New chronological evidence of the age of Huangyuan Group in the eastern segment of Mid-Qilian massif and its geological significance
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摘要: 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U Pb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 90 0Ma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Abstract: Recently, the U Pb isotope dating of single grain zircon from metavolcanic rock of Huangyuan Group yields an age of (910±6.7)Ma,and that from Xiangheer granite,which intrude into Huangyuan Group,yields an age of (917±12) Ma.In conbination with regional geological setting, it was considered that: (1) Huangyuan Group was formed not in Lower Proterozoic Subera, but in Middle Upper Proterozoic Subera, with upper age limit of about 900Ma; (2) Xiangheer granite was formed in Jinningian, rather than in Zhongtiaoian; and (3)both Huangyuan Group and the Jinningian granites which intrude into the former represent the crystalline basement of Jinningian cycle, not that of Zhongtiao cycle. The correction of the age of Huangyuan Group makes it necessary to further reexamine and study the previously established stratigraphic framework in east segment of Mid Qilian massif and its relationship with North China Plate and Yangtze Plate.
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王云山 ,陈基娘 .青海及毗邻地区变质地带及变质作用 [M] 北京 :地质出版社 ,1987 任纪舜 ,姜春发 ,张正坤等 .中国大地构造及其演化 [M] 北京 :科学出版社 ,1980 青海省地矿局 .青海省区域地质志 [M] 北京 :地质出版社 ,1991 孙大中 .前寒武纪地质年代学探讨 [J] 中国区域地质 ,1990 ,( 4 ) :2 89- 3 0 0 任纪舜 ,陈廷愚 ,牛宝贵等 .中国东部及邻区大陆岩石圈的构造演化与成矿 [M] 北京 :科学出版社 ,1990 程裕淇主编 .中国区域地质概论 [M] 北京 :地质出版社 ,1994 WANGHZandMOXX .AnOutlineofthetectonicevolutionofChina[J].Episodes,1995 ,18( 1- 2 ) :6- 16.
刘训 ,傅德荣 ,韦光明等 .从沉积特征研究格尔木—额济纳旗地学断面走廊域地体的构造演化史 [J] 地球物理学报 ,1995 ,3 8(增Ⅱ ) :114 - 12 9 夏林圻 ,夏祖春 ,徐学义 .北祁连山海相火山岩岩石成因 [M] 北京 :地质出版社 ,1996 冯益民 ,何世平 .祁连山大地构造与造山作用 [M] 北京 :地质出版社 ,1996
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