB); one a probable plume component (R3); two of unspecified mantle material but probably of R1 type, contaminated with local crustal Pb (R4 and R5); and the sixth a complex enriched reservoir of 2150 Ma age (R6). R1 is an end-member for all CRBG, except the Saddle Mountains Basalts. R2 is a second end-member for the Picture Gorge Basalt and CRBG, except the Saddle Mountains Basalts. R2 is a second end-member for the Picture Gorge Basalt and appears to be unique to it. R3 is the principal source for most of the Wanapum Basalt, as well as for most of the chemically evolved portions of the Grande Ronde Basalt. Volumetric and tectonic considerations require that one source of the CRBG be a plume or, at least, a nonlocal crustal or uppermost mantle source, and R3 is the ideal candidate for that role. R4 is the second source for the Imnaha Basalt, and R5 is the source for the (206)Pb-rich varieties of the Grande Ronde Basalt. R4 and R5 are identified with contamination by local Phanerozoic crust because of their similarity to local crustal Pb and because the rocks which contain them also have Cu contents correlated with their Pb isotopic compositions. R6 is the parent for Pb in all the Saddle Mountain Basalts. This last source appears to have been homogeneous 2150 m.y. ago but has since split into a number of separate, discrete pockets, each with its own characteristic Pb isotopic signature. Some of these appear in individual Saddle Mountain Basalt flows, while other sources have mixed with R4 to produce individual Saddle Mountain Basalt flows of the Ice Harbor

  12. Mercury, lead and lead isotope ratios in the teeth of moose (Alces alces) from Isle Royale, U.S. Upper Midwest, from 1952 to 2002.

    PubMed

    Vucetich, John A; Outridge, P M; Peterson, Rolf O; Eide, Rune; Isrenn, Rolf

    2009-07-01

    Assessing the effect of recent reductions in atmospheric pollution on metal concentrations in wildlife in North America has been difficult because of the sparse availability of historical samples with which to establish a "pre-regulation" baseline, and because many ecosystems may be affected by local point sources which could obscure broader-scale trends. Here we report a recent 50 yr annual record of Hg, Pb and Pb isotope ratios in the teeth of a resident population of moose (Alces alces) in Isle Royale National Park, a relatively remote island in Lake Superior, Michigan, USA. During the early 1980s, concentrations of tooth Hg abruptly declined by approximately 65% compared to the previous 30 years (p<0.001), similar to a previous study of Hg in herring gull eggs in the Great Lakes region. Lead declined at the same time, and by 2002 Pb in adult moose teeth was approximately 80% lower than it had been prior to the early 1980s (p<0.001). These trends were unaffected by normalization against the geogenic elements La and Sr, which indicates that the trends in Hg and Pb had an anthropogenic cause. Temporal patterns of Pb isotope ratios suggested that the primary sources of Pb at different times in the moose were combustion of U.S. coal and leaded gasoline. Reductions in emissions from coal combustion might explain the co-incident reductions of Hg and Pb in Isle Royale moose, with elimination of alkyl Pb additives also playing a role in the continued tooth Pb reductions after 1983.

  13. Tracing dust transport from Middle-East over Delhi in March 2012 using metal and lead isotope composition

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Aggarwal, S. G.; Malherbe, J.; Barre, J. P. G.; Berail, S.; Gupta, P. K.; Donard, O. F. X.

    2016-05-01

    A severe dust-storm which was originated in Middle-East crossed over Delhi during March 20-22, 2012. We have collected these dust-storm (DS) aerosol samples, and analyzed them for selected metals (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, Se, Sn, Sr, V and Zn) together with after dust-storm (ADS) and winter (WS) samples. High aerosol mass loadings were observed in DS samples (1097-1965 μg/m3). On the contrary, metals derived prominently from the anthropogenic sources were found lower in concentration compared to that of ADS and WS aerosols. We observed significantly high concentrations of Ni and V (which are abundantly found in crude oils of Middle-East origin) in the DS samples than that of ADS and WS samples. Also enrichment factor (EF) of these metals with respect to Fe shows no significant enrichment (<10). Fe (and Sr) concentrations were also 3-5 fold higher in DS samples compared to ADS and WS. These results suggest that Ni and V can be used as tracers for dust aerosols transported from Middle-East region. Lead isotope signatures can tell about the variation in the sources of urban aerosols. Therefore Pb isotope analyses of these samples were performed using MC-ICP-MS. The isotope ratios, 208Pb/206Pb is determined to be (mean ± sd) 2.1315 ± 0.0018, 2.1370 ± 0.0022 and 2.1389 ± 0.0016, whereas 206Pb/207Pb is 1.1311 ± 0.0022, 1.1244 ± 0.0017 and 1.1233 ± 0.0016 in DS, ADS and WS aerosols, respectively. There is a clear distinction in Pb isotope composition between DS and urban (ADS and WS) aerosols. Further, these results suggest that in urban aerosols, Pb is less radiogenic in nature compared to that of in transported dust aerosols collected in New Delhi.

  14. Lead isotope constraints on the origin of andesite and dacite magmas at Tungurahua volcano (Ecuador)

    NASA Astrophysics Data System (ADS)

    Nauret, Francois; Ancellin, Marie-Anne; Vlastelic, Ivan; Tournigand, Pierre-Yves; Samaniego, Pablo; Le Pennec, Jean Luc; Gannoun, Mouhcine; Hidalgo, Silvana; Schiano, Pierre

    2016-04-01

    Understanding the occurrence of large explosive eruptions involving silica-rich magmas at mostly andesitic volcanoes is crucial for volcanic hazard assessment Here we focus on the well-known active Tungurahua volcano (Ecuador), specifically its eruptive sequence for the last 3000 years BP, which are characterized by VEI 3 explosive events involving mostly homogeneous andesitic compositions (56-59 wt.% SiO2). However, some large eruptions (VEI ≥ 4) involving andesitic and dacitic magmas (up to 66 wt.% SiO2) also occur at 3000 BP, 1250 BP and 1886 AD. An additional outburst of siliceous magmas occurred during the last eruptive eruption of this volcano in 2006 [1]. Volcanic products at Tungurahua are described as been generated by a binary mixing between a silica-rich and a silica-poor end-member, but the origin of these components was not discussed [2]. Major, trace elements and Sr-Nd-Pb isotopes were used to investigate the genesis of the andesites and dacites. Andesites are heterogeneous in terms of Pb isotopes (206Pb/204Pb: 18.189-19.154, 207Pb/204Pb:15.658-15.696, 208Pb/204Pb: 38.752-38.918, 207Pb/206Pb: 0.8240-0.8275) but homogeneous in terms of major-trace element. Dacite are characterized by homogenous and low 207Pb/206Pb (0.8235±0.0001), very low Nb/U (1.97 to 4.49) and Ce/Pb (2.52-2.99) and high Th/La ratios (0.24 to 0.49). Triangular distribution of data in major element or trace element ratio vs. Pb isotopes plots suggests that at least three components control geochemical variability at Tungurahua. We interpret andesite compositions as reflecting mainly a deep mixture of two mantle components, with small addition of crustal material. We suggest that dacite results from a mixing between various andesite compositions and a larger amount of a contaminant derived from the volcanic basement of the Tungurahua made of late Cretaceous to Palaeogene oceanic plateau basalts and volcano-sedimentary rocks volcanic. Since andesite and dacite occur during the same

  15. [High-precision in situ analysis of the lead isotopic composition in copper using femtosecond laser ablation MC-ICP-MS and the application in ancient coins].

    PubMed

    Chen, Kai-Yun; Fan, Chao; Yuan, Hong-Lin; Bao, Zhi-An; Zong, Chun-Lei; Dai, Meng-Ning; Ling, Xue; Yang, Ying

    2013-05-01

    In the present study we set up a femtosecond laser ablation MC-ICP-MS method for lead isotopic analysis. Pb isotopic composition of fifteen copper (brass, bronze) standard samples from the National Institute of Standards Material were analyzed using the solution method (MC-ICP-MS) and laser method (fLA-MC-ICPMS) respectively, the results showed that the Pb isotopic composition in CuPb12 (GBW02137) is very homogeneous, and can be used as external reference material for Pb isotopic in situ analysis. On CuPb12 112 fLA-MC-ICPMS Pb isotope analysis, the weighted average values of the Pb isotopic ratio are in good agreement with the results analyzed by bulk solution method within 2sigma error, the internal precision RSEs of the 208 Pb/204 Pb ratio and 207 Pb/206 Pb ratio are less than 90 and 40 ppm respectively, and the external precision RSDs of them are less than 60 and 30 ppm respectively. Pb isotope of thirteen ancient bronze coins was analyzed via fLA-MC-ICPMS, the results showed that the Pb isotopic composition of ancient coins of different dynasties is significantly different, and not all the Pb isotopic compositions in the coins even from the same dynasty are in agreement with each other.

  16. Lead isotopes in North Pacific deep water - Implications for past changes in input sources and circulation patterns

    USGS Publications Warehouse

    van de Flierdt, T.; Frank, M.; Halliday, A.N.; Hein, J.R.; Hattendorf, B.; Gunther, D.; Kubik, P.W.

    2003-01-01

    The sources of non-anthropogenic Pb in seawater have been the subject of debate. Here we present Pb isotope time-series that indicate that the non-anthropogenic Pb budget of the northernmost Pacific Ocean has been governed by ocean circulation and riverine inputs, which in turn have ultimately been controlled by tectonic processes. Despite the fact that the investigated locations are situated within the Asian dust plume, and proximal to extensive arc volcanism, eolian contributions have had little impact. We have obtained the first high-resolution and high-precision Pb isotope time-series of North Pacific deep water from two ferromanganese crusts from the Gulf of Alaska in the NE Pacific Ocean, and from the Detroit Seamount in the NW Pacific Ocean. Both crusts were dated applying 10 Be/9Be ratios and yield continuous time-series for the past 13.5 and 9.6 Myr, respectively. Lead isotopes show a monotonic evolution in 206Pb/204Pb from low values in the Miocene (??? 18.57) to high values at present day (??? 18.84) in both crusts, even though they are separated by more than 3000 km along the Aleutian Arc. The variation exceeds the amplitude found in Equatorial Pacific deep water records by about three-fold. There also is a striking similarity in 207Pb/204Pb and 208Pb/ 204Pb ratios of the two crusts, indicating the existence of a local circulation cell in the sub-polar North Pacific, where efficient lateral mixing has taken place but only limited exchange (in terms of Pb) with deep water from the Equatorial Pacific has occurred. Both crusts display well-defined trends with age in Pb-Pb isotope mixing plots, which require the involvement of at least four distinct Pb sources for North Pacific deep water. The Pb isotope time-series reveal that eolian supplies (volcanic ash and continent-derived loess) have only been of minor importance for the dissolved Pb budget of marginal sites in the deep North Pacific over the past 6 Myr. The two predominant sources have been young

  17. Pb-Bi-Ag-Cu-(Hg) chemistry of galena and some associated sulfosalts. A review and some new data from Colorado California and Pennsylvania

    USGS Publications Warehouse

    Foord, Eugene E.; Shawe, Daniel R.

    1989-01-01

    Galena, associated with Pb-Bi-Ag sulfosalts and simple sulfides, contains varied amounts of Ag and Bi in the Dandy vein system, Idarado mine, Ouray, Colorado; the Jackass mine, Darwin District, California; and the Leadville district, Colorado. Silver- and bismuth-bearing galena associated with minor amounts of pyrite, chalcopyrite and sphalerite occur at the Pequea mine, Lancaster County, Pennsylvania. Ag and Bi contents in the Dandy suite of galena range from about 1.4 to 3.4 and 2.5 to 6.5 wt.% respectively, and are comparable or lower in galena from the other localities. Exsolved matildite is present in galena from the Dandy, Jackass and Leadville localities. The presence in significant amounts of both Ag and Bi in a Pb-rich sulfide system is necessary for formation of PbSss (galena solid-solution). If Ag (especially) and Bi (to a lesser extent) are absent, the galena formed will be essentially pure PbS. Some minor Sb may substitute for Bi. Compositional data for all of the galena samples are in agreement with a previously proposed linear relationship between a and Ag-Bi(Sb) content. Matildite and seven additional Pb-Bi-Ag-Cu sulfosalts have been identified from the Dandy vein system, based on electron-microprobe analyses and some X-ray powder-diffraction data.

  18. The End of Superdeformation: De-excitation to Spherical States in Lead Isotopes

    NASA Astrophysics Data System (ADS)

    Cizewski, Jolie A.

    1997-04-01

    Numerous examples of superdeformed rotational bands at high angular momenta have been observed in medium and heavy mass nuclei. The A ~190 region has been especially rich - superdeformed (SD) excitations have been identified in at least 22 isotopes and a large fraction of these bands have γ-ray energies which are simply related. However, the fundamental properties of excitation energy and spin-parity have only recently between determined. The first candidate for a discrete transition which links the SD band to ``normal" deformed (ND) excitations was observed in ^194Pb.(M. J. Brinkman, et al., Phys. Rev. C53), R1461 (1996). Subsequently, many transitions which connect SD and ND excitations in ^194Hg were observed, which allowed the determination of the excitation energy and spin.footnote T. L. Khoo, et al., Phys. Rev. Lett. 76, 1583 (1996). In ^194Pb as many as 12 discrete transitionsfootnote A. Lopez-Martens, et al., Phys. Lett. B380, 18 (1996) and K. Hauschild, et al., Phys. Rev. C (1996). have now been identified with the Eurogam or Gammasphere arrays of γ-ray detectors. This has allowed model-independent determinations of the excitation energy, spin, and parity of these states. The decay of the SD to ND states has been suggested to proceed via mixing between SD and ND excitations with similar excitation energies and angular momenta,(E. Vigezzi, et al., Phys. Lett. B249), 163 (1990). and allows a probe of the complex character of excitations at moderate temperatures in the ND well. In addition, the quasi-continuous spectrum of transitions which link SD and ND excitations can be used to probe level density and pairing degrees of freedom in hot, ND nuclei.footnote T. Dossing, et al., Phys. Rev. Lett. 75, 1276 (1995); A. Lopez-Martens, et al., PRL 77, 1707 (1996); and D.P. McNabb, et al., BAPS 41, 1237 (1996). Studies of the deexcitation of SD bands will be reviewed with a focus on the Pb isotopes.

  19. Hydrologic Effects of the 1988 Galena Fire, Black Hills Area, South Dakota

    USGS Publications Warehouse

    Driscoll, Daniel G.; Carter, Janet M.; Ohlen, Donald O.

    2004-01-01

    The Galena Fire burned about 16,788 acres of primarily ponderosa pine forest during July 5-8, 1988, in the Black Hills area of South Dakota. The fire burned primarily within the Grace Coolidge Creek drainage basin and almost entirely within the boundaries of Custer State Park. A U.S. Geological Survey gaging station with streamflow records dating back to 1977 was located along Grace Coolidge Creek within the burned area. About one-half of the gaging station's 26.8-square-mile drainage area was burned. The drainage basin for Bear Gulch, which is tributary to Grace Coolidge Creek, was burned particularly severely, with complete deforestation occurring in nearly the entirety of the area upstream from a gaging station that was installed in 1989. A study to evaluate effects of the Galena Fire on streamflow, geomorphology, and water quality was initiated in 1988. The geomorphologic and water-quality components of the study were completed by 1990 and are summarized in this report. A data-collection network consisting of streamflow- and precipitation-gaging stations was operated through water year 1998 for evaluation of effects on streamflow characteristics, including both annual-yield and peak-flow characteristics, which are the main focus of this report. Moderately burned areas did not experience a substantial increase in the rate of surface erosion; however, severely burned areas underwent surficial erosion nearly twice that of the unburned areas. The sediment production rate of Bear Gulch estimated 8 to 14 months after the fire was 870 ft3/acre (44 tons/acre). Substantial degradation of stream channels within the severely burned headwater areas of Bear Gulch was documented. Farther downstream, channel aggradation resulted from deposition of sediments transported from the headwater areas. The most notable water-quality effect was on concentrations of suspended sediment, which were orders of magnitude higher for Bear Gulch than for the unburned control area. Effects on

  20. ICP-MS determination of lead isotope ratios in legal and counterfeit cigarette tobacco samples.

    PubMed

    Judd, Christopher D; Swami, Kamal

    2010-12-01

    A method for the determination of Pb isotope ratios (IR) in cigarette tobacco by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) has been developed and applied to tobacco samples from genuine and counterfeit cigarettes obtained in the USA. The IR ²⁰⁷Pb/²⁰⁶Pb, (208)Pb/²⁰⁶Pb, ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb were measured using a Q-ICP-MS instrument. Two certified reference materials, grown in the USA and Bulgaria, were also analysed for comparison with the tobacco samples, as were tobacco samples from cigarettes obtained in Pakistan and China. The precision of the results was sufficient to distinguish between the counterfeit and genuine USA cigarettes. All of the genuine cigarettes and both reference materials, grown in different regions, were statistically distinct based on the measured ratios. The counterfeit cigarettes were indistinguishable from the reference material grown in Bulgaria. The technique shows promise as a method for identifying counterfeit cigarettes, possibly determining the source region.

  1. Lead Isotope Measurement by Lead Double Spike and Thallium Spike Using MC-ICP-MS and TIMS - a Comparison Using Basaltic Samples

    NASA Astrophysics Data System (ADS)

    Taylor, R. N.; Ishizuka, O.

    2001-12-01

    Multi-collector ICP-MS has provided a new level of precision to lead isotope analysis using Thallium addition as an internal mass bias monitor. Further enhancement of precision has been achieved by the application of double lead spike to measurement procedures. In this study, we directly compare results using thallium addition and the new SBL74 double lead spike on both TIMS and MC-ICP-MS (Micromass IsoProbe). The comparisons are performed using standard Pb solutions and basaltic matrix-bearing solutions. Analyses of standards measured over 8 analytical sessions using the thallium spike method are reproducible to within 100 ppm for 206Pb/204Pb, 130 ppm for 207Pb/204Pb and 220 ppm (2sd) for 208Pb/204Pb. If the ratios for individual analytical sessions are normalised to the SRM981{day average}/SRM981true the increasing error with greater mass difference of the ratio is eliminated and all ratios are less than ±85 ppm. This implies that variability between the Tl and Pb mass bias factors on a day-to-day basis is the cause of increasing imprecision with mass difference. Double spike MC-ICP-MS is found to produce similar levels of precision to the Tl method for standards. However, the decreasing precision with increasing mass difference is greatly reduced, indicating that the correlation is due to Tl and Pb differences. With basaltic matrix samples with a single anion exchange separation, the effects of Tl-Pb differential mass bias are slightly exaggerated. We present the results from mixtures of SRM981 with Pb-free Fe measured using MC-ICP-MS using Tl and double spike mass bias correction, to replicate the basaltic matrix analyses.

  2. Evaluation of particle dispersal from mining and milling operations using lead isotopic fingerprinting techniques, Rio Pilcomayo Basin, Bolivia.

    PubMed

    Miller, Jerry R; Lechler, Paul J; Mackin, Gail; Germanoski, Dru; Villarroel, Lionel F

    2007-10-01

    Mining and milling of ores from the Cerro Rico de Potosí precious metal-polymetallic tin deposits of Bolivia have led to severe contamination of water and sediments of the Rio Pilcomayo drainage system. Lead (Pb) isotopic data were used in this study to first document downstream dispersal patterns of Pb contaminated sediment within the channel of the Rio Pilcomayo, and then to determine the relative contribution of Pb from Cerro Rico within alluvial terrace soils that are used for agriculture. The concentration and isotopic composition of Pb within channel bed sediments differed significantly between 2000, 2002, and 2004. These differences presumably reflect changes in the type of ore mined and milled at Cerro Rico, and alterations in dispersal and grain-size dilution mechanisms associated with interannual variations in rainfall and runoff. Within agricultural terrace soils, both Pb concentrations and the percentage of Pb from Cerro Rico: (1) semi-systematically decrease downstream, (2) were found to decrease with terrace height above the channel, and (3) reflect the use of contaminated irrigation water. In upstream reaches (within 30 km of the mills), Pb from mining represents the most significant Pb source, accounting for more than 80% of Pb in the examined agricultural fields. At Sotomayor, located approximately 170 km from the mills, the relative contribution of Pb from Cerro Rico is highly variable between fields, but can be significant, ranging from approximately 15% to 35%. The analysis demonstrates that Pb isotopic ratios can be used to effectively trace contaminated particles through river systems and into adjacent alluvial soils, even where multiple Pb sources exist and Pb concentrations are similar to background values.

  3. Metal enrichment and lead isotope analysis for source apportionment in the urban dust and rural surface soil.

    PubMed

    Yu, Yang; Li, Yingxia; Li, Ben; Shen, Zhenyao; Stenstrom, Michael K

    2016-09-01

    To understand the metal accumulation in the environment and identify its sources, 29 different metal contents and lead (Pb) isotope ratios were determined for 40 urban dust samples, 36 surface soil samples, and one river sediment sample collected in the municipality of Beijing, China. Results showed that cadmium, copper (Cu), mercury, Pb, antimony (Sb), and zinc demonstrated to be the typical urban contaminants and mostly influenced by the adjacent human activities with higher content to background ratios and SD values. Among the 29 metal elements investigated, Cu and Sb were found to be the most distinct elements that were highly affected by the developing level and congestion status of the cities with much higher contents in dust in more developed and congested cities. There was a relatively wider range of Pb isotope ratios of country surface soil than those of urban dust. The results of source identification based on Pb isotope ratios showed that coal combustion was the first largest Pb source and vehicle exhaust was the second largest source. The sum of them accounted for 74.6% mass proportion of overall Pb pollution on average. The surface soil sample collected at an iron mine had the highest (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios indicating ore had much higher ratios than other sources. The fine particle subsamples had higher (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios than the coarse particle subsamples indicating more anthropogenic sources of coal combustion and vehicle exhaust for fine particles and more background influence for coarse particles. These results help with pinpointing the major Pb sources and applying suitable measures for the target sources. PMID:27376990

  4. Understanding the remobilization of copper, zinc, cadmium and lead due to ageing through sequential extraction and isotopic exchangeability.

    PubMed

    Kumar, Manish

    2016-06-01

    Artificial infiltration facilities (AIFs) are useful to control urban runoff and regulate combined sewer overflows. Over the years, AIFs accumulate significant amounts of soakaway sediments and organic matter. The prolonged retention of soakaway sediments in AIFs is likely to cause metal remobilization due to ageing processes. The measurement of the individual consequence of ageing demands homogeneity in physical and chemical profiles of samples. This leads to assessment of metal remobilization in a single soil core through solid-phase extractions and isotopic exchangeability (E value). Depth-wise variation in the physicochemical properties and metal content of the underlying soil (below 1 m of AIFs) was created through 2 weeks of continuous leaching with artificial road runoff (ARR). Ten samples obtained from a 50-cm core by sectioning it at 5-cm intervals were subsequently incubated for 18 months. The results suggest that degradation of organic matter and changes in functional groups due to ageing govern metal remobilization. In general, the top segment showed significant alteration due to ageing. Post incubation, Zn increased dramatically in contrast to subdued Cu and Pb levels in exchangeable fractions with concomitant rise in organic-bound fractions. Isotopic exchangeability of Cd and Zn showed pronounced effect of ageing, although the effect of ageing was distinct in chemical partitioning and isotopic exchangeability of metals; a comparative study of short-term versus long-term incubation will benefit assessment of initial dynamics and final equilibrium. Consequently, the outcome from this work is a viable tool in risk prediction related to soakaway sediment accumulation in AIF. PMID:27236447

  5. Lead isotopes and trace metal ratios of aerosols as tracers of Pb pollution sources in Kanpur, India

    NASA Astrophysics Data System (ADS)

    Sen, Indra; Bizimis, Michael; Tripathi, Sachchida; Paul, Debajyoti; Tyagi, Swati; Sengupta, Deep

    2015-04-01

    The anthropogenic flux of Pb in the Earth's surface is almost an order of magnitude higher than its corresponding natural flux [1]. Identifying the sources and pathways of anthropogenic Pb in environment is important because Pb toxicity is known to have adverse effects on human health. Pb pollution sources for America, Europe, and China are well documented. However, sources of atmospheric Pb are unknown in India, particularly after leaded gasoline was phased out in 2000. India has a developing economy with a rapidly emerging automobile and high temperature industry, and anthropogenic Pb emission is expected to rise in the next decade. In this study, we report on the Pb- isotope compositions and trace metal ratios of airborne particulates collected in Kanpur, an industrial city in northern India. The Pb concentration in the airborne particulate matter varies between 14-216 ng/m3, while the other heavy metals vary by factor of 10 or less, e.g. Cd=0.3-3 ng/m3, As=0.4-3.5 ng/m3, Zn=36-161 ng/m3, and Cu=3-22 ng/m3. The 206Pb/207Pb, 208Pb/206Pb, and 208Pb/207Pb vary between 1.112 - 1.129, 2.123-2.141, and 2.409-2.424 respectively, and are highly correlated with each other (R2>0.9). Pb isotopes and trace metal data reveals that coal combustion is the major source of anthropogenic Pb in the atmosphere, with limited contribution from mining and smelting processes. We further conclude that combination of Pb isotope ratios and V/Pb ratios are powerful tracers for Pb source apportionment studies, which is otherwise difficult to differentiate based only on Pb systematics [1] Sen and Peucker-Ehrenbrink (2012), Environ. Sci. Technol.(46), 8601-8609

  6. Metal enrichment and lead isotope analysis for source apportionment in the urban dust and rural surface soil.

    PubMed

    Yu, Yang; Li, Yingxia; Li, Ben; Shen, Zhenyao; Stenstrom, Michael K

    2016-09-01

    To understand the metal accumulation in the environment and identify its sources, 29 different metal contents and lead (Pb) isotope ratios were determined for 40 urban dust samples, 36 surface soil samples, and one river sediment sample collected in the municipality of Beijing, China. Results showed that cadmium, copper (Cu), mercury, Pb, antimony (Sb), and zinc demonstrated to be the typical urban contaminants and mostly influenced by the adjacent human activities with higher content to background ratios and SD values. Among the 29 metal elements investigated, Cu and Sb were found to be the most distinct elements that were highly affected by the developing level and congestion status of the cities with much higher contents in dust in more developed and congested cities. There was a relatively wider range of Pb isotope ratios of country surface soil than those of urban dust. The results of source identification based on Pb isotope ratios showed that coal combustion was the first largest Pb source and vehicle exhaust was the second largest source. The sum of them accounted for 74.6% mass proportion of overall Pb pollution on average. The surface soil sample collected at an iron mine had the highest (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios indicating ore had much higher ratios than other sources. The fine particle subsamples had higher (204)Pb/(206)Pb, (207)Pb/(206)Pb, and (208)Pb/(206)Pb ratios than the coarse particle subsamples indicating more anthropogenic sources of coal combustion and vehicle exhaust for fine particles and more background influence for coarse particles. These results help with pinpointing the major Pb sources and applying suitable measures for the target sources.

  7. Black Carbon, Metal Concentrations and Lead Isotopes Ratios in Aerosols as Tracers of Human and Natural Activities in Northern Vietnam

    NASA Astrophysics Data System (ADS)

    Guinot, B. P.

    2015-12-01

    Atmospheric brown clouds (ABC) observed as widespread layers of brownish haze are regional scale plumes of air pollutants with a hot spot of emission located in East Asia. ABC are mainly composed of aerosol particles such as Black Carbon (BC) emitted to the atmosphere during biomass burning and fossil fuels combustion. The atmospheric lifetime of BC ranges from a few days in wet season up to one month in dry season. The use of stable lead isotopes and 21 elements as tracers of air pollution was applied to identify and characterized the main sources of anthropogenic activities in Asian region. Aerosol samples from Haiphong (North Vietnam) were collected by a high volume sampler for a period of one year from October 2012 to October 2013. Vietnam's 207Pb/206Pb ratios were almost identical to those found for China. Ratios of 207Pb/206Pb ranged from 0.837 to 0.871 which agrees with values previously reported for the last 10 years in China (0.841 - 0.879). No significant variation in isotope ratio was observed during the sampling period, which suggests that there was no large seasonal variation in the isotope ratios of airborne lead. Trajectory analysis showed that almost two third of the air masses originated from East Northeast which implies that China was a major source of lead in atmosphere. Enrichment factor calculations indicated a large influence of coal activity (EF(Al) As = 1982 ± 796, EF(Al) Cd = 972 ± 659, EF(Al) Sb = 1358 ± 930) but the difference between combustion and mining exploitation could not be evidenced. Significant correlations were found between two others groups of elements: As, Cu, Ni, Zn, and Al, Fe K, Co. Wind dilution was effective on metals concentration variation. During the cold and dry season (winter) ambient concentrations were high and variable, during the warm and wet season (summer) concentrations were stable and low. Taken together, these factors also identified industrial and lithogenic activities in the region.

