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根据新近获得的中祁连地块东段湟源群中变质火山岩(910±6.7)Ma和侵位于湟源群中的响河尔花岗岩(917±12)Ma的单颗粒锆石UPb年龄,结合区域地质背景分析认为:(1)湟源群时代不是古元古代,而是中晚元古代,上限在900Ma左右;(2)响河尔花岗岩是晋宁期花岗岩而非中条期花岗岩;(3)湟源群及侵位于其中的晋宁期花岗岩代表了中祁连晋宁旋回结晶基底,并非中条旋回结晶基底。湟源群时代的重新厘定使得已经建立的中祁连地块东段前寒武纪地层格架和中祁连地块性质、归属等问题需要重新审视和研究
According to the UPg age of the newly obtained granulite (910 ± 6.7 Ma) in the Jiyuan Group in the eastern part of the Central Qilian Block and the granulite (917 ± 12) Ma in the Heyuan Granite sourced from the Jiyuan Group, The background analysis shows that: (1) The Quan source group age is not Paleoproterozoic, but Middle-Late Proterozoic with the upper limit of 900 Ma; (2) Gansu granite is Jinning granite instead of Mesozoic granite; (3) The Jiyuan group and the Jinning granite that invaded it represent the central Qilian Jinning cyclical crystalline basement rather than the Mesozoic recrystallized basement. The redetermination of the Juyuan Group era has made it necessary to re-examine and study the established Precambrian stratigraphic framework and the nature and ownership of the Qilian block in the eastern part of the Central Qilian Block