scholarly journals Lead Isotopes in Exploration for Basement-Hosted Structurally Controlled Unconformity-Related Uranium Deposits: Kiggavik Project (Nunavut, Canada)

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 512
Author(s):  
David Quirt ◽  
Antonio Benedicto
Keyword(s):  
Inductively Coupled Plasma ◽  
Structural Control ◽  
Lead Isotopes ◽  
Isotope Ratios ◽  
Uranium Content ◽  
Weak Acid ◽  
Pb Isotopes ◽  
Pb Isotope ◽  
Acid Leach ◽  
Partial Digestion

Pb-isotopes have been proposed as pathfinders for sandstone-hosted unconformity-related U deposits, with isotope ratios providing information on mineralization timing and element remobilization and migration. Pb-isotopes proximal to mineralization display radiogenic signatures, often with ‘excess Pb’ suggestive of derivation from greater U concentrations than are currently present. The U deposits in the Kiggavik project area (west of Baker Lake, NU, Canada) are basement-hosted, contain several generations of pitchblende mineralization, display a strong structural control, and are located in fault-related fracture systems and foliation-parallel veinlets. Drill core samples were analysed by Inductively-Coupled Plasma-Mass Spectrometer (ICP-MS) for Pb isotopes following multi-acid total-digestion, reverse Aqua Regia partial-digestion, and weak-acid-leach attacks, to evaluate the utility of the respective dissolution methods in Pb-isotope pathfinder geochemistry. Partial-digestion results are similar to weak-acid-leach results, indicating that interpretation of Pb-isotope signatures can be carried out from partial-digestion data if weak-acid-leach data are unavailable. Application of this pathfinder method at Kiggavik shows that Pb-isotope ratios display systematic trends useful for exploration vectoring. Uranium-content-adjusted 206Pb/204Pb ratios and 206Pb/204Pb ‘excess-lead’ data highlight anomalous isotopic values. 207Pb/206Pb ratios display downhole trends complementary to location of mineralization. Three-dimensional (3D) distributions of Pb-isotope data at the Contact U prospect show systematic trends and form halos around the mineralization. Isotopic footprints are limited to <50 m from the mineralization outline, reflecting host-rock and structural control, but indicate areas with elevated potential for U mineralization and provide vectoring information within basement lithologies.

Classification of the geographic origin of cigarettes according to Pb isotope ratios by inductively coupled plasma dynamic reaction cell mass spectrometry

2015 ◽  
Vol 30 (4) ◽  
pp. 986-993 ◽  
Author(s):  
Wei Guo ◽  
Shenghong Hu ◽  
Zhiwei Wu ◽  
Gaoyong Lan ◽  
Lanlan Jin ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Cell Mass ◽  
Geographic Origin ◽  
Isotope Ratios ◽  
Pb Isotope ◽  
Dynamic Reaction Cell ◽  
Reaction Cell ◽  
Plasma Dynamic ◽  
Inductively Coupled ◽  
Geographic Origins

ICP-DRC-MS was developed for the determination of Pb isotope ratios to distinguish between the geographic origins of cigarettes.

scholarly journals Preliminary Evaluation of Heavy Metal Contamination and Source Identification in Kuala Lumpur SMART Stormwater Pond Sediments Using Pb Isotopic Signature

2021 ◽  
Vol 13 (16) ◽  
pp. 9020
Author(s):  
Nabeel Abdullah Alrabie ◽  
Ferdaus Mohamat-Yusuff ◽  
Rohasliney Hashim ◽  
Zufarzaana Zulkeflee ◽  
Mohammad Noor Azmai Amal ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Coal Combustion ◽  
Inductively Coupled Plasma ◽  
Heavy Metal Contamination ◽  
Isotope Ratios ◽  
Isotopic Signature ◽  
Preliminary Evaluation ◽  
Kuala Lumpur ◽  
Pb Isotope ◽  
Urban Stormwater

