摘要
福建西南部的上杭盆地是少数呈北西向展布的红层盆地,盆地内出露一套紫红色粗-细粒碎屑岩组合,划分为沙县组和崇安组。此次研究在沙县组红层含火山碎屑岩夹层中,采集了2个火山碎屑岩样品进行了锆石U-Pb同位素测年,得出2组年龄分别为(101.1±1.3)Ma,(93.69±0.82)Ma,分析认为沙县组的时代为早白垩世晚期-晚白垩世早期。上杭红层盆地的形成主要受断裂的控制,其主干断裂为梯子岭断裂,盆地发育初期伴随有微弱的火山活动,沉积一套含凝灰质较高的砂泥岩建造。中期断陷活动加强,伴随较强烈的火山活动,覆盖了早期的沉积。晚期盆地继承了前期的断陷,构造应力转换,以粗复陆屑为主,盆地萎缩封闭。
The Shanghang Basin in southwest Fujian is a few red-layer basins from north to west.A set of burchsia thick-fine debris rock combinations emerges in the basin,divided into the Shaxian Formation and Chong’an Formation.In this study,two samples of pyroclastic rocks were collected from the red layer of the Shaxian Formation for zircon U-Pb isotopic dating.The ages of the two groups are(101.1±1.3)Ma and(93.69±0.82)Ma,respectively.The analysis indicates that the Shaxian Formation is from the late Early Cretaceous to the early Late Cretaceous.The formation of the Shanghang Red Formation Basin is mainly controlled by the fracture.Its main body fracture is a ladder ridge fracture.Early basin development was accompanied by weak volcanic activity,depositing a set of sandstone mudstone built with higher condensate.Strengthening of metaphase subsidence activity,accompanied by more intense volcanic activity,covered the early deposition.The late basin inherited the fault depression of the earlier stage,and the tectonic stress was transformed,which was dominated by coarse continental debris,and the basin shrank and closed.
作者
陈淑华
徐维光
张开毕
Chen Shuhua;Xu Weiguang;Zhang Kaibi(Fujian Institute of Geological Survey,Fuzhou,350013)
出处
《福建地质》
2021年第3期175-185,共11页
Geology of Fujian
基金
福建省地矿局科研项目“福建省白垩纪中晚期红层盆地形成与构造背景研究”
关键词
沙县组
红层
盆地演化
锆石U-Pb测定
上杭盆地
Shaxian group
red formation
rasin evolution
zircon U-Pb determination
Shanghang Basin
作者简介
陈淑华(1985-),女,工程师,从事区域地质、基础地质调查和研究工作。
