珠江口盆地惠州凹陷新近系坡折带成因类型及对地层沉积的控制作用

Genetic types of the Neogene slope-breaks and their controls on deposition in Huizhou Depression in Pearl River Mouth Basin

龙更生 施和生 王英民 杜家元 刘军 张晓宇 刘豪

Long Gengsheng Shi Hesheng Wang Yingmin Du Jiayuan Liu Jun Zhang Xiaoyu Liu Hao

惠州凹陷新近系地处浅海陆架背景,地层发育相对平缓,通过地震、钻测井等地质资料的综合研究,发现依然存在沉积坡折带、断裂坡折带和挠曲坡折带3种主要类型的坡折带。这些坡折带在平面上呈顺源多级坡折带组合、斜交组合、梳状组合和平行山梁组合4种组合类型。并且坡折带的演化具有明显的继承性、间歇性、规模递变性和迁移旋回性。研究进一步揭示,盆地北缘和南部的坡折带对地层的叠置样式及沉积体系的发育和空间展布起着明显的控制作用。

The Neogene in Huizhou Depression were deposited in neritic shelf environment and is gentle in dip.However,a comprehensive study of seismic,drilling,log data indicates that three types of slope-breaks (i.e.deposition breaks,fault breaks and flexural breaks) occur in the area.On the plane,these breaks combine with one another in four patterns,including multistage,diagonal,comb-shaped,and ridge-parallel.Their evolution presents such evident features as inheritance,periodicity,scale grading,and migration cyclicity.Slope-breaks in the north margin and south of the basin control the superimposing pattern of the sequences and the development and spatial distribution of depositional systems.

10.11743/ogg20090213