南海北部珠江口盆地新生代伸展过程及其区域差异性定量研究

A quantitative study on the Cenozoic extension process and its regional differences in the Pearl River Mouth basin of northern South China Sea based on balanced section restoration

以珠江口盆地为研究对象,自西向东选取了能控制区域构造格局的5条区域性大剖面,运用2D Move软件分别对其进行平衡剖面恢复,并计算出各剖面不同时期的伸展量、伸展率和伸展速率,以此为基础对珠江口盆地的构造演化过程及其区域性差异进行了定量研究。研究结果显示:(1)珠江口盆地新生代以来一直处于一个持续伸展的过程,并于32-30 Ma期间出现一个伸展高峰期,但总体呈现伸展率和伸展速率逐渐降低的趋势;(2)珠江口盆地新生代主要伸展变形时期其伸展的过程具有明显的区域性差异,即自西向东伸展率和伸展速率明显逐步变大。

Taking the Pearl River Mouth basin as the research object, five big regional sections which control the regional tectonic framework from the west to the east are selected to restore balance profile using 2D Move software. And in this paper,the extension quantity, the extension rate and the extension velocity are calculated, and then, the tectonic evolution process and its regional differences in the Pearl River Mouth basin are quantitatively studied using these data. The results indicate that：① The Pearl River Mouth basin has been undergoing continuous extension since the beginning of Cenozoic with one relatively fast extension phases during 32-30 Ma, but general extension rate and extension velocity have the trend of gradual reduce;② The main extension deformation process in Pearl River Mouth basin during the Cenozoic period has obvious regional differences, which show that from the west to the east, the extension rate and the extension velocity of basin extension become bigger and bigger gradually.