LATE QUATERNARY SEISMIC SEQUENCES AND SEDIMENTATION ALONG THE COAST OFF TAISHAN,GUANGDONG,AS REVEALE

• 作 者: 吴时国 黄孝健
• 机 构: Institute of Oceanology,Institute of Biogeochemistry and Marine Chemistry
• 出 处: 中国海洋湖沼学报
• 发表日期: 2004年期
• 关键词: seismic data stratigraphic analysis Late Quater nary

Seismic stratigraphic analysis of 150 km of high-resolution seismic profiles (G E OPULSE and 3.5 kHz) obtained along the muddy coast off Taishan, Guangdong pr ovided valuable information on the offshore Quaternary stratigraphy, tectonics, sedimentary evol ution, and environmental and engineering geology of this area.The following late Quaternary stratigraphic sequences were mapped. (1) Pleistoce ne alluvial silty sand and shallow marine clay; (2) coarse fluvial channel sand; (3 ) nearshore and bay clayey sediments. The incision of fluvial channels occurred in two stages: duri ng the Late Pleistocene and at the beginning of the Holocene. The Pleistocene fluvial channe ls have been filled by coarse sand overlain by more than 10 m of late Pleistocene clay and 20-30 m o f Holocene clay.The coastal area is dissected by two major fault systems: the first group strike s ENE-WSW and controls the evolution of the adjacent Quaternary basin, while the second one tr ends NNE-SSW. These fault systems must be taken into account in any coastal engineering consid erations. In addition, both granitic and metamorphic basements were recognized.