雷西南地洼盆地构造沉降及其演化

TECTONIC SUBSIDENCE AND EVOLUTION IN THE DIWA BASIN OF SOUTHWESTERN LEIZHOU PENINSULA

本文通过对雷西南地洼盆地地层资料的分析.认为该区自第三纪以来的构造沉降达1223m.构造沉降过程可划分为7个时期.其中渐新世和中新世为快速构造沉降时期.该地洼盆地的演化经历了幼—少年期(E_1—E_2).青年期(E_3—N_1~1)。壮年期(N_1~2—N_2)和中—老年期(Q_1—Q_4)等四个阶段.前三个阶段以构造沉降为主,第四阶段则转变为构造抬升为主.第二和第三阶段均存在一个Mckenzic旋回.青年期阶段是该地洼盆地演化的最主要阶段,壮年期则是其定型阶段.

The thesis analyses the data on sedimentary strata in the diwa basin of Southwestern Leizhou Peninsula. It is considered that the tectonic subsidence in the studied region is more than 1223 meters since Tertiary. The process of tectonic subsidence can be divided into 7 periods. The evolution of the sedimentary basin has experienced four stages, i. e. babyteenage stage (E_1-E_2), youth stage (E_3-N_1~1), adult stage (N_1~2-N_2), and medial-old stage (Q_1-Q_4). The first three stages were generally in the stage of tectonic subsidence, and the fourth stage turned a stage of tectonic uplift. There is a Mckenzie's circle both in the second and the third stage. The youth stage is the most important and the adult stage is the finalized.