南海西南次海盆NH973-1测线地震解释

针对973项目“南海大陆边缘动力学与油气资源潜力”2009年新采集的多道地震剖面NH973-1测线进行了研究分析,获得以下初步认识:(1)西南次海盆深海平原南端下伏巨厚沉积体,表明陆坡坡脚不是洋陆边界的位置,深海平原南端为陆壳分布区,也可解释为洋陆过渡带.这种情况在南海的洋陆边界确定过程中应加以考虑.(2)西南次海盆洋...

Tectonic and seismic interpretation of line NH973-1 along southwest sub-basin in South China Sea

We interpreted the new 2-D multi-channel seismic profile line NH973-1 which crossed southwest sub-basin of South China Sea (SCS) and was acquired in 2009 by Project-973 "South China Sea continental margin dynamics and petroleum resource potential". Our preliminary analyses are as follows: (1) We observed the thick sedimentary body beneath the abyssal plain at the southern end of southwestern sub-basin, considered that continental crust exists beneath the thick sedimentary body, and the toe of southern continental slope is not the COB (Continental and Oceanic crust Boundary), but is in COT (Continental and Oceanic crust Transition) zone. Therefore, it is necessary to consider this situation before we determine the COB of SCS. (2) There are two types of oceanic crust basement, which reflects different spreading rate, magmatism, and deformation for different stages of seafloor spreading.