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粤西黄岭岩组片麻状花岗质岩石的剪切深熔机理

杨坤光 彭少梅 郑建平   

  1. [1]中国地质大学 [2]广东省地质科学研究所
  • 收稿日期:1997-12-20 修回日期:1997-12-20 出版日期:1997-12-20 发布日期:1997-12-20

SHEARING ANATECTIC MECHANISM OF GNEISSIC GRANITIC ROCKS IN THE HUANGLING FORMATION, WESTERN GUANGDONG

Yang Kun-guang1, Peng Shao-mei2, Zheng JianPing1   

  1. 1. China University Geosciences, Wuhan 430074; 2. Instiute of Geological Sciences of Guangdong Province, GuangZhou 510080
  • Received:1997-12-20 Revised:1997-12-20 Online:1997-12-20 Published:1997-12-20

摘要: 粤西黄岭岩组片麻状花岗质岩石属于云开地块的基底岩系(2600Ma~1700Ma)。自下而上发育3种均造样式:下部透入性剪切变形带;中部平直均匀变形带;上部为揉皱带。应变分析表明,近水平分层剪切作用以及剪切应变带的向上迁移形成了上述不同构造样式,化学分析显示不同构造样式的花岗质岩石具有陆壳改造S型花岗岩特点。它们可能是形成于浅海一半深海的碎屑原岩在原地或准原地剪切深熔的结果。剪切深熔深度约13km~15km,峰期变形在2000Ma~1700Ma。

Abstract: Gneissic granitic rocks of the Huangling formation in western Guangdong are the basement metamorphic series (2600Ma~1700 Ma). Three different structural styles are developed in these rocks: penetrating shear zone in the lower part, regular affine deformation zone in the middle part, and corrugation deformation zone in the upper part. Strain analysis shows that different structural styles are produced by the approximate horizonta1 shearing and its continuous upward migration. Chemical analysis reveals that gneissic granitic rocks possess the characteristics of crustal reformed S-type granite. In fact, these gneissic granitic rocks are resulted groin autochthonous or near autochthonous shearing anatexis, whose protoliths arc neritic- hypoabyssal clasolites. The depth of shearing anatexis is above l3km~ 15km, and the peak of shear deformation occurred on 2000Ma~ 1700Ma.