2021 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)
Sep 15 - Sep 19, 2021Online
2021 Annual Meeting of Japan Association of Mineralogical Sciences (JAMS)
Sep 15 - Sep 19, 2021Online
[R8-05]The Physico-chemical evolution of carbonaceous material during low-grade metamorphism of Archean stromatolites by Raman spectroscopy and carbon isotopes
*Kiran Sasidharan1, Madhusoodhan Satish-Kumar1, Yoshihiro Nakamura2, Tomozaku Hokada3, Hiroaki Ohfuji4(1. Niigata Uni., 2. Geological Survey of Japan, AIST, 3. National Institute of Polar Research, 4. Tohoku Uni.)
Keywords:
Raman Spectra of carbonaceous material thermometry,Carbon isotope thermometry,Chitradurga Schist Belt,Hydrothermal infiltration,Degassing and dissolution reprecipitation
This study compares the carbonaceous material (CM) physicochemical conditions in carbonates during metamorphism, using Raman spectra of CM and carbon isotopic composition. Our results suggest that inconsistencies between the temperature of equilibration can be due to (1) post-metamorphic hydrothermal fluid infiltration inferred by a shift in δ18O without change in δ13C of carbonates (2) negative δ13C shift in CM is caused by dissolution recrystallization after CO2 degassing lowered CM crystallinity.