摘要
进行了 4个砂箱模型的模拟实验。其中基底收缩单侧挤压剖面模型以形成后冲叠瓦式断层为特征 ,基底无收缩单侧挤压剖面模型则以发育前冲叠瓦断层为特征。基底收缩斜向双侧挤压平面模型形成两组不同走向的逆断层 ,一组为与挤压带边界基本平行的主控断层 ,另一组为与挤压方向近于垂直的雁列断层。而基底无收缩斜向双侧挤压平面模型仅形成一组与挤压带边界基本平行的逆断层。这些模型的实验结果表明 ,基底收缩对挤压构造变形特征具有重要的影响。后冲 (或向陆冲向 )叠瓦式这种较为罕见挤压构造、以及与挤压方向近垂直的雁列断层的形成与基底的收缩作用有关。对于类似于焉耆盆地这种通常认为是压剪形成的挤压构造组合 ,笔者认为用“基底收缩条件下的斜向挤压作用”可更加贴切地加以解释。
Four sandbox-models have been investigated in our simulation experiment. In the section-model compressed from one direction with contractive substrate, the structures obtained are characterized by the imbricate thrusts with rearward vergence, but in that without contractive substrate the structures are mainly forward vergent imbricate thrusts. In the plane-model compressed obliquely from two directions with contractive substrate, two sets of thrusts with different strikes have been produced; one of which are major faults with strike nearly parallel to the margins of compression zone, and others are en echelon faults with strike nearly perpendicular to the compression direction. Whereas in the plane-model compressed obliquely from two directions without contractive substrate, only one set of thrusts nearly parallel to the margins of compression zone have been produced. The results of these models indicate that substrate contraction has important influence on the deformational characteristics of compressional structures. The uncommon imbricate thrusts with rearward (or landward) vergence and the en echelon faults with strike nearly perpendicular to the compression direction are mainly caused by substrate contracting. The structures just like that in the Yanqi Basin, which were usually considered as the results of transpressional deformation, would be better interpreted with viewpoint of oblique compression with substrate contracting.
出处
《地学前缘》
EI
CAS
CSCD
2002年第4期377-382,共6页
Earth Science Frontiers
基金
国家自然科学基金资助项目 (4 9872 0 68)
中国石油天然气集团公司中青年创新基金资助项目 (CX1990 6)
关键词
挤压构造
物理模拟
砂箱实验
compressional tectonics
physical modeling
sandbox experiment