Geochronology of middle Neoproterozoic volcanic deposits in Yangtze Craton interior of South China a

• 出 处: Science China(Earth Sciences)
• 发表日期: 2010年09期
• 关键词: volcanic Yangtze tectonic SHRIMP zircon dating magmatic indicative island interi

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 The characteristics of the igneous series are contrary to the model claiming that 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.