摘要
滇东及滇东北地区前寒武纪-寒武纪地层连续、出露良好,是全球重要的前寒武系-寒武系研究区域之一。区内发育众多典型剖面,包括滇东晋宁梅树村剖面、滇东北肖滩剖面以及会泽地区老林剖面和朱家箐剖面等。尽管这些剖面的生物地层学研究已较为详细,但同位素年代学研究相对缺乏,仅在梅树村剖面和肖滩剖面有报道。本次研究在会泽蜂子箐剖面纽芬兰统朱家箐组中谊村段下部发现了一凝灰岩层,实验获得LA-ICP-MS锆石U-Pb年龄(532.0±3.5)Ma。根据从该剖面朱家箐组中处理出的小壳化石以及岩石地层序列的详细调查,蜂子箐剖面可与滇东及滇东北典型剖面进行较好的岩石地层和生物地层对比。此外,该剖面中谊村段凝灰岩锆石年龄值与梅树村剖面第5层凝灰岩锆石年龄值相近,可能源于同一火山喷发事件,若此,该事件的沉积在滇东及滇东北有较为广泛的分布,可作为本区域纽芬兰统对比的一个新标志,值得今后研究关注。
The Ediacaran and Cambrian strata in east and northeast Yunnan are well-exposed, which is one of the most important Ediacaran and Cambrian research areas globally. There are many typical sections in these areas, including the Meishucun section from Jinning Country in east Yunnan, the Xiaotan section in northeast Yunnan and the Laolin section and Zhujiaqing section from the Huize area in northeast Yunnan. Despite the detailed biostratigraphic studies on these sections, the isotope chronostratigraphic research is only reported from the Meishucun section and the Xiaotan section. In this study, a tuff layer of the Zhongyicun Member, the Zhujiaqing Formation from the Fengziqing section in Huize area has been identified. The zircon U-Pb age of this tuff layer is (532.0±3.5) Ma by LA-ICP-MS. Based on the small shelly fossils from the Zhujiaqing Formation and detailed investigation of the stratigraphic sequences of the Fengziqing section,the correlations of lithostratigraphy and biostratigraphy between the Fengziqing section and the typical sections in east Yunnan and northeast Yunnan are possible. Besides,the zircon age of the tuff layer from the Zhongyicun Member in this section is close to that from the Bed 5 in the Meishucun section.The two tuff layers might be from the same volcanic eruption. If this hypothsis is true,the sediments of this volcanic eruption should be extensive in both east and northeast Yunnan areas.This might be a new mark for the Terreneuvian correlation in east Yunnan and northeast Yunnan,which is worth the future work.
作者
易雨昊
李先昀
冯庆来
Yi Yuhao;Li Xianyun;Feng Qinglai(Faculty of Earth Sciences,China University of Geosciences(Wuhan), Wuhan 430074, China;State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Wuhan), Wuhan 430074, China)
出处
《地质科技情报》
CSCD
北大核心
2019年第5期115-125,共11页
Geological Science and Technology Information
基金
国家自然科学基金项目(41430101)
关键词
小壳化石
锆石U-Pb年龄
纽芬兰统
朱家箐组
云南
small shelly fossil
zircon U-Pb dating data
Terreneuvian
Zhujiaqing Formation
Yunnan
