Chemical interaction driven by deep fluids in the damage zone of a seismogenic carbonate fault

We analyzed from meso-to microscale the chemical interaction (e.g., bleaching) between deep fluids and carbonate rocks in pelagic limestones exposed along the seismically active Gubbio normal fault (Northern Apennines), exhumed from ca. 2 km depth. Bleaching is enhanced by the exploitation of inherited stylolitic seams by fluids and is favored by the progressive leaching and mobilization of primary components (i.e., Ca, Fe, Pb, and Cu) and the precipitation of authigenic baryte due to temperature and/or redox potential contrast.