  8. Stable isotopes of lead and strontium as tracers of sources of airborne particulate matter in Kyrgyzstan

    EPA Science Inventory

    Central Asia is dominated by an arid climate and desert-like conditions, leading to the potential for long-range transport of desert dust within and out of the region. Of particular interest is the Aral Sea, which has receded in size largely due to water diversion. As a result, n...

  9. Stable isotopes of lead and strontium as tracers of sources of airborne particulate matter in Kyrgyzstan.

    EPA Science Inventory

    Central Asia is dominated by an arid climate and desert-like conditions, leading to the potential of long-range transport of desert dust. One potential source of dust to Central Asia is the Aral Sea, the surface area of which has receded in size from 68,000 km2 to 14,280 km2, lar...

  10. The isotopic composition of lead in potassium feldspars from some 1.0-b.y. old North American igneous rocks

    USGS Publications Warehouse

    Zartman, R.E.; Wasserburg, G.J.

    1969-01-01

    The isotopic composition of lead and the uranium, thorium and lead concentrations in potassium feldspars are determined for more than 30 1.0-b.y. old North American igneous rocks. Samples representing a broad spectrum in petrographic type and mode of occurrence were chosen; an effort was made to include only rocks having well-documented ages from 950 to 1140 m.y. and showing minimal evidence of subsequent metamorphism. Most samples, including those from extensive terranes of contemporaneous age, have limited lead isotope variations ( Pb206 Pb204 = 16.74-17.38; Pb207 Pb204 = 15.39-15.59; Pb208 Pb204 = 36.38-37.10), which yield model ages close to the radiometric ages. Granite, pegmatite, and rhyolite from within the Grenville province of Canada and age-equivalent rocks of New York, Virginia, Texas, and Colorado and granophyric units associated with the Duluth Gabbro Complex of Minnesota are among the materials yielding this main isotopic spectrum. Several samples were encountered which had isotopic compositions very different from the above group. Lead showing a marked deficiency in radiogenic isotopes was found in two granitic bodies associated with older Labrador Trough rocks from Quebec, in a rapakivi granite from southern Nevada, and in a small granite stock from Mellen, Wisconsin. These occurrences all involve small intrusions of granite which lie near considerably older areas of basement rock. Model ages calculated from the Pb206 Pb204 ratio are older than the age of the intrusions and approach the age of the host basement rock. Several possible interpretations are offered to explain the isotopic behavior encountered in this study. In particular, a "vertically differentiated crust" model is proposed which will account for both the main spectrum and the anomalous lead. The significance of lead isotopic studies in understanding crustal structure in continental regions is discussed. ?? 1969.

  11. Temporal evolution of lead isotope ratios in sediments of the Central Portuguese Margin: a fingerprint of human activities.

    PubMed

    Mil-Homens, Mário; Caetano, Miguel; Costa, Ana M; Lebreiro, Susana; Richter, Thomas; de Stigter, Henko; Trancoso, Maria A; Brito, Pedro

    2013-09-15

    Stable Pb isotope ratios ((206)Pb/(207)Pb, (208)Pb/(206)Pb), (210)Pb, Pb, Al, Ca, Fe, Mn and Si concentrations were measured in 7 sediment cores from the west coast of the Iberian Peninsula to assess the Pb contamination throughout the last 200 years. Independently of their locations, all cores are characterized by increasing Pb/Al rends not related to grain-size changes. Conversely, decreasing trends of (206)Pb/(207)Pb were found towards the present. This tendency suggest a change in Pb sources reflecting an increased proportion derived from anthropogenic activities. The highest anthropogenic Pb inventories for sediments younger than 1950s were found in the two shallowest cores of Cascais and Lisboa submarine canyons, reflecting the proximity of the Tagus estuary. Lead isotope signatures also help demonstrate that sediments contaminated with Pb are not constrained to estuarine-coastal areas and upper parts of submarine canyons, but are also to transferred to a lesser extent to deeper parts of the Portuguese Margin.

  12. Temporal evolution of lead isotope ratios in sediments of the Central Portuguese Margin: a fingerprint of human activities.

    PubMed

    Mil-Homens, Mário; Caetano, Miguel; Costa, Ana M; Lebreiro, Susana; Richter, Thomas; de Stigter, Henko; Trancoso, Maria A; Brito, Pedro

    2013-09-15

    Stable Pb isotope ratios ((206)Pb/(207)Pb, (208)Pb/(206)Pb), (210)Pb, Pb, Al, Ca, Fe, Mn and Si concentrations were measured in 7 sediment cores from the west coast of the Iberian Peninsula to assess the Pb contamination throughout the last 200 years. Independently of their locations, all cores are characterized by increasing Pb/Al rends not related to grain-size changes. Conversely, decreasing trends of (206)Pb/(207)Pb were found towards the present. This tendency suggest a change in Pb sources reflecting an increased proportion derived from anthropogenic activities. The highest anthropogenic Pb inventories for sediments younger than 1950s were found in the two shallowest cores of Cascais and Lisboa submarine canyons, reflecting the proximity of the Tagus estuary. Lead isotope signatures also help demonstrate that sediments contaminated with Pb are not constrained to estuarine-coastal areas and upper parts of submarine canyons, but are also to transferred to a lesser extent to deeper parts of the Portuguese Margin. PMID:23871578

  13. Lead isotope compositions of Late Cretaceous and early Tertiary igneous rocks and sulfide minerals in Arizona: Implications for the sources of plutons and metals in porphyry copper deposits

    USGS Publications Warehouse

    Bouse, R.M.; Ruiz, J.; Titley, S.R.; Tosdal, R.M.; Wooden, J.L.

    1999-01-01

    Porphyry copper deposits in Arizona are genetically associated with Late Cretaceous and early Tertiary igneous complexes that consist of older intermediate volcanic rocks and younger intermediate to felsic intrusions. The igneous complexes and their associated porphyry copper deposits were emplaced into an Early Proterozoic basement characterized by different rocks, geologic histories, and isotopic compositions. Lead isotope compositions of the Proterozoic basement rocks define, from northwest to southeast, the Mojave, central Arizona, and southeastern Arizona provinces. Porphyry copper deposits are present in each Pb isotope province. Lead isotope compositions of Late Cretaceous and early Tertiary plutons, together with those of sulfide minerals in porphyry copper deposits and of Proterozoic country rocks, place important constraints on genesis of the magmatic suites and the porphyry copper deposits themselves. The range of age-corrected Pb isotope compositions of plutons in 12 Late Cretaceous and early Tertiary igneous complexes is 206Pb/204Pb = 17.34 to 22.66, 207Pb/204Pb = 15.43 to 15.96, and 208Pb/204Pb = 37.19 to 40.33. These Pb isotope compositions and calculated model Th/U are similar to those of the Proterozoic rocks in which the plutons were emplaced, thereby indicating that Pb in the younger rocks and ore deposits was inherited from the basement rocks and their sources. No Pb isotope differences distinguish Late Cretaceous and early Tertiary igneous complexes that contain large economic porphyry copper deposits from less rich or smaller deposits that have not been considered economic for mining. Lead isotope compositions of Late Cretaceous and early Tertiary plutons and sulfide minerals from 30 metallic mineral districts, furthermore, require that the southeastern Arizona Pb province be divided into two subprovinces. The northern subprovince has generally lower 206Pb/204Pb and higher model Th/U, and the southern subprovince has higher 206Pb/204Pb and

  14. Lead pollution in subtropical ecosystems on the SE Gulf of California Coast: a study of concentrations and isotopic composition.

    PubMed

    Soto-Jiménez, Martin F; Páez-Osuna, Federico; Scelfo, Genine; Hibdon, Sharon; Franks, Rob; Aggarawl, Jugdeep; Flegal, A Russell

    2008-10-01

    Lead pollution was investigated in environmental matrices and biological indicators collected from two typical subtropical coastal ecosystems in the southeast Gulf of California, Mexico. Lead concentrations and isotopic compositions ((206)Pb/(207)Pb and (208)Pb/(207)Pb) were measured using high resolution inductively-coupled plasma-mass spectrometry (HR-ICP-MS) and thermal ionization mass spectrometry (TIMS), respectively. Lead in surface estuary sediments (10.0-34.2microgg(-1)) and particulate Pb (25.0-128.7microgg(-1), >98% of total Pb) in the water column were significantly higher than levels in natural bedrock soils (15.1+/-8.3microgg(-1)) and river runoff (1.9+/-1.4microgg(-1)). Aquatic plants had Pb concentrations between 2.5 and 7.2microgg(-1), while those in macroalgae ranged from 3 to 5microgg(-1). The ranges of mean Pb concentrations in the aquatic animals studied (ranges in microgg(-1)) were as follows: zooplankton 32+/-3, mussels 2.3-3.9, oysters 1.9-7.9, snail 2.0-7.7, barnacles 0.1-18.5, fish 1.4-8.9, crab 6.3-40.2 and polychaetae 8.5-16.7. Pb values in 20-40% of oyster and fish samples and in all samples of crab exceeded acceptable levels for a food source for human consumption. Pb isotope ratios (206)Pb/(207)Pb, (208)Pb/(207)Pb in biota ranged from 1.188 to 1.206 and 2.448 to 2.470, respectively. A plot of (206)Pb/(207)Pb versus (208)Pb/(207)Pb for the environmental and biological samples collected from two study areas indicates that they contain lead from ores mined in Mexico and used in the past to produce leaded gasoline in use until 1997, natural Pb weathered from the Sierra Madre Occidental mother rock, and the later influence of inputs from a more radiogenic source related to industrial activity in the United States. Statistical software IsoSource results revealed that the Pb contained in environmental matrices and biomonitors is mostly derived from gasoline (20-90%) and US emissions (10-40%).

  15. Isotopic characterisation of lead in contaminated soils from the vicinity of a non-ferrous metal smelter near Plovdiv, Bulgaria.

    PubMed

    Bacon, Jeffrey R; Dinev, Nikolai S

    2005-03-01

    Soil samples from the vicinity of a non-ferrous metal smelter near Plovdiv, Bulgaria contained very high concentrations of cadmium, lead and zinc (up to 140, 4900 and 5900 mg kg(-1), respectively). A roadside soil in a relatively uncontaminated area also contained high concentrations of the same metals (24, 1550 and 1870 mg kg(-1), respectively) indicating that the transport of ores could be a source of contamination. Even though the lead isotope ratios in all the samples fell within a very narrow range (for example, 1.186-1.195 for (206)Pb/(207)Pb), the samples could be differentiated into three distinct groups: ores ((206)Pb/(207)Pb and (208)Pb/(207)Pb ratios of 1.1874-1.1884 and 2.4755-2.4807, respectively), current deposition (1.1864 and 2.4704-2.4711, respectively) and local background (1.1927-1.1951 and 2.4772-2.4809, respectively). Although most of the current deposition has its origin in the ores used at the smelter, up to 12% could be from other sources such as petrol lead.

  16. Automated method for simultaneous lead and strontium isotopic analysis applied to rainwater samples and airborne particulate filters (PM10).

    PubMed

    Beltrán, Blanca; Avivar, Jessica; Mola, Montserrat; Ferrer, Laura; Cerdà, Víctor; Leal, Luz O

    2013-09-01

    A new automated, sensitive, and fast system for the simultaneous online isolation and preconcentration of lead and strontium by sorption on a microcolumn packed with Sr-resin using an inductively coupled plasma mass spectrometry (ICP-MS) detector was developed, hyphenating lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA). Pb and Sr are directly retained on the sorbent column and eluted with a solution of 0.05 mol L(-1) ammonium oxalate. The detection limits achieved were 0.04 ng for lead and 0.03 ng for strontium. Mass calibration curves were used since the proposed system allows the use of different sample volumes for preconcentration. Mass linear working ranges were between 0.13 and 50 ng and 0.1 and 50 ng for lead and strontium, respectively. The repeatability of the method, expressed as RSD, was 2.1% and 2.7% for Pb and Sr, respectively. Environmental samples such as rainwater and airborne particulate (PM10) filters as well as a certified reference material SLRS-4 (river water) were satisfactorily analyzed obtaining recoveries between 90 and 110% for both elements. The main features of the LOV-MSFIA-ICP-MS system proposed are the capability to renew solid phase extraction at will in a fully automated way, the remarkable stability of the column which can be reused up to 160 times, and the potential to perform isotopic analysis.

  17. High-precision Pb isotopic measurements of teeth and environmental samples from Sofia (Bulgaria): insights for regional lead sources and possible pathways to the human body

    NASA Astrophysics Data System (ADS)

    Kamenov, George D.

    2008-08-01

    High-precision Pb isotopic measurements on teeth and possible sources in a given area can provide important insights for the lead (Pb) sources and pathways in the human body. Pb isotopic analyses on soils from the area of Sofia, Bulgaria show that Pb is contributed by three end-members represented by two natural sources and leaded gasoline. Sequential leaching experiments reveal that the alumosilicate fraction of the soils is mainly controlled by natural Pb derived from two mountain massifs bordering the city. Around 1/3 to a half of the Pb in the soil leachates, however, can be explained by contamination from leaded gasoline. Contemporary teeth from Sofia residents show very similar Pb isotopic compositions to the soil leachates, also indicating that around 1/3 to a half of the Pb can be explained by derivation from leaded gasoline. The remarkable isotopic similarities between the teeth and the most labile fractions of the local soils suggest that the lead can be derived from the latter. Pb incorporation in the human body via soil-plant-human or soil-plant-animal-human chains is unlikely due to the fact that no significant farming occurs in the city area. The isotopic compositions of the local soil labile fractions can be used as approximation of the bioaccessible lead for humans. Considering all possible scenarios it appears that soil and/or soil-born dust inhalation and/or ingestion is the most probable pathway for incorporation of local soil lead in the local population. The high-precision Pb isotope data presented in this work indicate that apparently the local soil is what plays major role in the human Pb exposure.

  18. Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

    USGS Publications Warehouse

    Odigie, Kingsley; Cohen, A.D.; Swarzenski, Peter W.; Flegal, R

    2014-01-01

    Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p < 0.05) between the fluxes of Co, Cu, Mn, Ni, Pb, and Zn and those of iron (Fe) at both sites, (ii) positive correlations (r = 0.82–0.98, p < 0.01, n = 9) between the fluxes of elements (Al, Co, Cu, Fe, Mn, Ni, Pb, and Zn) and the mass accumulation rates at the offshore site, (iii) the low enrichment factors (EF < 5) of those trace elements, and (iv) the temporal consistencies of the isotopic composition of Pb in the sediment. These measurements indicate that accelerated weathering, rather than industrialization, accounts for most of the increases in trace element fluxes to Lake Tanganyika in spite of the development of mining and smelting operations within the lake’s watershed over the past century. The data also indicate that the mid-lake site is a much more sensitive and useful recorder of environmental changes than the nearshore site. Furthermore, the lead isotopic compositions

  19. Uranium-lead isotopic ages from the Sierra Nevada Batholith, California

    NASA Astrophysics Data System (ADS)

    Chen, James H.; Moore, James G.

    1982-06-01

    all in the range 99±3 m.y., indicating a relatively short period of emplacement and cooling for this nested group of plutons. U-Pb ages of a mafic inclusion and its host granodiorite indicate that both were derived from a common source or that the mafic inclusion was totally equilibrated with the granodioritic magma. Comparison of isotopic ages determined by different methods such as zircon U-Pb, sphene U-Pb, hornblende K-Ar, and biotite K-Ar suggests that zircon U-Pb ages generally approximate the emplacement age of a pluton. However, some plutons probably contain inherited or entrained old zircons, and the zircons of some samples are disturbed by younger thermal and metamorphic events. The ages reported here are consistent with U-Pb age determinations previously made on granitic rocks to the north [Stern et al., 1981], The age distribution of granitic belts determined here is in general agreement with those established by K-Ar dating [Evernden and Kistler, 1970] but does not differentiate the five epochs of plutonism determined in their study.

  20. Age of the moon: an isotopic study of uranium-thorium-lead systematics of lunar samples.

    PubMed

    Tatsumoto, M; Rosholt, J N

    1970-01-30

    Concentrations of U, Th, and Pb in Apollo 11 samples studied are low (U. 0.16 to 0.87; Th, 0.53 to 3.4; Pb, 0.29 to 1.7, in ppm) but the extremely radiogenic lead in samples allows radiometric dating. The fine dust and the breccia have a concordant age of 4.66 billion years on the basis of (207)Pb/(206)Pb, (206)Pb/(238)U, (207)Pb/(235U), and(208)Pb/(232)Th ratios. This age is comparable with the age of meteorites and with the age generally accepted for the earth. Six crystalline and vesicular samples are distinctly younger than the dust and breccia. The (238)U/(235)U ratio is the same as that in earth rocks, and (234)U is in radioactive equilibrium with parent (238)U.

  1. Age of the moon: An isotopic study of uranium-thorium-lead systematics of lunar samples

    USGS Publications Warehouse

    Tatsumoto, M.; Rosholt, J.N.

    1970-01-01

    Concentrations of U, Th, and Pb in Apollo 11 samples studied are low (U. 0.16 to 0.87; Th, 0.53 to 3.4; Pb, 0.29 to 1.7, in ppm) but the extremely radiogenic lead in samples allows radiometric dating. The fine dust and the breccia have a concordant age of 4.66 billion years on the basis of 207Pb/206Pb, 206Pb/238U, 207Pb/235U, and 208Pb/232Th ratios. This age is comparable with the age of meteorites and with the age generally accepted for the earth. Six crystalline and vesicular samples are distinctly younger than the dust and breccia. The 238U/235U ratio is the same as that in earth rocks, and 234U is in radioactive equilibrium with parent 238U.

  2. Lead isotopes in soils and groundwaters as tracers of the impact of human activities on the surface environment: The Domizio-Flegreo Littoral (Italy) case study

    USGS Publications Warehouse

    Grezzi, G.; Ayuso, R.A.; de Vivo, B.; Lima, A.; Albanese, S.

    2011-01-01

    The isotopic signature of geogenic and anthropogenic materials, in combination with concentration data for pollutants, can help trace the origin and the extent of contamination in the environment. This approach is particularly effective if naturally occurring and anthropogenically introduced metals have different isotopic ratios. Lead isotope analysis on soils from 7 profiles (1. m depth) and on groundwaters from 8 wells have been used to determine the impact of human activities on the surface environment of Domizio-Flegreo Littoral. Result obtained show that in sub-rural areas the isotopic composition of the samples collected along the soil profiles of Domizio-Flegreo Littoral is likely mostly controlled by the nature of the parent geologic material (natural) while in more urbanized areas (Giugliano) Pb isotopic composition in superficial soils is mostly influenced by anthropic sources such as motor vehicles. Lead isotopic ratios in groundwaters also show that the use of pesticides and, probably, the influence of aerosols and the presence of illegal waste disposal can influence water quality. ?? 2010 Elsevier B.V.

  3. Study on hydrogen isotopes permeation in fluidized state of liquid lithium-lead

    SciTech Connect

    Yoshimura, S.; Yoshimura, R.; Okada, M.; Fukada, S.; Edao, Y.

    2015-03-15

    Lithium-lead (Li-Pb) is one of the most promising candidate materials for the liquid blanket of fusion reactors. Hydrogen transfer under a fluidized condition of Li-Pb is investigated experimentally to design a Li-Pb blanket system. Li-Pb eutectic alloy flows inside a Ni tube in the experimental system, where H{sub 2} permeates into and out of the forced Li-Pb flow. The overall H{sub 2} permeation rate is analyzed using a mass balance model. Hydrogen atoms diffuse in Ni and Li-Pb. The steady-state H{sub 2} permeation rate obtained by this experiment is smaller than the result of the calculation model. A resistance factor is introduced to the present analysis in order to evaluate the influence of other H{sub 2} transfer mechanisms, such as diffusion in Li-Pb and dissolution reaction between Ni and Li-Pb. The contribution of the resistance to the overall H{sub 2} permeation rate becomes large when the flow rate of Li-Pb is low. This is because the boundary layer thickness between Ni and Li-Pb affects the overall H{sub 2} permeation rate. When the flow velocity of Li-Pb increases, the thickness of the boundary layer becomes thin, and the driving force of H{sub 2} permeation through the Ni wall becomes bigger. (authors)

  4. Hydrogeology and water quality of the Galena-Platteville aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1991

    USGS Publications Warehouse

    Mills, P.C.

    1993-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, investigated the hydrogeology of the Galena-Platteville aquifer and its relation to contaminant migration at the Parson's Casket Hardware Superfund site in Belvidere, Ill. This report presents the results of the second phase of the investigation, which lasted from March through October 1991. The uppermost bedrock units beneath the study site are the Galena and Platteville Groups1; these bedrock units immediately underlie a glacial drift aquifer. The Galena and Platteville Groups, which consist predominantly of dolomite, compose the Galena-Platteville aquifer, and extend from about 40 to 320 feet below land surface. The unconfined Galena-Platteville aquifer is partitioned into five hydrogeologic units. The uppermost unit, the weathered surface of the bedrock, has a horizontal hydraulic conductivity that ranges from about 1 to 200 feet per day. The four underlying units have hydraulic conductivities that range from about 0.01 to 1 foot per day. Vertical hydraulic gradients in the aquifer are typically downward. Horizontal groundwater flow generally is southward to southeastward from the site toward the Kishwaukee River. Three notable bedding-plane solution fissures and three fractures that crosscut the bedding planes are identified within the dolomite bedrock. The inclined fractures are assumed to function as conduits that connect high conductivity horizontal fissures, thus allowing more rapid vertical movement of ground water and contaminants than would be expected in the generally low conductivity dolomite matrix. A multiple-well, constant-discharge aquifer test confirms the heterogeneity and anisotropy of the dolomite aquifer. The hydraulic characteristics of the uppermost part of the bedrock aquifer are somewhat different than the characteristics of the deeper part(s) of the aquifer. This is because the principal conduits for water movement are in the deeper part(s) of the

  5. Radial distribution of lead and lead isotopes in stem wood of Norway spruce: A reliable archive of pollution trends in Central Europe

    NASA Astrophysics Data System (ADS)

    Novak, Martin; Mikova, Jitka; Krachler, Michael; Kosler, Jan; Erbanova, Lucie; Prechova, Eva; Jackova, Iva; Fottova, Daniela

    2010-08-01

    Annual growth rings of a common hardwood species, Picea abies L., were investigated as a potential archive of past atmospheric Pb pollution. Wide distribution of trees in terrestrial settings and straightforward chronology are two advantages of this potential geochemical archive, but several processes described in the literature may obscure the trends in past Pb deposition. These confounding factors include, e.g., radial post-depositional mobility of Pb in xylem, and ecosystem acidification leading to higher bioavailability of Pb. One- to five-year annual wood increments were analyzed for Pb concentrations and 206Pb/ 207Pb ratios at Jezeri (JEZ), Uhlirska (UHL) and Na Lizu (LIZ), three sites in the Czech Republic, differing in atmospheric Pb loads. Three to four trees per site were included in the study. Distinct Pb concentration maxima between 1960 and 1990 at the two heavily polluted sites (JEZ and UHL) coincided with historical Pb emissions known from inventories of industrial production. No Pb concentration maxima were found at one site, LIZ, situated in a national park 150 km from major pollution sources. Spruce tree rings from JEZ, located just 5 km from coal-burning power stations, contained a large proportion of coal-derived Pb (a high- 206Pb/ 207Pb ratio of 1.19). A coal-related maximum in 206Pb/ 207Pb in JEZ tree rings was found using two different analytical techniques, laser-ablation multi-collector ICP MS, and single-collector sector-field ICP MS. In a three-isotope graph ( 206Pb/ 207Pb vs. 208Pb/ 207Pb), tree-ring data plotted into the field of ombrotrophic (i.e., rain-fed) peat bogs, suggesting negligible contribution of bedrock-derived Pb in the xylem. We concluded that none of the potential confounding factors played a major role at our sites. Annual growth rings of P. abies in Central Europe faithfully recorded historical changes in atmospheric Pb depositions.

  6. Sulfur- and lead-isotope signatures of orogenic gold mineralisation associated with the Hill End Trough, Lachlan Orogen, New South Wales, Australia

    NASA Astrophysics Data System (ADS)

    Downes, P. M.; Seccombe, P. K.; Carr, G. R.

    2008-11-01

    The Hill End Trough (HET) is a deformed middle Silurian to Early Devonian sediment-dominated rift within the northeastern Lachlan Orogen. The HET hosts the Hill End, Hargraves, Napoleon Reefs, Stuart Town and Windeyer low-sulfide orogenic gold deposits. Adjacent to the HET are the Bodangora and Gulgong gold deposits. In this study we present 91 new sulfur- and 18 new lead-isotope analyses and collate a further 25 sulfur- and 32 lead-isotopes analyses from unpublished sources for these deposits. Larger gold deposits in the HET have near 0 δ34S‰ values indicating that sulfur in these systems was sourced from a magmatic reservoir. The dominant lead isotope signature for HET-hosted deposits reflects a crustal source however some mantle-derived lead has been introduced into the HET. Sulfur- and lead-isotopic results suggest that gold was sourced from mantle-derived magmatic units beneath the HET. The study supports earlier studies at Hill End by concluding that the majority of orogenic gold mineralisation in and adjacent to the HET formed during the Early Carboniferous period.

  7. Altitude, depth, and thickness of the Galena-Platteville Bedrock Unit in the subcrop area of Illinois and Wisconsin

    USGS Publications Warehouse

    Brown, Timothy A.; Dunning, Charles P.; Sharpe, Jennifer B.

    2000-01-01

    The report series will enable investigators involved in site-specific studies within the subcrop area to understand the regional geologic framework of the unit and to find additional reference sources. This report consists of four sheets that show the altitude (sheet 1), depth from land surface (sheet 2), total thickness (sheet 3), and location of altitude data (sheet 4) of the lithologic units that constitute the Galena-Platteville bedrock unit within the subcrop area. The sheets also show major known geologic features within the Galena-Platteville study area in Illinois and Wisconsin. A geographic information system (GIS) was used to generate data layers (coverages) from point data and from published and unpublished contour maps at various scales and detail. Standard GIS procedures were used to change the coverages into the maps shown on the sheets presented in this report. A list of references for the data used to prepare the maps is provided. 

  8. Coupling lead isotopes and element concentrations in epiphytic lichens to track sources of air emissions in the Alberta Oil Sands Region

    EPA Science Inventory

    A study was conducted that coupled use of element concentrations and lead (Pb) isotope ratios in the lichen Hypogymnia physodes collected during 2002 and 2008, to assess the impacts of air emissions from the Alberta Oil Sands Region (AOSR, Canada) mining and processing operations...

  9. Lead isotope relations in oceanic Ridge basalts from the Juan de Fuca-Gorda Ridge area N.E. Pacific Ocean

    USGS Publications Warehouse

    Church, S.E.; Tatsumoto, M.

    1975-01-01

    Lead isotopic analyses of a suite of basaltic rocks from the Juan de Fuca-Gorda Ridge and nearby seamounts confirm an isotopically heterogeneous mantle known since 1966. The process of mixing during partial melting of a heterogeneous mantle necessarily produces linear data arrays that can be interpreted as secondary isochrons. Moreover, the position of the entire lead isotope array, with respect to the geochron, requires that U/Pb and Th/Pb values are progressively increased over the age of the earth. Partial melting theory also dictates analogous behavior for the other incompatible trace elements. This process explains not only the LIL element character of MOR basalts, but also duplicates the spread of radiogenic lead data collected from alkali-rich oceanic basalts. This dynamic, open-system model of lead isotopic and chemical evolution of the mantle is believed to be the direct result of tectonic flow and convective overturn within the mantle and is compatible with geophysical models of a dynamic earth. ?? 1975 Springer-Verlag.

  10. Differences in the Elemental Isotope Definition May Lead to Errors in Modern Mass-Spectrometry-Based Proteomics.

    PubMed

    Claesen, Jürgen; Lermyte, Frederik; Sobott, Frank; Burzykowski, Tomasz; Valkenborg, Dirk

    2015-11-01

    The elemental isotope definition used to calculate the theoretical masses and isotope distribution of (bio)molecules is considered to be a fixed, universal standard in mass-spectrometry-based proteomics. However, this is an incorrect assumption. In view of the ongoing advances in mass spectrometry technology, and in particular the ever-increasing mass precision, the elemental isotope definition and its variations should be taken into account. We illustrate the effect of the elemental isotope uncertainty on the theoretical and experimental masses with theoretical calculations and examples.

