scholarly journals 238U/235U isotopic ratio as redox conditions marker in ediacarian paleobasin: section in Chaya river, Baikal-Patom highland, south of middle Siberia

2019 ◽  
Vol 485 (3) ◽  
pp. 356-360
Author(s):  
A. V. Chugaev ◽  
I. V. Chernyshev ◽  
B. G. Pokrovsky ◽  
G. V. Mandzhieva ◽  
B. I. Gareev ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Total Variation ◽  
Carbonate Rocks ◽  
Isotopic Ratio ◽  
Sedimentary Rocks ◽  
Central Siberia ◽  
Icp Ms ◽  
Variation Range ◽  
Double Isotope ◽  
Middle Siberia

This article is devoted to a study of variations in the U isotopic composition (238U/235U) in the section of clas- tic-carbonate Ediacaran sediments exposed along the Chaya River in the southern part of Central Siberia (Russia). Measurements of 238U/235U in the rocks were performed using a high-precision (±0.07%o, 2SD) MC-ICP- MS with a 233U-236U double isotope spike. The total variation range of S238U in the studied carbonate rocks was -0.91 to -0.01%. Extremely low values of S238U (-0.91%, -0.9%, and -0.84%), which were found in a number of samples from the lower part of the section, are interpreted as the result of postsedimentation processes affecting the rocks. In the overlying sediments, the range of S238U variations is smaller from -0.49 to -0.01%. Here, regular “weighting” of the U isotopic composition observed upwards through the section indicates an increase in the reduction conditions at this time (about 550 Ma) in the paleobasin. This conclusion is consistent with the elevated concentrations of U, Mo, and V in the Late Ediacaran sedimentary rocks of the region studied.

Chapter 10: Olympiada Gold Deposit, Yenisei Ridge, Russia

2020 ◽  
pp. 203-226
Author(s):  
A. M. Sazonov ◽  
K. V. Lobanov ◽  
E. A. Zvyagina ◽  
S. I. Leontiev ◽  
S. A. Silyanov ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Gold Mineralization ◽  
Sedimentary Rocks ◽  
Gold Deposits ◽  
Yenisei Ridge ◽  
Structural Factors ◽  
Tectonic Zone ◽  
Central Siberia ◽  
Western Margin ◽  
Clastic Sedimentary

Abstract The Olympiada deposit, containing >1,560 metric tons (t; 50 Moz) of gold at an average grade of 4 to 4.6 g/t Au, occurs in central Siberia, Russia. Over 30 years, the deposit produced more than 580 t of gold, including 200 t from oxidized ore grading 11.1 g/t. The deposit forms a 2-km-long, steeply dipping system, which is traced downdip for 1.7 km. It occurs in the Neoproterozoic orogen of the Yenisei Ridge at the western margin of the Siberian craton. This and other gold deposits in the district are controlled by the large, long-lived Tatarka-Ishimbino tectonic zone, marking a suture between terranes chiefly consisting of deformed Meso- to Neoproterozoic carbonate-clastic sedimentary rocks. The combination of lithologic and structural factors was critical for localization of gold mineralization associated with calcic and siliceous alteration accompanied by early arsenic and late antimony sulfides. As a result, very fine (10 μm) and high fineness (910–997) gold associates with diverse sulfides, especially arsenopyrite, and commonly contains mercury, similar to some characteristics of Carlin-type deposits. Geochronologic studies suggest that mineralization was formed during several stages between 817 and 660 Ma. The isotopic composition of Os and He, along with presence of anomalous Ni, Co, and Pt, points to a mantle mafic source, whereas isotopic composition of Pb and S suggest a contaminated crustal source, i.e., originating from a mix of mantle and crustal fluids.

scholarly journals A single-step purification method for the precise determination of the antimony isotopic composition of environmental, geological and biological samples by HG-MC-ICP-MS

2021 ◽  
Author(s):  
Ferrari Colin ◽  
Resongles Eléonore ◽  
Freydier Rémi ◽  
Casiot Corinne
Keyword(s):  
Isotopic Composition ◽  
Biological Samples ◽  
Precise Determination ◽  
Single Step ◽  
Functionalized Silica ◽  
Purification Method ◽  
Silica Powder ◽  
Icp Ms ◽  
Single Step Purification

Thiol-functionalized silica powder allowed single-step purification of antimony for exploring stable Sb isotope signatures in the environment.

Isotopic composition analysis of dissolved mercury in seawater with purge and trap preconcentration and a modified Hg introduction device for MC-ICP-MS

2015 ◽  
Vol 30 (2) ◽  
pp. 353-359 ◽  
Author(s):  
Haiying Lin ◽  
Dongxing Yuan ◽  
Bingyan Lu ◽  
Shuyuan Huang ◽  
Lumin Sun ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Isotopic Analysis ◽  
Composition Analysis ◽  
Analysis Method ◽  
Purge And Trap ◽  
Icp Ms ◽  
Dissolved Mercury ◽  
Preconcentration Method

A modified introduction device and a preconcentration method were developed to enhance the sensitivity of the Hg isotopic analysis method.

