丽水、椒江凹陷伸展运动分析

丽水、椒江凹陷是晚白垩世以来发展起来的大陆边缘裂隐盆地。利用剖面平衡技术，计算了东海陆架盆地丽水、椒江凹陷第三系和第四系地层的伸展量、伸展率和伸展系数，研究了丽水、椒江凹陷的伸展演化特征。同一时期不同地区的伸展量有所差异；同一地区不同时期的伸展量也有所不同，空白上，分地伸展率由南向北依次减小；时间上，水平伸展运动主要发生的晚白垩世－－早第三纪，最大伸展时期，南部早北部晚，南部在晚白垩世，北部在早古新世。盆地的仲展是在拉张应力场或右旋拉张应力场作用下形成的铲式或坡坪式正断层及幕式正断层的水平离距和断块的掀斜伸展形成的。

The Anylysis of the Basin's Extension in the Lishui-Jiaojiang Sag

The Lishui Jiaojiang Sag was a faulted basin developing on the continental margin from the late cretaceous epoch. The extensional quantities, coefficient and ratio of the basin in different areas during the different faulting time of extension have been obtained by means of the technique of balanced geological cross sections in this paper. The basin's extension differs in different period and different regions. The extensional ratio reduces from the south to the north. The main extensional period is from the late Cretaceous Epoch to the Paleocene Epoch and maximum extensional period is different in different regions. The maximum extension period is the late Cretaceous in the south Lishui Sag, the early Paleocene in the north Lishui Sag and the Jiaojiang Sag. The basin's extension results from the normal faults' drawing away in horizon and the faulted blocks' tilting extension.