Earth, Atmosphere & Environment Sciences
Title : | Effect of impurities on the isotope geochemistry of some important rock forming minerals: A combined theoretical and experimental study. |
Area of research : | Earth, Atmosphere & Environment Sciences |
Principal Investigator : | Dr. Swastika Chatterjee, Indian Institute Of Science Education And Research (IISER) Kolkata, West Bengal |
Timeline Start Year : | 2022 |
Timeline End Year : | 2025 |
Contact info : | swastika@iiserkol.ac.in |
Details
Executive Summary : | Theoretical analysis is crucial in understanding complex processes and revalidating experimental results. This project aims to investigate the effect of impurities/dopants on the isotope geochemistry of two important rock-forming minerals, calcite and olivine. The abundance of the doubly substituted CO₂ isotopologue produced during acid digestion of calcite/aragonite is proportional to the concentration of ¹³C-¹⁸O bonds in the reactant carbonate, which is a function of the carbonate growth temperature. The study aims to make the clumped isotope paleothermometer practical by studying the effect of impurities on fractionation. First principles density functional theory-based calculations and experiments will be performed to determine the effect of major and minor elements (Mg) on the extent of fractionation as a function of temperature. The study also focuses on the effect of Fe on Li isotopic fractionation in olivine. Lithium is an important geochemical tracer used to infer the thermal and chemical evolution of minerals, particularly in the Earth's upper mantle. All theoretical studies have studied the temperature-dependent fractionation of Li isotopes between different sites of forsterite (Mg₂SiO₄). Preliminary results indicate that Fe might influence the isotopic fractionation in olivine, but more elaborate calculations and experimental validation are needed to reach a conclusion. |
Co-PI: | Prof. Prosenjit Ghosh, Indian Institute Of Science, Bangalore, Karnataka-560012 |
Total Budget (INR): | 35,34,696 |
Organizations involved