Microchemical compositions of fault fill mineral veins and coseismic anoxic fluid

Abstract

We have investigated microchemical analyses of syn-tectonic veins along the Nobeoka thrust, the Shimanto belt, Kyushu. Fault fill veins are composed of Fe-carbonate with positive Europium anomaly, suggesting extremely anoxic environment during their deposition. This anoxic environment can be explained by mecanochemical Hydrogen generation caused by comminution processes during earthquake.