南海北部深水西区中中新世混合沉积模式及控制因素

作    者:杨涛涛,吕福亮,王彬,胡冰,贺晓苏,鲁银涛
单    位:中国石油杭州地质研究院
基金项目:国家重大专项”西沙海域油气地质综合研究及有利勘探区”(2008ZX05025-004)资助
摘    要:
以新采集的地震资料为基础,对南海北部深水西区的混合沉积作了初步研究。混合沉积在地震剖面上表现为平行—亚平行,振幅强—中,频率中等及连续性中等的反射特征。混合沉积分布在研究区地震资料覆盖范围的西北角,发育规模较大,最大长度达44.7 km,最大宽度33.2 km,面积1084km2,最大厚度为138m,纵向上分布在中中新统梅山组。综合南海北部构造演化、地震勘探等研究成果,建立了混合沉积模式。该混合沉积分布于半深海沉积区,由其南东东方向的西沙—广乐台地提供碳酸盐岩碎屑(同时也提供部分硅质碎屑),由其西侧的中南半岛提供主要的硅质碎屑。在南海北部深水西区,控制混合沉积分布的主要因素为构造作用(包括海平面变化)、物源供给及水动力条件等三个方面,这三者之间又具有密切的内在联系。
关键词:混合沉积;沉积分布;沉积模式;控制因素;新近纪;南海盆地

Modeling and Controlling Factors of Miocene Mixed Sedimentsin Western Deepwater Area, Northern South China Sea

Author's Name: Yang Taotao, L俟Fuliang, Wang Bin, Hu Bing,He Xiaosu,Lu Yintao
Institution: PetroChina Hangzhou Institute of Geology
Abstract:
Mixed sediments mean the mixed sedimentary carbonate clast and siliceous clast, which are common inmodern and ancient sediments. Based on the new seismic data, elementary study is finished to mixed sedimentsin west deepwater area, Northern South China Sea. The mixed sediments have some reflection features such as parallel-subparallel, medium-strong amplitudes, medium frequency and medium continuity on seismic profiles. The according area of mixed sediments that lies in the northwest of seismic area develop in a relatively wide range with an area of 1,084km2 and up to 138m of vertical thickness in middle Miocene Meishan Formation. A model of mixed sediments is set up based on the tectonic evaluation and seismic exploration in northern South China Sea.These mixed sediments that lie in the semi-deepwater area derive from carbonate clast and parts of siliceous clast, which are provided by Xisha-Guangle Terrace on the east-southeast, and siliceous clast, which are supplied by Indochina peninsula on the west. The main factors controlling the mixed sediments are tectonic action (including changes of sea levels), source supply and hydrodynamic condition, which are closely relative each other.
Keywords: Mixed sediment;Sedimentary distribution;Sedimentary modeling;Controlling factor;Neocene;South China Sea
投稿时间: 2009-11-16  
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