地质论评2009，Vol.55Issue(5)：639-646,8.
铜仁坝黄震旦系老堡组顶部晶屑凝灰岩SHRIMP锆石U-Pb年龄及其地质意义
SHRIMP Zircon U-Pb Age of Crystal Tuffs on the Top of Sinian Laobao Formation at Bahuang, Tongren Area, and Its Geological Implications
摘要
Abstract
Predecessors had carried out a lot of researches on the sedimentary—tectonic transformation of Proterozoic-Phanerozoic, but did not reach a common censensus. Through the field survey, the writers found that a layer of 10～20cm tuff interbed developed on the top of the siliceous rocks of the Sinian Laobao Formation around the Changping Bahuang, Tongren, which was located in the transitional phase of platform—basin of the south eastern margin of Upper Yangtze Block. Based on petrological study, the writers proved that the tuff interbed was a layer of crystal tuffs, and also measured the SHRIMP zircon U-Pb age of crystal tuffs, gaining the depositional age of 556±5Ma. Based on predecessors’ achievements of biostratigraphy and sedimentology, the writers believe that the interlayer between siliceous rocks and black shales on the top of the Laobao Formation represented an important depositional event during the sedimentary—tectonic transition of Proterozoic—Phanerozoic. The depositional event started at ca. 556Ma and was connected to the Rodinia Supercontinent eventual break-up and the formation of Iapetus Ocean at 550Ma, corresponding to these extensive volcanic events on the Yangtze Craton.关键词
震旦系/老堡组硅质岩/SHRIMP锆石U-Pb年龄/沉积相区/沉积-构造转换/贵州铜仁坝黄Key words
siliceous rocks/ Laobao Formation/ SHRIMP zircon U-Pb age/ sedimentary phase/ sedimentary-tectonic transformation/Bahuang/ Tongren area/Guizhou分类
天文与地球科学引用本文复制引用
卓皆文,汪正江,王剑,谢渊,杨平..铜仁坝黄震旦系老堡组顶部晶屑凝灰岩SHRIMP锆石U-Pb年龄及其地质意义[J].地质论评,2009,55(5):639-646,8.基金项目
国家油气专项"中-上扬子海相含油气盆地分析与油气成藏条件综合调查评价"项目(1212010733505)和"雪峰山西侧地区海相油气地质调查"项目(1212010782003)联合资助的成果. （1212010733505）
