甘肃北山中泥盆统砾岩中放射虫的发现及其地质意义
Discovery and significance of Radiolaria from Middle Devonian conglomerate in Beishan area,Gansu
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摘要: 笔者于甘肃北山地区墩墩山一带中泥盆统三个井群砾岩内的硅质岩砾石中发现放射虫,经鉴定主要为空滴虫类(Inaniguttids),有两个属:Inanigutta sp.(空滴虫)和Inanibigutta sp.(双壳空滴虫).这两个属在世界上主要见于奥陶—志留纪,我国华北地区主要产在奥陶纪.表明北山于泥盆纪碰撞造山时,墩墩山之北被抬升成山系,奥陶系含放射虫的硅质岩被剥蚀后向南搬运到墩墩山山前磨拉石盆地中沉积下来.结合区域地质特征,放射虫的发现为北山地区泥盆纪碰撞造山作用和磨拉石盆地的存在提供了佐证.Abstract: The Radiolaria fossils are collected from siliceous gravel in conglomerate of Middle Devonian Sangejing Group in Dundunshan of Beishan area,Gansu province.The Radiolarians are identified primarily to be Inaniguttids,including two genus,the Inanigutta sp.and Inanibigutta sp.,which are primarily found in the strata of Ordovician-Silurian systems in the world,and Ordovician in North China.This discovery suggests silicalite containing Radiolaria of Lower Ordovician Shajing Group was been denuded,southward stransported and finally deposited in Dundun shan mola sses basin d ring the collision-orogenic period of Devonian in Beishan.Accordingly there existed collision-orogeney and amolasses basinin Devonian in Beishan area.
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Keywords:
- Beishan area /
- Gansu province /
- Devonian conglomerate /
- Radiolarian
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