11:45 AM - 12:00 PM
[SMP09-07] Sr and Nd isotopes in metacarbonate rocks as proxies for paleo-tectonic reconstruction prior to supercontinent assembly
Keywords:Metacarbonate rocks, Gondwana, Sr isotopes, Nd isotopes, tectonic setting
We also compare the metacarbonate data with basement rocks from various neighboring Gondwana continents, wherein some regional affinities could be established. Nd model ages of cratonic basements from East Africa (Kalahari) and India (Dharwar) is obviously different from Balchen carbonate rocks from Sor Rondane in East Antarctica, and the possible existence of a cratonic nucleus within the East Antractic continent is speculated, surrounding which the carbonate rocks of the Balchen region might have deposited. Thus, the Sr and Nd isotopic compositions provide important information about depositional setting of sedimentary rocks and relationship with surrounding basement and continents. Geochemical proxies, such as Nd and Sr isotopes of metacarbonate rocks, can yield key information not only of paleo-oceans but also about the surrounding rocks of oceanic crust (basement) and continental crust during the time of deposition, which can lead us to a better understanding of paleo-tectonic setting of crustal fragments that assemble to form supercontinents.