Uncontrolled urbanization and growing industrialization are major sources of pollutants that affect the urban stormwater quality and, therefore, the receiving aquatic environment. The concentrations of heavy metals (As, Cd, Cr, Cu, Fe, Ni, Pb, and Zn), and Pb isotope ratios in surface sediment samples obtained from SMART holding and storage ponds located in Kuala Lumpur were investigated using inductively coupled plasma-mass spectrometry (ICP-MS). The highest metal concentrations were found at the SMART holding pond (SHP), the first recipient of urban stormwater runoff from the SMART system catchment area. As, Cd, Pb, and Zn are the dominant metal contaminants in the sediments of both SMART ponds, with values exceeding the average shale values. According to contamination indices applied to evaluate the environmental risk caused by heavy metals, As had the highest values among the metals examined, denoting moderate contamination. Hence, it can frequently cause harmful effects on the sediment-living species. The Pb isotope ratios (206Pb/207Pb and 208Pb/207Pb) indicated that coal combustion was the foremost source of anthropogenic Pb in the sediments of both SMART ponds. The control of coal combustion and sites undergoing intensive human activities should be given priority in the foreseeable future.

Geochemical exploration for buried sandstone-hosted uranium mineralisation using mobile U and Pb isotopes: case study of the REB deposit, Great Divide Basin, Wyoming

2021 ◽  
pp. geochem2021-043
Author(s):  
M.Z. Abzalov
Keyword(s):  
Lead Isotopes ◽  
Radioactive Decay ◽  
Acid Leaching ◽  
Weak Acid ◽  
Soil Samples ◽  
Pb Isotopes ◽  
Content Type ◽  
Great Divide ◽  
Deposit Type ◽  
Supplementary Material

Mobile radiogenic lead isotopes (206Pb, 207Pb, 208Pb, and 210Pb) represent products of radioactive decay of their parental uranium and thorium isotopes (238U, 235U, 232Th), and are considered potential geochemical pathfinders of the buried sandstone-type uranium deposits. Soil samples collected along a geochemical traverse intersecting buried uranium roll front mineralisation at the REB deposit in the Great Divide Basin, Wyoming, USA were studied. Mineralisation of this deposit is hosted in weakly lithified arkosic sands, at a depth of 120 - 200 metres, without a strong surficial expression of its presence at depth which makes discovery of this deposit type difficult, slow, and expensive. All soil samples have been analysed for ratios of the mobile long-lived Pb isotopes and their parental U and Th isotopes, determined from partial leach products obtained using a weak acid leaching technique. The samples were also analysed for trace elements, assayed both in the partial leach products and using conventional whole soil sample assays. Ratios of the mobile radiogenic Pb isotopes to their parental U and Th isotopes (206Pb/238U, 207Pb/235U and 208Pb/232Th) determined in the partial leach products exhibit anomalous contents in the soil samples collected above the uranium rolls. The anomalous values are several times greater than background values, to lateral distances of 350-400m outside of the roll fronts. Notably, conventional whole soil assays have failed to detect the anomalies which were detected using mobile Pb isotopes. Supplementary material:https://doi.org/10.6084/m9.figshare.c.5610980

scholarly journals Determination of Lead Elemental Concentration and Isotopic Ratios in Coal Ash and Coal Fly Ash Reference Materials Using Isotope Dilution Thermal Ionization Mass Spectrometry

2019 ◽  
Vol 16 (23) ◽  
pp. 4772 ◽  
Author(s):  
Chaofeng Li ◽  
Huiqian Wu ◽  
Xuance Wang ◽  
Zhuyin Chu ◽  
Youlian Li ◽  
...  
Keyword(s):  
Lead Isotope ◽  
Thermal Ionization Mass Spectrometry ◽  
Environmental Science ◽  
Coal Fly Ash ◽  
Lead Isotopes ◽  
Coal Ash ◽  
Isotope Ratios ◽  
Ionization Mass ◽  
Pb Isotope ◽  
Lead Isotope Ratios

