珠三坳陷西北部浅海陆架砂体时空演化及成因机制  

Temporal and spatial evolution and genetic mechanism of shallow continental shelf sandbodies in the northwestern Zhusan Depression

作　　者：宋广增 李明[3] 张帅 严德天 刘恩涛[2] 陈思[2] Song Guangzeng;Li Ming;Zhang Shuai;Yan Detian;Liu Entao;Chen Si(School of Water Conservancy and Environment,University of Jinan,Ji’nan 250022,China;Faculty of Earth Resources,China University of Geosciences,Wuhan 430074,China;Hainan Branch of China National Offshore Oil Corporation Limited,Haikou 570300,China)

机构地区：[1]济南大学水利与环境学院,山东济南250022 [2]中国地质大学资源学院,湖北武汉430074 [3]中海石油(中国)有限公司海南分公司,海南海口570300

出　　处：《海洋学报》2023年第2期62-73,共12页

基　　金：国家自然科学基金(42002127,41702114);山东省自然科学基金(ZR2019QD008)。

摘　　要：为阐明珠三坳陷西北部珠江组一段上亚段浅海陆架砂体成因机制,综合地质与地球物理数据,首先搭建了五级层序地层格架,并以此为约束,开展浅海陆架砂体识别与定量描述,剖析其时空演化规律,进而讨论其成因机制。结果表明:(1)研究区珠江组一段上亚段可划分为4个五级层序,自下向上编号为FS4、FS3、FS2与FS1;(2)研究区发育潮流沙脊与滨外沙坝两种类型陆架砂体,两者整体呈NW-SE向展布,潮流沙脊主要分布于研究区西部,滨外沙坝则集中于东部;(3)FS4、FS3与FS23个五级层序中,潮流沙脊与滨外沙坝均呈现较大规模与较多数量,最上部FS1五级层序中,规模与数量达到最小;(4)沉积基准面(水动力)、同沉积地貌、沉积物碎屑供给等因素共同影响了潮流沙脊与滨外沙坝的发育规模、展布特征与时空演化规律等,综合构成了珠三坳陷西北部浅海陆架砂体的成因机制。In order to clarify the genetic mechanism of shallow continental shelf sandbodies in the upper submember of the first member of Zhujiang Formation in the northwestern Zhusan Depression,with integrated use of geological and geophysical data,the five-order sequence framework was established firstly,inside of which,the shallow continental shelf sandbodies were identified and quantitatively described,and the temporal and spatial evolution of the shallow continental shelf sandbodies were analyzed,and the genetic mechanism was discussed.The results show that:(1) The upper submember of the first member of Zhujiang Formation in the study area can be divided into four five-order sequences,which were numbered as FS4,FS3,FS2 and FS1 from bottom to top.(2) There are two types of shelf sand bodies:tidal sand ridge and offshore sand bar,which are distributed in NW-SE direction.Tidal sand ridges are mainly distributed in the west of the study area,while offshore sand bars are concentrated in the east.(3) In the three five-order sequences FS4,FS3 and FS2,the scale and quantity of both tidal sand rdiges and offshore sand bars are relatively large,while in the upper five-order sequence FS1,the scale and quantity present poor.(4) Sedimentary base level(hydrodynamic condition),synsedimentary geomorphology and sediment debris supply jointly affected the development scale,distribution characteristics and temporal and spatial evolution of tidal sand ridges and offshore sand bars,which comprehensively constituted the genetic mechanism of shallow continental shelf sand bodies in the northwestern Zhusan Depression.

关 键 词：浅海陆架砂体 隐蔽圈闭 高频层序 基准面旋回 珠三坳陷 

分 类 号：P736.212[天文地球—海洋地质]