  11. Valence band gaps and plasma energies for galena, sphalerite, and chalcopyrite natural minerals using differential optical reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Todoran, R.; Todoran, D.; Szakacs, Zs.

    2015-12-01

    The paper presents the determinations of the valence band gaps and plasma energies of the galena, sphalerite and chalcopyrite natural minerals. The work was carried out using differential optical reflectance spectroscopy of the clean mineral surfaces. The determination of the optical properties such as refractive index, real part of the complex dielectric constant and the location of certain van Hove singularities, was carried out using the Kramers-Kronig formalism.

  12. Precambrian ophiolites of Arabia; a summary of geologic settings, U-Pb geochronology, lead isotope characteristics, and implications for microplate accretion, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Pallister, John S.; Stacey, J.S.; Fischer, L.B.; Premo, W.R.

    1988-01-01

    Feldspar lead-isotope data are of three types: 1) lead from the ophiolitic rocks and arc tonalites of the northwestern Arabian Shield and ophiolitic rocks of the Nabitah suture zone is similar to lead in present midocean ridge basalt, 2) anomalous radiogenic data from the Thurwah ophiolite are from rocks that contain zircons from pre-late Proterozoic continental crust, and 3) feldspar from the Urd ophiolite shows retarded uranogenic lead growth and is related either to an anomalous oceanic mantle source, or in an unknown manner to ancient continental mantle or lower crust of the eastern Arabian Shield.

  13. Field isotopic study of lead fate and compartmentalization in earthworm-soil-metal particle systems for highly polluted soil near Pb recycling factory.

    PubMed

    Goix, Sylvaine; Mombo, Stéphane; Schreck, Eva; Pierart, Antoine; Lévêque, Thibaut; Deola, Frédéric; Dumat, Camille

    2015-11-01

    Earthworms are important organisms in soil macrofauna and play a key role in soil functionality, and consequently in terrestrial ecotoxicological risk assessments. Because they are frequently observed in soils strongly polluted by metals, the influence of earthworm bioturbation on Pb fate could therefore be studied through the use of Pb isotopes. Total Pb concentrations and isotopic composition ((206)Pb, (207)Pb and (208)Pb) were then measured in earthworms, casts and bulk soils sampled at different distance from a lead recycling factory. Results showed decreasing Pb concentrations with the distance from the factory whatever the considered matrix (bulk soils, earthworm bodies or cast samples) with higher concentrations in bulk soils than in cast samples. The bivariate plot (208)Pb/(206)Pb ratios versus (206)Pb/(207)Pb ratios showed that all samples can be considered as a linear mixing between metallic process particulate matter (PM) and geochemical Pb background. Calculated anthropogenic fraction of Pb varied between approximately 84% and 100%. Based on Pb isotopic signatures, the comparison between casts, earthworms and bulk soils allowed to conclude that earthworms preferentially ingest the anthropogenic lead fraction associated with coarse soil organic matter. Actually, soil organic matter was better correlated with Pb isotopic ratios than with Pb content in soils. The proposed hypothesis is therefore a decrease of soil organic matter turnover due to Pb pollution with consequences on Pb distribution in soils and earthworm exposure. Finally, Pb isotopes analysis constitutes an efficient tool to study the influence of earthworm bioturbation on Pb cycle in polluted soils.

  14. Field isotopic study of lead fate and compartmentalization in earthworm-soil-metal particle systems for highly polluted soil near Pb recycling factory.

    PubMed

    Goix, Sylvaine; Mombo, Stéphane; Schreck, Eva; Pierart, Antoine; Lévêque, Thibaut; Deola, Frédéric; Dumat, Camille

    2015-11-01

    Earthworms are important organisms in soil macrofauna and play a key role in soil functionality, and consequently in terrestrial ecotoxicological risk assessments. Because they are frequently observed in soils strongly polluted by metals, the influence of earthworm bioturbation on Pb fate could therefore be studied through the use of Pb isotopes. Total Pb concentrations and isotopic composition ((206)Pb, (207)Pb and (208)Pb) were then measured in earthworms, casts and bulk soils sampled at different distance from a lead recycling factory. Results showed decreasing Pb concentrations with the distance from the factory whatever the considered matrix (bulk soils, earthworm bodies or cast samples) with higher concentrations in bulk soils than in cast samples. The bivariate plot (208)Pb/(206)Pb ratios versus (206)Pb/(207)Pb ratios showed that all samples can be considered as a linear mixing between metallic process particulate matter (PM) and geochemical Pb background. Calculated anthropogenic fraction of Pb varied between approximately 84% and 100%. Based on Pb isotopic signatures, the comparison between casts, earthworms and bulk soils allowed to conclude that earthworms preferentially ingest the anthropogenic lead fraction associated with coarse soil organic matter. Actually, soil organic matter was better correlated with Pb isotopic ratios than with Pb content in soils. The proposed hypothesis is therefore a decrease of soil organic matter turnover due to Pb pollution with consequences on Pb distribution in soils and earthworm exposure. Finally, Pb isotopes analysis constitutes an efficient tool to study the influence of earthworm bioturbation on Pb cycle in polluted soils. PMID:26025429

  15. Lead isotopes behavior in the fumarolic environment of the Piton de la Fournaise volcano (Réunion Island)

    NASA Astrophysics Data System (ADS)

    Vlastélic, I.; Staudacher, T.; Deniel, C.; Devidal, J. L.; Devouard, B.; Finizola, A.; Télouk, P.

    2013-01-01

    The recent activity of the Piton de la Fournaise volcano offers a rare opportunity to address the issue of Pb isotope behavior in volcanic fumaroles, as the composition of the degassing source is accurately and precisely known. Gas sublimates formed between 2007 and 2011 at temperature ranging from 400 to ca. 100 °C include Na-K sulfate (aphthitalite), Ca-Cu sulfate (e.g., gypsum), Na sulfate (thenardite), Ca-Mg-Al-Fe fluoride (e.g., ralstonite) and native sulfur. The high-temperature deposits show trace element patterns typical of volcanic gas (with Pb concentration up to 836 ppm) while the low-temperature deposits are depleted in most volatile elements (Pb <1 ppm) with the exception of Pd and Tl (in fluorides) and Se (in native sulfur). Only for low-temperature fluoride samples do Pb isotope compositions plot significantly outside the field of lavas. The isotopic shift is ascribed to leaching ubiquitous unradiogenic phases (e.g., sulfides) by acidic gas condensates. The similarity in Pb isotope signature between lavas and sublimate samples more representative of the gas phase (sulfates) indicates that the net fractionation of Pb isotopes resulting from volatilization and condensation processes is smaller than the precision of Pb isotope measurements (better than 60 ppm/a.m.u.). The absence of net fractionation could result from negligible isotope fractionation during Pb volatilization followed by extensive condensation of gaseous Pb, with possibly significant isotopic fractionation at this stage. Although this scenario has to be refined by more direct measurement of the gas phase, and its general applicability tested, it suggests that a small fraction (<10%) of initially volatilized Pb ultimately escapes to the atmosphere, while the remaining dominant fraction is trapped in sublimates. As sublimates are rapidly dissolved and entrained by runoff, the fumarolic environment appears as a factory efficiently transferring isotopically unfractionated Pb from magmas

  16. Lead isotope ratios in six lake sediment cores from Japan Archipelago: Historical record of trans-boundary pollution sources.

    PubMed

    Hosono, Takahiro; Alvarez, Kelly; Kuwae, Michinobu

    2016-07-15

    Sediment cores from six lakes situated from north to south on the Japanese Archipelago were collected during 2009-2010 to investigate the hypothesis that deposition of lead (Pb) was coming from East Asia (including China, South Korea and eastern part of Russia). Accumulation rates and ages of the lake sediment were estimated by the (210)Pb constant rate of supply model and (137)Cs inputs to reconstruct the historical trends of Pb accumulation. Cores from four lakes located in the north and central Japan, showed clear evidence of Pb pollution with a change in the (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios in the recent sediment as compared to the deeper sediment. Among the six studied lakes, significant inputs of anthropogenic lead emissions were observed at Lake Mikazuki (north Hokkaido in north Japan), Lake Chokai (north of Honshu), and Lake Mikuriga (central part of Honshu). Pb isotopic comparison of collected core sediment and previously reported data for wet precipitation and aerosols from different Asian regions indicate that, before 1900, Pb accumulated in these three lakes was not affected by trans-boundary sources. Lake Mikazuki started to receive Pb emissions from Russia in early 1900s, and during the last two decades, this lake has been affected by trans-boundary Pb pollution from northern China. Lake Chokai has received Pb pollutant from northern China since early 1900s until 2009, whereas for the Lake Mikuriga the major Pb contaminant was transported from southern China during the past 100years. The results of our study demonstrate that Japan Archipelago has received trans-boundary Pb emissions from different parts of East Asian region depending on location, and the major source region has changed historically. PMID:27058126

  17. Lead isotopic composition of trinitite melt glass: evidence for the presence of Canadian industrial lead in the first atomic weapon test.

    PubMed

    Bellucci, Jeremy J; Simonetti, Antonio; Wallace, Christine; Koeman, Elizabeth C; Burns, Peter C

    2013-08-01

    The Pb isotopic compositions for 51 spots of melt glass in 11 samples of trinitite have been determined by laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). Trinitite glass yields a large range of Pb isotopic compositions (i.e., (206)Pb/(204)Pb = 17.08-19.04), which reflect mixing between industrial Pb from materials used in the Trinity test and natural geologic components. Areas within trinitite melt glass containing high concentrations of both Cu and Pb, which are derived from the bomb and blast site-related components, were used for delineating the Pb isotopic composition corresponding to the anthropogenic Pb component. Comparison between the isotopic composition estimated here for the industrial Pb used in the Trinity test and those from known Pb deposits worldwide indicates close agreement with ore from the Buchans mine (Newfoundland, Canada). The Buchans mine was active during the time of the Trinity test and was operated by the American Smelting and Refining Company, which could have provided the Pb used in the test. The industrial Pb used in the Trinity test materials is not documented in the literature (or declassified) but could have been present in bricks, solder, pigs, or some other anthropogenic component related to the experiment. PMID:23829180

  18. Application of laser ablation multicollector inductively coupled plasma mass spectrometry for the measurement of calcium and lead isotope ratios in packaging for discriminatory purposes.

    PubMed

    Santamaria-Fernandez, Rebeca; Wolff, Jean-Claude

    2010-07-30

    The potential of high-precision calcium and lead isotope ratio measurements using laser ablation coupled to multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) to aid distinction between four genuine and five counterfeit pharmaceutical packaging samples and further classification of counterfeit packaging samples has been evaluated. We highlight the lack of reference materials for LA-MC-ICP-MS isotope ratio measurements in solids. In this case the problem is minimised by using National Institute of Standards and Technology Standard Reference Material (NIST SRM) 915a calcium carbonate (as solid pellets) and NIST SRM610 glass disc for sample bracketing external standardisation. In addition, a new reference material, NIST SRM915b calcium carbonate, has been characterised in-house for Ca isotope ratios and is used as a reference sample. Significant differences have been found between genuine and counterfeit samples; the method allows detection of counterfeits and aids further classification of packaging samples. Typical expanded uncertainties for measured-corrected Ca isotope ratio values ((43)Ca/(44)Ca and (42)Ca/(44)Ca) were found to be below 0.06% (k = 2, 95% confidence) and below 0.2% for measured-corrected Pb isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb). This is the first time that Ca isotope ratios have been measured in packaging materials using LA coupled to a multicollector (MC)-ICP-MS instrument. The use of LA-MC-ICP-MS for direct measurement of Ca and Pb isotopic variations in cardboard/ink in packaging has definitive potential to aid counterfeit detection and classification. PMID:20552700

  19. Application of laser ablation multicollector inductively coupled plasma mass spectrometry for the measurement of calcium and lead isotope ratios in packaging for discriminatory purposes.

    PubMed

    Santamaria-Fernandez, Rebeca; Wolff, Jean-Claude

    2010-07-30

    The potential of high-precision calcium and lead isotope ratio measurements using laser ablation coupled to multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) to aid distinction between four genuine and five counterfeit pharmaceutical packaging samples and further classification of counterfeit packaging samples has been evaluated. We highlight the lack of reference materials for LA-MC-ICP-MS isotope ratio measurements in solids. In this case the problem is minimised by using National Institute of Standards and Technology Standard Reference Material (NIST SRM) 915a calcium carbonate (as solid pellets) and NIST SRM610 glass disc for sample bracketing external standardisation. In addition, a new reference material, NIST SRM915b calcium carbonate, has been characterised in-house for Ca isotope ratios and is used as a reference sample. Significant differences have been found between genuine and counterfeit samples; the method allows detection of counterfeits and aids further classification of packaging samples. Typical expanded uncertainties for measured-corrected Ca isotope ratio values ((43)Ca/(44)Ca and (42)Ca/(44)Ca) were found to be below 0.06% (k = 2, 95% confidence) and below 0.2% for measured-corrected Pb isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb). This is the first time that Ca isotope ratios have been measured in packaging materials using LA coupled to a multicollector (MC)-ICP-MS instrument. The use of LA-MC-ICP-MS for direct measurement of Ca and Pb isotopic variations in cardboard/ink in packaging has definitive potential to aid counterfeit detection and classification.

  20. Neodymium, strontium, and lead isotopes in the Maloin Ranch Pluton, Wyoming: Implications for the origin of evolved rocks at anorthosite margins

    SciTech Connect

    Kolker, A.; Hanson, G.N. ); Frost, C.D. ); Geist, D.J. )

    1991-08-01

    Neodymium, strontium, and lead isotopic data are used in this study to investigate the origin of chemically evolved rocks in the Maloin Ranch Pluton, a composite body that borders and intrudes the Laramie Anorthosite. In the Maloin Ranch Pluton, these include ferrodiorite at the base of the intrusion, overalain progressively by fine-grained monzonite, monzosyenite, and porphyritic granite. Biotite gabbro and fine-grained granitic dikes are present locally at various levels of this sequence. The origin of the evolved rocks and their possible relation to associated anorthositic bodies has been much debated. In the Maloin Ranch Pluton, each rock type has distinct isotopic characteristics which, together with trace-element data previously reported, suggest different source characteristics for each member. Strontium and neodymium isotopic data for Maloin Ranch ferrodiorite and Laramie anorthositic rocks show considerable overlap, consistent with a comagmatic relation. Biotite gabbro is chemically and isotopically the most primitive rock type in the Maloin Ranch Pluton. The data suggest that biotite gabbro has a mantle source, but has undergone extensive fractionation in the crust. The authors' results suggest that the remainder (and bulk) of the intrusion formed by partial melting of the lower crust due to the emplacement of the Laramie Anorthosite. Trace-element and isotopic characteristics of the fine-grained monzonite are explained by partial melting of mantle-dervied lower crust, added to the margin of the Archean Wyoming craton at about 1.8 Ga. Neodymium, strontium, and lead isotope data for Maloin Ranch monzosyenite and porphyritic granite also suggest a lower crustal source.

  1. A 500 year sediment lake record of anthropogenic and natural inputs to Windermere (English Lake District) using double-spike lead isotopes, radiochronology, and sediment microanalysis.

    PubMed

    Miller, Helen; Croudace, Ian W; Bull, Jonathan M; Cotterill, Carol J; Dix, Justin K; Taylor, Rex N

    2014-07-01

    A high-resolution record of pollution is preserved in recent sediments from Windermere, the largest lake in the English Lake District. Data derived from X-ray core scanning (validated against wavelength dispersive X-ray fluorescence), radiochronological techniques ((210)Pb and (137)Cs) and ultrahigh precision, double-spike mass spectrometry for lead isotopes are combined to decipher the anthropogenic inputs to the lake. The sediment record suggests that while most element concentrations have been stable, there has been a significant increase in lead, zinc, and copper concentrations since the 1930s. Lead isotope down-core variations identify three major contributory sources of anthropogenic (industrial) lead, comprising gasoline lead, coal combustion lead (most likely source is coal-fired steam ships), and lead derived from Carboniferous Pb-Zn mineralization (mining activities). Periods of metal workings do not correlate with peaks in heavy metals due to the trapping efficiency of up-system lakes in the catchment. Heavy metal increases could be due to flood-induced metal inwash after the cessation of mining and the weathering of bedrock in the catchment. The combination of sediment analysis techniques used provides new insights into the pollutant depositional history of Windermere and could be similarly applied to other lake systems to determine the timing and scale of anthropogenic inputs.

  2. U-Th-Pb isotope chronology of sulfide ores and rocks in the early Proterozoic metavolcanic belt of northern Wisconsin.

    USGS Publications Warehouse

    Afifi, A.; Doe, B.R.; Sims, P.K.; Delevaux, M.H.

    1984-01-01

    Lead from galena of massive sulphide deposits in the metavolcanic belt of northern Wisconsin was probably derived from 3700 m.y. old source material 1800-1900 m.y. ago. Approximately 3500 m.y. old rocks occur within 100-300 km to the north and west. The U-Th-Pb systems of the metavolcanic and granitic rocks in the belt were reset about 1600 m.y. ago during retrogressive metamorphism. The ages from lead isotope data are in accord with Rb/Sr whole-rock, Rb/Sr and K/Ar mineral, and U-Th-Pb zircon dating. A concordia plot of whole-rock lead data shows that many of the rocks lost lead 200-400 m.y. ago during uplift and erosion. Meta-volcanic rocks near Crandon, Wisconsin, had lead isotope compositions 20 m.y. ago that match those in the Pb-Zn ores in Palaeozoic rocks of the upper Mississippi valley. Possibly the volcanic rocks were a source of lead for the Pb-Zn ores. Similar ores might therefore occur between the northern Wisconsin metavolcanic belt and the upper Mississippi valley.-G.J.N.

  3. The potential source of lead in the Permian Kupferschiefer bed of Europe and some selected Paleozoic mineral deposits in the Federal Republic of Germany

    USGS Publications Warehouse

    Wedepohl, K.H.; Delevaux, M.H.; Doe, B.R.

    1978-01-01

    New lead isotopic compositions have been measured for Paleozoic bedded and vein ore deposits of Europe by the high precision thermal emission (triple filament) technique. Eleven samples have been analyzed from the Upper Permian Kupferschiefer bed with representatives from Poland to England, three samples from the Middle Devonian Rammelsberg deposit and one from the Middle Devonian Meggen deposit, both of which are conformable ore lenses and are in the Federal Republic of Germany (FRG); and also two vein deposits from the FRG were analyzed, from Ramsbeck in Devonian host rocks and from Grund in Carboniferous host rocks. For Kupferschiefer bed samples from Germany, the mineralization is of variable lead isotopic composition and appears to have been derived about 250 m.y. ago from 1700 m.y. old sources, or detritus of this age, in Paleozoic sedimentary rocks. Samples from England, Holland, and Poland have different isotopic characteristics from the German samples, indicative of significantly different source material (perhaps older). The isotopic variability of the samples from the Kupferschiefer bed in Germany probably favors the lead containing waters coming from shoreward (where poor mixing is to be expected) rather than basinward (where better mixing is likely) directions. The data thus support the interpretation of the metal source already given by Wedepohl in 1964. Data on samples from Rammelsberg and Meggen tend to be slightly less radiogenic than for the Kupferschiefer, about the amount expected if the leads were all derived from the same source material but 100 to 150 m.y. apart in time. The vein galena from Ramsbeck is similar to that from Rammelsberg conformable ore lenses, both in rocks of Devonian age; vein galena from Grund in Upper Carboniferous country rocks is similar to some bedded Kupferschiefer mineralization in Permian rocks, as if the lead composition was formed at about the same time and from similar source material as the bedded deposits

  4. Determination of lead, cadmium, indium, thallium and silver in ancient ices from Antarctica by isotope dilution-thermal ionization mass spectrometry

    USGS Publications Warehouse

    Matsumoto, A.; Hinkley, T.K.

    1997-01-01

    The concentrations of five chalcophile elements (Pb, Cd, In, Tl and Ag) and the lead isotope rarios in ancient ices from the Taylor Dome near coastal Antarctica, have been determined by the isotope dilutionthermal ionization mass spectrometry (ID-TIMS), with ultra-clean laboratory techniques. The samples were selected from segments of cores, one of which included a visible ash layer. Electric conductivity measurement (ECM) or dielectric properties (DEP) gave distinctive sharp peaks for some of the samples c hosen. Exterior portions of the sample segments were trimmed away by methods described here. Samples w ere evaporated to dryness and later separated into fractions for the five elements using an HBr-HNO3 a nion exchange column method. The concentrations are in the range 2.62-36.7 pg Pb/g of ice, 0.413-2.83 pg Cd/g, 0.081-0.34 pg In/g, 0.096-2.8 pg Tl/g and 0.15-0.84 pg Ag/g. respectively. The dispersions in duplicate analyses are about ??1% for lead and cadmium, ??2% for indium. ??4% for thallium and ??6% for silver, respectively. The concentrations of lead obtained are commonly higher than those in the present-day Antarctic surface snows, but the isotope ratios are distinctively higher than those of the present-day snows and close to those of the other ancient ice collected from a different Antarctic area.

  5. Lead isotopes combined with a sequential extraction procedure for source apportionment in the dry deposition of Asian dust and non-Asian dust.

    PubMed

    Lee, Pyeong-Koo; Yu, Soonyoung

    2016-03-01

    Lead isotopic compositions were determined in leachates that were generated using sequential extractions of dry deposition samples of Asian dust (AD) and non-Asian dust (NAD) and Chinese desert soils, and used to apportion Pb sources. Results showed significant differences in (206)Pb/(207)Pb and (206)Pb/(204)Pb isotopic compositions in non-residual fractions between the dry deposition samples and the Chinese desert soils while (206)Pb/(207)Pb and (206)Pb/(204)Pb isotopic compositions in residual fraction of the dry deposition of AD and NAD were similar to the mean (206)Pb/(207)Pb and (206)Pb/(204)Pb in residual fraction of the Alashan Plateau soil. These results indicate that the geogenic materials of the dry deposition of AD and NAD were largely influenced by the Alashan Plateau soil, while the secondary sources of the dry deposition were different from those of the Chinese desert soils. In particular, the lead isotopic compositions in non-residual fractions of the dry deposition were homogenous, which implies that the non-residual four fractions (F1 to F4) shared the primary anthropogenic origin. (206)Pb/(207)Pb values and the predominant wind directions in the study area suggested that airborne particulates of heavily industrialized Chinese cities were one of the main Pb sources. Source apportionment calculations showed that the average proportion of anthropogenic Pb in the dry deposition of AD and NAD was 87% and 95% respectively in total Pb extraction, 92% and 97% in non-residual fractions, 15% and 49% in residual fraction. Approximately 81% and 80% of the anthropogenic Pb was contributed by coal combustion in China in the dry deposition of AD and NAD respectively while the remainder was derived from industrial Pb contamination. The research result proposes that sequential extractions with Pb isotope analysis are a useful tool for the discrimination of anthropogenic and geogenic origins in highly contaminated AD and NAD.

  6. Reconnaissance shallow seismic investigation of depth-to-bedrock and possible methane-bearing coalbeds, Galena, Alaska

    USGS Publications Warehouse

    Stephenson, William J.; Williams, Robert A.; Odum, Jack K.; Worley, David M.; Barker, Charles E.; Clark, Arthur C.; Clough, James G.

    2002-01-01

    A reconnaissance shallow seismic reflection/refraction investigation in and around the city of Galena, Alaska suggests that Tertiary and/or Cretaceous bedrock, and possible coalbeds within the Cretaceous, is at least as deep as 550 feet in the immediate vicinity of town. Rock could be deeper than 1000 feet under alternate interpretations. Reflections recorded in these data are believed to be from the sediment/bedrock interface. Analysis of these reflections and associated refractions indicates that this interface, interpreted at most of the six profile locations, has a high seismic velocity, possibly indicating non-sedimentary rock (e.g. volcanic or igneous).

  7. A comparison of the isotopic composition of lead in rainwater, surface vegetation and tree bark at the long-term monitoring site, Glensaugh, Scotland, in 2007.

    PubMed

    Farmer, John G; Eades, Lorna J; Graham, Margaret C; Cloy, Joanna M; Bacon, Jeffrey R

    2010-08-01

    The lead concentrations and isotopic ratios (206Pb/207Pb, 208Pb/206Pb, 208Pb/207Pb) of 31 rainwater (September 2006-December 2007) and 11 surface vegetation (moss, lichen, heather) samples (October 2007) from the rural upland catchment of Glensaugh in northeast Scotland and of nine bark samples (October 2007) from trees, predominantly Scots pine, in or near Glensaugh were determined. The mean 206Pb/207Pb ratios for rainwater in 2006 and 2007 were similar to those previously determined for 2000 to 2003 at Glensaugh, yielding an average mean annual value of 1.151+/-0.005 (+/-1 SD) for the period from 2000, when an outright ban on leaded petrol came into force in the UK, to 2007. The mean 206Pb/207Pb ratio (1.146+/-0.004; n=7) for surface vegetation near the top (430-450 m) of the catchment was not significantly different (Student's t test) from that of rainwater (1.148+/-0.017; n=24) collected over the 12-month period prior to vegetation sampling, but both were significantly different, at the 0.1% (i.e. p<0.001) and 1% (p<0.01) level, respectively, from the corresponding mean value (1.134+/-0.006; n=9) for the outermost layer of tree bark. When considered in conjunction with similar direct evidence for 2002 and indirect evidence (e.g. grass, atmospheric particulates, dated peat) for recent decades in the Glensaugh area, these findings confirm that the lead isotopic composition of surface vegetation, including that of suitably located moss, reflects that of the atmosphere while that of the outermost layer of Scots pine bark is affected by non-contemporaneous lead. The nature and relative extent of the different contributory sources of lead to the current UK atmosphere in the era of unleaded petrol, however, are presently not well characterised on the basis of lead isotopic measurements.

  8. Post-eruptive alteration of silicic ignimbrites and lavas, Gran Canaria, Canary Islands - Strontium, neodymium, lead, and oxygen isotopic evidence

    NASA Technical Reports Server (NTRS)

    Cousens, Brian L.; Spera, Frank J.; Dobson, Patrick F.

    1993-01-01

    The isotopic composition of lavas from oceanic islands provides important information about the composition and evolution of the earth's mantle. Isotopic analyses of Miocene comenditic, pantelleritic, and trachyphonolitic ignimbrites and lavas from the Canary islands were performed. Results provide evidence for posteruptive mobility of Rb and Sr during low temperature postemplacement interaction with circulating ground water. Calculated Sr isotope ratios define a magmatic trend in the stratigraph section. 87Sr/86Sr ratios in hydrated vitrophyte and devitrified matrix separates indicate significant posteruptive interaction with meteoric water starting soon after deposition. This process extends patchily through the entire pyroclastic flow and may be ongoing. 87Sr/86Sr ratios determined by whole rock analysis of silicic rocks from oceanic islands are suspect and should not be incorporated into mantle tracer studies. Anorthoclase phenocrysts are resistant to these processes and may produce useful data.

  9. Uptake and elimination of lead, zinc, and copper by caddisfly larvae (Trichoptera: Hydropsychidae) using stable isotope tracers.

    PubMed

    Evans, R D; Balch, G C; Evans, H E; Welbourn, P M

    2006-07-01

    Stable isotopes of Pb, Zn, and Cu were used in laboratory experiments to determine the uptake and elimination of these metals by stream-dwelling caddisfly (Trichoptera: Hydropsychidae) larvae. For Pb and Cu, larvae were exposed to environmentally realistic levels (2.5 and 4.5 microg x L(-1), respectively) of one isotope for 9 days followed by a 9-day exposure to either the same isotope, to a second stable isotope of the same metal, or to RW containing no added isotope (two phases in total). For zinc, the exposure concentration was 15 microg x L(-1), and the experiment lasted for a total of 27 (i.e., three phases) rather than 18 days to see if uptake and elimination changed during the extended time period. The uptake clearances (k(u)) determined for the various metals averaged 7.8, 1.4, and 0.6 L x g dw(-1) x d(-1) for Pb, Zn, and Cu, respectively, if the total metal concentration in the water was used in the calculations. The clearance rate constants (k(e)) were less variable, averaging 0.15 d(-1) for Pb, 0.22 d(-1) for Zn, and approximately 0.1 d(-1) for Cu and were similar in both the presence (i.e., elimination) and absence (i.e., depuration) of metal in the water. These values are also comparable with those reported in the literature for other aquatic invertebrates. The use of stable isotopes thus allowed simultaneous measurement of uptake and clearance (elimination and depuration) of these metals at environmentally realistic concentrations and could be of great benefit for determining partitioning, assimilation efficiency, and pathways of these and other metals in the environment.

