摘要
临澧县白土坡玻屑凝灰岩(或半固结火山灰)赋存在第四系下更新统,层状或似层状,岩石松散,镜下具典型的玻屑凝灰结构。主要由流纹质火山玻屑,少量斜长石、石英及黑云母晶屑以及粘上矿物等组成。流纹质火山玻璃的电子探针分析平均值(%):SiO_274.97、Al_2O_314.046、CaO0.326、KzO6.933、Na_2O2.536、FeO0.51,总量99.52。
The vitric tuff(or partly consolidated volcanic ash)occurs in Iower Pleistocene series in Baitupo, Linli asaloose layer orastratoid,which has a typical texture of vitric tuff under micro-scope. And it is composed predominantly of clasts of rhyolitic volcanic glass,minor crystal clasts of plagiclase,quartz and bio- tite, and less clay minerals etc. Average compositions of rhyolitic glass analyzed by electronic microprobe are; SiO_2 74.97, Al_2O_3 14.046,CaO 0.326,K_2O 6.933,Na_2O 2.536,FeO 0.51,totaliy 99.52(in wt%)。
出处
《湖南地质》
1994年第2期94-98,共5页
Hunan Geology
关键词
玻屑凝灰岩
岩石学
凝灰岩
vitric tuff, rhyolitic glass, Lower Pleistocene,Linli county