摘要
丽水 -椒江凹陷是晚白垩世以来发展起来的大陆边缘裂陷盆地。本文利用平衡剖面技术恢复计算了丽水 -椒江凹陷不同构造部位各裂陷伸展期的盆地伸展量、伸展系数和伸展率。研究表明 :研究区晚白垩世至古新世裂陷作用具有“幕式”渐进发展的特征 ,可划分为三个裂陷伸展期 :早期 (晚白垩世 )的断陷主要由相对分散、独立的小断陷组成 ,控制半地堑凹陷的主断层主要以书斜式 (domino- style)为主 ;中、晚期 (古新世 )的断陷由相互连通的半地堑凹陷组成 ,其主干断层以犁状 (listric)或坡坪状 (ramp- flat)正断层为特征。研究区不同构造部位其水平伸展率不同 ,表现为水平伸展量由南西向北东由大变小的特征 。
The Lishui Jiaojiang Sag was a fault basin developed on the continental margin from the Late Cretaceous epoch. The amount of extension, the extensional coefficient and the extensional ratio of the basin at the different areas during the varied faulting time of extension have been obtained by means of the technique of balanced geological cross sections in this paper. Characteristically, the basin was developed by the episodic rifting during the Late Cretaceous to the Paleocene in the Lishui Jiaojiang Sag. The evolution of the fault basin can be divided into three stages, of which the fault sags in Late Cretaceous were composed of some relatively dispersal and independent small half grabens controlled by “domino style” normal faults, the fault sags in Early Paleocene composed of “rollover style” half grabens controlled by listric normal faults, and the fault depressions in Late Paleocene composed of “composite” half grabens controlled by ramp flat normal faults. The lateral extensional ratio is varied in different parts of the studied area, the amount of lateral extension became larger from the northeast to the southwest, and correspondingly, the time of major extension became later from the southwest to the northeast.
出处
《地质科学》
CAS
CSCD
北大核心
2000年第4期441-448,共8页
Chinese Journal of Geology(Scientia Geologica Sinica)
关键词
丽水-椒江凹陷
裂陷幕
运动学
断裂构造
The Lishui-Jiaojiang Sag, Fault phase, Balanced geological cross section, Kinematics, Extensional ratio