  10. Mineralogical and isotopic studies of base metal sulfides from the Jiawula Ag-Pb-Zn deposit, Inner Mongolia, NE China

    NASA Astrophysics Data System (ADS)

    Niu, Si-Da; Li, Sheng-Rong; Santosh, M.; Zhang, De-Hui; Li, Zeng-Da; Shan, Meng-Jie; Lan, Yi-Xiang; Gao, De-Rong; Zhao, Wen-Bin

    2016-01-01

    The Jiawula Ag-Pb-Zn deposit is located in the northern part of the Da Hinggan Mountains metallogenic belt in the eastern section of the Central Asian Orogenic Belt. Sphalerite, galena, pyrite, chalcopyrite, and arsenopyrite are the major sulfide minerals occurring in this deposit. Here we report results from electron probe micro-analysis (EPMA), thermoelectricity, and sulfur isotope studies of the constituent silver minerals and sulfide phases of the Jiawula deposit. Petrographic observations and EPMA study reveal abundant silver mineralization in the ore, especially within sphalerite and galena. Discrete grains of silver minerals (including argentite, pyrargyrite, and canfieldite) and isomorphism in silver-bearing sulfides are identified. Silver and tellurium contents in galena are relatively high and show interrelationship. Significant substitution of S by Te in the galena lattice facilitates silver entering the galena structure, which might have been promoted by relatively low lg fS2. The thermoelectric coefficient of pyrite shows a marked gradient from N-type to P-type from pre- to post-metallogenic stages. Pyrites in Jiawula are enriched in Co and As and in the absence of Ni, displaying features typical of epithermal deposits. The isotopic data present a close relationship between the sulfur source and magmatism.

  11. Geology, hydrology, and ground-water quality of the Galena-Platteville Aquifer in the vicinity of the Parson's Casket Hardware Superfund Site, Belvidere, Illinois

    USGS Publications Warehouse

    Kay, Robert T.

    2000-01-01

    The geology, hydrology, and distribution of contaminants in the Galena-Platteville aquifer in the vicinity of the Parson?s Casket Hardware Superfund site in northeastern Belvidere, Ill., were characterized on the basis of data collected from boreholes using geophysical logging and packer assemblies. Horizontal flow in the Galena- Platteville aquifer is affected by a network of subhorizontal fractures that are concentrated in the weathered part of the bedrock, vugs and fractures present from the bottom of the weathered bedrock to the top of a shaley layer at about 662 ft (feet) above sea level, and through a widespread subhorizontal fracture at about 524 ft. Inclined fractures provide pathways for vertical flow within the Galena-Platteville aquifer. Some fractures and flow pathways appear to be affected by the stratigraphy of the Galena-Platteville deposits. Water-level data indicate the potential for downward flow within the Galena-Platteville aquifer. During periods when pumping in nearby municipal-supply wells is minimal or absent, the direction of flow through the fracture at about 524 ft above sea level is south toward two industrial-supply wells. Flow through the fracture is toward the municipal-supply wells when they are being pumped. Flow in the upper part of the Galena-Platteville aquifer does not appear to be affected by pumping in nearby water-supply wells. Chlorinated ethenes were the volatile organic compounds detected most often and at the highest concentration in the Galena-Platteville aquifer beneath northeastern Belvidere. Volatile organic compounds are migrating primarily to the southeast toward the Kishwaukee River, with components of movement to the north, east, and west. Volatile organic compound and monitored natural attenuation parameter data indicate reductive dechlorination of some chlorinated ethene compounds is occurring under either nitrate or iron-reducing conditions in the unconsolidated deposits and possibly the upper part of the

  12. Isotope geochemistry of waters affected by acid mine drainage in old labour sites (SE, Spain).

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Garcia-Lorenzo, Maria Luz; Agudo, Ines; Hernandez-Cordoba, Manuel; Recio, Clemente

    2015-04-01

    The ore deposits of this zone have iron, lead and zinc as the main metal components. Iron is present in oxides, hydroxides, sulfides, sulfates, carbonates, and silicates; lead and zinc occur in sulfides (galena and sphalerite, respectively), carbonates, sulfates, and lead or zinc-bearing (manganese, iron) oxides. Mining started with the Romans and activity peaked in the second half of the 19th century and throughout the 20th century until the 1980's. From 1940 to 1957, mineral concentration was made by froth flotation and, prior to this, by gravimetric techniques. The mining wastes, or tailings, with a very fine particle size were deposited inland (tailings dams) and, since 1957, huge releases were made in directly the sea coast. The objective of this work was to evaluate processes affecting waters from abandoned mine sites by way of stable isotopic analysis, particularly H and O stable isotopes from water and S and O from dissolved sulfates. Several common chemical and physical processes, such as evaporation, water-rock interaction and mixing could alter water isotopic composition. Evaporation, which causes an enrichment in δD and δ18O in the residual water, is an important process in semiarid areas. The results obtained indicate that, for sites near the coast, waters are meteoric, and marine infiltration only takes place in the deepest layers near the shore or if water remains stagnated in sediments with low permeability. The main source of sulfate was the oxidation of sulfides, resulting in the liberation of acid, sulfate and metals. In order to assess the mechanism responsible for sulfide oxidation, the stoichiometric isotope balance model and the general isotope balance model were tested, suggesting that the oxidation via Fe3+ was predominant in the surface, and controlled by A. ferrooxidans, while at depth, sulfate reduction occurred.

  13. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC): A Lead and Strontium Isotope Mortuary Analysis.

    PubMed

    Valentine, Benjamin; Kamenov, George D; Kenoyer, Jonathan Mark; Shinde, Vasant; Mushrif-Tripathy, Veena; Otarola-Castillo, Erik; Krigbaum, John

    2015-01-01

    Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people's movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC) cemetery burials at Harappa (Pakistan) and Farmana (India) provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape.

  14. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC): A Lead and Strontium Isotope Mortuary Analysis

    PubMed Central

    Valentine, Benjamin; Kamenov, George D.; Kenoyer, Jonathan Mark; Shinde, Vasant; Mushrif-Tripathy, Veena; Otarola-Castillo, Erik; Krigbaum, John

    2015-01-01

    Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people’s movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC) cemetery burials at Harappa (Pakistan) and Farmana (India) provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape. PMID:25923705

  15. COEXISTING GALENA, PbS//S//S AND SULFOSALTS: EVIDENCE FOR MULTIPLE EPISODES OF MINERALIZATION IN THE ROUND MOUNTAIN AND MANHATTAN GOLD DISTRICTS, NEVADA.

    USGS Publications Warehouse

    Foord, Eugene E.; Shawe, Daniel R.; Conklin, Nancy M.

    1988-01-01

    Studies of galena and Pb-Bi-Ag-Cu(Hg) sulfosalts of varied compositions in the Round Mountain and Manhattan gold districts of Nevada corroborate the occurrence of several distinct mineralized systems characterized by different mineral compositions and assemblages. The different episodes of mineralization are related to different Cretaceous and Tertiary magmatic-hydrothermal events, although the assignment of specific mineral compositions and associations with dated mineralized systems is still incomplete. At the Fairview mine, galena associated with Pb-Bi-Ag sulfosalts and simple sulfides occurs as intergrowths of discretely different composition controlled by silver and bismuth content. A galena-type phase (Pbs//s//s) with solid solution toward matildite, AgBiS//2(composition Gal//6//0Mat//4//0) was found. If silver and, to a lasser extent, bismuth are absent, the galena formed will be almost pure PbS. Some minor antimony may substitute for bismuth. This study confirms a linear relationship between a cell edge and Ag-Bi(Sb) content for galena containing less than about 15 wt. percent Ag and Bi(Sb).

  16. Lead isotopes in trade wind aerosols at Barbados: the influence of European emissions over the North Atlantic

    SciTech Connect

    Hamelin, B.; Grousset, F.E.; Biscaye, P.E.; Zindler, A. ); Prospero, J.M. )

    1989-11-15

    Previous studies have shown that Pb can be used as a transient tracer in the atmosphere and the ocean because of strong time-variability of industrial inputs and because Pb isotopic composition can be used to identify contribution from different sources. We present Pb isotopic measurements on aerosols collected from the North Atlantic Ocean in the trade wind belt. Aerosols sampled at Barbados during the 1969--1985 period have a Pb isotopic compositions different from that observed by previous investigators in Bermuda corals and Sargasso Sea waters. Barbados aerosols appear to contain significant amounts of relatively unradiogenic industrial and automotive Pb that is derived from Europe and carried to Barbados by the trade winds. In contrast, Bermuda corals and Sargasso sea waters are influenced mainly by U.S.-derived emissions, which contain more radiogenic Pb originating from Missouri-type ores. This difference generates a strong latitudinal Europe-U.S.A. isotopic gradient, thus allowing study of trans-Atlantic atmospheric transport and ocean mixing processes. {copyright} American Geophysical Union 1989

  17. Lead isotopes in trade wind aerosols at Barbados - The influence of European emissions over the North Atlantic

    NASA Technical Reports Server (NTRS)

    Hamelin, B.; Grousset, F. E.; Biscaye, P. E.; Zindler, A.; Prospero, J. M.

    1989-01-01

    Previous studies have shown that Pb can be used as a transient tracer in the atmosphere and the ocean because of strong time-variability of industrial inputs and because Pb isotopic composition can be used to identify contributions from different sources. Pb isotopic measurements on aerosols collected from the North Atlantic Ocean in the trade wind belt are presented. Aerosols sampled at Barbados during the 1969-1985 period have a Pb isotopic composition different from that observed by previous investigators in Bermuda corals and Sargasso Sea waters. Barbados aerosols appear to contain significant amounts of relatively unradiogenic industrial and automotive Pb that is derived from Europe and carried to Barbados by the trade winds. In contrast, Bermuda corals and Sargasso sea waters are influenced mainly by U.S.-derived emissions, which contain more radiogenic Pb originating from Missouri-type ores. This difference generates a strong latitudinal Europe-U.S.A. isotopic gradient, thus allowing study of trans-Atlantic atmospheric transport and ocean mixing processes.

  18. Uranium-lead dating method at the Pará-Iso isotope geology laboratory, UFPA, Belém - Brazil.

    PubMed

    Krymsky, Robert S; Macambira, Moacir J B; Lafon, Jean-Michel; Estumano, Gérson S

    2007-03-01

    Analytical procedures for U-Pb isotope dilution analyses at the Pará-Iso isotope geology laboratory of the Federal University of Pará (UFPA) are described in detail. The procedures are applied to zircon, titanite, rutile, apatite, columbite-tantalite and whole rock. Reagent preparation and chemical processing are done in clean-room conditions. Samples are dissolved using Teflon microcapsules in steel jacket Teflon Parr Instrument bomb or Teflon screw cap containers. U and Pb are separated using anion exchange AG 1 x 8 resin columns. Typical blanks for mineral sample amounts of 0.01 to 1.0 mg are less than 1 pg U and 20-30 pg Pb. Isotope analysis of the U and Pb from the same filament are carried out using a Finnigan MAT 262 mass-spectrometer in static and dynamic modes. The current analytical level is demonstrated on analyses of international standard zircon 91500 with three different 235U-205Pb and 235U-208Pb isotope tracers and whole rock standards. Results of analyses of two zircon samples are also presented. PMID:17401481

  19. Genetic aspects of a gold deposit in high grade Cambro-Ordovician metasediments, Nova Scotia: geological, mineral, geochemical and isotopic evidence

    SciTech Connect

    Smith, P.K.

    1985-01-01

    The Cochrane Hill gold deposit is hosted by amphibolite grade turbidite metasediments of the Cambro-Ordovician Goldenville Formation. Interbedded pelitic, semipelitic and psammite host sediments were polydeformed, metamorphosed and intruded by granitoid plutons during the Devonian Acadian Orogeny. Six distinct types of quartz veins are recognized from the 30m wide mineralized zone. Textural evidence suggests that vein emplacement commenced prior to deformation and ceased after the termination of the Acadian Orogeny. Essential mineralogy of the veins is quartz, plagioclase, phyllo-silicates, aluminosilicates, amphiboles and garnet. Arsenopyrite, pyrrhotite, loellingite, pyrite, marcasite, sphalerite, galena, chalcopyrite, Fe-Ti oxides and gold are the ore minerals. FeO/MgO, Na/sub 2/O/K/sub 2/O and Al/sub 2/O/sub 3//K/sub 2/O ratios in biotite and muscovite increase in the ore zone. Whole rock geochemistry of pelitic lithologies shows marked increases in TiO/sub 2//MgO, TiO/sub 2//Fe/sub 3/O/sub 3/, TiO/sub 2//P/sub 2/O/sub 5/ and Na O/K/sub 2/O ratios across the ore horizon. In the psammitic units TiO/sub 2//P/sub 2/O/sub 5/ shows marked increase whereas CaO/MgO and Na/sub 2/O/K/sub 2/O ratios decrease slightly in the auriferous zone. Fluid inclusion temperatures from quartz vary from 260 to +450/sup 0/C. Preliminary lead isotope data on galenas from Cochrane Hill are substantially more radiogenic than whole rock leads from the Goldenville Formation. These lead isotopic data, which are similar to those from granite-hosted mineral deposits together with other lines of evidence, support a granite related epigenetic gold models.

  20. Lead Isotopes in Olivine-Phyric Shergottite Tissint: Implications for the Geochemical Evolution of the Shergottite Source Mantle

    NASA Technical Reports Server (NTRS)

    Moriwaki, R.; Usui, T.; Simon, J. I.; Jones, J. H.; Yokoyama, T.

    2015-01-01

    Geochemically-depleted shergottites are basaltic rocks derived from a martian mantle source reservoir. Geochemical evolution of the martian mantle has been investigated mainly based on the Rb-Sr, Sm-Nd, and Lu-Hf isotope systematics of the shergottites [1]. Although potentially informative, U-Th- Pb isotope systematics have been limited because of difficulties in interpreting the analyses of depleted meteorite samples that are more susceptible to the effects of near-surface processes and terrestrial contamination. This study conducts a 5-step sequential acid leaching experiment of the first witnessed fall of the geochemically-depleted olivinephyric shergottite Tissint to minimize the effect of low temperature distrubence. Trace element analyses of the Tissint acid residue (mostly pyroxene) indicate that Pb isotope compositions of the residue do not contain either a martian surface or terrestrial component, but represent the Tissint magma source [2]. The residue has relatively unradiogenic initial Pb isotopic compositions (e.g., 206Pb/204Pb = 10.8136) that fall within the Pb isotope space of other geochemically-depleted shergottites. An initial µ-value (238U/204Pb = 1.5) of Tissint at the time of crystallization (472 Ma [3]) is similar to a time-integrated mu- value (1.72 at 472 Ma) of the Tissint source mantle calculated based on the two-stage mantle evolution model [1]. On the other hand, the other geochemically-depleted shergottites (e.g., QUE 94201 [4]) have initial µ-values of their parental magmas distinctly lower than those of their modeled source mantle. These results suggest that only Tissint potentially reflects the geochemical signature of the shergottite mantle source that originated from cumulates of the martian magma ocean

  1. Reduction of arsenic content in a complex galena concentrate by Acidithiobacillus ferrooxidans

    PubMed Central

    Makita, Mario; Esperón, Margarita; Pereyra, Benito; López, Alejandro; Orrantia, Erasmo

    2004-01-01

    Background Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. This technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. So far the most studied microorganism in bioleaching is Acidithiobacillus ferrooxidans. There are a few studies about the benefit of metals of low value through bioleaching. From all of these, there are almost no studies dealing with complex minerals containing arsenopyrite (FeAsS). Reduction and/or elimination of arsenic in these ores increase their value and allows the exploitation of a vast variety of minerals that today are being underexploited. Results Arsenopyrite was totally oxidized. The sum of arsenic remaining in solution and removed by sampling represents from 22 to 33% in weight (yield) of the original content in the mineral. The rest of the biooxidized arsenic form amorphous compounds that precipitate. Galena (PbS) was totally oxidized too, anglesite (PbSO4) formed is virtually insoluble and remains in the solids. The influence of seven factors in a batch process was studied. The maximum rate of arsenic dissolution in the concentrate was found using the following levels of factors: small surface area of particle exposure, low pulp density, injecting air and adding 9 K medium to the system. It was also found that ferric chloride and carbon dioxide decreased the arsenic dissolution rate. Bioleaching kinetic data of arsenic solubilization were used to estimate the dilution rate for a continuous culture. Calculated dilution rates were relatively small (0.088–0.103 day-1). Conclusion Proper conditions of solubilization of arsenic during bioleaching are key features to improve the percentage (22 to 33% in weight) of arsenic removal. Further studies are needed to determine other factors that influence specifically the solubilization of arsenic in

  2. Lead isotopic compositions in olivine-hosted melt inclusions from HIMU basalts and possible link to sulfide components

    NASA Astrophysics Data System (ADS)

    Yurimoto, Hisayoshi; Kogiso, Tetsu; Abe, Kanshi; Barsczus, Hans G.; Utsunomiya, Atsushi; Maruyama, Shigenori

    2004-08-01

    Pb isotopic compositions of melt inclusions in olivine phenocrysts of lava samples from Mangaia and Rarotonga, Cook-Austral islands, have been determined by secondary ion mass spectrometry. The Pb isotopic compositions of melt inclusions from Rarotonga are consistent with those of bulk rock. On the other hand, Pb isotopic compositions of sulfide-free melt inclusions from Mangaia Island are widely distributed along the join between HIMU (i.e. highly radiogenic Pb) and less radiogenic components. The variation is much wider than that in bulk-rock samples that are invariably end-member HIMU values. In contrast, Pb isotopic compositions of sulfide and carbonate inclusions are restricted to HIMU end-member values. The variations in Pb isotopic ratios can be explained by mixing between the HIMU component and another component with less radiogenic Pb, and suggests that the HIMU component is enriched in sulfide and carbonate phases as well as Pb compared with the less radiogenic component. It seems paradoxical that a sulfide-rich component is associated with highly radiogenic Pb, because sulfides generally have extremely low U/Pb and Th/Pb ratios, which result in quite unradiogenic Pb. Subducted oceanic crust is not a likely source for such a sulfide-rich component because sulfides in subducted crust may not survive dehydration processes in subduction zones, although it can produce highly radiogenic Pb. The association of highly radiogenic Pb and sulfides implies that sulfides and radiogenic Pb in the HIMU source originate from distinct reservoirs. A possible origin of the sulfides is the Earth's core, because the core is the largest sulfur budget in the Earth. The highly radiogenic Pb may originate from subducted oceanic crust which resides at the core-mantle boundary. Alternative source for radiogenic Pb is Ca-perovskite in the lower mantle, which is the main host of incompatible elements in the lower mantle and has high U/Pb and Th/Pb ratios. The core-derived sulfides

  3. Investigating the sources of the labile fraction in sediments from silicate-drained rocks using trace elements, and strontium and lead isotopes.

    PubMed

    Négrel, Philippe; Roy, Stéphane

    2002-10-21

    Elemental concentrations of the trace elements Rb, Sr, Th, Pb, Zn, Cu, Ni, Cd and Sb, as well as Sr and Pb isotopic compositions, were determined on the labile fraction (called acid-extracted matter AEM, Négrel et al., Chem. Geol. 166 (2000) 271-85) of soil and sediment along two small rivers located in the centre of France, one flowing from basalt, the other one on granite-gneiss. Oxide-mineral form in AEM (i.e. Fe-Mn oxides), acts as the main carrier phase. Analysis of the relationships between the trace elements, and lead and strontium isotopes allows the origin of the elements (i.e. natural and anthropogenic) and their history, both in the sediment and soil from the small watersheds to be assessed. Lead-isotope compositions in AEM display large fluctuation in the two watersheds and show a large scatter between natural input (basalt and granite), atmospheric input from gasoline, and input from past mining activities. On the basaltic watershed, Pb and other trace elements like Sb deriving from past mining waste are mainly related to atmospheric origin, while on the granitic terrain Pb originates from mineralization. The Sr-isotope compositions of AEM, water and residues are similar in the watershed draining basalt. On the watershed draining granite, AEM and streamwater shows 87Sr/86Sr ratios similar in the upstream part of the watershed and a divergence between the two ratios appears in the downstream part of the watershed implying that oxides have precipitated upstream and are not re-equilibrated during their transport downstream.

  4. Lead Speciation And Bioavailability In Apatite-Amended Sediments

    EPA Science Inventory

    The in situ sequestration of lead (Pb) in sediment with a phosphate amendment was investigated by Pb speciation and bioavailability. Sediment Pb in preamendment samples was identified as galena (PbS) with trace amounts of absorbed Pb. Sediment exposed to atmospheric conditions ...

  5. A novel in situ method for sampling urban soil dust: particle size distribution, trace metal concentrations, and stable lead isotopes.

    PubMed

    Bi, Xiangyang; Liang, Siyuan; Li, Xiangdong

    2013-06-01

    In this study, a novel in situ sampling method was utilized to investigate the concentrations of trace metals and Pb isotope compositions among different particle size fractions in soil dust, bulk surface soil, and corresponding road dust samples collected within an urban environment. The aim of the current study was to evaluate the feasibility of using soil dust samples to determine trace metal contamination and potential risks in urban areas in comparison with related bulk surface soil and road dust. The results of total metal loadings and Pb isotope ratios revealed that soil dust is more sensitive than bulk surface soil to anthropogenic contamination in urban areas. The new in situ method is effective at collecting different particle size fractions of soil dust from the surface of urban soils, and that soil dust is a critical indicator of anthropogenic contamination and potential human exposure in urban settings.

  6. Determination of the geographic origin of rice by chemometrics with strontium and lead isotope ratios and multielement concentrations.

    PubMed

    Ariyama, Kaoru; Shinozaki, Miyuki; Kawasaki, Akira

    2012-02-22

    The objective of this study was to develop a technique for determining the country of origin of rice in the Japanese market. The rice samples included a total of 350 products grown in Japan (n = 200), the United States (n = 50), China (n = 50), and Thailand (n = 50). In this study, (87)Sr/(86)Sr and Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios and multielement concentrations (Al, Fe, Co, Ni, Cu, Rb, Sr, and Ba) were determined by high-resolution inductively coupled plasma mass spectrometry. By combining three chemometric techniques based on different principles and determination criteria, the countries of origin of rice were determined. The predictions made by 10-fold cross-validation were around 97% accurate. The presented method demonstrated the effectiveness of determining the geographic origin of an agricultural product by combining several chemometric techniques using heavy element isotope ratios and multielement concentrations.

  7. Post-eruptive alteration of silicic ignimbrites and lavas, Gran Canaria, Canary Islands: Strontium, neodymium, lead, and oxygen isotopic evidence

    SciTech Connect

    Cousens, B.L. ); Spera, F.J. ); Dobson, P.F. )

    1993-02-01

    Isotopic analyses of Miocene comenditic, pantelleritic, and trachyphonolitic ignimbrites and lavas from Gran Canaria, Canary Islands, provide evidence for posteruptive mobility of Rb, Sr, and O. Calculated initial [sup 87]Sr/[sup 86]Sr ratios in whole-rock samples from basaltic lavas and feldspar mineral separates from ignimbrites define a magmatic trend in the stratigraphic section, from ratios of 0.70340 at the base of the Mogan Formation to 0.70305 in the lower Fataga Formation. However, calculated apparent initial [sup 87]Sr/[sup 86]Sr ratios in hydrated vitrophyre and devitrified matrix separates range from 0.7035 to 0.7090. [delta][sup 18]O ratios in basalts and feldspars vary little, from +5.7 to +6.1, yet range from +6.5 to +15.0 in the ignimbrite matrices. In contrast to the Sr and O isotope ratios, Pb and Nd isotope ratios are identical within analytical error in feldspars and their silicic ignimbrite matrices. Sequential leaching experiments and the oxygen data suggest that low-temperature, posteruptive interaction with meteoric water, perhaps containing a small seawater component, has modified Rb and Sr concentrations in the matrices, such that calculated apparent initial [sup 87]Sr/[sup 86]Sr ratios are not those of the magmas when they were erupted. Mobilization of Rb and Sr must occur significantly after eurption. Nd and Pb isotope systems appear to be unaffected by this process. Therefore, [sup 87]Sr/[sup 86]Sr ratios determined by whole rock analysis of silicic rocks from hotspot-type oceanic islands are suspect and should not be incorporated into mantle tracer studies, although analysis of phenocrysts may produce useful data. 40 refs., 5 figs., 3 tabs.

  8. Helium- and lead-isotope geochemistry of oceanic volcanic rocks from the East Pacific and South Atlantic. Doctoral thesis

    SciTech Connect

    Graham, D.W.

    1987-01-01

    Glassy basalts erupted at young Pacific seamounts and along the mid-ocean ridge in the South Atlantic, and volcanic rocks from the island of St. Helena were studied for He and Pb isotopes. (U+TH)/He ages of seamount alkali basalts were determined from the isotope disequilibrium of (3)He/(4)He between He trapped in vesicles and that dissolved in the glass phase. The method allows alkalic lavas to be dated in the age range of 103 to 106 years. Tholclites at the EPR seamounts have He, Pb, Sr and Nd isotope compositions indistinguishable from MORB, while associated alkali basalts show more radiogenic signatures. The low (3)He/(4)He in the vesicles of alkali basalts (1.2-2.6 RA), their low helium concentrations, and systematic variations with extent of differentiation suggest that magmatic processes influence (3)He/(4)He in these alkalic lavas. Pb-Sr-Nd isotopes at Shimada seamount (17 deg N, 117 deg W) indicate the presence of enriched mantle beneath the East Pacific which resembles that beneath Samoa. Low (3)He/(4)He (4-5 RA) appears to be an inherent characteristic of the component. Much of the South Atlantic ridge axis displays (3)He/(4)He lower than normal MORB, and is apparently contaminated by off-axis hotspots. He-Pb systematics along the ridge suggest that (3)He/(4)He at St. Helena is less than MORB, consistent with values measured by in vacuo crushing of olivine and pyroxene in St. Helena rocks (approx. 5.8 RA).

  9. Reconstructing lead isotope exposure histories preserved in the growth layers of walrus teeth using the SHRIMP II ion microprobe

    SciTech Connect

    Stern, R.A.; Outridge, P.M.; Davis, W.J.; Stewart, R.E.A.

    1999-05-15

    Development of a microprobe technique to determine Pb isotope ratios within the growth layers of mammal teeth could have widespread applications in Pb toxicology, Pb pollution tracing, and human and animal ecology. Here, the SHRIMP II ion microprobe is shown to possess sufficient sensitivity, accuracy, and precision to satisfactorily determine Pb isotope ratios in the canine tooth cementum of a walrus (Odobenus rosmarus rosmarus), with a sampling resolution of 130 {micro}m. The tooth layers were estimated to contain only 1--3 {micro}g/gf Pb. By combining multiple replicates within each annual layer, the {+-}1 SE uncertainty was typically {+-}1% for {sup 206}Pb/{sup 207}Pb and {+-}0.5% for {sup 208}Pb/{sup 207}Pb. Significant isotopic differences were found between layers deposited at age 10 and ages 2, 27, and 30. This result, together with corroborative data on excised cementum fragments analyzed by thermal ionization mass spectrometry, indicates that the animal migrated into different geological terrains several times during its life. There was no evidence of exchange between the Pb deposited in early growth layers and more recent ambient Pb.

  10. Lead Isotope Compositions of Acid Residues from Olivine-Phyric Shergottite Tissint: Implications for Heterogeneous Shergottite Source Reservoirs

    NASA Technical Reports Server (NTRS)

    Moriwaki, R.; Usui, T.; Yokoyama, T.; Simon, J. I.; Jones, J. H.

    2015-01-01

    Geochemical studies of shergottites suggest that their parental magmas reflect mixtures between at least two distinct geochemical source reservoirs, producing correlations between radiogenic isotope compositions and trace element abundances. These correlations have been interpreted as indicating the presence of a reduced, incompatible element- depleted reservoir and an oxidized, incompatible- element-enriched reservoir. The former is clearly a depleted mantle source, but there is ongoing debate regarding the origin of the enriched reservoir. Two contrasting models have been proposed regarding the location and mixing process of the two geochemical source reservoirs: (1) assimilation of oxidized crust by mantle derived, reduced magmas, or (2) mixing of two distinct mantle reservoirs during melting. The former requires the ancient Martian crust to be the enriched source (crustal assimilation), whereas the latter requires isolation of a long-lived enriched mantle domain that probably originated from residual melts formed during solidification of a magma ocean (heterogeneous mantle model). This study conducts Pb isotope and trace element concentration analyses of sequential acid-leaching fractions (leachates and the final residues) from the geochemically depleted olivine-phyric shergottite Tissint. The results suggest that the Tissint magma is not isotopically uniform and sampled at least two geochemical source reservoirs, implying that either crustal assimilation or magma mixing would have played a role in the Tissint petrogenesis.

