2:30 PM - 2:45 PM
[R4-13] Pyrite framboid analysis of the Lower Triassic Osawa Formation in the Southern Kitakami Terrane, Japan: an insight into the redox conditions
Keywords:pyrite framboids, Triassic, redox conditions, sulfate reduction
It has been suggested that the Lower Triassic Osawa Formation was deposited under the anoxic-dysoxic conditions. Because there was no reliable explanation of how the oxygen-poor condition happened, we analyzed facies and pyrite framboids to reconstruct redox conditions. The present data show that the pyrite framboids formed in sediments at a prodelta where abundant organic matter is deposited. Moreover, smaller pyrite framboids imply the formation in the water column.