闽西南苏桥-小溪洋井田推(滑)覆构造形成演化

Evolutionary history and deformation mechanism of thrust-nappes structure in Suqiao-xiaoxiyang well field,southwestern Fujian

结合区域地质资料和前人资料,深入研究了闽西推覆构造带前峰处的苏桥-小溪洋井田地质特征。结果显示:井田剖面几何形态为一典型的"仑"型背骑式逆冲推覆构造;逆冲推覆构造和层间拆离滑覆构造是井田两种基本的构造类型;层间拆离滑覆构造形成于早印支期,逆冲推覆构造主要形成于燕山早期、燕山晚期和喜山期;井田在区域拉张环境下遭受剥蚀改造,发育飞来峰构造,并使F5、F6断层产生反转。从而,在构造推覆体下找煤应特别注意地层缺失情况,区域隐伏煤田的预测应采用物探与钻探相结合的方法。

Based on previous study data and the systematic studying the character of geometry and kinematics of the thrust-nappe structures in Suqiao-xiaoxiyang well field, the paper suggests that deformation mechanism is a＂仑＂style, the thrust-nappe faults and layer sliding faults are basic structural styles in the field. The layer sliding faults formed in Early Indosinian Epoch and the thrust-nappes formed through Early Yanshanian and Himalayan Epoch. The well field suffered erosion and deformation under regional stretching conditions, resulting in a series of thrusts and made the faults F5 and F6 reversion. At last it is suggested that during coal exploration should pay enough attention to the disappear of strata, and emphasized the combination of geophysics and drilling under the thrust-nappes structure.