  11. Determination of the provenance of cocoa by soil protolith ages and assessment of anthropogenic lead contamination by pb/nd and lead isotope ratios.

    PubMed

    Manton, William I

    2010-01-27

    The Pb contents of chocolate and the products it flavors are among the highest of all commonly consumed substances. Others have shown that this Pb is acquired by cocoa beans after harvesting and is concentrated in their shells, portions of which are ground up with the cotyledons during processing. It is shown here that the shells also contain the lanthanides Nd and Sm, which they appear to take up more slowly than Pb when dried on bare soil. Consideration of Pb/Nd ratios, model Sm-Nd ages and the isotope ratios of Pb and Sr indicates that, in the absence of contamination, the relationship between Pb and Nd in shells is y = 13.1x(-0.383), where x is the Nd concentration in microg/kg and y is the Pb/Nd ratio. For cocoa powders, the relationship is y = 114x(-0.988). Samples that plot above these curves are probably contaminated. Model ages indicate where the cocoa of cocoa powders is grown, and these same considerations point to African samples being uncontaminated but samples from Asia containing 50% anthropogenic Pb of Australian origin. No measurable Pb contamination occurs during the transport of beans and the manufacture of chocolate.

  12. Chemical and isotopic studies of granitic Archean rocks, Owl Creek Mountains, Wyoming: Uranium-thorium-lead systematics of an Archean granite from the Owl Creek Mountains, Wyoming

    SciTech Connect

    Stuckless, J.S.; Nkomo, I.T.; Butt, K.A.

    1986-01-01

    Isotopic analyses of apparently unaltered whole-rock samples of a granite from the Owl Creek Mountains, Wyo., yield a lead-lead isochron age of 2730 {plus minus} 35 Ma, which is somewhat older than the age obtained by the rubidium-strontium whole-rock method. Thorium-lead data for the same samples deviate markedly from an isochronal relation; however, calculated initial {sup 208}Pb/{sup 204}Pb ratios correlate with whole-rock {delta}{sup 18}O values and lead to the conclusion that the {sup 232}Th-{sup 208}Pb data are not colinear because of an originally heterogeneous granitic magma. Relationships in the {sup 207}Pb/{sup 235}U-{sup 206}Pb/{sup 238}U system show that uranium was mobilized during early Laramide time or shortly before, such that most surface and shallow drill-core samples lost 60-80 percent of their uranium, and some fractured, deeper drill-core samples gained from 50 to 10,000 percent uranium. Fission-track maps show that much uranium is located along edges and cleavages of biotite and magnetic where it is readily accessible to oxidizing ground water. Furthermore, qualitative comparisons of uranium distribution in samples with excess radiogenic lead and in samples with approximately equilibrium amounts of uranium and lead suggest that the latter contain more uranium in these readily accessible sites. Unlike other granites that have uranium distributions and isotopic systematics similar to those observed in this study, the granite of the Owl Creek Mountains is not associated with economic uranium deposits.

  13. Comparison of digestion procedures and methods for quantification of trace lead in breast milk by isotope dilution inductively coupled plasma mass spectrometry

    PubMed Central

    Amarasiriwardena, Chitra J.; Jayawardene, Innocent; Lupoli, Nicola; Barnes, Ramon M.; Hernandez-Avila, Mauricio; Hu, Howard

    2014-01-01

    Measurement of lead in breast milk is an important public health consideration and can be technically quite challenging. The reliable and accurate determination of trace lead in human breast milk is difficult for several reasons including: potential for contamination during sample collection, storage, and analysis; complexities related to the high fat content of human milk; and poor analytic sensitivity at low concentrations. Breast milk lead levels from previous published studies should therefore be reviewed with caution. Due to the difficulty in identifying a method that would successfully digest samples with 100% efficiency, we evaluated three different digestion procedures including: (1) dry ashing in a muffle furnace, (2) microwave oven digestion, and (3) digestion in high pressure asher. High temperature, high pressure asher digestion was selected as the procedure of choice for the breast milk samples. Trace lead analysis was performed using isotope dilution (ID) inductively coupled plasma mass spectrometry (ICP-MS). Measured lead concentrations in breast milk samples (n = 200) from Mexico ranged from 0.2 to 6.7 ng ml−1. The precision for these measurements ranged from 0.27–7.8% RSD. Use of strict contamination control techniques and of a very powerful digestion procedure, along with an ID-ICP-MS method for lead determination, enables us to measure trace lead levels as low as 0.2 ng ml−1 in milk (instrument detection limit = 0.01 ng ml−1). PMID:24808927

  14. Comparison of digestion procedures and methods for quantification of trace lead in breast milk by isotope dilution inductively coupled plasma mass spectrometry.

    PubMed

    Amarasiriwardena, Chitra J; Jayawardene, Innocent; Lupoli, Nicola; Barnes, Ramon M; Hernandez-Avila, Mauricio; Hu, Howard; Ettinger, Adrienne S

    2013-01-01

    Measurement of lead in breast milk is an important public health consideration and can be technically quite challenging. The reliable and accurate determination of trace lead in human breast milk is difficult for several reasons including: potential for contamination during sample collection, storage, and analysis; complexities related to the high fat content of human milk; and poor analytic sensitivity at low concentrations. Breast milk lead levels from previous published studies should therefore be reviewed with caution. Due to the difficulty in identifying a method that would successfully digest samples with 100% efficiency, we evaluated three different digestion procedures including: (1) dry ashing in a muffle furnace, (2) microwave oven digestion, and (3) digestion in high pressure asher. High temperature, high pressure asher digestion was selected as the procedure of choice for the breast milk samples. Trace lead analysis was performed using isotope dilution (ID) inductively coupled plasma mass spectrometry (ICP-MS). Measured lead concentrations in breast milk samples (n = 200) from Mexico ranged from 0.2 to 6.7 ng ml(-1). The precision for these measurements ranged from 0.27-7.8% RSD. Use of strict contamination control techniques and of a very powerful digestion procedure, along with an ID-ICP-MS method for lead determination, enables us to measure trace lead levels as low as 0.2 ng ml(-1) in milk (instrument detection limit = 0.01 ng ml(-1)). PMID:24808927

  15. The electrooxidation mechanism of formic acid on platinum and on lead ad-atoms modified platinum studied with the kinetic isotope effect

    NASA Astrophysics Data System (ADS)

    Bełtowska-Brzezinska, M.; Łuczak, T.; Stelmach, J.; Holze, R.

    2014-04-01

    Kinetics and mechanism of formic acid (FA) oxidation on platinum and upd-lead ad-atoms modified platinum electrodes have been studied using unlabelled and deuterated compounds. Poisoning of the electrode surface by CO-like species was prevented by suppression of dissociative chemisorption of FA due to a fast competitive underpotential deposition of lead ad-atoms on the Pt surface from an acidic solution containing Pb2+ cations. Modification of the Pt electrode with upd lead induced a catalytic effect in the direct electrooxidation of physisorbed FA to CO2. With increasing degree of H/D substitution, the rate of this reaction decreased in the order: HCOOH > DCOOH ≥ HCOOD > DCOOD. HCOOH was oxidized 8.5-times faster on a Pt/Pb electrode than DCOOD. This primary kinetic isotope effect proves that the C-H- and O-H-bonds are simultaneously cleaved in the rate determining step. A secondary kinetic isotope effect was found in the dissociative chemisorption of FA in the hydrogen adsorption-desorption range on a bare Pt electrode after H/D exchange in the C-H bond, wherein the influence of deuterium substitution in the O-H group was negligibly small. Thus the C-H bond cleavage is accompanied by the C-OH and not the O-H bond split in the FA decomposition, producing CO-like species on the Pt surface sites.

  16. Evidencing lead deposition at the urban scale using "short-lived" isotopic signatures of the source term (Pb-Zn refinery)

    NASA Astrophysics Data System (ADS)

    Franssens, Matthias; Flament, Pascal; Deboudt, Karine; Weis, Dominique; Perdrix, Espéranza

    2004-09-01

    To demonstrate the ability of the lead isotope signature technique to evidence the spatial extent of an industrial Pb deposition plume at a local scale, dry deposition of lead in the urban environment of a Pb-Zn refinery was investigated, as a study case, using transient ("short-lived") isotopic signatures of the industrial source. Sampling campaigns were achieved in representative weather conditions, on an 8-h basis. Dry deposition rates measured downwind from refinery emissions (≈102-103 μg Pb m-2 h-1), cross-sectionally in a 3-5 km radius area around the plant, represent 10-100 times the urban background dry fallout, measured upwind, as well as fallout measured near other potential sources of anthropogenic Pb. The Pb-Zn refinery isotopic signature (approx. 1.100<206Pb/207Pb<1.135) is made identifiable, using the same set of Pb and Zn ores for 2 days before sampling and during field experiments, by agreement with the executive staff of the plant. This source signature is less radiogenic than signatures of urban background Pb aerosols (1.155<206Pb/207Pb<1.165) and minor sources of Pb aerosols (1.147<206Pb/207Pb<1.165). By a simple binary mixing model calculation, we established the extension of the industrial Pb deposition plume. Fifty to eighty percents of total lead settled by the dry deposition mode, 3-4 km away from the refinery, still have an industrial origin. That represents from 40 to 80 μg Pb m-2 h-1, in an area where the blood lead level exceeds 100 μg Pb l-1 for 30% of men and 12% of women living there. We demonstrate here that stable Pb isotope analysis is able to evidence the Pb dry deposition plume in stabilised aerodynamic conditions, using a short-lived source term, suggesting that this methodology is able to furnish valuable data to validate industrial Pb aerosols dispersion models, at the urban scale.

  17. New isomers in the full seniority scheme of neutron-rich lead isotopes: the role of effective three-body forces.

    PubMed

    Gottardo, A; Valiente-Dobón, J J; Benzoni, G; Nicolini, R; Gadea, A; Lunardi, S; Boutachkov, P; Bruce, A M; Górska, M; Grebosz, J; Pietri, S; Podolyák, Zs; Pfützner, M; Regan, P H; Weick, H; Alcántara Núñez, J; Algora, A; Al-Dahan, N; de Angelis, G; Ayyad, Y; Alkhomashi, N; Allegro, P R P; Bazzacco, D; Benlliure, J; Bowry, M; Bracco, A; Bunce, M; Camera, F; Casarejos, E; Cortes, M L; Crespi, F C L; Corsi, A; Denis Bacelar, A M; Deo, A Y; Domingo-Pardo, C; Doncel, M; Dombradi, Zs; Engert, T; Eppinger, K; Farrelly, G F; Farinon, F; Farnea, E; Geissel, H; Gerl, J; Goel, N; Gregor, E; Habermann, T; Hoischen, R; Janik, R; Klupp, S; Kojouharov, I; Kurz, N; Lenzi, S M; Leoni, S; Mandal, S; Menegazzo, R; Mengoni, D; Million, B; Morales, A I; Napoli, D R; Naqvi, F; Nociforo, C; Prochazka, A; Prokopowicz, W; Recchia, F; Ribas, R V; Reed, M W; Rudolph, D; Sahin, E; Schaffner, H; Sharma, A; Sitar, B; Siwal, D; Steiger, K; Strmen, P; Swan, T P D; Szarka, I; Ur, C A; Walker, P M; Wieland, O; Wollersheim, H-J; Nowacki, F; Maglione, E; Zuker, A P

    2012-10-19

    The neutron-rich lead isotopes, up to (216)Pb, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond (208)Pb.

  18. New isomers in the full seniority scheme of neutron-rich lead isotopes: the role of effective three-body forces.

    PubMed

    Gottardo, A; Valiente-Dobón, J J; Benzoni, G; Nicolini, R; Gadea, A; Lunardi, S; Boutachkov, P; Bruce, A M; Górska, M; Grebosz, J; Pietri, S; Podolyák, Zs; Pfützner, M; Regan, P H; Weick, H; Alcántara Núñez, J; Algora, A; Al-Dahan, N; de Angelis, G; Ayyad, Y; Alkhomashi, N; Allegro, P R P; Bazzacco, D; Benlliure, J; Bowry, M; Bracco, A; Bunce, M; Camera, F; Casarejos, E; Cortes, M L; Crespi, F C L; Corsi, A; Denis Bacelar, A M; Deo, A Y; Domingo-Pardo, C; Doncel, M; Dombradi, Zs; Engert, T; Eppinger, K; Farrelly, G F; Farinon, F; Farnea, E; Geissel, H; Gerl, J; Goel, N; Gregor, E; Habermann, T; Hoischen, R; Janik, R; Klupp, S; Kojouharov, I; Kurz, N; Lenzi, S M; Leoni, S; Mandal, S; Menegazzo, R; Mengoni, D; Million, B; Morales, A I; Napoli, D R; Naqvi, F; Nociforo, C; Prochazka, A; Prokopowicz, W; Recchia, F; Ribas, R V; Reed, M W; Rudolph, D; Sahin, E; Schaffner, H; Sharma, A; Sitar, B; Siwal, D; Steiger, K; Strmen, P; Swan, T P D; Szarka, I; Ur, C A; Walker, P M; Wieland, O; Wollersheim, H-J; Nowacki, F; Maglione, E; Zuker, A P

    2012-10-19

    The neutron-rich lead isotopes, up to (216)Pb, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond (208)Pb. PMID:23215071

  19. A study of radionuclides, metals and stable lead isotope ratios in sediments and soils in the vicinity of natural U-mineralisation areas in the Northern Territory.

    PubMed

    Frostick, A; Bollhöfer, A; Parry, D

    2011-10-01

    Australian guidelines recommend that tailings materials from uranium (U) mining and milling be contained without any detrimental impact on the environment for at least 1000 years. Natural analogue sites are being investigated to determine if they can provide data on the rates of natural erosion processes which occur over these timescales, for input into predictive geomorphic computer models. This paper presents radionuclide, metal and stable lead (Pb) isotope data from sediment cores and surface soils in the vicinity of two mineralised areas in the Alligator Rivers Region. Surface scrapes from the natural Anomaly #2, south of the Ranger mineral lease, exhibit radiogenic (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios, and elevated U and metal concentrations typical for a near surface U anomaly. In contrast, samples taken from the Koongarra mineral lease (KML) show radionuclide activity and metal concentrations similar to natural areas elsewhere in the Alligator Rivers Region and Pb isotope ratios are closer to present day average crustal ratios (PDAC), as the orebodies at KML are covered by surficial sand. A sediment core collected from Anbangbang Billabong, downstream of KML, exhibits small variations in Pb isotope ratios that indicate that approximately 1% of the upper sediments in the sediment core may be derived from material originating from the U anomaly at Koongarra.

  20. Determination of trace element concentrations and stable lead, uranium and thorium isotope ratios by quadrupole-ICP-MS in NORM and NORM-polluted sample leachates.

    PubMed

    Mas, J L; Villa, M; Hurtado, S; García-Tenorio, R

    2012-02-29

    This work focuses on the monitoring of the potential pollution in scenarios that involve NORM-related industrial activities (environmental or in-door scenarios). The objective was to develop a method to determine extent and origin of the contamination, suitable for monitoring (i.e. simple, fast and economical) and avoiding the use of too many different instruments. It is presented a radiochemical method that allows the determination of trace element concentrations and 206Pb/207Pb/208Pb, 238U/234U and 232Th/230Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA® extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area.

  1. Lead isotopes in lichen transplants around a Cu smelter in Russia determined by MC-ICP-MS reveal transient records of multiple sources.

    PubMed

    Spiro, B; Weiss, D J; Purvis, O W; Mikhailova, I; Williamson, B J; Coles, B J; Udachin, V

    2004-12-15

    Transplants of the lichen Hypogymnia physodes, which is relatively tolerant to SO2 and heavy metals, were deployed for 3 months over a 60 km long SW-NE transect centered on a highly polluting Cu smelter and its adjoining town of Karabash, southern Urals, Russia. The abundance of 206Pb, 207Pb, 208Pb, and 204Pb were determined by MC-ICP-MS. The measurement of 204Pb revealed critical features, which would otherwise remain concealed: (i) The precise isotope ratios referenced to 204Pb allowed several different sources to be resolved even within the small area covered: (a) the obvious pollutant source of the Karabash Cu smelter; (b) two dispersed sources, likely to include soil with lower and different contributions of thorogenic and uranogenic lead; and (c) one anthropogenic source with higher contribution of 235U derived Pb. (ii) In part of the transect, the Pb isotope composition changed while the Pb concentrations remained the same. This indicates that the Pb content of the transplantation material from the background site was largely replaced and that the transplants provide a transient record reflecting a continuous accumulation and loss of environmental Pb, probably mainly in the form of extracellular particles. Overall, the method of lichen transplantation coupled with Pb isotope ratio determinations proved effective in assessing the usefulness of lichens in biomonitoring and in resolving different sources of atmospheric deposition.

  2. Reconstruction of historical atmospheric Pb using Dutch urban lake sediments: a Pb isotope study.

    PubMed

    Walraven, N; van Os, B J H; Klaver, G Th; Middelburg, J J; Davies, G R

    2014-06-15

    Lake sediments provide a record of atmospheric Pb deposition and changes in Pb isotope composition. To our knowledge, such an approach has not previously been performed in The Netherlands or linked to national air monitoring data. Results are presented for Pb content and isotope composition of (137)Cs dated lake sediments from 2 Dutch urban lakes. Between 1942 and 2002A.D. anthropogenic atmospheric Pb deposition rates in the two lakes varied from 12±2 to 69±16μgcm(-2)year(-1). The rise and fall of leaded gasoline is clearly reflected in the reconstructed atmospheric Pb deposition rates. After the ban on leaded gasoline, late 1970s/early 1980s, atmospheric Pb deposition rates decreased rapidly in the two urban lakes and the relative contributions of other anthropogenic Pb sources - incinerator ash (industrial Pb) and coal/galena - increased sharply. Atmospheric Pb deposition rates inferred from the lake record a clear relationship with nearby measured annual mean air Pb concentrations. Based on this relationship it was estimated that air Pb concentrations between 1942 and 2002A.D. varied between 5 and 293ng/m(3).

  3. Uranium-lead Isotope Evidence in the Shelyabinsk LL5 Chondrite Meteorite for Ancient and Recent Thermal Events

    NASA Technical Reports Server (NTRS)

    Lapen, T. J.; Kring, D. A.; Zolensky, M. E.; Andreasen, R.; Righter, M.; Swindle, T. D.; Beard, S. P.; Swindle, T. D.

    2014-01-01

    The impact histories on chondrite parent bodies can be deduced from thermochronologic analyses of materials and isotope systems with distinct apparent closure temperatures. It is especially critical to better understand the geological histories and physical properties of potenally hazardous near-Earth asteroids. Chelyabinsk is an LL5 chondrite meteorite that was dispersed over a wide area tens of kilometers south of the town of Chelyabinsk, Russia by an explosion at an altitude of 27 km at 3:22 UT on 15 Feb 2013 [1,2]. The explosion resulted in significant damage to surrounding areas and over 1500 injuries along with meteorite fragments being spread over a wide area [1].

  4. Isotopic identification of natural vs. anthropogenic lead sources in marine sediments from the inner Ría de Vigo (NW Spain).

    PubMed

    Álvarez-Iglesias, P; Rubio, B; Millos, J

    2012-10-15

    San Simón Bay, the inner part of the Ría de Vigo (NW Spain), an area previously identified as highly polluted by Pb, was selected for the application of Pb stable isotope ratios as a fingerprinting tool in subtidal and intertidal sediment cores. Lead isotopic ratios were determined by inductively coupled plasma mass spectrometry on extracts from bulk samples after total acid digestion. Depth-wise profiles of (206)Pb/(207)Pb, (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)Pb and (208)Pb/(207)Pb ratios showed, in general, an upward decrease for both intertidal and subtidal sediments as a consequence of the anthropogenic activities over the last century, or centuries. Waste channel samples from a nearby ceramic factory showed characteristic Pb stable isotope ratios different from those typical of coal and petrol. Natural isotope ratios from non-polluted samples were established for the study area, differentiating sediments from granitic or schist-gneiss sources. A binary mixing model employed on the polluted samples allowed estimating the anthropogenic inputs to the bay. These inputs represented between 25 and 98% of Pb inputs in intertidal samples, and 9-84% in subtidal samples, their contributions varying with time. Anthropogenic sources were apportioned according to a three-source model. Coal combustion-related emissions were the main anthropogenic source Pb to the bay (60-70%) before the establishment of the ceramic factory in the area (in the 1970s) which has since constituted the main source (95-100%), followed by petrol-related emissions. The Pb inputs history for the intertidal area was determined for the 20th century, and, for the subtidal area, the 19th and 20th centuries.

  5. Uranium-Lead Zircon Ages and Sr, Nd, and Pb Isotope Geochemistry of Selected Plutonic Rocks from Western Idaho

    USGS Publications Warehouse

    Unruh, Daniel M.; Lund, Karen; Kuntz, Mel A.; Snee, Lawrence W.

    2008-01-01

    Across the Salmon River suture in western Idaho, where allochthonous Permian to Cretaceous oceanic rocks are juxtaposed against Proterozoic North American rocks, a wide variety of plutonic rocks are exposed. Available data indicate much variation in composition, source, and structural state of these plutons. The plutonic rocks were long described as the western border zone of the Cretaceous Idaho batholith but limited pre-existing age data indicate more complicated origins. Because the affinity and age of the plutonic rocks cannot be reliably determined from field relations, TIMS U-Pb dating in conjunction with Sr, Nd, and Pb isotopic studies of selected plutons across the suture in western Idaho were undertaken. The data indicate three general groups of plutons including (1) those that intruded the island arc terranes during the Triassic and Jurassic, those that intruded near the western edge of oceanic rocks along the suture in the Early Cretaceous, and the plutons of the Idaho batholith that intruded Proterozoic North American rocks in the Late Cretaceous. Plutons that intruded Proterozoic North American rocks commonly include xenocrystic zircons and in several cases, ages could not be determined. The least radiogenic Sr and most radiogenic Nd are found among the Blue Mountains superterrane island arc samples. Suture-zone plutons have isotopic characteristics that span the range between Idaho batholith and island arc samples but mostly follow island arc signatures. Plutons of the Idaho batholith have the most radiogenic initial Pb and Sr ratios and the least radiogenic Nd of the samples analyzed.

  6. Comparison of the concentrations of metal elements and isotopes of lead found in rice and rice bran.

    PubMed

    Dai, Shouhui; Yang, Hui; Yang, Lan; Wang, Fuhua; Du, Ruiying; Wen, Dian

    2014-08-01

    Very few studies have investigated the difference in the distribution of metal elements between rice and rice bran samples. In this study, the concentrations of 27 metal elements (Li, Be, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb, and U) in 56 polished rice and their corresponding bran samples were determined. A significant difference in concentrations of all elements except Ag and Cd was found between rice and bran (P < 0.05), with bran/rice ratios of 1.21 to 36.3. High concentrations of metal elements, especially that of the heavy metal Cr, in bran samples present a potential safety issue for bran products, such as food and feed containing bran. Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios also were determined. The (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios in bran were generally higher than those in rice (P < 0.0001), and rice and bran samples were distinctly different from each other, indicating that Pb isotope composition is an effective for discriminating between bran and rice samples.

  7. Comparison of the concentrations of metal elements and isotopes of lead found in rice and rice bran.

    PubMed

    Dai, Shouhui; Yang, Hui; Yang, Lan; Wang, Fuhua; Du, Ruiying; Wen, Dian

    2014-08-01

    Very few studies have investigated the difference in the distribution of metal elements between rice and rice bran samples. In this study, the concentrations of 27 metal elements (Li, Be, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb, and U) in 56 polished rice and their corresponding bran samples were determined. A significant difference in concentrations of all elements except Ag and Cd was found between rice and bran (P < 0.05), with bran/rice ratios of 1.21 to 36.3. High concentrations of metal elements, especially that of the heavy metal Cr, in bran samples present a potential safety issue for bran products, such as food and feed containing bran. Pb isotope ((204)Pb, (206)Pb, (207)Pb, and (208)Pb) ratios also were determined. The (206)Pb/(207)Pb and (208)Pb/(207)Pb ratios in bran were generally higher than those in rice (P < 0.0001), and rice and bran samples were distinctly different from each other, indicating that Pb isotope composition is an effective for discriminating between bran and rice samples. PMID:25198608

  8. Identification of trace metal pollution in urban dust from kindergartens using magnetic, geochemical and lead isotopic analyses

    NASA Astrophysics Data System (ADS)

    Zhu, Zongmin; Sun, Guangyi; Bi, Xiangyang; Li, Zhonggen; Yu, Genhua

    2013-10-01

    In the present study, magnetic measurements were combined with geochemical analysis and stable Pb isotopic ratios to reveal the distribution and origination of trace metal pollutants in kindergarten dusts from a typical urban environment of Wuhan, central China. The geoaccumulation index (Igeo) of magnetic properties was more prominent than those of individual metals. The magnetic susceptibility (MS) and trace metals (Zn, Pb, and Cu) in this study together with published results from other Chinese cities formed a liner relationship, suggesting that metal contaminants in Chinese urban areas had similar MS to metal ratios, which could be used as an indicator for identification of pollution sources between Chinese cities and the other Asian cities. Stable Pb isotopic ratios (1.1125-1.1734 for 206Pb/207Pb and 2.4457-2.4679 for 208Pb/207Pb) in the urban dusts from Wuhan were characterized by higher 208Pb component in comparison with those from other Chinese cities. This result combined with principal component analysis (PCA) indicated that metal pollutants in the dusts were derived from industrial activities and coal combustion, whereas the traffic emissions were no longer a predominant pollution source in urban environment. Our study demonstrated that environmental magnetic methods could not only reveal the overall situation of trace metal contamination, but also prove evidence in the identification of pollution sources.

  9. Distribution of toxic elements and transfer from the environment to humans traced by using lead isotopes. A case of study in the Sarno River basin, south Italy.

    PubMed

    Cicchella, Domenico; Hoogewerff, Jurian; Albanese, Stefano; Adamo, Paola; Lima, Annamaria; Taiani, Manuela V E; De Vivo, Benedetto

    2016-04-01

    The results of a large geochemical study on various environmental media (soil, stream sediment, groundwater, surface water, lettuce and human hair) of the Sarno River basin, which is one of the most polluted areas in Italy, are presented. Further, it aims to deepen our understanding of the distribution of Pb and its isotope composition for the differentiation between natural and anthropogenic metal sources. Our results show the environmental media to be significantly enriched in Cr, Cu, Pb, Hg, Zn, and to a lesser extent in Sb, Cd and Ni compared to the natural local background variation. The numerous industrial activities (mainly tanneries) have caused environmental pollution especially Cr and Hg in soils and sediment samples. Such contamination is also evident in lettuce and in the hair of the resident population, which shows particularly high values for both Cr and Hg. The unusually high As, Be and Sn concentrations arise mostly from natural sources due to the volcanic nature of the investigated area. Lead isotope measurements indicate a trend suggesting mixing between two end-members, one of clear natural origin (geogenic) and another related to human activities (anthropogenic). Lead isotope results demonstrate that Pb in hair of inhabitants is similar to those in the local topsoil and that gasoline is one of the main, but not the only source of metal pollution. The most important exposure risks within the study area are associated with toxic elements levels in topsoil and stream sediment, and the ingestion of locally grown lettuce. The high concentrations of these elements in hair are a further confirmation of this exposure pathway.

  10. Source and distribution of lead in the surface sediments from the South China Sea as derived from Pb isotopes.

    PubMed

    Zhu, Laimin; Guo, Laodong; Gao, Ziyou; Yin, Guan; Lee, Ben; Wang, Fei; Xu, Jiang

    2010-11-01

    Rapid economic development in East Asian countries has inevitably resulted in environmental degradation in the surrounding seas, and concern for the environment and its protection against pollutants is increasing. Identification of sources of contaminants and evaluation of current environmental status are essential to environmental pollution management, but relatively little has been done in the South China Sea (SCS). In order to investigate the abundance, distribution, and sources of Pb within the SCS, stable Pb isotopes and their ratios were employed to assess the contamination status and to differentiate between natural and anthropogenic origins of Pb in the surface sediments. The total Pb concentrations in sediments varied from 4.18 to 58.7 mg kg(-1), with an average concentration of 23.6 ± 8.9 mg kg(-1). The observed Pb isotope ratios varied from 18.039 to 19.211 for (206)Pb/(204)Pb, 15.228 to 16.080 for (207)Pb/(204)Pb, 37.786 to 39.951 for (208)Pb/(204)Pb, 1.176 to 1.235 for (206)Pb/(207)Pb, and 2.468 to 2.521 for (208)Pb/(207)Pb. The majority of these ratios are similar to those reported for natural detrital materials. Combined with Pb enrichment factor values, our results show that Pb found within most of the SCS sediments was mainly derived from natural sources, and that there was not significant Pb pollution from anthropogenic sources before 1998. Further studies are needed to reconstruct deposition history and for trend analysis.

