Rupture of wet mantle wedge by self-promoting carbonation

Abstract More than one teramole of carbon per year is subducted as carbonate or carbonaceous material. However, the influence carbonation/decarbonation reactions on seismic activity within subduction zones poorly understood. Here we present field and microstructural observations, including stable isotope analyses, veins Higuchi serpentinite body, Japan. We find that oxygen compositions indicate carbonic fluids originated from organic materials in metasediments. Thermodynamic calculations reveal carbonation was accompanied by a solid volume decrease, dehydration, high magnesium mobility. propose mantle wedge occurs episodically self-promoting way controlled contraction fluid overpressure. In our conceptual model, brittle fracturing precipitation were followed ductile flow carbonates hydrous minerals; this might explain occurrence episodic tremor slip serpentinized wedge.