摘要
本文对胶莱盆地万家—蓝村一带浅覆盖区白垩纪陆相"红层"中火山岩夹层流纹质熔结凝灰岩进行同位素年代学研究,揭示火山岩形成时代,划分岩石地层单位。通过LA-ICP-MS锆石U-Pb测年,获得了24个测点构成的谐和线上交点年龄数值为118.32±0.73Ma(MSWD=1.00),该年龄代表了流纹质熔结凝灰岩的形成时间,指示白垩纪陆相"红层"的沉积时代为早白垩世。将这套以紫、红色为主,以细—粉砂岩、泥岩为主,夹少量砂砾岩、灰岩的河流-湖泊相沉积"红层"划归为王氏群辛格庄组。火山活动大致与区域上石前庄旋回相当。本研究为胶莱盆地王氏群辛格庄组沉积时限提供了年代依据,同时揭示了该时期火山活动的特点,为胶莱盆地白垩纪原型盆地恢复和古地理演化提供了参考。
The study carried out the isotopic geochronology of Cretaceous continental"red layer"volcanic rock in Wanjia-Lancun area from Jiaolai basin to determine the formation age and the petro-genesis,to divide rock formation units.Based on the zircon U-Pb dating research,the harmonic linear intersection age value of118.32±0.73 Ma(MSWD=1.00)is obtained for 24 points,which represents the formation time of rhyolitic welded tuff.The sedimentary age of the "red layer"of the terrestrial phase of the Cretaceous period is the Early Cretaceous.This set is dominated by river and lake facies"red layer"which is purple and red,mainly fine-siltstone,mudstone,and a small amount of gravel and limestone deposits that is assigned to the Wangshi Group Xingezhuang Formation.Volcanic activity is roughly equivalent to the cyclops of Shiqianzhuang in the region.This study provides a reference for the sedimentary time of the Wangshi Group Singezhuang Formation in Jiaolai basin,and also reveals the characteristics of early Cretaceous volcanic activity in this period,and provides reference for the restoration of the Cretaceous prototype basin and the evolution of paleogeography in Jiaolai basin.
作者
徐伟祥
XU Weixiang(No.4 Institute of Geological and Mineral Resources Exploration of Shandong Province,Weifang,Shandong,261021;Key Laboratory of Coastal Zone Geological Environment Protection,Shandong Geology and Mineral Exploration and Development Bureau,Weifang,Shandong,261021)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2019年第S01期29-36,共8页
Acta Geologica Sinica
基金
中国地质调查局项目“胶东成矿区栖霞-牟平地区地质矿产调查”(编号DD20160044)
“胶东成矿带栖霞-乳山地区金矿地质调查”(编号DD20190155)
山东省重大创新工程项目“沂沭断裂带深部结构及对资源环境的影响”(编号2017CXGC1602)联合资助成果.
