Chronological Study on Detrital Zircons and Its Geological Significance from MesoproterozoicDagushi Group in the Dahongshan Area, North Margin of the Yangtze Block
Kong Lingyao
Mao Xinwu
Chen Chao
Deng Qianzhong
Zhang Hanjin
Yang Qingxiong
Li Linjing
Li Qiwen
Abstract：There are many Pre-Nanhua strata and magmatic rocks in Yangtze Block, the detrital zircon preserved in sedimentary clastic rocks have great significances for limiting rock`s age, tracing the source of sediments and revealing early evolution of the continent.This study is the first research of detrital zircon geochronology in both Lijiazui Formation and Luohanling Formation of Dagushi Group in the Dahongshan area, northern margin of the Yangtze block.The detrital zircons from Lijiazui Formation are dated a youngest age of 1250±64Ma, and several main age peaks of about 2078Ma, 2437Ma, 2659Ma and 3084Ma;the youngest age of Lijiazui Formation is 1077±51Ma, and it`s ages peaks are about 1126Ma, 2044Ma, 2458Ma and 2635Ma.It is inferred that the sedimentary age of Lijiazui Formation is between 1250±64Ma and 1126Ma, and of Luohanling Formation is later than 1077±51Ma, indicating that Dagushi Group belongs to Mesoproterozoic.In addition, the age-histogram comparison of Dagushi Group and Shennongjia Goup, Kunyang Group, Dongchuan Group from different areas of Yangtze block, show that the source of these stratigraphic units are different from each other, which means the magmatic events and tectonic evolutions of each stratigraphic unit are different.Combined with previous research data of Yangtze block, we conclude that the blocks represented by each stratigraphic units are independent continent fragments in Mesoproterozoic, and amalgamated into the crystalline basement of the Yangtze block gradually in Mesoproterozoic to Neoproterozoic.
Keywords：Yangtze blockMesoproterozoicDagushi Groupdetrital zircongeochronology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：17( 485-501 )