摘要
南海北部陆坡发育众多海底峡谷,其形成、发育、演化过程都存在较大差异。本文选取南海北部陆坡典型的珠江口外海底峡谷群、东沙海底峡谷、台湾浅滩南海底峡谷和澎湖海底峡谷进行研究,通过高分辨率多道地震数据和多波束测深数据,结合前人研究成果,对4条典型海底峡谷的形态特征、沉积充填特征及结构、形成发育过程及控制因素进行研究。结果表明,南海北部陆缘各个海底峡谷的形成受多个控制因素的影响,其影响程度及方式都有差别。构造活动、海平面变化及沉积物重力流与海底峡谷的演化密切相关,而陆地河流和局部构造因素也以不同方式影响着海底峡谷的发育。对于发育在主动大陆边缘的台湾岛东南侧的澎湖海底峡谷,其板块运动和岩浆活动活跃,其上发育的海底峡谷的控制因素以内营力地质作用为主。而具有被动大陆边缘属性的其他3条峡谷,由于构造运动较少或停止,其上发育的海底峡谷的控制因素以外营力地质作用为主。
Submarine canyons are well developed in the northern continental slope of the South China Sea, featured with different evolution history and controlling factors. Four typical submarine canyons in this region, including the Pearl River Canyon system, Dongsha Canyon, Taiwan Bank Canyon, and Penghu Canyon were selected in this study. Based on combined geological interpretations with multi-channel seismic data and high-resolution bathymetric data, as well as previous works, the morphological characteristics, sedimentary structures, the formation processes, and the controlling factors of these submarine canyons were studied. Results show that the formation of various submarine canyons in the northern continental slope of the South China Sea are dominated by various factors, including the tectonic activities, sea level change and sediment gravity flow. The rivers on land and local tectonics(such as magma intrusion, uplifting) also affect their formation. For submarine canyon developed on the active continental margin, such as the Penghu Canyon, is mainly controlled by tectonic activities. While for those developed on the passive margins, their formations are dominated by Cenozoic tectonics, sediment supply, and eustasy. The exogenic process is the main influencing factor.
作者
刘丛舒
丁巍伟
殷绍如
方鹏高
丁航航
LIU Cong-shu;DING Wei-wei;YIN Shao-ru;FANG Peng-gao;DING Hang-hang(Key Laboratory of Submarine Geosciences,SOA,Hangzhou 310012,China;Second Institute of Oceanography,MNR,Hangzhou 310012,China;Earth Science College,Zhejiang University,Hangzhou 310027,China)
出处
《海洋学研究》
CSCD
北大核心
2019年第2期28-43,共16页
Journal of Marine Sciences
基金
国家自然科学基金面上项目资助(41676027)。
关键词
海底峡谷
控制因素
南海
主、被动大陆边缘
submarine canyon
controlling factors
South China Sea
active margin
passive margin