![]() DuringĮxpedition 354, these deposits were documented in space and time,Īnd the recovered sediments have Himalayan mineralogical and ![]() Shift over hundreds of kilometers on millennial timescales. Mostly following transport channels, sedimentsĭeposit on and between levees while depocenters laterally Sediments originateįrom Himalayan rivers, documenting terrestrial changes of HimalayanĮrosion and weathering, and are transported through a deltaĪnd shelf canyon, supplying turbidity currents loaded with a full System that comprises the Bengal deep-sea fan. Holes give a spatial overview of the primarily turbiditic depositional Three deep-penetration and an additional four shallow 354 drilled a seven site, 320 km long tr ansect across the Bengal Fan. This project aims to collate all of the research related to International Ocean Discovery Program Expedition 354.Įxp. These results resolve the previous inconsistencies. Based on the above evidences, we proposed that the South China Sea may have experienced a short period of NS oriented spreading after earlier SE spreading. Located between the relict ridges of East and Southwest Subbasins, NS trending Zhongnan‐Liyue Fracture Zone had acted as the latest transform fault. Magnetic anomalies and ocean bottom seismometer velocity suggest that the latest relict ridge of the East Subbasin coincides with the EW trending seamount chain. These observations are consistent with geophysical features. Crosscutting relationship suggests that NE trending structures formed first, followed by NS and finally WNW trending structures. Thus, NE and NS trending structures in basalt are most possibly formed by seafloor spreading. At U1433, no structures were found in postspreading sediment. At U1431, sediments show mainly WNW trending slickensides, different from that of basalt. The structures in the basalt of both sites suggest two dominant orientations of NS and NE. These two sites are close to the East and Southwest relict spreading ridges and provide critical information on the latest spreading stages. In order to resolve the inconsistency between NS trending fracture zones and NE oriented spreading fabrics of the South China Sea during the latest spreading stage, we analyzed macrostructures identifiable from the basalt and consolidated sediment samples of the Integrated Ocean Drilling Program (IODP) Sites U1431 and U1433. Macrostructures preserved in deformed rocks are essential for the understanding of their evolution, especially when the deformation is weak and hard to discriminate in regional scale or purely through geophysical data.
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