Tissint, a new unaltered piece of Martian volcanic material and having characteristics of impact-induced melting and deformation, is the most silica poor and Mg-Fe-rich igneous rock among the “depleted” olivine-phyricshergottites. Petrogenesis of Tissint appears to be similar to LAR 06319, an enriched olivine-phyricshergottite, during early to intermediate stage of crystallization. A severe shock-induced deformation resulted in remelting (10–15 vol%), recrystallization (most Fe-rich phases) and exhumation of Tissint in a time scale of 1–8 yr.
Understanding the chronology and geodynamics of crust building and reworking processes in the Southern Granulite Terrane, India involving LA-ICPMS zircon U-Pb dating and LA-MC-ICPMS zircon Hf isotopic compositions of the dated zircons apart from detailed whole rock petrology, geochemistry of 11 of selected charnockite orthogneiss samples from the Madurai, Trivandrum, and Nagercoil blocksis revealed four distinct episodes of felsic magmatism of the SGT were identified.
Chemical weathering and the ensuing atmospheric carbon dioxide consumption has long been considered to work on geological time periods until recently when some modelling and natural records have shown that the weathering-related CO2 consumption can change at century to glacial-interglacial time scale. The multi-proxy data (Al/K, CIA, Rb/Sr, 87Sr/86Sr for degree of weathering and 143Nd/144Nd for provenance) reveal an increase in silicate weathering with initiation of interglacial warm climate at ~17.7ka followed by a major change at 15.5ka. Inferred changes in chemical weathering have varied in tandem with the regional monsoonal proxies (δ18Osw-salinity changes of Northern Indian Ocean, effective Asian moisture content and δ18O records of Chinese caves) and are synchronous with changes in summer insolation at 30°N and δ18O of GISP2 implying that chemical weathering was not a later amplifier but worked in tandem with global climate change.
|Dr. Babu E. V. S. S. K||Chief Scientist|
|Dr. Sunder Raju P. V||Senior Principal Scientist|
|Dr. Sukumaran N. P||Senior Principal Scientist|
|Dr. Sreenivas B||Senior Principal Scientist|
|Ms. Sabitha D||Senior Scientist|
|Dr. M. S. Kalpana||Senior Scientist|
|Dr. Vijaya Kumar T||Senior Scientist|
|Mr. Netramani Sagar||Senior Scientist|
|Ms. Manju S||Senior Scientist|
|Dr. Monalisa Mallick||Scientist|
|Mr. Venkatesam K||Senior Technical Officer(1)|
|Mr. Balu G||Technical Officer|
|Mr. Rama Murthy P. B||Technical Officer|
|Mr. Waseem Raza||Technical Officer|
|Dr. Pavan Miriyala||Technical Assistant|
|Mr. MD. Arif||Technical Assistant|
Page Last Updated On : 12-06-2020