%0 Journal Article
%T Mesozoic sedimentation of the southern Hefei basin and exhumation of the Dabieshan metamorphic terrane<br>中生代合肥盆地南部的沉积过程与大别山变质地体的剥露
%A MENG QingRen
%A LI RenWei
%A LI ShuangYing
%A <br>孟庆任[
%A ] 李任伟 李双应
%J 岩石学报
%D 2005
%I 
%X Mesozoic tectono-sedimentary evolution of the southern Hefei basin can be divided into two distinct stages.The first stage is featured by extensional subsidence and southward expansion of the basin in Jurassic time,while the second stage is characterized by vigorous volcanic eruptions in the southern margin of the basin and northward migration of main depositional area.The Hefei basin was initiated in the Early Jurassic,but the Mid Late Jurassic saw a period of pronounced subsidence.Alluvial fan and braided fluvial systems dominated proximal areas of the basin,and were evidently controlled by basin-border faults.The basin expanded to the south as a result of the south-directed migration of the normal faulting.Fluvial lacustrine sedimentation were prevalent in the main area of the basin.Sediments were demonstrated to have come from the Dabieshan metamorphic terrane,as indicated by the restored paleo-current directions.Detrital Triassic metamorphic zircons with coesite inclusions have recently been recognized in Lower Jurassic Fanghushan Formation,thereby suggesting that the ultrahigh-pressure metamorphic rocks must have been exhumed to the surface in the Early Jurassic.Occurrence of eclogite gravels in the Fenghuangtai Formation indicates that the Dabieshan terrane experienced marked denudation in the Late Jurassic.The southern Hefei basin underwent the uplift in association of vigorous volcanism,and basin depositional area was shifted far to the north.The two-stage evolution of the Hefei basin is indicative of a change of tectonic settings in the Dabieshan terrane and adjacent regions.It is proposed that the ultrahigh-pressure rocks might have been brought up to the surface by means of laterally upward extrusion.The extrusion model not only explains Jurassic extensional subsidence of the Hefei basin to the north of the Dabie Shan terrane,but also accounts for coeval development of fold-thrust system of the southern Dabie Shan and formation of foreland basin to the south.Regional crustal extension and striking magmatism within the Dabieshan terrane and surrounding areas are considered the consequence of the upwelling of asthenospheric hot materials,presumably triggered by the foundering of subducted lithospheric slab.
%K Hefei basin
%K Dabie Shan
%K Mesozoic
%K sedimentation
%K exhumation<br>合肥盆地
%K 大别山
%K 中生代
%K 沉积作用
%K 构造剥露
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=2013B5467E3054B1614CEC199353FCED&aid=DA7869AC70679626&yid=2DD7160C83D0ACED&vid=659D3B06EBF534A7&iid=E158A972A605785F&sid=F9AB8F3D624A89DB&eid=59B00AA7F83CF649&journal_id=1000-0569&journal_name=岩石学报&referenced_num=3&reference_num=93