江苏沉积变质型磷矿带含磷岩系LA-ICP-MS锆石U-Pb年龄及其地质意义
LA-ICP-MS U-Pb dating of zircons from meta-sedimentary phosphate deposits in Jiangsu Province,and its geological implications
陈冬 1胡森林 1缪柏虎 1关俊朋 1孙清钟1
作者信息
- 1. 江苏省地质调查研究院,江苏 南京 210049
- 折叠
摘要
江苏沉积变质型磷矿带位于大别—苏鲁造山带东段,锦屏岩组是带内唯一赋矿地层,因其遭受过多期强烈的变形变质作用改造,层序杂乱,勘查难度大,研究程度低,目前其形成时代尚无定论.本文应用LA-ICP-MS锆石U-Pb定年方法,对锦屏岩组各类岩性进行测试,获得绿色片岩类岩石原岩年龄为(956±7)Ma～(691±14)Ma,浅色片岩类岩石原岩年龄不早于(833±39)Ma,片麻岩类岩石原岩年龄不早于(772±31)Ma.结合成矿带内含磷岩系中古生物化石资料,将锦屏岩组原岩形成时代界定为新元古代,将磷矿原始沉积时间限定在震旦纪,为江苏磷矿勘查与研究提供了新的基础资料.
Abstract
The meta-sedimentary phosphate ore belt in Jiangsu Province is located in the eastern part of the Dabie-Sulu Orogen.The Jinping Formation is the only ore-bearing stratum in the belt.Due to multiple periods of intense deformation and metamorphism,the sequence is disordered,which increasing difficults in the exploration and research.Currently,the formation age of the Jinping Formation is poorly constrained.In this study,LA-ICP-MS zircon U-Pb dating method is used to study various rocks of the Jinping Formation.The data suggest that the age of green schists is(691±14)Ma-(956±7)Ma,and the ages of light-colored schists and gneisses were younger than(833±39)Ma and(772±31)Ma,respectively.Combined with the previous fossil data of the phosphorite series,the original rocks of the Jinping Formation were formed at the Neoproterozoic,and the depositional timing of phosphorite is Sinian.Provided new basic data for the exploration and research of phosphate deposits in Jiangsu Province.
关键词
沉积变质型磷矿床/锆石U-Pb定年/大别—苏鲁造山带/江苏省Key words
meta-sedimentary phosphate deposit/zircon U-Pb dating/fossil paleontology/Dabie-Sulu Orogen/Jiangsu Province引用本文复制引用
基金项目
江苏省地质勘查专项资金项目(苏财建[2016]140)
江苏省地质勘查专项资金项目(苏财资环[2020]20)
出版年
2024
NETL
NSTL
维普
万方数据