The rapid expansion of coal-fired power plants around the world has produced a huge volume of toxic elements associated with combustion residues such as coal fly ash (CFA) and coal ash (CA), which pose great threats to the global environment. It is therefore crucial for environmental science to monitor the migration and emission pathway of toxic elements such as CFA and CA. Lead isotopes have proved to be powerful tracers capable of dealing with this issue. Unfortunately, up to now, few high precision lead isotope data of CFA and CA certified reference materials (CRMs) determined by using the double spike technique have been reported. Hence, to facilitate the application of lead isotopes in environmental science, it is indispensable and urgent to determine a suite of high precision Pb isotope ratios and Pb elemental contents for CFA and CA CRMs. Here, we measured lead isotope ratios from four CFA and CA CRMs using thermal ionization mass spectrometry (TIMS) combined with the 204Pb–207Pb double spike method. Lead isotope ratios values of CRMs (GBW11124, GBW08401, GBW11125d, and JCFA-1) covered wide variation ranges from 17.993 to 19.228 for 206Pb/204Pb, from 15.513 to 15.675 for 207Pb/204Pb, and from 38.184 to 39.067 for 208Pb/204Pb. Lead isotope ratios of these CRMs, except for GBW11124, show good external reproducibility (2 RSD, n = 8), which is better than 0.05% for 206Pb/204Pb and 207Pb/204Pb, 0.07% for 208Pb/204Pb, 0.04% for 206Pb/207Pb, and 0.05% for 208Pb/206Pb. The Pb concentrations of these CRMs were determined using 207Pb single spike method. The reproducibility (1 RSD, n = 4) of Pb elemental content was <0.60%. This indicates the distribution of Pb elements in these CRMs is homogeneous. With the exception of GBW11124, the suite of CRMs can be used for determining CFA and CA matrix composition for quality control of Pb isotope analyses.

scholarly journals Using 206/207Pb isotope ratios to estimate phosphorus sources in historical sediments of a lowland river system

2020 ◽  
Vol 21 (1) ◽  
pp. 613-626
Author(s):  
A. M. Tye ◽  
S. Chenery ◽  
M. R. Cave ◽  
R. Price
Keyword(s):  
Principal Component Analysis ◽  
Sewage Treatment ◽  
Principal Component ◽  
Isotope Ratios ◽  
Component Analysis ◽  
Water Bodies ◽  
Pb Isotopes ◽  
Lowland River ◽  
Pb Isotope ◽  
First Order

Abstract Purpose Engineering and dredging strategies to manage sediment, along with river-scouring, can reveal older sediments. These present a unique opportunity to assess past sources of phosphorus (P) inputs into river sediments. We used the sediment concentrations of P, lead (Pb) and 206/207Pb isotopes to produce ‘first-order’ estimates of the source (diffuse agricultural or sewage treatment) of phosphorus. Materials and methods Sediment cores (n = 30) were collected from the length of the non-tidal River Nene, a lowland river in eastern England. Cores were analysed for sediment elemental concentrations and Pb isotopes. Principal component analysis and linear regression modelling were used to assess the relationships between P, Pb and Pb isotopes. Monte-Carlo simulations and boot-strapping were undertaken to estimate, with 95% confidence intervals, the source of P in these sediments. Results and discussion Analysis of the relationships between PTotal, PbTotal and 206/207Pb isotope ratios suggested that sediments were deposited largely prior to the phasing out of tetra-ethyl Pb (PbBHT) from petrol. Regression models showed positive correlations between PTotal and PbTotal (R2 = 0.85). Principal component analysis suggested a strong sewage treatment signal for Pb and P enrichment. In the rural upper three water bodies, little sewage treatment work (STW)-derived P was found in the sediment, a consequence of limited STW input and greater sediment transport. In the more urbanised water bodies 4–6, ‘first-order estimates’ of STW P suggest that median concentrations were 30–40% of PTotal. Conclusions The strong relationships between Pb and P concentrations in river water provided the opportunity to use 206/207Pb isotope ratios to calculate ‘first-order’ estimates of the proportion of P released from STWs in the historical sediment. Understanding the sources of historical sediment P can be used to assess the success of current sediment management strategies and to base further mitigation measures. Results suggest that whilst much recent sediment P is removed, the legacy sediment remains to contribute P to the water body. Thus, options regarding the practical removal of these sediments and the extent to which this would improve water P status need to be assessed and balanced against options such as further decreasing soil P or STW P stripping.

