摘要
本文报导了耀岭河群中上部变安山岩的全岩 Rb—Sr 同位素等时年龄数据,并据东秦岭造山作用演化,对年龄进行了解释。同时与邻区该群同位素年龄比较,确定了陕西耀岭河群变火山岩的时代。认为耀岭河群地层时代为晚元古代青白口纪,Rb—Sr 全岩等时年龄为1058±48Ma。在该群形成后,于扬子旋回晚期(约636±29Ma)遭受过区域变质作用。
The whole-rock Rb-Sr isochron age data of the meta-andesite from the middle-upper part of the Yaolinghe Group are introduced and interpreted according to the evolution of the eastern Qinling orogeny in this paper.Then the age of the metavolcanics in the Yaolinghe Group is determined accurat- ely on the basis of the isotopic age of the group in this area and contiguous regions.It is concluded that the stratigraphic time of the Yaolinghe Group should belong to the late Proterozoic Qingbaikou Period.The whole-rock Rb-Sr isochron age is 1058+48Ma.After the Yaolinghe Group formed,it suffered from the regional metamorphism in the late Yangtze cycle (about 636±29Ma).
出处
《陕西地质》
1990年第A02期53-58,共6页
Geology of Shaanxi
