Pre-Devonian tectonic evolution of the eastern South China Block:Geochronological evidence from detrital zircons

作     者：Lei Xiang LiangShu Shu 

作者机构：Nanjing Univ Sch Earth Sci & Engn State Key Lab Mineral Deposits Res Nanjing 210093 Peoples R China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2010年第53卷第10期

页      面：1427-1444页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：supported by National Natural Science Foundation of China (Grant Nos.40634022,40972132) State Key Laboratory for Mineral Deposits Research of Nanjing University (Grant No.2008-I-01) 

主　　题：detrital zircon U-Pb dating tectonic evolution pre-Devonian South China 

摘      要：Using the U-Pb LA-ICP-MS analysis technique we analyzed geochronological features of detrital zircons from Devonian and Ordovician coarse sandstone in southern Jiangxi Province,northern Cathaysia *** ancient crustal information was *** 350 groups of U-Pb age center on five ranges:2600-2300 Ma(peak at 2470 Ma),1100-900 Ma(peak at 980 Ma),900-700 Ma(peak at 800 Ma),650-520 Ma(peak at 600 Ma) and 450-400 Ma(peak at 440 Ma).We also found a detrital zircon of ~3.5 *** is the oldest age in northern Cathaysia Block obtained so *** the analysis we concluded that:(1) the 2600-2300 Ma period,characterized by a global continent-building,records late Neoarchean magmatism that did not occur in the neighboring area of Cathaysia;(2) the marked peak at 1100-900 Ma corresponds with the assembly time of the Neoproterozoic supercontinent,Rodinia,suggesting that the Cathaysia Block was once a part of Rodinia,and numerous euhedral zircons with similar ages likely resulted from the Grenville event;(3) the peak at 900-700 Ma corresponds to the breakup of Rodinia,as evidenced by wide occurrence of Neoproterozoic granite,basic dyke swarms and continental rift-type deposition;(4) the 650-520 Ma period is the typical time of the Pan-African event,but as yet no associated magmatic rock has been reported in this area;and(5) the peak at 450-400 Ma,representing the early Paleozoic orogeny,was recorded in various igneous *** Silurian-Lower Devonian granitic plutons,orthogneisses and their zircon U-Pb dating ages(450-400 Ma) are important evidence of an early Paleozoic orogenic *** data support the interpretation of an Early Paleozoic tectonic heat event in Cathaysia,which was likely to be caused by intracontinental collision.