Geochronologic interpretations of Pb isotope ratios in nickel sulfides of the Thompson Belt, Manitoba

1982 ◽  
Vol 19 (12) ◽  
pp. 2306-2324 ◽  
Author(s):  
G. L. Cumming ◽  
O. R. Eckstrand ◽  
W. V. Peredery
Keyword(s):  
Lead Isotopes ◽  
Isotope Ratios ◽  
Probable Error ◽  
The Other ◽  
Dyke Swarm ◽  
Pb Isotope ◽  
Geological Evidence ◽  
Metasedimentary Rocks ◽  
Nickel Deposits ◽  
Nickel Ores

Lead isotopes in nickel sulfides from seven deposits in the Thompson Belt appear to record events of four distinct ages. The earliest and most prominent of these may represent the emplacement of the nickel ores and their ultramafic hosts.Typical massive and disseminated low-lead nickeliferous sulfides were selected for analysis, and several partitioning techniques were used in order to obtain information about the range of isotope ratios in different phases and fractions of the samples. The data were interpreted in terms of the isotopic systematics discussed by Gale and Mussett.Data from four deposits produce two well defined, parallel "primary" isochrons whose calculated mean slope corresponds to an age of 2320 ± 30 Ma. Interpretation of this date as the time of emplacement of the nickel deposits and their ultramafic hosts is consistent with geological evidence that points to a post-Archean, pre-Hudsonian age. The 2320 Ma date may be consistent, within probable error limits, with the age inferred from Rb/Sr data (2100 Ma) for deposition of metasedimentary rocks of the Thompson Belt, into which the ultramafic lenses were intruded (Brooks and Theyer).The other isotopically recorded events occurred at 2015 ± 15 Ma (possibly early folding of the Thompson Belt supracrustal rocks), 1620 ± 25 Ma (probably a late retrograde stage of the Hudsonian Orogeny), and 1125 ± 60 Ma (possibly a thermal event associated with emplacement of the Mackenzie dyke swarm).

Interpretation of Pb isotope compositions of galenas from the Midland Valley of Scotland and adjacent regions

1984 ◽  
Vol 75 (2) ◽  
pp. 85-96 ◽  
Author(s):  
John Parnell ◽  
Ian Swainbank
Keyword(s):  
Lower Devonian ◽  
Lead Isotope ◽  
Sedimentary Rocks ◽  
Isotope Ratios ◽  
Igneous Rocks ◽  
Pb Isotope ◽  
Lower Carboniferous ◽  
Granite Magma ◽  
Lower Palaeozoic ◽  
Caledonian Granite

ABSTRACTThe lead isotope compositions of 61 galenas from central and southern Scotland vary markedly between different regions. Most galenas from the southern Grampian Highlands yield isotope ratios (206Pb/204Pb 17·77 ± 0·25, 207Pb/204Pb 15·47 ± 0·05, 208Pb/204Pb 37·63 ± 0·26) less radiogenic than those from Midland Valley galenas (18·22 ± 0·12, 15·55 ± 0·05, 38·13 ± 0·14) whilst galena lead from the Southern Uplands (18·28 ± 0·12, 15·56 ± 0·03, 38·21 ± 0·18) is more radiogenic than that from the southern Midland Valley (18·12 ± 0·06, 15·52 ± 0·02, 38·06 ±0·10). The change in isotopie composition across the Highland Boundary fault reflects the presence or absence of Dalradian rocks which included a magmatic component of lead. Galenas from the Dalradian sequence in Islay, where igneous rocks are lacking, have a composition (18·14±0·04, 15·51±0·01, 37·90±0·02) more like Midland Valley galenas. In the Southern Uplands, galenas yield lead isotope ratios similar to those of feldspars from Caledonian granite (18·30 ± 0·14, 15·57 ± 0·04, 37·96 ± 0·15) analysed by Blaxland et al. (1979). The similar ratios reflect the incorporation of Lower Palaeozoic sedimentary rocks into the granite magma, rather than a granitic source for the mineralisation. The granites were then thermal-structural foci for later mineralising fluids which leached metals from the surrounding rocks. Within the Midland Valley, galenas hosted in Lower Devonian-Lower Carboniferous lavas are notably more radiogenic (18·31 ±0·12, 15·58 ± 0·06, 38·20 ± 0·16) than sediment-hosted galenas (18·14 ± 0·07, 15·52 ± 0·02, 38·08 ± 0·10). The Devonian lavas at least may have inherited lead from subducted (? Lower Palaeozoic) rock incorporated in the primary magma.

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