华北盆地新生代裂陷机制与过程的数值模拟

采用McKenzie的纯剪切动力学模型对似环状的“大华北盆地”的形成机制与过程进行初步的数值模拟。模拟结果表明：(1)“大华北盆地”新生代以来经历了两次伸展减薄--热事件．而不是原来所认为的一次事件的两个阶段；(2)第二次伸展减薄--热事件(即新近纪一第四纪)的沉降幅度要小于第一次伸展减薄--热事件(即古近纪)的沉降幅度；(3)“大华北盆地”古近纪的第一次伸展减薄一热事件可能已经进入后裂谷相，并且是处于后裂谷相的初期；(4)现今盆地的演化可能处于第二次伸展减薄--热事件的同裂谷相的晚期。这一研究对认识华北地区新生代的盆地演化及动力学背景有重要的意义。

SIMULATION TO THE MECHANISM AND PROCESS OF THE FORMATION OF CENOZOIC NORTH CHINA RIFT BASINS

This paper simulates the mechanism and process of the formation of the ring-like "Large North China Basin" by McKenzie's pure-shear model. The simulation indicates: (1) the "Large North China Basin" has experienced two extended-thinned and thermal events, not two phases of one extended-thinned and thermal event which has been considered. (2) The subsidence caused by the second extended-thinned and thermal event (Neogene-Quaternary) is less than that by the first extended-thinned and thermal event (Eogene).(3) The evolvement of the first extended-thinned and thermal event of "Large North China Basin" in Eogene had probably been into post-rift phase, but it may be initial post-rift phase. (4) Currently the evolvement of the basin is probably in late syn-rift phase of the second event. This research result will have an important signification to the evolution and dynamic background of Cenozoic Basin in North China.