R8：変成岩とテクトニクス

[R8P-08] スリランカハイランド複合岩体に産する変成炭酸塩岩中黄鉄鉱の硫黄同位体に関する研究

*𠮷岡 葵¹、Madhusoodhan Satish-Kumar²、後藤 孝介³、下田 玄³、 Sanjeewa P. K. Malaviarachchi ⁴ (1. 新潟大・院自然、2. 新潟大・理、3. 産総研、4. ペラデニア大, スリランカ)

キーワード：硫黄同位体、変成作用、微生物硫酸塩還元、ハイランド複合岩体、スリランカ

Sulfur isotope ratios of pyrite in carbonate rocks retain changes in marine sulfate reservoirs associated with sedimentary environments and elevated oxygen concentrations. Pyrite in Sri Lankan meta-carbonate rocks exhibits high δ³⁴S values reflecting microbial sulfate reduction (MSR). Comparison of sulfur isotope ratios with unmetamorphosed carbonate rocks shows similar sulfur isotope values, suggesting that metamorphism has no effect on sulfur isotope ratios. Thus, carbonate rocks may provide important information for paleoceanography.