太湖穹窿中逆－逆冲断层及外围的推覆构造

太湖穹窿中逆－逆冲断层均发育在褶皱的翼部，并在平面上成放射状排列。而推覆构造为浅成的、弧立的飞来峰散布在穹窿的外围．通过几何学、运动学的研究，揭示这些构造与太湖穹窿在成因上有密切联系．即当垂直构造力向上顶托形成隆起时，岩层沿下震旦统软弱层发生垂直半径方向的收缩，产生侧向挤压，形成穹窿褶边褶皱，并在褶皱陡翼产生逆－逆冲断层，组合成放射状构造。而在穹窿的中心顶部出现正断层，受正断层切割的顶部地层失去相互牵制力，在重力作用下发生向四周滑动，形成散布在穹窿外围的推覆体。穹窿顶部成为构造剥蚀区，其缺失的地层与推覆体相对应．因此逆断层、逆冲断层、推覆构造、褶边褶皱是形成太湖穹窿时，同一构造力作用的产物，并组成统一的构造系统。

REVERSE FAULT THRUSTS IN THE TAIHU LAKE DOME AND NAPPE STRUCTURES OVER THE MARGIN OF THE DOME

everse fault thrusts are developed at one flank of each fold in a radiating pattern in the skirt-fringe fold belt of the Taihu Dome. Nappes are some shallow structures which contain some small isolated klippes over the margin of the dome. Based on studying their features of geometry and kinetics,it shows that these structures are related to the Taihu Lake dome. When vertical stress upwarped to form the dome, the edges of the bedded block would move toward the center of the dome along lower Sinian System relatively weak layers in all directions. Meanwhile,the lateral compression with vertical movement caused skirt-fringe folds and reverse fault thrusts were formed at each one stepper flank of those folds and ranged in radiating patterns. Normal faults developed. at crest of the dome, the beds cut by the normal faults slided in all directions along weak layers under gravitation. The nappes wrer thus formed and distributed over the margin of the dome. So reverse fault thrusts,nappes and folds are corrected with dome formation.