前陆盆地层序地层学研究简介

前陆盆地层序地层学是将层序地层学理论应用于构造活动的前陆盆地分析的一个特例。前陆盆地三级层序成因并非受全球统一的海平面变化控制，而是与盆缘造山带区域本报特约记者运动、盆内沉积作用和相对海平面变化的联合作用有关，代表了前陆分地一个成盆期的不同发育阶段。层序界面是相对海平面下降和区域构造隆的联合作用面。在盆地演化的不对称沉降阶充填阶段，邻造山带区为低水位浊积扇沉积层序；远离造山带区，低水位体系域不发育

INTRODUCTION ON SEQUENCE STRATIGRAPHY OFFORELAND BASINS

Sequence stratigraphy of foreland basin is a special application of the theory of sequence stratigraphy to the tectonically active foreland basins.The origin of the third-ordercycle sequences in foreland basins are obviously controlled by regional tectonism adjacent tothe orogenic belt,sedimentation within the basins and the relative sea-level fluctuation.Thesequence boundary is an interplay of relative sea-level drop and local tectonic uplift.n theasymmetric subsidence filling stage of foreland basin evolution,there are two types of sequences.Lowstand turbidite fan sequence is on the proximal side to the orogenic belt.Awayfrom the orogenic belt,erosional sequence boundaries and transgressive surfaces are merged,with no record of lowstand system tracts,or with a few of shelf margin system tracts underthe transgressive surface.Each sequence is composed of transgressive system tract,condensedsection,early highstand system tract and late highstand system tract.