황해 남동해역 고해상탄성파를 이용하여 퇴적환경 및 퇴적층서 연구

Abstract

High-resolution (Chirp and Sparker system) seismic profiles were analyzed to investigate the sedimentary sequence and distribution pattern of the late Holocene deposits in the southeastern Yellow Sea. The sedimentary sequence includes three units bounded by erosional bounding surface: (1) almost transparent and homogeneous seismic facies (Unit A), (2) acoustically parallel to subparallel reflections and transgressive sand deposits (Unit B) and (3) confused inner reflectors and regressive to transgressive incision-fills (Unit C). The uppermost sedimentary sequence was classified based on the discrete echo types (1) flat seafloor with sharp bottom echoes (echo types 1-1 and 1-2, transgressive sediment sheets or wedge form (echo types 1-3, Holocene muds), (3) flat seafloor with regularly spaced, wavy bedforms (echo type 1-4; largescale dunes), (4) mounded seafloor with either smooth surface of superposed bedforms (echo types 2-1, 2-2 and 2-3; tidal ridges), and (5) various-scale eroded seafloor (echo types 3-1 and 3-2; channels). Suspect featyres of acoustic turbid zones are found whech is related to gas charged sediment.