Geochronology of middle Neoproterozoic volcanic deposits in Yangtze Craton interior of South China and its implications to tectonic settings  

作　　者：WANG ZhengJiang1, WANG Jian1, DUAN TaiZhong2, XIE Yuan1, ZHUO JieWen1,3 & YANG Ping1 1 Chengdu Institute of Geology and Mineral Resources, Ministry of Land and Resources, Chengdu 610082, China 2 Marathon Oil UK Ltd., Aberdeen, Scotland, AB15 6FZ, UK 3 Graduate Department, Chinese Academy of Geological Sciences, Beijing 100037, China 

出　　处：《Science China Earth Sciences》2010年第9期1307-1315,共9页中国科学（地球科学英文版）

基　　金：supported by Surveying and Evaluating Project for Marine Basin Bearing Oil and Gas and Its Accumulation Factors in Upper and Middle Yangtze Block,China Geolog-ical Survey (Grant No.1212010733505)

摘　　要：Here we report new SHRIMP dating results of the crystal tuff in Ejiaao Formation of middle Banxi Group in northern Guizhou. The results indicate that the volcanic deposition occurred at ~780 Ma. We also suggests that the igneous activities across Yangtze Craton with diabase dyke swarms and basal volcanic rocks during middle Banxi time are indicative of the episodic, extensive and vigorous great bimodal igneous events during middle Neoproterozoic (825-720 Ma) in South China. The characteristics of the igneous series are contrary to the model claiming they are of island-arc origin, but suggest that they are the records of rifting process and may be related to the episodic plume activities leading to the break-up of Rodinia.Here we report new SHRIMP dating results of the crystal tuff in Ejiaao Formation of middle Banxi Group in northern Guizhou. The results indicate that the volcanic deposition occurred at ~780 Ma. We also suggests that the igneous activities across Yangtze Craton with diabase dyke swarms and basal volcanic rocks during middle Banxi time are indicative of the episodic, extensive and vigorous great bimodal igneous events during middle Neoproterozoic (825-720 Ma) in South China. The characteristics of the igneous series are contrary to the model claiming they are of island-arc origin, but suggest that they are the records of rifting process and may be related to the episodic plume activities leading to the break-up of Rodinia.

关 键 词：Yangtze CRATON MIDDLE NEOPROTEROZOIC Ejiaao Formation of Banxi Group SHRIMP zircon U-Pb dating EPISODIC and BIMODAL IGNEOUS series 

分 类 号：P597.3[天文地球—地球化学]