摘要
四川盆地是我国具有代表性的中新生代沉积盆地,喜马拉雅运动使之发生褶皱变形。野外观察和深部探测资料表明,褶皱及与之相伴的断裂通常在3～5千米的深度上消失,为典型的浅层构造。上下层位构造形态的不协调现象是沿软弱层位发生滑脱作用的结果。盆地内的地震活动性比四川西部活动构造区明显减弱,仅有的几个中强地震震例表明,它们具有震源浅、震级低,烈度高且震中位置与背斜构造关系密切的特点。本文旨在通过盆地内盖层滑动及其与盖层沼皱、断裂的成因机制的讨论,探索导致盆地内地震活动特殊现象的原因。并预测盆地内未来地震的可能强度。
The Sichuan basin is one of representative basinsof Mesozoic and Cenozoic Era in China. The Himalayan diastrophisni resulted the deformation of the Sichuan basin to create a series of folds. The folds and companing faults of coverlayers usually disappear at the depth of 3-5km according to deep structure surveying and the field investigation,indicating a disharmonious feature that caused by the de'collement. Information of earthquake activity suggests that the seismicity of the basin is obviously lower than that of the tectonically active region in the western Sichuan. Situations of a few of moderate earthquakes indicate that the seismicities in the basin are of the features of shallow depth, low magnitude,high intensity as well as that epicenters are related with fold structures. The present paper is aimed at searching after the causes of generating the features of seismicity in the Sichuan basin by the discussion on the creating mechanism of the coverlayer de'collement,and predicting the sizes of the possibally future earthquakes of the basin.
出处
《四川地震》
1992年第3期13-18,共6页
Earthquake Research in Sichuan
关键词
地震
地质
盆地
四川
Sichuan basin,fold,.fault ,de'collement,earthquake
