Episodicity of structural flow in an active subduction system, new insights from mud volcano's carbonate veins – Scientific Ocean drilling expedition IODP 366

This study's goal is to understand the structural events and episodes of fluid flow recorded in calcium carbonate precipitation sampled Mariana forearc serpentine mud volcanoes. Those active mounts provide a unique window deep affecting subduction channel mélange zone subducted Pacific Plate. To build conceptual model vein precipitations from volcanoes edifice, we unravelled origin, timing, mechanisms those with multidisciplinary study veins, samples drilled flank Fantangisña Seamount during International Ocean Discovery Program (IODP) Expedition 366. Structural analysis network revealed stages dissolution. The most ancient minerals underwent high tectonic stress several degrees silicification. U-Pb dates ranged Early Cretaceous present day, recording potential pre-convergence calibrating an episodic building start convergence day. UCC-normalized LREE pattern, 87Sr/86Sr ratios ranging 0.704977 0.705798 δ18O signature 18.7 19.8 (‰, V-SMOW) veins indicate mixed origin precipitated fluids influenced by signature. were episodically built day function activity. They are complex systems internally composed fault providing multiple circulation pathways that can be successively opened or closed.