【摘要】 本文首先讨论了渭河盆地的不对称性,并提出了不对称盆地主控断裂和次控断裂的概念。渭河盆地的不对称性主要表现在:(1)盆地的横剖面形态不对称;(2)盆地南北两侧边界断裂的构造特征及其活动性具有明显的差异性;(3)深部构造形态不对称。最后,以渭河盆地为例,建立了“悬臂梁模型”,对不对称盆地边界控制断裂的发展演化以及形成机制进行了计算分析和讨论。计算结果表明:(1)弯曲导致应力集中,并形成拉破裂;(2)破裂陡倾向自由端;(3)当梁的长度增大时,有可能在固定端形成新的拉破裂。更多还原

【Abstract】 Asymmetry of the Weihe Basin is discussed in the paper, and also the main-controlled-fault, sec-ondary-controlled-fault of asymmetric basin is proposed in the paper. The asymmetry of the Weihe basin is as follows: (1) Its shape of cross-section is unsymmetrical; (2) The tectonic activity of the south margin fault and the north margin fault is apparently different; (3) Its deep tectonics is unsymmetrical. At last, this paper takes"cantilever"model for calculations. The results show: (1)Fluxure will lead to stress accumulation and forming tensional crack; (2)Crack slopes steeply towards freedom end; (3) When the length of beam becomes longer, it is possible that new tensional crack will occur in the new fixed end.更多还原