瓯江口南部海域第四纪声学地层

Acoustic stratigraphy of the Quaternary in the south of the Oujiang River Estuary

利用瓯江口南部海域气枪单道地震剖面资料和第四纪钻孔1的岩芯资料,对研究区第四纪地层结构进行了划分。将根据地震剖面划分的6个声学地层单元(SU1-SU6)与钻孔1岩芯划分的沉积地层单元对比,发现二者具有很好的对应关系。其中,SU1和SU3单元分别为MIS 1、MIS 3形成的海相沉积,SU2和SU4单元分别对应MIS 2、MIS 4期陆相河流或河湖相沉积地层,SU5单元对应MIS 5河流-海相沉积地层,SU6单元则对应MIS 6期及更早的陆相河湖相沉积。对研究区第四纪地层格架的建立和沉积层序分析可为东海第四纪地质和古环境演化研究提供参考。

Based on the signal-channel seismic data of air-gun source and lithological data of the Borehole 1,the Quaternary stratigraphy in the south of Oujiang River estuary was recognized.By comparing six stratigraphic units(SU1~SU6)interpreted from seismic profiles and sedimentary data from Borehole 1,we found that the seismic units agree well with the borehole ones.The sedimentary units of SU1 and SU3 are marine deposits cor-responding to seismic units of MIS 1 and MIS 3,while SU2 and SU4 are fluvial or fluvial-lacustrine deposits cor-responding to MIS 2 and MIS 4,respectively.The SU5 unit is fluvial-marine deposit that can be assigned to MIS 5,whereas SU6 is fluvial-lacustrine deposit corresponding to MIS 6 and the older ones.The establishment of the Quaternary stratigraphic framework and the analysis of sedimentary sequence in this study provides an important reference for the Quaternary geology and paleo-environment evolution of the East China Sea.