摘要
南海东北部及邻区,特别是洋陆转换带地区的复杂地壳结构特征一直是南海岩石层结构研究的热点.本文在Pn波地震层析成像结果和深部地震探测剖面的约束下,利用重力数据建立该区两条剖面的密度模型.两条重力剖面二度半密度正反演的拟合结果支持琼粤隆起至吕宋岛弧区一带的地壳结构中存在下地壳高速层的观点,同时认为台西南盆地的拟合结果表明南部凹陷区仍属于过渡型地壳.本文认为剖面AA′和剖面BB′的构造属性虽然均总体倾向于火山岩型,但二者的地质结构并不完全一致,表明了北部陆缘深部结构的横向差异与构造属性的复杂.
The feature of complex crustal structure in Northeastern South China Sea and adjacent region, especially in continental-oceanic boundary zone, is a keystone for lithosphere structure research of the South China Sea. The 2.5D density models are given in this paper according to gravity data constrained by Pn wave velocity tomography result and deep seismic sounding profiles. The 2. 5D density modeling results support the view point that a high velocity layer exists in the lower crust in northeastern region （from Qiongyue lift to Luzon island arc） and indicate that the crust of southern depression of Taixinan basin should belong to transitional crust type. Although the tectonic feature in northeastern shelf of South China Sea belongs to volcanic type, the density and tectonic features of the two models are different, which indicates the complexity of crustal structure in northeastern shelf of South China Sea.
出处
《地球物理学报》
SCIE
EI
CSCD
北大核心
2008年第6期1785-1796,共12页
Chinese Journal of Geophysics
基金
国家基础研究973项目(2007CB4117-01)
863计划(2006AA09A101-0201,2006AA09Z359)
航遥中心项目联合资助
关键词
南海东北部
密度剖面
反演
拟合
大陆边缘
Northeastern South China Sea, Density profile, Inversion, Fitting, Continental margin
