Scanning electron microscopy and sulfur isotopic characterization of pyrite in silicified wood fragment in Japan

摘要: Five samples of fine-grained, authigenic pyrite seams in silicified woods from Tertiary marine to brackish sediments Japan were examined on surface morphology by scanning electron microscopy (SEM) combination with energy dispersive X-ray spectrometry (EDX) and sulfur isotopic composition (δ34S). The as revealed SEM varied long fibrous (pseudomorph after original plant fiber), spongy, blocky/cubic framboidal (spherical aggregates minute crystals). Except two Chikuho coal mine area northern Kyushu (Ebitsu: spongy fabric, δ34S=+3.5‰, +12.2‰), all characterised fairly low δ34S values ranging −40.0 −20.1‰, suggesting be the products steady state sulfate reduction, under an open system, seawater-sulfate sulfate-reducing bacteria. Pyrite deposits Ebitsu is also bacteriogenic, but probably formed a closed system where debris deposit. Any clear trend between was not found.