摘要
欠补偿周缘前陆盆地发育于陆间造山带的早期阶段。前陆褶冲带不同的前缘断裂活动样式决定了前陆盆地发育不同的结构。以低角度、盲逆冲活动为特征的前缘断裂所控制的前陆盆地发育了复杂的次级构造单元 ,具体可识别出楔顶、前渊、前隆和隆后 4个沉积带。这类前陆盆地发育了 3种类型的沉积序列 :1靠陆一侧初始前隆区发育的“欠补偿三位一体”充填序列 ;2前渊带靠陆一侧发育的陆棚沉没充填序列 ;3初始前渊深海—半深海区发育的沉积颗粒向上变粗、沉积环境向上变浅的沉积充填序列。欠补偿周缘前陆盆地沉积物扩散方向转换面、碳酸盐岩台地沉没不整合面等关键界面的时空位置是标定碰撞构造的主要地层学标志。
Underfilled peripheral foreland basins develop in the initial stage of intercontinental orogenic belts.Their basin architectures are mainly controlled by the frontal thrust pattern in the foreland fold thrust belts.While in the basins controlled by the low angle,blind frontal thrusts,four discrete tectonic zones can be distinguished,namely,from orogen to foreland,wedge top,foredeep,forebulge,back bulge depozones.Three types of filling sequences are developed in the underfilled peripheral foreland basins:①underfilled trinity,developed in the initial forebulge regions,②the shelf drowning depositing sequence,developed in the part of foredeep depozones that are transformed from continental shelves,and ③a coursing upward,shoaling upward mega sequence,developed in the part of foredeep depozones transformed from the continental slopes,which is composed of re circled orogenic detrital turbidites and wedge top sediments.The stratigraphic constraints on the collision tectonics,found in underfilled peripheral basins,includes the transition surface of sediment dispersal direction,shelf drowning surface and forebulge unconformity surface,the age of which is equivalent to the beginning age of an intercontinental orogen.The analysis of the isochron maps of the above key surfaces is very useful for the identifying the collision pattern and history of an intercontinental orogen.
出处
《地质科技情报》
CAS
CSCD
北大核心
2003年第1期35-40,共6页
Geological Science and Technology Information
基金
科学技术部国家攀登专项 (95 -专 -0 4)
国家自然科学基金资助项目 (4 0 0 3 2 0 10 )
