Structural and Stratigraphic Setting and Fluid Flow Features of the Svyatogor Ridge, a Sediment Drift South of the Molloy Transform

Abstract

High-resolution two-dimensional (2D) multichannel seismic data was acquired in 2014 from the Svyatogor Ridge, a sediment drift on the northwestern flank of the Knipovich spreading ridge. Seismic data is here processed, and together with multibeam bathymetry data and a correlation with Ocean Drilling Program (ODP) Hole 909, an interpretation of the structural and stratigraphic framework of the Svyatogor Ridge is established. The Svyatogor Ridge is highly influenced by tectonic processes from both the ultraslow spreading Knipovich Ridge and its northward intersection with the Molloy Transform Fault. From this interpretation a gas hydrate system has been identified by a prominent Bottom-Simulating Reflector (BSR) and pockmark features on the seafloor with evidence of fluid pathways underlain. The underlying young oceanic crust is possibly serpentinized, and hypothesized to provide the overlying sediments with abiotic gas though large basement faults, here interpreted as detachment faults, and a series of normal faults pervading most of the sedimentary stratigraphy on the west of the ridge apex.