Large-scale sediment redistribution on the equatorial Pacific seafloor

Abstract

Understanding if and how particles are laterally transported before final deposition is crucial for accurately reconstructing paleoceanographic conditions from pelagic sediments. We use digital seismic reflection data from the AMAT03 site survey cruise for IODP EXP 320/321 to investigate the Neogene and Quaternary pelagic sedimentation across the eastern-‐central equatorial Pacific (110–130°W). Spatially continuous stratigraphy was derived from five latitudinal seismic transects between the Clipperton and Galapagos Fracture Zones, revealing evidence of widespread sediment redistribution increasing towards the western part of this region. A large-scale anomaly in sediment thickness in the northwestern part of the surveyed area suggests that sediment focusing and/or bottom-current induced resedimentation has been occurring in the central Pacific on timescales of millions of years. The relatively confined character of this anomaly does not support a longitudinally continuous focusing of sediments on the equator, as has been suggested to occur during the Pleistocene glacial stages.