赣南—粤北余田群的再认识  

New Knowledge of the Yutian Group in South Jiangxi—North Guangdong

作　　者：巫建华[1] 张树明[1] 周维勋[1] 

机构地区：[1]华东地质学院,江西临川344000

出　　处：《地层学杂志》1999年第4期295-302,共8页Journal of Stratigraphy

摘　　要：赣南—粤北中生代晚期存在上、中、下３个不同时代的火山岩系，其中下火山岩系称为余田群，可进一步划分为水头迳组和菖蒲组。水头迳组以沉积岩为主、夹火山碎屑岩，代表火山活动初始期的产物；菖蒲组为玄武岩、流纹岩和流纹质凝灰岩，有时夹砂岩，代表火山活动喷发期的产物。同位素年龄数据显示，余田群菖蒲组的地质时代为中侏罗世—晚侏罗世早期。There are three igneous rock series during the Late Mesozoic in South Jiangxi—North Guangdong:upper,middle and lower igneous rock series.The lower igneous rock series is called Yutian Group,which can be subdivided into the Shuitoujing and Changpu Formations.The Shuitoujing Formation is mainly sedimentary rock and interstratified pyroclastic rock,representing the product of the initial volcanic activity;the Changpu Formation is basalt,rhyolite and rhyotaxitic tuff and locally interstratified sandstones,repesenting the product of the volcanic eruption.The whole rock Rb Sr isochron age of the basalt of the Changpu Formation in Changpu Basin is 176Ma,and that of the rhyolite is 150Ma.The whole rock K Ar isochron age of the basalt of the Changpu Formation in Longnan Basin is 157.8~162.8Ma,and the whole rock Rb Sr isochron age of the basalt is 175.6 Ma.The whole rock Rb Sr isochron age of the rhyolite is 165.97~147.64Ma.Consequently,the geological age of the Yutian Group is from Middle Jurassic to eraly Late Jurassic.The Shuitoujing Formation at the bottom of the Yutian Group possibiy includes the Early Jurassic deposit.

关 键 词：余田群 水头迳组 菖蒲组 江西 广东 侏罗纪 

分 类 号：P534.52[天文地球—古生物学与地层学]