Direct analysis of cotton swipes for plutonium isotope determination by microextraction-ICP-MS

2021 ◽  
Author(s):  
Benjamin T Manard ◽  
Shalina Metzger ◽  
Kayron T. Rogers ◽  
Brian W. Ticknor ◽  
N. Alex Zirakparvar ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Environmental Sample ◽  
Direct Analysis ◽  
Plutonium Isotope ◽  
Low Level ◽  
Icp Ms ◽  
Isotope Determination

This study demonstrates a method for determining the isotopic composition of low-level (sub-pg) plutonium (Pu) directly from a cotton swipe. Environmental sample (ES) swipes are routinely employed as a tool...

ISOTOPE-GEOCHEMICAL FEATURES OF AUTHENIC CARBONATES OF THE YU1 PRODUCING HORIZON OF THE VERKH-TARSKOYE OIL FIELD (SOUTH OF WESTERN SIBERIA)

2020 ◽  
pp. 20-28
Author(s):  
L. G. Vakulenko ◽  
◽  
O. D. Nikolenko ◽  
D. A. Novikov ◽  
P. A. Yan ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Carbonate Rocks ◽  
Western Siberia ◽  
Oil Field ◽  
Third Generation ◽  
The Third ◽  
First Time ◽  
Different Sources ◽  
Sources Of Co2 ◽  
Comprehensive Study

A comprehensive study of the composition of sand and silt deposits of the Yu1 horizon of the Vasyuganskaya Formation upper part of the Verkh-Tarskoye oil field has been carried out. Associations of authigenic minerals have been determined in their cement, among which the calcite is the most widespread. According to petrographic parameters, three generations of calcite have been identified for which detailed isotopicgeochemical and ultramicroscopic studies were carried out for the first time. Wide and multi directional changes in the isotopic composition of carbon and oxygen and in the chemical composition of carbonate minerals were recorded, they indicate significant variations in the conditions of diagenesis and catagenesis, primarily temperature, and different sources of CO2. Significant variations in the isotopic composition of formation waters and its relationship with the isotopic composition of carbonates have been established. Thus, a narrow interval of close δ13C values was revealed, amounting to –10.5 to –9.1 ‰ in the formation waters of group II, and from –10.7 to –9.1 ‰ in calcites of the third generation. The source of CO2 in this system should be considered a carbon dioxide, which is formed in the process of metamorphism of carbonate rocks of the Paleozoic age.

scholarly journals Supplemental Material: Himalayan Miocene adakitic rocks, a case study of the Mayum pluton: Insights into geodynamic processes within the subducted Indian continental lithosphere and Himalayan mid-Miocene tectonic regime transition

2020 ◽  
Author(s):  
Chao Lin ◽  
Jinjiang Zhang ◽  
et al.
Keyword(s):  
Isotopic Composition ◽  
Continental Lithosphere ◽  
Isotopic Data ◽  
Element Geochemistry ◽  
Adakitic Rocks ◽  
Icp Ms ◽  
Geodynamic Processes ◽  
Data Statistics

Table S1: Bulk element geochemistry and isotopic composition of the Mayum pluton; Table S2: Zircon LA-ICP-MS U-Pb data for the Mayum pluton; Table S3: Zircon in situ Lu-Hf isotopic data for the Mayum pluton; Table S4: Data statistics for Himalayan Eocene and Miocene adakitic rocks.

scholarly journals Stable isotopic composition of top consumers in Arctic cryoconite holes: revealing divergent roles in a supraglacial trophic network

2021 ◽  
Vol 18 (5) ◽  
pp. 1543-1557
Author(s):  
Tereza Novotná Jaroměřská ◽  
Jakub Trubač ◽  
Krzysztof Zawierucha ◽  
Lenka Vondrovicová ◽  
Miloslav Devetter ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Isotopic Ratio ◽  
Isotopic Fractionation ◽  
Mechanistic Explanation ◽  
High Arctic ◽  
Biologically Active ◽  
Glacier Surface ◽  
Stable Isotopic Composition ◽  
Stable Isotopic ◽  
Trophic Network

