安徽北淮阳复向斜形成时间及其构造意义

本文运用盆-山耦合的研究方法,探讨了北淮阳复向斜的形成。石炭纪以后、晚三叠世以前,华北南部的淮南地区和北淮阳地区的沉积特征和构造特征是可以对比的。北淮阳构造带叠加复式向斜和淮南复向斜及“徐宿弧”具有相似的褶皱构造形态、轴迹展布方向和矿物拉伸线理方向,并在统一的应力体制下产生,系北西西向左行走滑作用的强制性褶皱。据此,间接地确定了北淮阳复向斜的形成时间为中—晚三叠世。大别地块的隆升可能是大陆折返过程中“构造挤出”的结果,导致不同类型和不同等级变质岩共存在一起,形成构造加积杂岩。

The timing and tectonic implications for the North Huaiyang synclinoria

The timing and tectonic implications for the North Huaiyang synclinoria are explored on the basis of the principles of basin-range coupling,and the comparison is made for the sedimentary and tectonic features in the North Huaiyang and Huainan reqions.during the Carboniferous and Late Triassic in southern North China.There are many striking similarities in the morphology of folded structures,trace orientation and mineral elongation lineation orientation for the North Huaihang synclinoria,Huainan synclinoria and "Xuzhou-Suzhou arc".It can be indirectly inferred that the North Huaiyang synclinoria were formed during the Middle and late Triassic.The uplift of the Dabie landmass may be attributed to the "tectonic extrusion" during the continental return,thus resulting in the formation of the tectonicallyaccretedcomplexes composed of metamorphic rocks of different types and grades.