Shallow seismic investigations of the accretionary complex offshore Central Chile

Thrust ridges are accretionary structures often associated with local uplift along splay faults and cold seep activity. We study the influence of a NS-trending thrust ridge system on transition between prism continental framework (shelf break) offshore Maule Region (central Chile at 35°–36°S) by examining its 2-D 3-D seismic velocity structure. The experiment comprises five densely spaced refraction lines running subparallel to trench recorded nine OBH/S (ocean bottom hydrophone/seismometers) deployed central line. Results show narrow margin-parallel volume (approximately 6 × 50 5 km3) whose distribution is consistent sedimentary rocks. shallow unit characterized presence very low hydrate-bearing sediments (<1.7 km/s), which interpreted as highly porous rocks (>50% porosity) within Gas Hydrate Stability Zone (GHSZ) suggesting hydrate content. These zones spatially correlate fluid activity in vicinity NS trending based high heat flow values (>40 mWm‐−2) seepage mapping. On other hand, that crop out flanks might be responsible for tectonically induced vertical migration.