Research Projects

Transition metals Ti, Cr, Fe, and Ni are major moderately volatile siderophile elements that play an important role in the differentiation of planets (Lodders, 2003; Palme and O’Neill, 2003). Also, Cr, Fe, and Ni have similar volatility (condensation temperatures in the solar nebula Tcond ~ 1300 K, Lodders, 2003). Terrestrial planets (such as Mercury, Earth, and Mars) and asteroids show variable abundances and isotope compositions of these elements (e.g., Trinquier et al., 2007; Dauphas et al., 2017; Steele et al., 2011). These variations are likely developed during nebular sorting of the planetary precursors and later processing of the planetary bodies. Nucleosynthetic isotope anomalies observed in the planetary materials mainly result from processes that involve mass independent isotopic variations in the planetary materials and their precursors. e.g., nucleosynthetic anomalies in 54Cr, 50Ti, and 48Ca (Trinquier et al. 2009; Dauphas et al., 2014). These variations are mainly attributed to the heterogeneous distribution of presolar grains from supernovae ejecta in the protoplanetary disk. The detailed study of carriers of neutron-rich isotopes of Ca, Cr, Ti, and Ni in different planetary objects including primitive meteorites, Earth, Moon, Mars and Vesta will be useful to understand radial mixing of nebular dust and gas and fractionation processes at different heliocentric distances in the solar nebula. Overall, to constrain the source/s and heterogeneity of neutron rich isotopes of the elements near Fe -peak, combined studies of element pairs are needed to understand the nebular environment and dynamics in first few million years and its role on the bulk composition of Earth and other terrestrial planets. So far, most studies are only focused on isotope anomalies in individual elements, which is not sufficient to constrain the nebular, accretionary, and post accretionary processing of the planetary material. Components of chondrites, such as calcium-aluminum-rich Inclusions and chondrules show large variations in the r-process anomalies (Chen et al., 2015). Therefore, in this project, I would like to develop methods to simultaneously determine mass independent fractionations of Cr and Ni isotopes from the most primitive chondrite components that formed early in the solar nebula as a tool to understand, i) nucleosynthetic carriers of mass independent anomalies in the solar system objects, ii) if the chemical complementarity is mirrored by isotopic complementarity in the primitive refractory and volatile materials of the solar system, iii) relative dating using two pairs of short-lived chronometers to understand the homogeneity of short-lived radionuclides in the early solar system and to constrain their initial abundances and accretion ages of chondrites, and, iv) to understand the physical and chemical processes in the early solar nebula and their implications for the evolution of the Earth and other planetary bodies in the solar system.