  11. Using biochemical and isotope geochemistry to understand the environmental and public health implications of lead pollution in the lower Guadiana River, Iberia: a freshwater bivalve study.

    PubMed

    Company, R; Serafim, A; Lopes, B; Cravo, A; Shepherd, T J; Pearson, G; Bebianno, M J

    2008-11-01

    Lead is a natural component of aquatic ecosystems with no known biological role and is highly toxic. Its toxicity stems from its ability to mimic biologically important metals and to produce membrane damage through lipid peroxidation (LPO). Most lead poisoning symptoms are thought to occur by interfering with an essential enzyme, delta-aminolevulinic acid dehydratase (ALAD), the activity of which is markedly inhibited by lead. The purpose of this work was to study the levels and effects of lead pollution (responses of ALAD and oxidative stress biomarker LPO) in the freshwater bivalve Corbicula fluminea along the lower Guadiana River (Portugal and Spain); a major river system impacted by historic mining pollution and more recent anthropogenic inputs. The results show that the enzymatic activity of ALAD is negatively correlated with the total Pb concentration of the whole tissue suggesting that ALAD has considerable potential as a biomarker of lead exposure in C. fluminea. To identify the sources of lead to which bivalves have been exposed, high precision (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)/Pb ratios for C. fluminea confirm that historical mining activities in the Iberian Pyrite Belt are the dominant source of lead pollution in the lower Guadiana River. The isotope patterns however exhibit marked seasonal and geographic variation in response to rainfall and river water management. Locally, other anthropogenic sources of lead have been detected in C. fluminea close to population centres, thus adding to its versatility as a freshwater bio-indicator. Overall, the study highlights the value of natural ecosystems as monitors of water quality and their importance for public health assessment and surveillance.

  12. Sulfur isotope study of the Velardeña skarn (Zn-Pb), Durango, Mexico

    NASA Astrophysics Data System (ADS)

    Jimenez, A.

    2012-04-01

    Sulfur isotope study of the Velardeña skarn (Zn-Pb), Durango, Mexico Abigail Jimenez-Franco1*, Pura Alfonso Abella2, Carles Canet3, Eduardo González-Partida4 1 Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Ciudad Universitaria, Delegación Coyoacán, 04510 México D.F., Mexico 2 Departament d'Enginyeria Minera i Recursos Naturals, Universitat Politècnica de Catalunya, Av de Les Bases de Manresa 61-73, 08242 Manresa. 3Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, Delegación Coyoacán, 04510 México D.F., Mexico 4Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, 76230 Santiago de Querétaro, Qro., Mexico The Velardeña mining district is located in north-eastern part of the state of Durango, in northern of Mexico. The ore deposit is a lead-zinc, garnet-rich skarn developed at the contact between granite porphyry dikes (Eocene) and well-laminated limestones with interbedded chert (Albian-Cenomanian). A study of sulfur isotopes has been carried out in various sulfide minerals of the ores of Velardeña, in order to: (a) constrain the possible sources of sulfur and, therefore, better understand the sulfide mineralizing processes, and (b) to estimate the temperature of the ore-forming stage of the skarn. Sulfur isotope analyses were performed in 21 pure fractions of sulfide minerals of the ore mineralization (pyrite, chalcopyrite, sphalerite and galena). The mineral separation was performed using a series of sieves, and the purity of the samples was verified under a binocular microscope. Isotopic analyses were done on a Finnigan MAT Delta C flow elemental analyzer coupled to a TC-EA, according with the method of Giesemann et al. (1974). The δ34S values of the analyzed sulfides range mostly between -0.6 and +2.6 ‰ (relative to the CDT standard). These values are indicative of a magmatic source of sulfur. A single analysis falls

  13. Anthropogenic and natural lead isotopes in Fe-hydroxides and Fe-sulphates in a watershed associated with arsenic-enriched groundwater, Maine, USA

    USGS Publications Warehouse

    Ayuso, Robert A.; Foley, Nora K.

    2008-01-01

    A survey of the natural and anthropogenic sources of lead contributing to secondary minerals in sulphidic schists associated with arsenic-enriched groundwater in Coastal Maine shows that the most likely source is natural Pb, particularly from coexisting sulphide minerals. The secondary minerals also reflect notable contributions from anthropogenic Pb. The Pb isotopes establish pathways by which Pb, and by inference As, could have been transported from As-bearing minerals (arsenian pyrite, arsenopyrite, lollingite, orpiment, arsenic oxide and others), via sulphide oxidation or carbonation reactions into multiple generations of secondary minerals (goethite, hematite, jarosite, natrojarosite and others). Lead isotopic compositions of the sulphides and secondary minerals determined by thermal ionization mass spectrometry (n=53) range widely. Lead and As contents of the sulphides and secondary minerals overlap, and are generally positively correlated. Pyrite, the dominant sulphide in sulphidic schists associated with As-enriched groundwater in Coastal Maine, has values of 206Pb/204Pb from 18.186 to 18.391, 207Pb/204Pb from 15.617 to 15.657, 208Pb/204Pb from 38.052 to 38.210, 206Pb/207Pb from c. 1.1625 to 1.1760 and 208Pb/207Pb from c. 2.4276 to 2.4394. Mixtures of Fe-hydroxide and oxide minerals (predominantly goethite and hematite) and secondary Fe-sulphate minerals (jarosite, natrojarosite, rozenite and melanterite) in the sulphidic schists have overlapping but generally higher values of 206Pb/204Pb from 18.495 to 19.747 (one sample at 21.495), 207Pb/204Pb from 15.595 to 15.722 (one sample at 15.839), 208Pb/204Pb from 38.186 to 39.162,206Pb/207Pb from c.1.1860 to 1.2575 (one sample at 1.3855) and 208Pb/207Pb from c. 2.4441 to 2.4865 than the sulphides. Sulphides from Zn-Pb metal mines are somewhat less radiogenic than sulphides from the schists. Other sulphides (mostly pyrite) associated with pegmatites and granitic rocks are heterogeneous and more

  14. Metal/metalloid contamination and isotopic composition of lead in edible mushrooms and forest soils originating from a smelting area.

    PubMed

    Komárek, Michael; Chrastný, Vladislav; Stíchová, Jana

    2007-07-01

    High metal contents in edible mushrooms growing in severely contaminated industrial areas pose an important toxicological risk. In the presented study, trace element (Pb, Cd, Zn, Cu, Ag, As, Se) contents were determined in caps and stipes of three different edible mushroom species (Boletus edulis Bull. Fr., Xerocomus badius Fr. Gilb., Xerocomus chrysenteron Bull. Quél.). Additionally, information about the chemical fractionation of metals in separate soil horizons and Pb isotopic data from soils and fruiting bodies allowed a more detailed insight on the uptake mechanisms of metals by the studied mushroom species. Total metal and metalloid concentrations in the organic soil horizons reached 36234 mg Pb kg(-1); 11.9 mg Cd kg(-1); 519 mg Zn kg(-1); 488 mg Cu kg(-1); 25.1 mg Ag kg(-1); 120 mg As kg(-1) and 5.88 Se mg kg(-1). In order to evaluate the accumulation capacity of the studied species, bioconcentration factors (BCF) were calculated for separate trace elements. For selected metals (Pb, Cd, Zn, Cu), a modified BCF calculation (using EDTA-extractable concentrations of metals in soil) was proposed. High contents of Pb (up to 165 mg kg(-1)) and Cd (up to 55 mg kg(-1)) exceeded all the regulatory limits in all the studied species. This was also the case for Se (up to 57 mg kg(-1)) in B. edulis. Intensive consumption of this species grown in such polluted areas can therefore pose toxicological risks for human health. A novel finding was that X. badius can act as an Ag accumulating species when grown at polluted sites due to the high concentrations of Ag (up to 190 mg kg(-1)) in caps. Pb isotopic data showed that Pb originating from the recent air pollution control residues is present mainly in the exchangeable/acid-extractable fraction of the organic horizons and is taken up by fruiting bodies; especially in the case of B. edulis, where fast Pb accumulation occurs. Due to the high species-dependent variations of metal contents, the studied mushrooms are not suitable

  15. A century long sedimentary record of anthropogenic lead (Pb), Pb isotopes and other trace metals in Singapore.

    PubMed

    Chen, Mengli; Boyle, Edward A; Switzer, Adam D; Gouramanis, Chris

    2016-06-01

    Reconstructing the history of metal deposition in Singapore lake sediments contributes to understanding the anthropogenic and natural metal deposition in the data-sparse Southeast Asia. To this end, we present a sedimentary record of Pb, Pb isotopes and eleven other metals (Ag, As, Ba, Cd, Co, Cr, Cu, Ni, Tl, U and Zn) from a well-dated sediment core collected near the depocenter of MacRitchie Reservoir in central Singapore. Before the 1900s, the sedimentary Pb concentration was less than 2 mg/kg for both soil and sediment, with a corresponding (206)Pb/(207)Pb of ∼1.20. The Pb concentration increased to 55 mg/kg in the 1990s, and correspondingly the (206)Pb/(207)Pb decreased to less than 1.14. The (206)Pb/(207)Pb in the core top sediment is concordant with the (206)Pb/(207)Pb signal of aerosols in Singapore and other Southeast Asian cities, suggesting that Pb in the reservoir sediment was mainly from atmospheric deposition. Using the Pb concentration in the topmost layer of sediment, the estimated atmospheric Pb flux in Singapore today is ∼1.6 × 10(-2) g/m(2) yr. The concentrations of eleven other metals preserved in the sediment were also determined. A principal component analysis showed that most of the metals exhibit an increasing trend towards 1990s with a local concentration peak in the mid-20(th) century.

  16. A century long sedimentary record of anthropogenic lead (Pb), Pb isotopes and other trace metals in Singapore.

    PubMed

    Chen, Mengli; Boyle, Edward A; Switzer, Adam D; Gouramanis, Chris

    2016-06-01

    Reconstructing the history of metal deposition in Singapore lake sediments contributes to understanding the anthropogenic and natural metal deposition in the data-sparse Southeast Asia. To this end, we present a sedimentary record of Pb, Pb isotopes and eleven other metals (Ag, As, Ba, Cd, Co, Cr, Cu, Ni, Tl, U and Zn) from a well-dated sediment core collected near the depocenter of MacRitchie Reservoir in central Singapore. Before the 1900s, the sedimentary Pb concentration was less than 2 mg/kg for both soil and sediment, with a corresponding (206)Pb/(207)Pb of ∼1.20. The Pb concentration increased to 55 mg/kg in the 1990s, and correspondingly the (206)Pb/(207)Pb decreased to less than 1.14. The (206)Pb/(207)Pb in the core top sediment is concordant with the (206)Pb/(207)Pb signal of aerosols in Singapore and other Southeast Asian cities, suggesting that Pb in the reservoir sediment was mainly from atmospheric deposition. Using the Pb concentration in the topmost layer of sediment, the estimated atmospheric Pb flux in Singapore today is ∼1.6 × 10(-2) g/m(2) yr. The concentrations of eleven other metals preserved in the sediment were also determined. A principal component analysis showed that most of the metals exhibit an increasing trend towards 1990s with a local concentration peak in the mid-20(th) century. PMID:26967352

  17. FORMATION OF CHLOROPYROMORPHITE FROM GALENA (PBS) IN THE PRESENCE OF HYDROXYAPATITE

    EPA Science Inventory

    Transformation of unstable lead [Pb(II)] forms into insoluble pyromorphite, [Pb5(PO4)3(OH, Cl, F...)], by addition of phosphate to Pb contaminated soil has been proposed as a remediation technology which reduces the mobility and bioavailability of Pb. Under aerobic condition, ox...

  18. 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

    USGS Publications Warehouse

    Seal, Robert R.; Ayuso, Robert A.; Foley, Nora K.; Clark, Sandra H.B.

    2001-01-01

    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 with pyrite–barite associations and provide insights into both the pre-metamorphic Late Proterozoic hydrothermal and the Paleozoic regional metamorphic histories of the deposit. The δ34S values of massive barite cluster tightly between 25.0 and 28.0‰, which closely match the published values for Late Proterozoic seawater and thus support a seafloor hydrothermal origin. The δ34S values of massive sulfide range from 1.0 to 5.3‰ and fall within the range of values observed for modern and ancient seafloor hydrothermal sulfide deposits. In contrast, δ34S values for finer-grained, intergrown pyrite (5.1–6.8‰) and barite (21.0–23.9‰) are higher and lower than their massive counterparts, respectively. Calculated sulfur isotope temperatures for the latter barite–pyrite pairs (Δ=15.9–17.1‰) range from 332–355 °C and probably reflect post-depositional equilibration at greenschist-facies regional metamorphic conditions. Thus, pyrite and barite occurring separately from one another provide pre-metamorphic information about the hydrothermal origin of the deposit, whereas pyrite and barite occurring together equilibrated to record the metamorphic conditions. Preliminary fluid inclusion data from sphalerite are consistent with a modified seawater source for the mineralizing fluids, but data from quartz and barite may reflect later metamorphic and (or) more recent meteoric water input. Lead isotope values from pyrites range for 206Pb/204Pb from 18.005–18.294, for 207Pb/204Pb from 15.567–15.645, and for 208Pb/204Pb from 37.555–38.015. The data

  19. Hydrogeology and water quality of the Galena-Platteville aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1991-92

    USGS Publications Warehouse

    Mills, P.C.

    1993-01-01

    The purpose of this letter is to describe the results of the final phase (phase 3) of the U.S. Geological Survey's (USGS) ground-water investigation at the Parson's Casket Hardware site, Belvidere, Ill. (figs. 1 and 2), for the U.S. Environmental Protection Agency (USEPA). Included in this letter are brief descriptions of (1) study methods employed in the phase 3 investigation that have not been previously described in earlier reports, and (2) results of the phase 3 investigation as they relate to the results of the previous phases of the investigation. The data from the phase 3 investigation that are presented and described herein were collected during November 1991-January 1992. The Galena-Platteville aquifer is the uppermost bedrock aquifer beneath the site. The Glenwood Formation of Ordovician age, a potential confining unit, separates the Galena-Platteville aquifer from the underlying St. Peter Sandstone aquifer (fig. 3). The St. Peter Sandstone aquifer is an important source of ground water to Belvidere and other cities in the region. The phase 3 investigation was done (1) to determine the lithology of the Glenwood Formation; (2) to determine the vertical distribution of horizontal hydraulic conductivity (K) and concentrations of volatile organic compounds (VOC's) in the upper 150 ft (feet) of the Galena-Platteville aquifer at an existing monitoring location, borehole G127GP (figs. 2 and 3) ; and (3) to confirm the presence or absence of VOC's in the St. Peter Sandstone aquifer at a new monitoring location, well G127SP (figs. 2 and 3). Additional components of the site investigation described in this letter include determination of vertical hydraulic gradients between the Galena-Platteville and St. Peter Sandstone aquifers and in situ measurement of selected water-quality characteristics (pH, temperature, specific conductance, Eh, and dissolved oxygen) in borehole G127GP. The results of the first and second phases of the USGS investigation at the Parson

  20. Ore genesis of the Weibao lead-zinc district, Eastern Kunlun Orogen, China: constrains from ore geology, fluid inclusion and isotope geochemistry

    NASA Astrophysics Data System (ADS)

    Fang, Jing; Chen, Huayong; Zhang, Li; Zheng, Yi; Li, Dengfeng; Wang, Chengming; Shen, Dengliang

    2015-07-01

    The Weibao lead-zinc district, composed by two deposits named the East Weibao deposit and the West Weibao deposit, respectively, is located in the Qimantagh area, Eastern Kunlun Orogen. Although both controlled by skarn alternation and experienced similar mineralization processes, the East Weibao deposit is dominated by massive ores, while the West Weibao deposit is characterized by banded ores. The ore-forming processes of both the deposits can be divided into four stages including prograde skarn stage, retrograde skarn stage, sulfide stage and carbonate stage. Three types of fluid inclusions, i.e., pure CO2 fluid inclusion (PC-type), CO2-bearing fluid inclusion (C-type) and aqueous types (W-type), have been identified in quartz, calcite and sphalerite from different stages. Noteworthily, only sulfide stage of the East Weibao deposit contains carbonic fluid inclusions, whereas only aqueous fluid inclusions were observed in sulfide stage of the West Weibao deposit. The CO2-rich and aqueous-type fluid inclusions in sulfide stage of the East Weibao deposit were homogenized at temperatures between 263 and 424 °C, concentrating at 360-400 °C, with salinities ranging between 3.2 and 13.6 wt% NaCl eqv.; the W-type fluid inclusions in sulfide stage of the West Weibao deposit were homogenized at temperatures between 228 and 381 °C, concentrating at 280-340 °C, with salinities between 1.6 and 9.0 wt% NaCl eqv.; and the aqueous-type fluid inclusions in carbonate stage in both deposits were homogenized at temperatures between 115 and 336 °C, concentrating at 200-240 °C, with salinities between 0.2 and 5.9 wt% NaCl eqv. The ore-forming fluid in sulfide stage at the East Weibao deposit yielded calculated and δ18D values of 4.2 to 5.6 and -88 to -83 ‰, respectively. The results are 8.8 to 10.8, -99 to -92 ‰ for the sulfide stage at the West Weibao deposit and -1.0 to -0.2, -50 to -45 ‰ for carbonate stages in both deposits. The lead isotopic ratios of sulfide

  1. Lead isotope ratios in bone ash of blesbok (Damaliscus pygargus phillipsi): a means of screening for the accumulation of contaminants from uraniferous rocks.

    PubMed

    Nöthling, Johan O; Du Toit, Johannes S; Myburgh, Jan G

    2014-09-19

    This study was done to determine whether blesbok (Damaliscus pygargus phillipsi) from the Krugersdorp Game Reserve (KGR) in Gauteng Province, South Africa have higher concentrations of (238)U and higher (206)Pb/(204)Pb and (207)Pb/(204)Pb ratios in their bone ash than blesbok from a nearby control reserve that is not exposed to mine water and has no outcrops of uraniferous rocks. Eight blesbok females from the KGR and seven from the control site, all killed with a brain shot, were used. A Thermo X-series 2 quadrupole ICPMS was used to measure the concentrations of (238)U and lead and a Nu Instruments NuPlasma HR MC-ICP-MS to measure the lead isotope ratios in the tibial ash from each animal. KGR blesbok had higher mean concentrations of (238)U (P = 0.02) and ratios of (206)Pb/(204)Pb and (207)Pb/(204)Pb (P < 0.00001) than the control blesbok. The probability of rejecting the false null hypothesis of no difference in the (206)Pb/(204)Pb or (207)Pb/(204)Pb ratios between KGR and control reserve animals (the power of the test) was 0.999. The blesbok from the KGR accumulated contaminants from an uraniferous environment. The (206)Pb/(204)Pb and (207)Pb/(204)Pb ratios in tibial ash proved effective in confirming accumulation of contaminants from uraniferous rocks.

  2. Revealing the powdering methods of black makeup in Ancient Egypt by fitting microstructure based Fourier coefficients to the whole x-ray diffraction profiles of galena

    NASA Astrophysics Data System (ADS)

    Ungár, T.; Martinetto, P.; Ribárik, G.; Dooryhée, E.; Walter, Ph.; Anne, M.

    2002-02-01

    Galena (PbS) is a major ingredient in ancient Egyptian eye makeup. The microstructure of PbS in Egyptian cosmetic powders is used as a fingerprint and is matched with the microstructures produced artificially in geological galena minerals. The microstructure of PbS is determined by x-ray diffraction peak profile analysis in terms of dislocation density, crystallite size, and size distribution. High-resolution powder diffractograms were measured at the ESRF Grenoble synchrotron source with high resolution and high peak-to-background ratios. The Fourier coefficients of the first nine measured reflections of galena are fitted using physically based Fourier coefficients of strain and size functions. Strain anisotropy is accounted for by the dislocation model of the mean square strain. The x-ray data are supplemented by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs, and are compared with archæological documents. It enables us to describe the procedures of eye makeup manufacturing in the Middle and New Kingdoms of Egypt some 2000 years before Christ.

  3. Lead fluxes and 206Pb/207Pb isotope ratios in rime and snow collected at remote mountain-top locations (Czech Republic, Central Europe): Patterns and sources

    NASA Astrophysics Data System (ADS)

    Cimova, Nikoleta; Novak, Martin; Chrastny, Vladislav; Curik, Jan; Veselovsky, Frantisek; Blaha, Vladimir; Prechova, Eva; Pasava, Jan; Houskova, Marie; Bohdalkova, Leona; Stepanova, Marketa; Mikova, Jitka; Krachler, Michael; Komarek, Arnost

    2016-10-01

    During three winter seasons (2009-2011), Pb concentrations were measured in precipitation at 10 high-elevation sites in the Czech Republic, close to the borders with Austria, Germany, Poland, and Slovakia. Soluble and insoluble Pb forms were quantified in snow (vertical deposition), and rime (horizontal deposition). The objective was to compare Pb input fluxes into ecosystems via vertical and horizontal deposition, and to identify the residual Pb pollution sources in an era of rapidly decreasing industrial pollution. Lead soluble in diluted HNO3 made up 96% of total Pb deposition, with the remaining 4% Pb bound mainly in silicates. Three times higher concentrations of soluble Pb in rime than in snow, and 2.5 times higher concentrations of insoluble Pb in rime than in snow were associated with slightly different Pb isotope ratios. On average, the 206Pb/207Pb ratios in rime were higher than those in snow. Higher mean 206Pb/207Pb ratios of insoluble Pb (1.175) than in soluble Pb (1.165) may indicate an increasing role of geogenic Pb in recent atmospheric deposition. A distinct reversal to more radiogenic 206Pb/207Pb ratios in snow and rime in 2010, compared to literature data from rain-fed Sphagnum peatlands (1800-2000 A.D.), documented a recent decrease in anthropogenic Pb in the atmosphere of Central Europe. Since the early 1980s, Pb concentrations in snow decreased 18 times in the rural south of the Czech Republic, but only twice in the industrial north of the Czech Republic. Isotope signatures indicated that Pb in today's atmospheric deposition is mainly derived from Mesozoic ores mined/processed in Poland and coal combustion in the Czech Republic and Poland.

  4. Uranium-lead isotope systematics and apparent ages of zircons and other minerals in precambrian granitic rocks, Granite Mountains, Wyoming

    USGS Publications Warehouse

    Ludwig, K. R.; Stuckless, J.S.

    1978-01-01

    Zircon suites from the two main types of granite in the Granite Mountains, Wyoming, yielded concordia-intercept ages of 2,640??20 m.y. for a red, foliated granite (granite of Long Creek Mountain) and 2,595??40 m.y. for the much larger mass of the granite of Lankin Dome. These ages are statistically distinct (40??20 m.y. difference) and are consistent with observed chemical and textural differences. The lower intercepts of the zircon chords of 50??40 and 100+ 75 m.y. for the granite of Long Creek Mountain and granite of Lankin Dome, respectively, are not consistent with reasonable continuous diffusion lead-loss curves but do correspond well with the known (Laramide) time of uplift of the rocks. Epidote, zircon, and apatite from silicified and epidotized zones in the granites all record at least one postcrystallization disturbance in addition to the Laramide event and do not define a unique age of silicification and epidotization. The lower limit of ???2,500 m.y. provided by the least disturbed epidote, however, suggests that these rocks were probably formed by deuteric processes shortly after emplacement of the granite of the Lankin Dome. The earlier of the two disturbances that affected the minerals of the silicified-epidotized rock can be bracketed between 1,350 and 2,240 m.y. ago and is probably the same event that lowered mineral K-Ar and ages in the region. Zircon suites from both types of granite show well-defined linear correlations among U content, common-Pb content, and degree of discordance. One of the zircon suites has an extremely high common-Pb content (up to 180 ppm) and exhibits a component of radiogenic-Pb loss that is apparently unrelated to radiation damage. ?? 1978 Springer-Verlag.

  5. Archean Pb Isotope Evolution: Implications for the Early Earth.

    NASA Astrophysics Data System (ADS)

    Vervoort, J. D.; Thorpe, R.; Albarede, F.; Blichert-Toft, J.

    2008-12-01

    The U-Pb isotope system provides us with a powerful tool for understanding the chemical evolution of the Earth. Pb isotopes in Archean rocks, however, have not been widely utilized because U mobility makes initial Pb isotope ratios from old silicate rocks difficult, if not impossible, to determine. Galenas in syngenetic volcanogenic massive sulfide (VMS) deposits, however, provide snapshots of initial Pb ratios because their Pb isotopic composition is time invariant at their formation (U/Pb=0). The Pb isotopic record from galenas from rocks of all age have been utilized for over 70 years to answer a wide range of scientific problems beginning with Al Nier's pioneering work analyzing Pb isotopes in the 1930's but are no longer widely used by the isotopic community because they have been produced by older TIMS techniques. We have begun a re-examination of Archean Pb by an extensive analysis of over 100 galena samples from Archean VMS deposits throughout the Superior and Slave Provinces in Canada as well as from other VMS deposits in Finland, South Africa and Western Australia. The goal of this work is to provide modern, high precision measurements and update an old, but venerable, Pb isotopic data set. We feel these data provide important constraints on not only the Pb isotopic evolution of the Earth, but planetary differentiation and recycling processes operating in the first 2 b.y. of Earth's history. Our analytical techniques include dissolving the Pb sulfide minerals, purifying them with ion chromatography, and analyzing them using MC-ICPMS at both Washington State University (Neptune) and Ecole Normale Superieure in Lyon, France (Nu). All Pb solutions are doped with Tl in order to correct for mass fractionation. In this abstract we report preliminary galena Pb isotope data from 6 VMS deposits in the Abitibi greenstone belt: Chibougamu, Matagami, Noranda, Normetal, Timmins, and Val d"Or. These deposits are all approximately 2.7 Ga in age but in detail vary from 2

  6. Origin of lead in eight Central European peat bogs determined from isotope ratios, strengths, and operation times of regional pollution sources.

    PubMed

    Novák, Martin; Emmanuel, Simon; Vile, Melanie A; Erel, Yigal; Véron, Alain; Paces, Tomás; Wieder, R Kelman; Vanecek, Mirko; Stepánová, Markéta; Brízová, Eva; Hovorka, Jan

    2003-02-01

    Lead originating from coal burning, gasoline burning, and ore smelting was identified in 210Pb-dated profiles through eight peat bogs distributed over an area of 60,000 km2. The Sphagnum-dominated bogs were located mainly in mountainous regions of the Czech Republic bordering with Germany, Austria, and Poland. Basal peat 14C-dated at 11,000 years BP had a relatively high 206Pb/207Pb ratio (1.193). Peat deposited around 1800 AD had a lower 206Pb/207Pb ratio of 1.168-1.178, indicating that environmental lead in Central Europe had been largely affected by human activity (smelting) even before the beginning of the Industrial Revolution. Five of the sites exhibited a nearly constant 206Pb/207Pb ratio (1.175) throughout the 19th century, resembling the "anthropogenic baseline" described in Northern Europe (1.17). At all sites, the 206Pb/207Pb ratio of peat decreased at least until 1980; at four sites, a reversal to more radiogenic values (higher 206Pb/207Pb), typical of easing pollution, was observed in the following decade (1980-1990). A time series of annual outputs for 14 different mining districts dispersing lead into the environment has been constructed for the past 200 years. The production of Ag-Pb, coal, and leaded gasoline peaked in 1900, 1980, and 1980, respectively. In contrast to other European countries, no peak in annual Pb accumulation rates was found in 1900, the year of maximum ore smelting. The highest annual Pb accumulation rates in peat were consistent with the highest Pb emission rates from coal-fired power plants and traffic (1980). Although maximum coal and gasoline production coincided in time, their isotope ratios were unique. The mean measured 206Pb/207Pb ratios of local coal, ores, and gasoline were 1.19, 1.16, and 1.11, respectively. A considerable proportion of coal emissions, relative to gasoline emisions, was responsible for the higher 206Pb/207Pb ratios in the recent atmosphere (1.15) compared to Western Europe (1.10). As in West European

  7. Geology and geochemistry of the Reocín zinc-lead deposit, Basque-Cantabrian Basin, Northern Spain

    USGS Publications Warehouse

    Velasco, Francisco; Herrero, Jose Miguel; Yusta, Inaki; Alonso, Jose Antonio; Seebold, Ignacio; Leach, David

    2003-01-01

    fluids responsible for sulfide deposition and the infilling of karst cavities were broadly contemporaneous, indicating a post-Albian age. Vitrinite reflectance data are consistent with previously measured fluid inclusion temperatures and indicate temperatures of ore deposition that were less than 100??C. Carbon and oxygen isotopic data from samples of regional limestone, host-rock dolostone and ore-stage dolomite suggest an early hydrothermal alteration of limestone to dolostone. This initial dolomitization was followed by a second period of dolomite formation produced by the mixing of basinal metal-rich fluids with local modified seawater. Both dolomitization events occurred under similar conditions from fluids exhibiting characteristics of basinal brines. The ??34S values of sulfides are between -1.8 and +8.5 per mil, which is consistent with thermochemical sulfate reduction involving organic matter as the main source of reduced sulfur. Galena lead isotope compositions are among the most radiogenic values reported for Zn-Pb occurrences in Europe, and they are distinct from values reported for galena from other Basque-Cantabrian deposits. This suggests that a significant part of the lead was scavenged from the local underlying Asturian sediments. The stratigraphic and structural setting, timing of epigenetic mineralization, mineralogy, and isotopic geochemistry of sulfide and gangue minerals of the Reoci??n deposit are consistent with the features of most of Mississippi Valley-type ore deposits.

