珠江口盆地白云凹陷海底峡谷沉积模式  

A DEPOSITIONAL MODEL OF SUBMARINE CANYONS IN BAIYUN SAG,PEARL RIVER MOUTH BASIN

作　　者：吴嘉鹏[1,2] 王英民[1,2] 徐强[3] 

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国海洋石油研究总院,北京100027

出　　处：《海洋地质前沿》2011年第8期26-31,共6页Marine Geology Frontiers

基　　金：国家自然科学基金项目(40972077);国家基础研究发展规划项目(2009CB219407)

摘　　要：利用高分辨率三维地震资料,在珠江口白云凹陷三维工区中发现形态以及发育特征相似的7个海底峡谷。通过对其现今地貌特征研究,将其分为上、中、下段。综合地震反射振幅、连续性及外部结构形态等信息,识别出了峡谷侵蚀基底、谷底沉积、谷壁滑塌等峡谷地震相单元。结合峡谷不同位置处的各类地震相的发育情况,可知峡谷的这3个地貌单元具有不同的沉积特点,分别为上部侵蚀下切段、中部侵蚀—沉积段以及下部沉积充填段。最终提出了白云凹陷海底峡谷的沉积模式。Based on the high resolution 3D seismic data,seven submarine canyons are studied on their morphological and sedimentary characteristics in a block in the Baiyun Sag,northern South China Sea.Upon morphological features,the canyons are divided into three segments,namely upper,middle and lower segments.According to the continuity and amplitude of the reflection,integrated with seismic reflection configuration,the basal erosional discontinuity and two seismic facies,i.e.thalweg facies and slide facies,were recognized.The upper reach of a canyon is an erosional area characterized by the erosional discontinuity.In stead,the lower reach is in fact a depositional area,while the middle reach is characterized by the coexistence of erosional and depositional features.A depositional model for the submarine canyons in the Baiyun Sag is proposed as the results of the study.

关 键 词：海底峡谷 地貌 地震相 沉积模式 白云凹陷 

分 类 号：P539.2[天文地球—古生物学与地层学]