摘要
沿海原断裂带发育 3个级别的拉分盆地 ,其中 ,发育于中新世的老龙湾盆地是规模最大的拉分盆地 ,长度超过 5 0km。为了估计盆地拉分量 ,本文建立了数学模型 ,相关参数包括盆地沉积厚度、盆地长度、滑脱面深度等。计算得到老龙湾盆地的拉分量为 30km。对于另外两个较小规模的拉分盆地 ,本文利用前人资料和平均走滑速率方法得到盆地拉分量分别为 2 2km和 8km。这样 ,沿海原断裂带新生代以来的拉分总量约 60km。该数值与景泰至靖远的黄河位错量接近。
Pull-apart basins of three scales were found in Haiyuan fault zone.The largest one is more than 50km long,named Laolongwan basin developed in Miocene.A model was built to calculate the amount of pull-apart of an extensional basin.Parameters used in calculations include thickness and length of deposition and depth of detachment.The results of calculations show that the amount of pull-apart of the Laolongwan Basin is about 30km.Based on previous studies and calculation by average slip rate,amount of pull-apart of the other two smaller scale basins are 22km and 8km.Thus,the total displacement of strike-slip along the Haiyuan fault zone is about 60km which is close to the offset of the Yellow River from Jingtai to Jingyuan.
出处
《中国地震》
CSCD
北大核心
2001年第2期167-175,共9页
Earthquake Research in China
基金
国家自然科学基金 ( 4 973 2 0 95 )
国家重点基础研究发展规划项目"大陆强震机理与预测"( 95 13 0 10 2 )资助