  8. Trace Metal Inventories and Lead Isotopic Composition Chronicle a Forest Fire’s Remobilization of Industrial Contaminants Deposited in the Angeles National Forest

    PubMed Central

    Odigie, Kingsley O.; Flegal, A. Russell

    2014-01-01

    The amounts of labile trace metals: [Co] (3 to 11 µg g−1), [Cu] (15 to 69 µg g−1), [Ni] (6 to 15 µg g−1), [Pb] (7 to 42 µg g−1), and [Zn] (65 to 500 µg g−1) in ash collected from the 2012 Williams Fire in Los Angeles, California attest to the role of fires in remobilizing industrial metals deposited in forests. These remobilized trace metals may be dispersed by winds, increasing human exposures, and they may be deposited in water bodies, increasing exposures in aquatic ecosystems. Correlations between the concentrations of these trace metals, normalized to Fe, in ash from the fire suggest that Co, Cu, and Ni in most of those samples were predominantly from natural sources, whereas Pb and Zn were enriched in some ash samples. The predominantly anthropogenic source of excess Pb in the ash was further demonstrated by its isotopic ratios (208Pb/207Pb: 206Pb/207Pb) that fell between those of natural Pb and leaded gasoline sold in California during the previous century. These analyses substantiate current human and environmental health concerns with the pyrogenic remobilization of toxic metals, which are compounded by projections of increases in the intensity and frequency of wildfires associated with climate change. PMID:25259524

  9. Trace metal inventories and lead isotopic composition chronicle a forest fire's remobilization of industrial contaminants deposited in the angeles national forest.

    PubMed

    Odigie, Kingsley O; Flegal, A Russell

    2014-01-01

    The amounts of labile trace metals: [Co] (3 to 11 µg g-1), [Cu] (15 to 69 µg g-1), [Ni] (6 to 15 µg g-1), [Pb] (7 to 42 µg g-1), and [Zn] (65 to 500 µg g-1) in ash collected from the 2012 Williams Fire in Los Angeles, California attest to the role of fires in remobilizing industrial metals deposited in forests. These remobilized trace metals may be dispersed by winds, increasing human exposures, and they may be deposited in water bodies, increasing exposures in aquatic ecosystems. Correlations between the concentrations of these trace metals, normalized to Fe, in ash from the fire suggest that Co, Cu, and Ni in most of those samples were predominantly from natural sources, whereas Pb and Zn were enriched in some ash samples. The predominantly anthropogenic source of excess Pb in the ash was further demonstrated by its isotopic ratios (208Pb/207Pb: 206Pb/207Pb) that fell between those of natural Pb and leaded gasoline sold in California during the previous century. These analyses substantiate current human and environmental health concerns with the pyrogenic remobilization of toxic metals, which are compounded by projections of increases in the intensity and frequency of wildfires associated with climate change.

  10. Isotopic evidence for trapped fissiogenic REE and nucleogenic Pu in apatite and Pb evolution at the Oklo natural reactor

    NASA Astrophysics Data System (ADS)

    Horie, Kenji; Hidaka, Hiroshi; Gauthier-Lafaye, François

    2004-01-01

    A part of the boundary layer of reactor zone 10 at the Oklo natural reactor shows a unique petrologic texture, which contains high-grade uraninite and massive apatite concretions. In order to study distribution behavior of fission products around the boundary between the reactor zone and the wall rock and to clarify the relation of migration mechanisms of fission products with geochemical factors, in-situ isotopic analyses of Nd, Sm, Gd, Pb and U in uraninite and apatite from the sample were performed by Sensitive High Resolution Ion Microprobe (SHRIMP). Sm and Gd isotopic ratios of uraninite and apatite show evidence of neutron irradiation with fluence between 4.4-6.8×10 19 n/cm 2. Judging from the isotopic anomalies of Nd and U, the apatite coexisting with the uraninite plays an important role in trapping fissiogenic LREE and nucleogenic 239Pu into the structure. Systematic Pb isotopic data from apatite, uraninite, galena and minium suggest the following chronological interpretations. The apatite formed 1.92±0.01 Ga ago and trapped fissiogenic light REE and nucleogenic 239Pu that migrated from the reactor during the criticality. The uraninite around the boundary between reactor and sandstone dissolved once 1.1˜1.2 Ga ago. Galena grains were formed by U-Pb mobilization in association with the intrusion of dolerite dyke 0.45˜0.83 Ga ago. Minium was derived from recent dissolution of galena under locally oxidizing conditions.

  11. A comparison of lead-isotope measurements on exploration-type samples using inductively coupled plasma and thermal ionization mass spectrometry

    USGS Publications Warehouse

    Gulson, B.L.; Meier, A.L.; Church, S.E.; Mizon, K.J.

    1989-01-01

    Thermal ionization mass spectrometry (TI-MS) has long been the method of choice for Pb-isotope determinations. More recently, however, inductively coupled plasma mass spectrometry (ICP-MS) has been used to determine Pb-isotope ratios for mineral exploration. The ICP-MS technique, although not as precise as TI-MS, may promote a wider application of Ph-isotope ratio methods because it allows individual isotopes to be determined more rapidly, generally without need for chemical separation (e.g., Smith et al., 1984; Hinners et al., 1987). To demonstrate the utility of the ICP-MS method, we have conducted a series of Pb-isotope measurements on several suites of samples using both TI-MS and ICP-MS. ?? 1989.

  12. Geology, hydrology, and results of tracer testing in the Galena-Platteville aquifer at a waste-disposal site near Byron, Illinois

    USGS Publications Warehouse

    Kay, Robert T.; Yeskis, Douglas J.; Prinos, Scott T.; Morrow, William S.; Vendl, Mark

    1999-01-01

    A study was conducted by the U.S. Geological Survey and the U.S. Environmental Protection Agency of the geohydrology of the dolomite bedrock at a waste-disposal site near Byron, Illinois. The study was designed to identify and characterize the flow pathways through the bedrock aquifer beneath the site. The geologic units of concern at the site are the Glenwood Formation of the Ancell Group, and the Platteville and Galena Groups. These deposits compose the Galena-Platteville aquifer and the underlying Harmony Hill Shale semiconfining unit. The Galena-Platteville aquifer is an unconfined aquifer. Geophysical logging, water levels, and aquifer-test data indicate the presence of interconnected, hydraulically active fractures in the middle of the Galena-Platteville aquifer (the upper flow pathway), and a second set of hydraulically active fractures (the lower flow pathway). The lower flow pathway may be present through much of the site. Few hydraulically active fractures are present in the upper part of the aquifer near the center of the site, but appear to be more numerous in the upper part of the aquifer in the western and northeastern parts of the site. Water-level data obtained during the tracer test indicate that pumping effects were present near the pumped wells. Pumping effects may have been present at several wells located along directions of identified fracture orientation from the pumped well. The upper part of the aquifer did not appear to be hydraulically well connected to the flow pathways supplying water to the pumped well. Large background changes in water levels obscured the effects of pumping and prevented calculation of aquifer properties. The velocity of the bromide tracer through the lower flow pathway under the hydraulic gradient resulting from the pumping was about 152 feet per day. Solution of the Darcy velocity equation results in a calculated effective porosity for this interval of 3.5 percent, indicating hydraulic interconnection between the

  13. Radium, Thorium and Radioactive Lead Isotopes in Groundwaters: Application to the in Situ Determination of Adsorption-Desorption Rate Constants and Retardation Factors

    NASA Astrophysics Data System (ADS)

    Krishnaswami, S.; Graustein, William C.; Turekian, Karl K.; Dowd, John F.

    1982-12-01

    Five groundwater samples taken from different Hydrogeologie settings in Connecticut were analyzed for major cation chemistry and the concentration of U and Th decay series nuclides 238U, 234Th, 226Ra, 222Rn, 210Pb, 210Po, 232Th, 228Ra, 228Th, and 224Ra. The concentration of 222Rn in the waters ranged between 103 and 104 dpm l-1 and was three to four orders of magnitude greater than that of the short-lived alpha daughters 224Ra, 228Ra, and 234Th, even though the rates of supply of these four nuclides to solution are expected to be similar. We infer that sorption removes radium and thorium from these groundwaters on a time scale of 3 minutes or less. The (224Ra/228Ra) and (234Th/228Th) activity ratios in these waters indicate that desorption of these nuclides occurs on a time scale of a week or less and that equilibrium between solution and surface phases is established. In situ retardation factors for radium, thorium, and lead may therefore be calculated directly from the isotopic data; values range from 4,500 to 200,000. Neither sorption time scales nor retardation factors are strongly dependent on the nuclide or on hydrogeology of the aquifer. Since our study includes nuclides with diverse chemical properties, we suggest that other uncomplexed heavy metals and transuranic elements will also behave in a manner similar to those measured here. The approach presented here should therefore find application in developing site-specific models of the transport of radioactive or stable elemental waste through water-saturated media.

  14. A possible climate signal in the surface morphology and internal structure of Galena Creek Rock Glacier, Wyoming

    NASA Astrophysics Data System (ADS)

    Petersen, Eric; Holt, John; Levy, Joseph; Stuurman, Cassie; Nerozzi, Stefano; Cardenas, Benjamin; Pharr, James; Aylward, Dan; Schmidt, Logan; Hoey, William; Prem, Parvathy; Rambo, Jackie; Lim, YeJin; Maharaj, Kian

    2016-04-01

    Galena Creek Rock Glacier (GCRG) has been shown in previous studies to be a debris-covered glacier (e.g. Ackert, Jr., 1998), and is thus a target of interest as a record of climate and an element of the mountain hydrological system. The goal of this study was to investigate possible relationships between surface morphology and internal structure and composition of GCRG. This was achieved using ground-penetrating radar (GPR), time-domain electromagnetic sounding (TEM), and photogrammetry to produce digital terrain models (DTMs). We acquired 6 longitudinal GPR surveys at 50 and 100 MHz, 2 common midpoint GPR surveys, and 28 TEM soundings on GCRG from the head to the toe, and ground-based photogrammetry data were collected to produce a DTM of its cirque at 10 cm resolution. TEM soundings locally constrained the bulk thickness of GCRG to 26-75 meters. Common midpoint and hyperbola analyses of GPR surveys produced dielectric constants in the near subsurface of 4 in the upper glacier to 5-9 in the middle and lower glacier. These are consistent with clean ice and a mélange of rock with air and/or ice, respectively. GPR revealed a pervasive shallow reflector at 1-2.5m depth that we interpret to be the interface between the surface debris layer and glacier ice. There is increased structure and clutter in the GPR data beneath this interface as one moves down glacier. Observations were additionally made of a 40m wide, 4-5m deep circular thermokarst pond located on upper GCRG in the cirque. The walls of the pond revealed a cross-section of the top several meters of GCRG's interior: a dry surface layer of rocky debris 1-1.5m thick overlying pure glacier ice. An englacial debris band was also observed, roughly 50 cm thick and presenting at an apparent up-glacier dip of ~30 degrees, intersecting the surface near a subtle ridge resolved in the photogrammetry DTM. A GPR transect conducted near the pond over 6 similar ridges imaged 6 corresponding up-glacier dipping reflectors that

  15. Mesozoic igneous intrusions in New England and Quebec: Implications from lead (Pb) isotopes on petrogenesis and mantle sources (Ascutney Mountain, Vermont; Mont Saint Hilaire, Quebec; Pliny Complex, New Hampshire)

    SciTech Connect

    Schucker, D.E.

    1992-01-01

    Lead isotopes are used to study Mesozoic intrusions from New England and Quebec, specifically the igneous complexes of Ascutney Mountain (Vermont), Mont Saint Hilaire (Quebec), and Pliny (New Hampshire). The main objectives are to address the: (1) petrogenesis of specific complexes using Pb isotopes along with previous results; and (2) sources of parental magmas in the context of a possible plume source for the Cretaceous intrusions and New England Seamounts. Analytical procedures for Pb and U are also described in detail. For each of the three complexes, significant variation in apparent initial [sup 208]Pb/[sup 204]Pb, [sup 207]Pb/[sup 204]Pb, and [sup 206]Pb/[sup 204]Pb ratios are observed. These variations reflect crustal contamination and local country rocks are isotopically suitable contaminants. Contamination lowers the Pb isotopic ratios of the modified magmas. The Pb ratios of the parental magmas are constrained by defining trends resulting from crustal contamination. At the Ascutney complex, granites appear to be uniform at the time of formation based on feldspar results. Granite whole rocks exhibit open system U-Pb behavior which is attributed to significant recent U loss (of up to 38%). Both local schists and gneisses are important contaminants with generally <25% contamination. Significant isotopic variations are apparent at Mont Saint Hilaire where rock-feldspar variations are apparently not in isotopic equilibrium. Feldspars reflect magmatic values and indicate crustal contamination of a parental magma for the Hilaire complex. A limited data set for the Pliny complex suggests a parental magma. The Pb results support a common mantle source for the Cretaceous continental intrusions (Ascutney and Mont Saint Hilaire) and the New England Seamounts. They imply magma from a sublithospheric mantle-plume, and that magmas ascended with little or no lithospheric interaction. The magma source for the Jurassic Pliny complex appears to be different.

  16. Climate-related changes in lead isotopes over the past 800,000 years in the EPICA Dome C Antarctic ice core

    NASA Astrophysics Data System (ADS)

    Han, C.; Hur, S.; Burn, L. J.; Gabrielli, P.; Vallelonga, P. T.; Barbante, C.; Boutron, C. F.; Hong, S.

    2013-12-01

    A record of Pb isotopic compositions from 3,260 m deep Antarctic ice, recovered at Dome C on the East Antarctic plateau, and covering the past 800 kyr, is presented. Pb isotopic compositions have been determined using thermal ionization mass spectrometry (TRITON, Thermo Scientific). All sample handling and analytical operations were performed inside a Class 1 - Class 10 clean room provided with High Efficiency Particulate Air (HEPA) multi-staged filtration (Curtin University) and under a class 10 laminar airflow bench or booth in class 1000 clean laboratories (KOPRI). Lower 206Pb/207Pb ratios are found during glacial periods when Pb concentrations are high, while higher values are found during warm periods when Pb concentrations are low. The characteristics of Pb isotopes vary with climatic conditions, which is likely associated with the relative strength of dust and volcanic contributions to Pb deposition in central East Antarctica. Using Pb, Sr and Nd isotopes in Antarctic deep ice cores, previous studies suggested that Southern South America (SSA) was an important source of dust in Antarctic ice during both glacial and interglacial periods, with negligible contributions from Australian mineral dust. Here we present the first Pb isotopic evidence that dust from Eastern Australia could be an important source of Antarctic dust between 300 kyr BP and 600 kry BP.

  17. Lead and strontium isotopic evidence for crustal interaction and compositional zonation in the source regions of Pleistocene basaltic and rhyolitic magmas of the Coso volcanic field, California

    USGS Publications Warehouse

    Bacon, C.R.; Kurasawa, H.; Delevaux, M.H.; Kistler, R.W.; Doe, B.R.

    1984-01-01

    The isotopic compositions of Pb and Sr in Pleistocene basalt, high-silica rhyolite, and andesitic inclusions in rhyolite of the Coso volcanic field indicate that these rocks were derived from different levels of compositionally zoned magmatic systems. The 2 earliest rhyolites probably were tapped from short-lived silicic reservoirs, in contrast to the other 36 rhyolite domes and lava flows which the isotopic data suggest may have been leaked from the top of a single, long-lived magmatic system. Most Coso basalts show isotopic, geochemical, and mineralogic evidence of interaction with crustal rocks, but one analyzed flow has isotopic ratios that may represent mantle values (87Sr/86Sr=0.7036,206Pb/204Pb=19.05,207Pb/204Pb=15.62,208Pb/204Pb= 38.63). The (initial) isotopic composition of typical rhyolite (87Sr/86Sr=0.7053,206Pb/204Pb=19.29,207Pb/204Pb= 15.68,208Pb/204Pb=39.00) is representative of the middle or upper crust. Andesitic inclusions in the rhyolites are evidently samples of hybrid magmas from the silicic/mafic interface in vertically zoned magma reservoirs. Silicic end-member compositions inferred for these mixed magmas, however, are not those of erupted rhyolite but reflect the zonation within the silicic part of the magma reservoir. The compositional contrast at the interface between mafic and silicic parts of these systems apparently was greater for the earlier, smaller reservoirs. ?? 1984 Springer-Verlag.

  18. Influences upon the lead isotopic composition of organic and mineral horizons in soil profiles from the National Soil Inventory of Scotland (2007-09).

    PubMed

    Farmer, John G; Graham, Margaret C; Eades, Lorna J; Lilly, Allan; Bacon, Jeffrey R

    2016-02-15

    Some 644 individual soil horizons from 169 sites in Scotland were analyzed for Pb concentration and isotopic composition. There were three scenarios: (i) 36 sites where both top and bottom (i.e. lowest sampled) soil horizons were classified as organic in nature, (ii) 67 with an organic top but mineral bottom soil horizon, and (iii) 66 where both top and bottom soil horizons were mineral. Lead concentrations were greater in the top horizon relative to the bottom horizon in all but a few cases. The top horizon (206)Pb/(207)Pb ratio was lesser (outside analytical error) than the corresponding bottom horizon (206)Pb/(207)Pb ratio at (i) 64%, (ii) 94% and (iii) 73% of sites, and greater at only (i) 8%, (ii) 3% and (iii) 8% of sites. A plot of (208)Pb/(207)Pb vs. (208)Pb/(206)Pb ratios showed that the Pb in organic top (i, ii) and bottom (i) horizons was consistent with atmospherically deposited Pb of anthropogenic origin. The (206)Pb/(207)Pb ratio of the organic top horizon in (ii) was unrelated to the (206)Pb/(207)Pb ratio of the mineral bottom horizon as demonstrated by the geographical variation in the negative shift in the ratio, a result of differences in the mineral horizon values arising from the greater influence of radiogenic Pb in the north. In (iii), the lesser values of the (206)Pb/(207)Pb ratio for the mineral top horizon relative to the mineral bottom horizon were consistent with the presence of anthropogenic Pb, in addition to indigenous Pb, in the former. Mean anthropogenic Pb inventories of 1.5 and 4.5 g m(-2) were obtained for the northern and southern halves of Scotland, respectively, consistent with long-range atmospheric transport of anthropogenic Pb (mean (206)Pb/(207)Pb ratio~1.16). For cultivated agricultural soils (Ap), this corresponded to about half of the total Pb inventory in the top 30 cm of the soil column. PMID:26674702

  19. New Insights into Arctic Tectonics: Uranium-Lead, (Uranium-Thorium)/Helium, and Hafnium Isotopic Data from the Franklinian Basin, Canadian Arctic Islands

    NASA Astrophysics Data System (ADS)

    Anfinson, Owen Anthony

    More than 2300 detrital zircon uranium-lead (U-Pb) ages, 32 176Hf/177Hf (eHf) isotopic values, 37 apatite helium (AHe) ages, and 72 zircon helium (ZHe) ages represent the first in-depth geochronologic and thermochronologic study of Franklinian Basin strata in the Canadian Arctic and provide new insight on >500 M.y. of geologic history along the northern Laurentian margin (modern orientation). Detrital zircon U-Pb age data demonstrate that the Franklinian Basin succession is composed of strata with three distinctly different provenance signatures. Neoproterozoic and Lower Cambrian formations contain detrital zircon populations consistent with derivation from Archean to Paleoproterozoic gneisses and granites of the west Greenland--northeast Canadian Shield. Lower Silurian to Middle Devonian strata are primarily derived from foreland basin strata of the East Greenland Caledonides (Caledonian orogen). Middle Devonian to Upper Devonian strata also contain detrital zircon populations interpreted as being primarily northerly derived from the continental landmass responsible for the Ellesmerian Orogen (often referred to as Crockerland). U-Pb age data from basal turbidites of the Middle to Upper Devonian clastic succession suggest Crockerland contributed sediment to the northern Laurentian margin by early-Middle Devonian time and that prior to the Ellesmerian Orogeny Crockerland had a comparable geologic history to the northern Baltica Craton. Detrital zircon U-Pb ages in Upper Devonian strata suggest Crockerland became the dominant source by the end of Franklinian Basin sedimentation. Mean eHf values from Paleozoic detrital zircon derived from Crockerland suggest the zircons were primarily formed in either an island arc or continental arc built on accreted oceanic crust setting. ZHe cooling ages from Middle and Upper Devonian strata were not buried deeper than 7 km since deposition and suggest Crockerland was partially exhumed during the Caledonian Orogen. AHe cooling ages

  20. Preliminary mineralogic, fluid inclusion, and stable isotope study of the Mahd adh Dhahab gold mine, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Rye, Robert O.; Hall, W.E.; Cunningham, C.G.; Czamanske, G.K.; Afifi, A.M.; Stacey, J.S.

    1983-01-01

    reservoir at depth. The d18O values of all stages of vein quartz in the South orebody range between 8.5 and 11.1 per mil. This range is similar to that for quartz from the North orebody and indicates that the hydrothermal system consisted of dominantly exchanged meteoric water, which was uniform in temperature and d18O content throughout the area during the entire period of mineralization. Lead isotope analyses of two galena samples indicate that the lead in the South orebody is less radiogenic than that from the North orebody and confirm that the lead was derived from oceanic crust approximately 700 Ma ago.

  1. Statistical clumped isotope signatures.

    PubMed

    Röckmann, T; Popa, M E; Krol, M C; Hofmann, M E G

    2016-08-18

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules.

  2. Statistical clumped isotope signatures

    PubMed Central

    Röckmann, T.; Popa, M. E.; Krol, M. C.; Hofmann, M. E. G.

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules. PMID:27535168

  3. Statistical clumped isotope signatures

    NASA Astrophysics Data System (ADS)

    Röckmann, T.; Popa, M. E.; Krol, M. C.; Hofmann, M. E. G.

    2016-08-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules.

  4. Statistical clumped isotope signatures.

    PubMed

    Röckmann, T; Popa, M E; Krol, M C; Hofmann, M E G

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a molecule, which is the conventional reference. When multiple indistinguishable atoms of the same element are present in a molecule, this reference is calculated from the bulk (≈average) isotopic composition of the involved atoms. We show here that this referencing convention leads to apparent negative clumped isotope anomalies (anti-clumping) when the indistinguishable atoms originate from isotopically different populations. Such statistical clumped isotope anomalies must occur in any system where two or more indistinguishable atoms of the same element, but with different isotopic composition, combine in a molecule. The size of the anti-clumping signal is closely related to the difference of the initial isotope ratios of the indistinguishable atoms that have combined. Therefore, a measured statistical clumped isotope anomaly, relative to an expected (e.g. thermodynamical) clumped isotope composition, may allow assessment of the heterogeneity of the isotopic pools of atoms that are the substrate for formation of molecules. PMID:27535168

  5. Lead and strontium isotopes and related trace elements as genetic tracers in the Upper Cenozoic rhyolite-basalt association of the Yellowstone Plateau volcanic field.

    USGS Publications Warehouse

    Doe, B.R.; Leeman, W.P.; Christiansen, R.L.; Hedge, C.E.

    1982-01-01

    Pb, U, Th, Rb and Sr contents and Pb- and Sr-isotopic compositions, together with field and petrological data, are consistent with the hypothesis of derivation of the basaltic and rhyolitic magmas of this volcanic field from source regions in the upper mantle and lower crust, respectively. It is suggested that the isotopic signatures of the basalts were inherited from a 2600 m.y.-old mantle 'keel' attached to the continental crust and were essentially unaffected by passage of the magma through the latter.R.J.P.

  6. Highly accurate isotope composition measurements by a miniature laser ablation mass spectrometer designed for in situ investigations on planetary surfaces

    NASA Astrophysics Data System (ADS)

    Riedo, A.; Meyer, S.; Heredia, B.; Neuland, M. B.; Bieler, A.; Tulej, M.; Leya, I.; Iakovleva, M.; Mezger, K.; Wurz, P.

    2013-10-01

    An experimental procedure for precise and accurate measurements of isotope abundances by a miniature laser ablation mass spectrometer for space research is described. The measurements were conducted on different untreated NIST standards and galena samples by applying pulsed UV laser radiation (266 nm, 3 ns and 20 Hz) for ablation, atomisation, and ionisation of the sample material. Mass spectra of released ions are measured by a reflectron-type time-of-flight mass analyser. A computer controlled performance optimiser was used to operate the system at maximum ion transmission and mass resolution. At optimal experimental conditions, the best relative accuracy and precision achieved for Pb isotope compositions are at the per mill level and were obtained in a range of applied laser irradiances and a defined number of accumulated spectra. A similar relative accuracy and precision was achieved in the study of Pb isotope compositions in terrestrial galena samples. The results for the galena samples are similar to those obtained with a thermal ionisation mass spectrometer (TIMS). The studies of the isotope composition of other elements yielded relative accuracy and precision at the per mill level too, with characteristic instrument parameters for each element. The relative accuracy and precision of the measurements is degrading with lower element/isotope concentration in a sample. For the elements with abundances below 100 ppm these values drop to the percent level. Depending on the isotopic abundances of Pb in minerals, 207Pb/206Pb ages with accuracy in the range of tens of millions of years can be achieved.

  7. Bibliography of selected references on the hydrogeologic and chemical properties of the Galena-Platteville bedrock unit in Illinois and Wisconsin, 1877-1997

    USGS Publications Warehouse

    Brown, Timothy A.; Dunning, Charles P.; Batten, William G.

    1997-01-01

    This report presents selected references concerning the Galena-Platteville deposits in Illinois and Wisconsin published from 1877 to 1997. Sources of the bibliographic information are the Universities of Illinois and Wisconsin Library Computer Systems; Illinet Online; the Illinois and Wisconsin District Libraries of the U.S. Geological Survey; U.S. Geological Survey Selected Water Resources Abstracts; U.S. Environmental Protection Agency reports; and Federal, State, and local agencies, corporations, and consultants. The bibliography is arranged alphabetically, by county, in Illinois and Wisconsin. The references available for each county are arranged alphabetically by author. In addition, one or more selected hydrogeologic key words describing the content of the reference follow each listing. These key words are geophysical properties, hydraulic properties, inorganic geochemistry, lithology, organic geochemistry, physical properties, and water use. Included in the bibliography are 186 references obtained for 15 counties in Illinois and 21 counties in Wisconsin.

  8. High-precision analysis on annual variations of heavy metals, lead isotopes and rare earth elements in mangrove tree rings by inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Yu, Ke-Fu; Kamber, Balz S.; Lawrence, Michael G.; Greig, Alan; Zhao, Jian-Xin

    2007-02-01

    Annual variations from 1982 to 1999 of a wide range of trace elements and reconnaissance Pb isotopes ( 207Pb/ 206Pb and 208Pb/ 206Pb) were analyzed by solution ICP-MS on digested ash from mangrove Rhizophora apiculata, obtained from Leizhou Peninsula, along northern coast of South China Sea. The concentrations of the majority of elements show a weak declining trend with growth from 1982 to 1999, punctuated by several high concentration spikes. The declining trends are positively correlated with ring width and negatively correlated with inferred water-use efficiency, suggesting a physiological control over metal-uptake in this species. The episodic metal concentration-peaks cannot be interpreted with lateral movement or growth activities and appear to be related to environmental pollution events. Pb isotope ratios for most samples plot along the 'Chinese Pb line' and clearly document the importance of gasoline Pb as a source of contaminant. Shale-normalised REE + Y patterns are relatively flat and consistent across the growth period, with all patterns showing a positive Ce anomaly and elevated Y/Ho ratio. The positive Ce anomaly is observed regardless of the choice of normaliser, in contrast to previously reported REE patterns for terrestrial and marine plants. This pilot study of trace element, REE + Y and Pb isotope distribution in mangrove tree rings indicates the potential use of mangroves as monitors of historical environmental change.

