关键词: 二叠纪, 沉积体系, 吉中地区, 沉积相, 构造背景

Abstract:

Based on the analyses of sedimentary systems, mineralogy and geochemistry, this paper discusses the sedimentary features of the Permian System in the central Jilin Province,and then the sedimentary paleogeography and tectonogeography have been recovered, in coincidence with the existing tectonogeographical models. The central Jilin Province was of a complex marginal basin along an active continental margin in the Early and Middle Permian. The Lower Permian System is composed of a shallowing-upward succession, including sedimentary systems of a shelf, a marginal sedimentary basin, and a sub-deep sedimentary basin. At the beginning of the Middle Permian, an active tectonic setting was evinced by the development of volcanoclastics in the region, followed by sedimentary systems of alluvium fans, sub-deep basin and a shallowing-upward carbonate ramp. Because of the collisions of the North China block with relatively small blocks from northeastern China along the West Lamulun River-Changchun-Yanji suture zone, major paleogeographical change took place during the Late Permian. Terrestrial environments dominated in the region during the Late Permian, including sedimentary systems of lacustrine alluvial fans and sub-deep lakes. Remaining marine environments were confined at some places

Key words: Permian, sedimentary system, central Jilin Province, sedimentary facies, tectonic background