南天山造山带志留—泥盆纪盆地恢复与构造旋回地层学初探

PRELIMINARY STUDY ON TECTONIC CYCLE SEQUENCE AND RECONSTRUCTION OF THE SILURIAN-DEVONIAN PROTOTYPE BASIN IN SOUTH TIANSHAN OROGENIC BELT

用动力旋回地层学观点对南天山造山带进行了初步探讨 ,建立该区域志留—泥盆纪构造沉积演化模式 :南天山南缘洋盆早志留世已出现 ,晚志留世为孤立碳酸盐台地发育阶段 :泥盆纪南天山南缘洋盆开始向北俯冲 ,导致了相对海平面上升 ,使碳酸盐台地被淹没 ,出现深水浊流盆地背景 ,并伴随来自哈尔克山、艾尔宾山南缘火山岛弧带的火山碎屑沉积。至石炭纪 ,由于洋壳俯冲加剧 ,在南天山北缘出现火山弧、南缘盆地形成超覆沉积 ,总体反映了海平面不断上升的过程。同时 ,对造山带中变形盆地对原型盆地响应进行了探讨 ,提出了超构造岩片、构造岩片、微构造岩片及地层序列四级岩片划分方案。针对有限史密斯地层进行了动力旋回层序的研究 ,将上志留统至泥盆系划分为四个二级动力旋回层序及

A preliminary discussion is carried out on South Tianshan orogenic belt in the view of dynamic cycle stratigraphy and the evolution pattern of tectonic sediment of Silurian- Devonian in this region is established:The oceanic basin at the southern edge of South Tianshan Mountains appeared in early Silurian,in the stage of Late Silurian,it Developed into an isolated Carbonate plateform;During Devonian ,the oceanic basin of the southern edge of south Tianshan Mountains began subduct northward,which resulted the sealevel a reletive rise and made the carbonate plateform submerged,produced a deep turbidity basin background and followed a sediment of volcanic classtics from the volcanic island arc belt of the South edge of Erbeng Mountains and Halik Mountains.When it came to Carboniferous,with the oceanic crust subduction rapided,a volcanic arc appeared at the north edge of South Tianshan Mountains and a overlape Sediment formed in the basin at South edge,generally,it reflects a constant rise of the sea level.At the same time, through the discussion about the effect on the prototype basin by the deformation basin within the orogenic belt,it presents a four grade division plan of rock sheets which consist of super tectonic rock sheet,tectonic rock sheet,micro tectonic rock sheetand stratigraphic sequence.Based on the study of dynamic cycle sequence in accordance with the finite Smith stratigraphy,it is divided into 4 second grade dynamic cycle sequences and 14third grade dynamic cycle sequences from Silurian to Devonian