  9. The influence of breeding colony and sex on mercury, selenium and lead levels and carbon and nitrogen stable isotope signatures in summer and winter feathers of Calonectris shearwaters.

    PubMed

    Ramos, Raül; González-Solís, Jacob; Forero, Manuela G; Moreno, Rocío; Gómez-Díaz, Elena; Ruiz, Xavier; Hobson, Keith A

    2009-03-01

    Contamination in marine foodwebs is nowadays of great environmental concern owing to the increasing levels of pollution in marine ecosystems from different anthropogenic sources. Seabirds can be used as indicators of regional contaminant patterns across large temporal and spatial scales. We analysed Hg, Se and Pb levels as well as stable isotope ratios of C(13C/12C, delta13C) and N(15N/14N, delta15N) in breeding- and winter-season feathers on males and females of two related shearwater species, providing information on spatiotemporal patterns of contaminants as well as the influence of the trophic ecology of these seabirds on contaminant levels. During the breeding season, Se and Pb concentrations were highest at the Cape Verde archipelago, showing no differences among the other colonies or between the sexes. However, Hg levels varied among colonies, being highest in the Mediterranean, probably resulting from the larger emissions and fallout of this pollutant in Europe. Feathers grown during breeding also showed sexual differences in Hg concentrations and delta13C. Differences in Hg concentration between sexes are mainly due to egg-laying decontamination in females. In contrast, differences in Hg among colonies are probably related to differences in trophic ecology, as indicated by delta13C and delta15N measurements. Contaminant concentrations in winter-grown feathers did not show any relationship with stable isotope values but were affected by contaminant loads associated with the breeding season. These findings suggest that the interpretation of contaminant levels of migratory species from feathers moulted out of the breeding season should be made with caution because those values could reflect exposures to contaminants acquired during the breeding season. We conclude that factors other than feeding ecology may play an important role in the interpretation of contaminant levels and their annual dynamics at several spatial scales. Consideration of the relevant

  10. Did a drought crisis lead to cultural changes in Eolian Islands during the Bronze Age? New data from archaeological excavations and carbon isotopes analysis of archaeobotanical remains

    NASA Astrophysics Data System (ADS)

    Fiorentino, Girolamo; Caracuta, Valentina; Martinelli, Maria Clara; Quarta, Gianluca; Calcagnile, Lucio

    2010-05-01

    Agricultural potential is commonly regarded as a key factor for the development of pre-modern complex societies in Mediterranean regions. For this reason, the assessment of paleo-rainfall regimes is considered fundamental to understand the influence of short-term climate fluctuations on ancient human communities, especially in those areas characterised by critical environmental conditions such as Eolian archipelagos. Usually, plant remains in archaeological contexts are used to assess agricultural practices and any strategies adopted by ancient populations to face climate changes. Within this work we intend to extend the traditional archaeobotanical approach by using carbon isotope analysis of ancient plant remains in order to infer paleorainfall trends. For this purpose fourty samples of plant remains recovered from Bronze Age archaeological contexts recently excavated in Filicudi and Salina islands, Eolian archipelagos, were selected to be submitted to AMS (Accelerator Mass Spectrometry) radiocarbon dating, archaeobotanaical and carbon stable isotopes analyses. This approach allowed the reconstruction in the analyzed samples of the variation of the carbon isotope composition, expressed through the δ13C term, in a diachronic scale as obtained by the combined radiocarbon dating analyses performed on the same archaeological material. The obtained results show clear chronological pattern of variation of the δ13C term in the plant tissues which find correspondence with other climatic proxy records and from which paleoclimatic information have been inferred. From the archaeological point of view, the obtained results allow the evaluation of the influence of climate on the dynamics of population of Eolian island by reconsidering archaeological indicators coming from the recent excavations carried out in the sites of Filicudi and Salina.

  11. Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ferrat, Marion; Weiss, Dominik J.; Dong, Shuofei; Large, David J.; Spiro, Baruch; Sun, Youbin; Gallagher, Kerry

    2012-04-01

    A full understanding of the atmospheric Pb cycle in Asia during the Holocene is key to palaeoclimate studies of past atmospheric circulation patterns, as well as to assess the impact of increasing industrial activities in this region. However, long-term records of atmospheric Pb isotopic trends in Asia are still sparse. Consequently, we study changes in the concentrations, fluxes and isotopic signature of deposited Pb contained in a 14C-dated peat core from the eastern Qinghai-Tibetan Plateau, dating back to 9.5 kyr BP, and present the first peat record of the changing isotopic composition of atmospheric Pb in dust in Asia during this time. Lead concentrations and fluxes vary between 2.96-21.58 μg g-1 and 0.06-3.52 mg m-2 y-1, respectively, with an average Pb baseline of 6.80 ± 4.18 μg g-1. These values agree with other Pb studies of lake and peat archives in China but are one order of magnitude larger than early and mid-Holocene values measured in Europe. Lead isotopic variability throughout the core is small, varying between 206Pb/207Pb = 1.190-1.197, 206Pb/204Pb = 18.648-18.786, 207Pb/204Pb = 15.666-15.694 and 208Pb/204Pb = 38.890-39.090. The application of Bayesian trans-dimensional changepoint modelling to the Pb dataset enabled the identification of eight significant changes in the isotopic composition of the deposited Pb. Such changes mark different phases of atmospheric Pb deposition, and hence variations in atmospheric circulation patterns and environmental conditions. Temporal variations in the potential natural and/or anthropogenic Pb sources are assessed based on the 206Pb, 207Pb, 208Pb and 204Pb isotopic composition and the 1/[Pb] ratio of the peat samples. Our results suggest that Pb deposition throughout the Holocene was governed by local deposition and long-range input from natural dust sources in northwestern (Taklamakan desert and Qaidam basin) and northern China (Badain Jaran and Tengger deserts). Input from the northern sources seems to have

  12. A salt diapir-related Mississippi Valley-type deposit: the Bou Jaber Pb-Zn-Ba-F deposit, Tunisia: fluid inclusion and isotope study

    NASA Astrophysics Data System (ADS)

    Bouhlel, Salah; Leach, David L.; Johnson, Craig A.; Marsh, Erin; Salmi-Laouar, Sihem; Banks, David A.

    2016-08-01

    evaporation of seawater to halite saturation and requires a dilution of more than two times by meteoric water. The higher K/Na values in fluid inclusions from barite suggest that the brines interacted with K-rich rocks in the basement or siliciclastic sediments in the basin. Carbonate gangue minerals (ankerite and calcite) have δ13C and δ18O values that are close to the carbonate host rock and indicate fluid equilibrium between carbonate host rocks and hydrothermal brines. The δ34S values for sphalerite and galena fall within a narrow range (1 to 10 ‰) with a bulk value of 7.5 ‰, indicating a homogeneous source of sulfur. The δ34S values of barite are also relatively homogeneous (22 ‰), with 6 ‰ higher than the δ34S of local and regional Triassic evaporites (15 ‰). The latter are believed to be the source of sulfate. Temperature of deposition together with sulfur isotope data indicate that the reduced sulfur in sulfides was derived through thermochemical sulfate reduction of Triassic sulfate via hydrocarbons produced probably from Late Cretaceous source rocks. The 87Sr/86Sr ratio in the Bou Jaber barite (0.709821 to 0.711408) together with the lead isotope values of Bou Jaber galena (206Pb/204Pb = 18.699 to 18.737; 207Pb/204Pb = 15.635 to 15.708 and 208Pb/204Pb = 38.321 to 38.947) show that metals were extracted from homogeneous crustal source(s). The tectonic setting of the Bou Jaber ore deposit, the carbonate nature of the host rocks, the epigenetic style of the mineralization and the mineral associations, together with sulfur and oxygen isotope data and fluid inclusion data show that the Bou Jaber lead-zinc mineralization has the major characteristics of a salt diapir-related Mississippi Valley-type (MVT) deposit with superimposed events of fluorite and of barite deposition. Field relations are consistent with mineral deposition during the Eocene-Miocene Alpine orogeny from multiple hydrothermal events: (1) Zn-Pb sulfides formed by mixing of two fluids: one

  13. A salt diapir-related Mississippi Valley-type deposit: the Bou Jaber Pb-Zn-Ba-F deposit, Tunisia: fluid inclusion and isotope study

    NASA Astrophysics Data System (ADS)

    Bouhlel, Salah; Leach, David L.; Johnson, Craig A.; Marsh, Erin; Salmi-Laouar, Sihem; Banks, David A.

    2016-08-01

    evaporation of seawater to halite saturation and requires a dilution of more than two times by meteoric water. The higher K/Na values in fluid inclusions from barite suggest that the brines interacted with K-rich rocks in the basement or siliciclastic sediments in the basin. Carbonate gangue minerals (ankerite and calcite) have δ13C and δ18O values that are close to the carbonate host rock and indicate fluid equilibrium between carbonate host rocks and hydrothermal brines. The δ34S values for sphalerite and galena fall within a narrow range (1 to 10 ‰) with a bulk value of 7.5 ‰, indicating a homogeneous source of sulfur. The δ34S values of barite are also relatively homogeneous (22 ‰), with 6 ‰ higher than the δ34S of local and regional Triassic evaporites (15 ‰). The latter are believed to be the source of sulfate. Temperature of deposition together with sulfur isotope data indicate that the reduced sulfur in sulfides was derived through thermochemical sulfate reduction of Triassic sulfate via hydrocarbons produced probably from Late Cretaceous source rocks. The 87Sr/86Sr ratio in the Bou Jaber barite (0.709821 to 0.711408) together with the lead isotope values of Bou Jaber galena (206Pb/204Pb = 18.699 to 18.737; 207Pb/204Pb = 15.635 to 15.708 and 208Pb/204Pb = 38.321 to 38.947) show that metals were extracted from homogeneous crustal source(s). The tectonic setting of the Bou Jaber ore deposit, the carbonate nature of the host rocks, the epigenetic style of the mineralization and the mineral associations, together with sulfur and oxygen isotope data and fluid inclusion data show that the Bou Jaber lead-zinc mineralization has the major characteristics of a salt diapir-related Mississippi Valley-type (MVT) deposit with superimposed events of fluorite and of barite deposition. Field relations are consistent with mineral deposition during the Eocene-Miocene Alpine orogeny from multiple hydrothermal events: (1) Zn-Pb sulfides formed by mixing of two fluids: one

  14. A salt diapir-related Mississippi Valley-type deposit: The Bou Jaber Pb-Zn-Ba-F deposit, Tunisia: Fluid inclusion and isotope study

    USGS Publications Warehouse

    Bouhlel, Salah; Leach, David; Johnson, Craig A.; Marsh, Erin; Salmi-Laouar, Sihem; Banks, David A.

    2016-01-01

    simply by the evaporation of seawater to halite saturation and requires a dilution of more than two times by meteoric water. The higher K/Na values in fluid inclusions from barite suggest that the brines interacted with K-rich rocks in the basement or siliciclastic sediments in the basin. Carbonate gangue minerals (ankerite and calcite) have δ13C and δ18O values that are close to the carbonate host rock and indicate fluid equilibrium between carbonate host rocks and hydrothermal brines. The δ34S values for sphalerite and galena fall within a narrow range (1 to 10 ‰) with a bulk value of 7.5 ‰, indicating a homogeneous source of sulfur. The δ34S values of barite are also relatively homogeneous (22 ‰), with 6 ‰ higher than the δ34S of local and regional Triassic evaporites (15 ‰). The latter are believed to be the source of sulfate. Temperature of deposition together with sulfur isotope data indicate that the reduced sulfur in sulfides was derived through thermochemical sulfate reduction of Triassic sulfate via hydrocarbons produced probably from Late Cretaceous source rocks. The 87Sr/86Sr ratio in the Bou Jaber barite (0.709821 to 0.711408) together with the lead isotope values of Bou Jaber galena (206Pb/204Pb = 18.699 to 18.737;207Pb/204Pb = 15.635 to 15.708 and 208Pb/204Pb = 38.321 to 38.947) show that metals were extracted from homogeneous crustal source(s). The tectonic setting of the Bou Jaber ore deposit, the carbonate nature of the host rocks, the epigenetic style of the mineralization and the mineral associations, together with sulfur and oxygen isotope data and fluid inclusion data show that the Bou Jaber lead-zinc mineralization has the major characteristics of a salt diapir-related Mississippi Valley-type (MVT) deposit with superimposed events of fluorite and of barite deposition. Field relations are consistent with mineral deposition d

  15. Lead and strontium isotope data for thermal waters of the regional geothermal system in the Twin Falls and Oakley areas, South-Central Idaho

    SciTech Connect

    Mariner, R.H.; Young, H.W.

    1995-12-31

    Thermal fluids obviously related to aquifers in both rhyolite and limestone occur in the Twin Falls-Oakley area of south-central Idaho. Limestone-related waters (high calcium with low silica and fluoride) occur in the middle and upper (southern) parts of the area. Rhyolite-related waters (low calcium but high in silica and fluoride) occur in the lower (northern) part of the area. The relation of thermal fluids in Paleozoic limestone to thermal fluids in Tertiary rhyolite is unknown. Thermal fluids from limestone are dilute, so water-rock reaction in rhyolite could obliterate chemical evidence of fluid residence in a limestone. However, isotopic tracers such as {sup 206}Pb/{sup 204}Pb, {sup 207}Pb/{sup 204}Pb, {sup 208}Pb/{sup 204}Pb, and {sup 87}Sr/{sup 86}Sr might preserve evidence of fluid residence in limestone. Systematic relations between these isotopes and dissolved constituents in the water demonstrate the presence of limestone beneath most if not all of the study area and that aquifers in the limestone and rhyolite are hydrologically connected.

  16. Trace and minor element variations and sulfur isotopes in crystalline and colloform ZnS: Incorporation mechanisms and implications for their genesis

    USGS Publications Warehouse

    Pfaff, Katharina; Koenig, Alan; Wenzel, Thomas; Ridley, Ian; Hildebrandt, Ludwig H.; Leach, David L.; Markl, Gregor

    2011-01-01

    Various models have been proposed to explain the formation mechanism of colloform sphalerite, but the origin is still under debate. In order to decipher influences on trace element incorporation and sulfur isotope composition, crystalline and colloform sphalerite from the carbonate-hosted Mississippi-Valley Type (MVT) deposit near Wiesloch, SW Germany, were investigated and compared to sphalerite samples from 52 hydrothermal vein-type deposits in the Schwarzwald ore district, SW Germany to study the influence of different host rocks, formation mechanisms and fluid origin on trace element incorporation. Trace and minor element incorporation in sphalerite shows some correlation to their host rock and/or origin of fluid, gangue, paragenetic minerals and precipitation mechanisms (e.g., diagenetic processes, fluid cooling or fluid mixing). Furthermore, crystalline sphalerite is generally enriched in elements like Cd, Cu, Sb and Ag compared to colloform sphalerite that mainly incorporates elements like As, Pb and Tl. In addition, sulfur isotopes are characterized by positive values for crystalline and strongly negative values for colloform sphalerite. The combination of trace element contents, typical minerals associated with colloform sphalerite from Wiesloch, sulfur isotopes and thermodynamic considerations helped to evaluate the involvement of sulfate-reducing bacteria in water-filled karst cavities. Sulfate-reducing bacteria cause a sulfide-rich environment that leads in case of a metal-rich fluid supply to a sudden oversaturation of the fluid with respect to galena, sphalerite and pyrite. This, however, exactly coincides with the observed crystallization sequence of samples involving colloform sphalerite from the Wiesloch MVT deposit.

  17. Determination of the total and extractable mass fractions of cadmium and lead in mineral feed by using isotope dilution inductively coupled plasma mass spectrometry.

    PubMed

    Vassileva, Emilia; Hoenig, Michel

    2011-09-01

    This paper describes the determination of the total and extractable mass fractions of Cd and Pb in mineral feed test sample distributed by the Community Reference Laboratory for Heavy Metals in Feed and Food (CRL-HM), in the frame of the fifth interlaboratory comparison for the European Union National Reference Laboratories (NRL). The developed in this study protocol for the total and extractable mass fractions of Pb and Cd in mineral feed sample is based on isotope dilution inductively coupled plasma mass spectrometry (ID ICP-MS). The applied dual spiking approach reduced by 50% the number of analytical steps. The addition of hydrofluoric acid in the digestion step was found necessary to ensure a full decomposition and complete isotope equilibration. Quadrupole inductively coupled plasma mass spectrometer equipped with collision reaction interface (CRI) was employed for the measurements of Cd and Pb. Two methods for the determination of Cd were applied and compared. In the first one the high molybdenum content was reduced by introduction of matrix separation step followed by standard ICP-MS mode measurement, whereas in the second one CRI mode was used for the determination of Cd without preliminary matrix separation. The estimation of the combined uncertainty was performed according to the ISO guidelines. Uncertainty propagation was used as a tool for validation of proposed analytical procedure. Contributions from the correction for moisture content, sample homogeneity, procedural blank, instrumental background and dead time effects were evaluated in both cases. The largest uncertainty contributors for Cd and Pb is due to the within bottle homogeneity of the mineral feed sample - 50.3% and 90% respectively. The IUPAC data for isotope composition are the second major contributor to the combined uncertainty of the result for the total mass fraction of Cd in mineral feed - 43.3%. However, the ID ICP-MS results achieved from the two series of samples (partial and

  18. Chemical speciation of lead dust associated with primary lead smelting.

    PubMed Central

    Spear, T M; Svee, W; Vincent, J H; Stanisich, N

    1998-01-01

    The research presented in this article assessed geochemical factors relating to dust produced during primary lead smelting. Bulk dust samples and size-selective airborne dust samples were collected from four areas of a primary lead smelter and analyzed by X-ray diffraction and sequential chemical extraction. X-ray diffraction showed that the smelter dusts were composed primarily of sulfides, oxides, sulfates, and silicates of metal ores, with galena being the primary dust component. Sequential extraction revealed the solubility of lead compounds at less than 7% in the exchangeable and mildly acidic steps for the bulk dusts collected from four smelter areas. The later steps of the extraction procedure were more effective in dissolving the lead compounds associated with the bulk dust samples, with 43%, 26%, and 8% of the total lead, in the ore storage, sinter, and blast/dross smelter areas, respectively, being extracted in the residual step. Sequential extraction of coarse airborne dust samples from the ore storage and sinter plant showed that 1.2% and 4.1% of the total lead, respectively, was exchangeable. The finer particle size fractions from these areas of the smelter showed higher percentages of exchangeable lead. Of the course airborne dust from the blast/dross furnace processes, 65% of the total lead was exchangeable. However, the largest percentage of lead from these areas was associated with the finer particle-size fractions. If lead bioavailability is related to its solubility as determined through sequential extraction, the health hazards associated with lead exposure may be appreciably enhanced in the blast and dross furnace processes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9721256

  19. Isotopic Biogeochemistry

    NASA Technical Reports Server (NTRS)

    Hayes, J. M.

    1985-01-01

    An overview is provided of the biogeochemical research. The funding, productivity, personnel and facilities are reviewed. Some of the technical areas covered are: carbon isotopic records; isotopic studies of banded iron formations; isotope effects in microbial systems; studies of organic compounds in ancient sediments; and development in isotopic geochemistry and analysis.

  20. Fluid inclusion and stable isotope study of telluride mineralization at Mahd Adh Dhahab, Saudi Arabia

    SciTech Connect

    Afifi, A.M.; Kelly, W.C.

    1985-01-01

    Mahd Adh Dhahab is unique among Precambrian gold deposits in that it displays many characteristics of epithermal precious metal districts. Au-Ag-Cu-Zn-Pb mineralization occurs principally in the third of five generations of quartz veins. Sulfur isotopic equilibrium was generally maintained among sulfides which range in delta/sup 34/S from -1.8 (galena) to 6.4 (pyrite). The narrow range in delta/sup 34/S of sulfides is inconsistent with large variations in f02 calculated from chlorite +/- pyrite +/- hematite assemblages. Galena-sphalerite pairs yield temperatures in the range 160-270/sup 0/C for stage 3 veins, which fall within the 120-300/sup 0/C range defined by fluid inclusion thermometry. Fluid salinities are in the range 0.5 wt.% NaCl equivalent. The trends indicate mixing of delta/sup 18/O approx. = 0 waters with heavier more oxidized waters during stage 4 deposition which led to non-equilibrium oxidation of H/sub 2/S. deltaD values of vein chlorites fall within a narrow range of -65 to -75, while deltaD measurements of inclusion fluids in quartz display a wider spread from -13 to -43; the lighter values may reflect contamination by secondary inclusions. The stable isotope data indicate probable derivation of both sulfur and carbon from igneous sources. District-wide variation in sulfur and oxygen isotopes indicate the presence of several hydrothermal centers, which has possible significance to exploration.

  1. Isotopically engineered semiconductors

    NASA Astrophysics Data System (ADS)

    Haller, E. E.

    1995-04-01

    Scientific interest, technological promise, and increased availability of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This review of mostly recent activities begins with an introduction to some past classical experiments which have been performed on isotopically controlled semiconductors. A review of the natural isotopic composition of the relevant elements follows. Some materials aspects resulting in part from the high costs of enriched isotopes are discussed next. Raman spectroscopy studies with a number of isotopically pure and deliberately mixed Ge bulk crystals show that the Brillouin-zone-center optical phonons are not localized. Their lifetime is almost independent of isotopic disorder, leading to homogeneous Raman line broadening. Studies with short period isotope superlattices consisting of alternating layers of n atomic planes of 70Ge and 74Ge reveal a host of zone-center phonons due to Brillouin-zone folding. At n≳40 one observes two phonon lines at frequencies corresponding to the bulk values of the two isotopes. In natural diamond, isotope scattering of the low-energy phonons, which are responsible for the thermal conductivity, is very strongly affected by small isotope disorder. Isotopically pure 12C diamond crystals exhibit thermal conductivities as high as 410 W cm-1 K-1 at 104 K, leading to projected values of over 2000 W cm-1 K-1 near 80 K. The changes in phonon properties with isotopic composition also weakly affect the electronic band structures and the lattice constants. The latter isotope dependence is most relevant for future standards of length based on crystal lattice constants. Capture of thermal neutrons by isotope nuclei followed by nuclear decay produces new elements, resulting in a very large number of possibilities for isotope selective doping of semiconductors. This neutron transmutation of isotope nuclei, already used

  2. Behaviour mechanisms and correlation between lead (Pb) and its isotope (210)Pb in industrial residue as an indicator for waste characterization.

    PubMed

    Vaasma, Taavi; Bityukova, Liidia; Kiisk, Madis; Özden, Banu; Tkaczyk, Alan Henry

    2016-12-01

    Total lead and (210)Pb concentrations were determined in various ash fractions (collected from two of the world's largest oil shale-fired power plants) by inductively coupled plasma mass-spectrometry (ICP-MS) and gamma spectrometry. Results show a clear increase in total lead (values up to 193 ppm in filter ashes) and (210)Pb (values up to 148 Bq kg(-1) in filter ashes) concentrations in the ash fractions from the furnace towards the filter ashes. A strong positive linear correlation (Pearson's bivariate correlation remained between 0.86 and 0.99) was determined between total lead concentration (ppm) and (210)Pb activity concentration (Bq kg(-1)) within all the boilers under observation. The constant concentration ratio between total lead and (210)Pb remained around one (with minor exceptions), independent of the sampling location and the used combustion technology. The determined concentration ratio can be applicable as an indicative tool in waste material characterization. It also provides multiple additions to the general material characterization approach, by integrating radiological and elemental studies and providing an option to rapidly obtain initial indicative information about the residues. This in turn helps to generate the initial information to work out the next steps in waste material management.

  3. Behaviour mechanisms and correlation between lead (Pb) and its isotope (210)Pb in industrial residue as an indicator for waste characterization.

    PubMed

    Vaasma, Taavi; Bityukova, Liidia; Kiisk, Madis; Özden, Banu; Tkaczyk, Alan Henry

    2016-12-01

    Total lead and (210)Pb concentrations were determined in various ash fractions (collected from two of the world's largest oil shale-fired power plants) by inductively coupled plasma mass-spectrometry (ICP-MS) and gamma spectrometry. Results show a clear increase in total lead (values up to 193 ppm in filter ashes) and (210)Pb (values up to 148 Bq kg(-1) in filter ashes) concentrations in the ash fractions from the furnace towards the filter ashes. A strong positive linear correlation (Pearson's bivariate correlation remained between 0.86 and 0.99) was determined between total lead concentration (ppm) and (210)Pb activity concentration (Bq kg(-1)) within all the boilers under observation. The constant concentration ratio between total lead and (210)Pb remained around one (with minor exceptions), independent of the sampling location and the used combustion technology. The determined concentration ratio can be applicable as an indicative tool in waste material characterization. It also provides multiple additions to the general material characterization approach, by integrating radiological and elemental studies and providing an option to rapidly obtain initial indicative information about the residues. This in turn helps to generate the initial information to work out the next steps in waste material management. PMID:27144415

  4. United States Air Force 611th Civil Engineer Squadron, Elmendorf AFB, Alaska. Final engineering evaluation/cost analysis potential tce impact to the drinking water supply, Galena Airport, Alaska

    SciTech Connect

    1996-02-05

    This decision document presents the selected removal action to address potential trichloroethene (TCE) impact to drinking water supply wells, located in the Installation Restoration Program (IRP) site ST009, otherwise known as the West Unit, at Galena Airport, Alaska. The information fron the RI Report is summarized, along with an analysis of potential removal action alternatives, in the Engineering Evaluation/Cost Analysis (EE/CA).

  5. Methods of isotopic geochronology

    NASA Astrophysics Data System (ADS)

    Gorokhov, I. M.; Levchenkov, O. A.

    Papers are presented on such topics as the age of the chemical elements; the age of meteorites, the moon, and the earth; isotopic ages of the most ancient terrestrial formations; and the Archean evolution of Enderby Land in the Antarctic as evidenced by isotopic dating. Consideration is also given to a uranium-lead geochronology technique for investigating Precambrian ore deposits, a Pb-Pb technique of zircon dating, and the potentials and limitations of Sm-Nd geochronology.

  6. Vertical distribution of hydraulic characteristics and water quality in three boreholes in the Galena-Platteville Aquifer at the Parson's Casket Hardware Superfund site, Belvidere, Illinois, 1990

    USGS Publications Warehouse

    Mills, P.C.

    1993-01-01

    The U.S. Geological Survey investigated contaminant migration in the Galena-Platteville aquifer at the Parson's Casket Hardware site in Belvidere, Ill. This report presents the results of the first phase of the investigation, from August through December 1990. A packer assembly was used to isolate various depth intervals in three 150-foot-deep boreholes in the dolomite aquifer. Aquifer-test data include vertical distributions of vertical hydraulic gradient, horizontal hydraulic conductivity (K), and response of water levels in observation wells to borehole pumping. Water-quality data include vertical distributions of field-measured properties and laboratory determinations of concentrations of volatile organic compounds (VOC's). vertical hydraulic gradients in the aquifer were downward. The downward gradients ranged from less than 0.01 to 0.37 foot/foot. The largest gradient was associated with an elevated-K interval at 115 to 125 feet below land surface. The hydraulic characteristics of strata within the aquifer seem to be generally consistent across the site. The strata can be subdivided into five hydraulic units with the following approximate depth ranges-and K's : (1) a 1- to 5-foot-thick weathered surface at about 35 feet below land surface, 1-200 ft/d (feet per day); (2) 35-80 feet, 0.05-0.5 ft/d; (3) 80-115 feet, 0.5 ft/d; (4) 115-125 feet, 0.5-10 ft/d; and (5) 125-150 feet, 0.5 ft/d. Water-level drawdowns were detected in one shallow bedrock observation well during pumping of some of the packed intervals in a nearby borehole, indicating that the degree of vertical connection between some intervals in the aquifer may be greater than that between others. During development pumping of one borehole, drawdowns were detected in a nearby well screened in the lower part of the overlying glacial-drift deposits, indicating hydraulic connection between the glacial drift aquifer and the bedrock aquifer. VOC's were detected throughout the upper half (about 150 feet ) of

  7. A cross-site comparison of methods used for hydrogeologic characterization of the Galena