scholarly journals Accessories in Kaiserstuhl carbonatites and related rocks as accurate and faithful recorders of whole rock age and isotopic composition

2021 ◽  
Author(s):  
Mahdi Ghobadi ◽  
Gerhard P. Brey ◽  
Axel Gerdes ◽  
Heidi E. Höfer ◽  
Jörg Keller
Keyword(s):  
Fission Track ◽  
Isotope Ratios ◽  
Rock Types ◽  
Icp Ms ◽  
Mid Ocean Ridge ◽  
Fission Track Ages ◽  
Oceanic Island Basalts ◽  
Five Phases ◽  
Ocean Ridge

AbstractThe accessories perovskite, pyrochlore, zirconolite, calzirtite and melanite from carbonatites and carbonate-rich foidites from the Kaiserstuhl are variously suited for the in situ determination of their U–Pb ages and Sr, Nd- and Hf-isotope ratios by LA-ICP-MS. The 143Nd/144Nd ratios may be determined precisely in all five phases, the 176Hf/177Hf ratios only in calzirtite and the 87Sr/86Sr ratios in perovskites and pyrochlores. The carbonatites and carbonate-rich foidites belong to one of the three magmatic groups that Schleicher et al. (1990) distinguished in the Kaiserstuhl on the basis of their Sr, Nd and Pb isotope ratios. Tephrites, phonolites and essexites (nepheline monzogabbros) form the second and limburgites (nepheline basanites) and olivine nephelinites the third. Our 87Sr/86Sr isotope data from the accessories overlap with the carbonatite and olivine nephelinite fields defined by Schleicher et al. (1990) but exhibit a much narrower range. These and the εNd and εHf values plot along the mantle array in the field of oceanic island basalts relatively close to mid-ocean ridge basalts. Previously reported K–Ar, Ar–Ar and fission track ages for the Kaiserstuhl lie between 16.2 and 17.8 Ma. They stem entirely from the geologically older tephrites, phonolites and essexites. No ages existed so far for the geologically younger carbonatites and carbonate-rich foidites except for one apatite fission track age (15.8 Ma). We obtained precise U–Pb ages for zirconolites and calzirtites of 15.66, respectively 15.5 Ma (± 0.1 2σ) and for pyrochlores of 15.35 ± 0.24 Ma. Only the perovskites from the Badberg soevite yielded a U–P concordia age of 14.56 ± 0.86 Ma while the perovskites from bergalites (haüyne melilitites) only gave 206Pb/238U and 208Pb/232Th ages of 15.26 ± 0.21, respectively, 15.28 ± 0.48 Ma. The main Kaiserstuhl rock types were emplaced over a time span of 1.6 Ma almost 1 million years before the carbonatites and carbonate-rich foidites. These were emplaced within only 0.32 Ma.

scholarly journals In-situ determination of antimony isotope ratios in Sb minerals by femtosecond LA-MC-ICP-MS

2021 ◽  
Author(s):  
Andreas Benjamin Kaufmann ◽  
Marina Lazarov ◽  
Stefan Kiefer ◽  
Juraj Majzlan ◽  
Stefan Weyer
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Isotope Ratios ◽  
Icp Ms

Here we present a method for in-situ determination of stable antimony (Sb) isotope compositions by ultraviolet (UV)-femtosecond-laser-ablation-multi-collector-ICP-MS (fs-LA-MC-ICP-MS). Metallic antimony and a number of Sb minerals (stibnite, senarmontite, chalcostibite, tetrahedrite,...

scholarly journals Supplemental Material: Identification of ca. 520 Ma mid-ocean-ridge–type ophiolite suite in the inner Cathaysia block, South China: Evidence from shearing-type oceanic plagiogranite

2021 ◽  
Author(s):  
Longming Li
Keyword(s):  
South China ◽  
Nd Isotope ◽  
Icp Ms ◽  
Mid Ocean Ridge ◽  
Ophiolite Suite ◽  
Cathaysia Block ◽  
Ocean Ridge ◽  
Oceanic Plagiogranite ◽  
Felsic Rocks ◽  
Os Isotope

Table S1: Zircon SIMS U-Pb data and d18O values for the meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S2: LA-ICP-MS analysis of trace elements in zircon from the meta-felsic rocks, Shitun area, Cathaysia block, South China; Table S3: Zircon Hf isotope compositions of the meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S4: Major- and trace-element compositions of the serpentinites, meta-ultramafic rocks, and meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S5: Whole-rock Re-Os isotope compositions of the serpentinites from Shitun area, Cathaysia block, South China; and Table S6: Sr-Nd isotope compositions of the meta-ultramafic and meta-felsic rocks from Shitun area, Cathaysia block, South China.