Abstract. Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by the dynamic nature of their formation and functioning. The most common cryoconite apex consumers are the cosmopolitan invertebrates – tardigrades and rotifers. Several studies have highlighted the potential relevance of tardigrades and rotifers to cryoconite holes' ecosystem functioning. However, due to the dominant occurrence of prokaryotes, these consumers are usually out of the major scope of most studies aimed at understanding biological processes on glaciers. The aim of this descriptive study is to present pioneering data on isotopic composition of tardigrades, rotifers and cryoconite from three High Arctic glaciers in Svalbard and discuss their role in a cryoconite hole trophic network. We found that tardigrades have lower δ15N values than rotifers, which indicates different food requirements or different isotopic fractionation of both consumers. The δ13C values revealed differences between consumers and organic matter in cryoconite among glaciers. However, the mechanistic explanation of these variations requires further investigation focused on the particular diet of cryoconite consumers and their isotopic ratio. Our study introduces the first observation of carbon and nitrogen stable isotopic composition of top consumers in cryoconite holes analysed by an improved method for cryoconite sample processing, paving the way for further studies of the supraglacial trophic network.

scholarly journals Strontium and 87Sr/86Sr isotopic ratio of ground brines in the northeastern Angara-Lena artesian basin

2021 ◽  
Vol 44 (2) ◽  
pp. 98-105
Author(s):  
L. P. Alekseeva ◽  
S. V. Alekseev
Keyword(s):  
Isotopic Composition ◽  
High Salinity ◽  
Isotopic Ratio ◽  
Sedimentary Basins ◽  
Formation Processes ◽  
Salt Composition ◽  
Strontium Content ◽  
Mass Spectrometers ◽  
Ionic Salt

The purpose of this study is to identify the major formation processes of the ionic and isotopic composition of chloride brines in the sedimentary basins of the Siberian platform. The object and subject of research are deep-seated strong, very strong and extremely saturated brines as well as their strontium content and the ratio of Sr stable isotopes. The groundwater ionic-salt composition was determined by traditional methods (titrimetric, gravimetric, flame photometry), the 87Sr/86Sr isotopic ratio was measured using mass-spectrometers (Irkutsk, Russia and Canada). The brines lying at the depth of 1500–3000 m were tapped and classified into saline and subsalt hydrogeological formations. Their feature is high salinity (385–530 g/L) and high content of strontium (2.3–7 g/L). The 87Sr/86Sr isotopic ratio ranges from 0.708 to 0.713062. By isotopic composition most of the brine samples are close to the waters of the Vendian-Cambrian paleoocean. However, some brine samples from the subsalt part of the sedimentary section of the basin are significantly enriched in the isotope 87Sr compared to the paleoocean waters and other samples. It could be due to the substantial input of 87Sr into the brines during the long-term interaction of groundwater with the host Lower Cambrian sandstones.

scholarly journals Correction: A single-step purification method for the precise determination of the antimony isotopic composition of environmental, geological and biological samples by HG-MC-ICP-MS

2021 ◽  
Author(s):  
Colin Ferrari ◽  
Eléonore Resongles ◽  
Rémi Freydier ◽  
Corinne Casiot
Keyword(s):  
Isotopic Composition ◽  
Biological Samples ◽  
Precise Determination ◽  
Single Step ◽  
Purification Method ◽  
Icp Ms ◽  
Single Step Purification

Correction for ‘A single-step purification method for the precise determination of the antimony isotopic composition of environmental, geological and biological samples by HG-MC-ICP-MS’ by Colin Ferrari et al., J. Anal. At. Spectrom., 2021, 36, 776–785, DOI: "https://doi.org/10.1039/D0JA00452A">10.1039/D0JA00452A.

scholarly journals Differentiation Among Romanian Wine Regions Based on Lead Isotope Signatures

2019 ◽  
Vol 76 (2) ◽  
pp. 179
Author(s):  
Florin Dumitru BORA ◽  
Anamaria CĂLUGĂR ◽  
Claudiu Ioan BUNEA ◽  
Ionut RACZ
Keyword(s):  
Atmospheric Pollution ◽  
Lead Isotope ◽  
Isotopic Ratio ◽  
Isotope Ratios ◽  
Red Wines ◽  
Average Value ◽  
Icp Ms ◽  
Pb Concentration

The objective of this study is to determine the Pb concentration and 206Pb/204Pb, 206Pb/207Pb, 206Pb/208Pb from several Romanian winemaking regions, in order to highlight credible geographical markers of wine origin. The Pb level concentration and the ratios of 206Pb/204Pb, 206Pb/207Pb, 206Pb/208Pb were determined in 25 white and 9 red wines using ICP-MS techniques. Based on 206Pb/207Pb isotope ratios it can be concluded that the vines grown in the Tîrnave vineyard [Blaj (1.1790 average value)], Huși vineyard [Huși (1.1958 average value wine center), Averești (1.1908 average value)] and Iași vineyard [Copou (1.1875 average value) wine center], show traces of atmospheric pollution with lead [if 206Pb/207Pb=~1.1700-1.2200 (atmospheric pollution)]. Combining the 206Pb/204Pb with 206Pb/208Pb isotopic ratio may carry out a separation on the vineyards and wine-growing centers. Based on 206Pb/204Pb, 206Pb/207Pb and 208Pb/206Pb a separation of the wine samples was possible.

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