The role of Messinian salt in mud volcanoes’ genesis: interactions and effects of evaporites on eastern Mediterranean cold seep features

• Applicant: Dr. Shuhui Xu
• Subject Area: Geology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546928825

Mud volcanoes (MVs), key features for the discharge of solids and fluids from depth, represent prominent manifestations of cold seep phenomena on the seafloor. These geological structures are located predominantly along convergent plate margins, regions characterized by dynamic mass transfer processes and intense tectonic activity. One of the regions most affected by MVism can be found in the Mediterranean Sea, which is remarkably characterized by the presence of giant salt bodies buried from a few to thousands of meters below the subsurface. However, the role of the evaporites in the genesis of MVs remains unassessed. To address this gap, the proposed research will explore the influence of the evaporites on the formation of MVs and examine how these salt bodies interacts with the fluids within the MVs. The study will focus on the Olimpi MV field, which is notable for its high density of MVs in the Mediterranean region, and employ a multi-methodological approach, combining seismic interpretation, laboratory experiments, and numerical modeling. Seismic profiles will provide insights into the presence, extent, and thickness of the evaporites. By conducting laboratory tests for permeability and employing numerical models to simulate pore pressure evolution, this research will quantify the influence of evaporite seals on episodic venting phenomena. Additionally, through chemical and isotopic analyses of pore waters from MVs, the geochemical contribution of salt in mud volcanic and seepage processes will be evaluated, and the underlying mechanism of contrasting pore water salinity patterns in different cold seep structures will be revealed. While the proposed research is centered on the eastern Mediterranean region, its findings are expected to have global implications as evaporites associated with MVs are found in various geological settings worldwide, e.g. in the Gulf of Mexico.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 527: Bereich Infrastruktur - "International Ocean Discovery Program" (IODP)
• International Connection: Italy, Spain
• Co-Investigators: Professor Dr. Gerhard Bohrmann; Professor Dr. Achim Kopf
• Cooperation Partners: Dr. Jonathan Ford; Professor Dr. Luis Gibert; Dr. Walter Menapace