In situ determination of precise stable Si isotope ratios by UV-femtosecond laser ablation high-resolution multi-collector ICP-MS

2008 ◽  
Vol 249 (1-2) ◽  
pp. 155-166 ◽  
Author(s):  
Jérôme Chmeleff ◽  
Ingo Horn ◽  
Grit Steinhoefel ◽  
Friedhelm von Blanckenburg
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Isotope Ratios ◽  
Icp Ms ◽  
Si Isotope

Evaluation of the accuracy of the determination of lead isotope ratios in wine by ICP MS using quadrupole, multicollector magnetic sector and time-of-flight analyzers

Talanta ◽  
2001 ◽  
Vol 54 (2) ◽  
pp. 307-317 ◽  
Author(s):  
Mireille Barbaste ◽  
Ludwik Halicz ◽  
Albert Galy ◽  
Bernard Medina ◽  
Hakan Emteborg ◽  
...  
Keyword(s):  
Lead Isotope ◽  
Time Of Flight ◽  
Isotope Ratios ◽  
Magnetic Sector ◽  
Lead Isotope Ratios ◽  
Icp Ms

Application of lead isotope ratios for pollution source investigation in the marine environment

2020 ◽  
Author(s):  
Emiliya Vassileva ◽  
Anna Maria Orani ◽  
Sergey Assonov
Keyword(s):  
Isotopic Composition ◽  
Lead Isotope ◽  
Isotope Ratios ◽  
Environmental Matrices ◽  
Total Uncertainty ◽  
Lead Isotope Ratios ◽  
Icp Ms ◽  
Seawater Samples ◽  
Biota Samples

<p><span><span>Lead is a non-essential toxic element that at high levels of human exposure causes damage to many organs of the human body. This element naturally occurs in the Earth crust, but its biogeochemical cycle has been altered by anthropogenic activities, which have introduced high amount of this element from different sources. Among inorganic contaminants, Pb is perhaps the most studied, but the determination of its total concentration only is not sufficient for a proper evaluation of contamination sources. Discrimination of anthropogenic and geogenic lead sources requires both precise and accurate isotope ratio determination as well as high versatility due to the complexity of environmental matrices, such as sediments, biota and seawater. This element has a partially radiogenic isotopic composition with 208Pb, 206Pb and 207Pb originating from the radioactive decay of 238U, 235U and 232Th respectively and 204Pb representing the only natural stable isotope. This characteristic isotopic composition represents a powerful analytical tool as it allows to trace the sources, fate and effects of possible Pb contamination. The most common way to express the Pb isotopic composition is using the ratio 206Pb/207Pb, because of the easy interference-free determination and isotopes’ abundance. The determination of 204Pb by ICP-MS is quite challenging as this is also the least abundant among Pb isotopes (about 1.4%) and it is also affected by isobaric interference from 204Hg. The latter derives from both sample matrices and from plasma/sweep gas supplies and it represents a big analytical challenge, especially for marine biota samples, where the amount of Hg can be up to 100 times higher than Pb. </span></span></p><p><span><span>In this work we present the development and the application of analytical methodology for the accurate and precise determination of Pb isotope ratios by HR-ICP-MS in different marine environmental matrices (sediments, seawater and biota). Analytical procedures are involving a separation of Pb from the sample matrix and mercury, present in the sample. For seawater samples, the use of the SeaFAST automated system allowed simultaneous matrix separation and analyte pre-concentration before ICP-MS analysis. A comparison of results for lead isotope ratios obtained with MC-ICP-MS and HR ICP-MS in the same samples, in all cases, showed very good agreement . The total uncertainty associated to each result was estimated and all major contributions to the combined uncertainty of the obtained results were identified. As all such studies involve companions of different datasets, the uncertainty estimation is critical to ensure correct companions.  The developed methodology was applied to different marine samples, namely sediments from Caribbean, Baltic and Namibian coasts, biota samples from French Polynesia, seawater samples from Mediterranean and Arctic seas.</span></span><span><span> </span></span></p>

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