摘要
贝加尔裂谷系的断裂发育阶段和沉积作用过程基本一致，除沉积作用前的前裂谷断裂已经活化外，整个裂谷系的发育及演化过程大体可划分为两个阶段，即始新世中晚期—上新世早期（Ｅ２－３２—Ｎ１２）的开始阶段和上新世中晚期—第四纪（Ｎ２－３２—Ｑ）的主要阶段。前者属塑性形变，地形反差小，断裂活动弱；后者属脆性形变，地形反差大，断裂活动强。贝加尔裂谷拗陷是贝加尔裂谷系中发育最早、规模最大的水下拗陷，新构造运动表现明显，升降幅度自西南向东北增大。区内及其四周断块山体及盆地多显示了自西向东翘起的特点。夷平面及冲、洪积扇发生大量拱曲和拗曲。各方向断裂力学属性组合特征。
The history of faulting of the Baikal rift system is esentially coincident with the associated sedimentary processes.The evolution of the rift system can be broadly divided into two stages:Primary stage ranging in age from middle late Eocene to early Pliocene (E 2 3 2-N 1 2)and main stage from middle late pliocene to Quaternary(N 2 3 2-Q). The former is characterized by plastic deformation with no significant relief and weak fault activity,while the latter by brittle deformation with sharp relief and strong fault activity. The Baikal depression is the earlist and the largest undewater depression of the Baikal rift system,where occurred notable neotectonic activities with an vertical movement from southwest to north east.There are indications of a broadtilting from the west to the east in the area and the surrouding block mountains and basins.There have occurred bending and doming of a large number of planation surfaces and alluvialpluvial fans.The combination of different trend and mechanical properties suggests a NE SW compression.
出处
《地质力学学报》
CSCD
1996年第4期7-14,共8页
Journal of Geomechanics
