胶东半岛乳山地区低角度韧性剪切带几何学、运动学特征:对中国东部岩石圈减薄作用的启示  

Geometrical and kinematic characteristics of low angle ductile shear zone in Rushan area of Jiaodong Peninsula and their implications for lithospheric thinning in eastern China

作　　者：郝志宣 金超 田忠华[3] 李同宇 文飞 Hao Zhixuan;Jin Chao;Tian Zhonghua;Li Tongyu;Wen Fei(School of Earth Sciences and Engineering,Hebei University of Engineering,Handan,Hebei 056038;Hebei Key Laboratory of Resource Survey and Research,Handan,Hebei 056038;Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029)

机构地区：[1]河北工程大学地球科学与工程学院,河北邯郸056038 [2]河北省资源勘测研究重点实验室,河北邯郸056038 [3]中国地质科学院地质研究所,北京100037 [4]中国科学院地质与地球物理研究所,北京100029

出　　处：《地质科学》2022年第1期43-60,共18页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：河北省高等学校青年拔尖人才基金项目(编号:BJ2018010);国家自然科学基金青年基金项目(编号:42005133);中国地质调查局地质大调查项目“华北陆块中部与东部前寒武纪基础地质调查”(编号:DD20190003);中国地质科学院基本科研业务费项目(编号:J2030)资助。

摘　　要：大规模伸展构造是华北克拉通东部岩石圈减薄的重要表现形式。部分低角度韧性剪切带是地壳伸展变形后所展现的构造形式。本文研究了王格庄韧性剪切带的岩石学、几何学、运动学等特征显示:韧性剪切带走向近南北向,剪切带断层面倾向多变(倾向西、西南、西北方向)。大部分区域面理低角度倾向西,矿物拉伸线理近东西向,不对称旋转碎斑及S-C组构指示顶端指向西的剪切特征。结合研究区西侧与伸展构造相匹配的半地堑伸展盆地证据:本研究认为伸展构造的形成可能与西太平洋板块的后撤相关,即大规模伸展构造作用引发了华北克拉通东部的地壳减薄作用。Large-scale extensional tectonic is an essential manifestation of lithospheric thinning in the eastern North China Craton. Part of the low-angle ductile shear zone is a structural exhibition after crust deformation. In this paper, we decipher the petrological, geometric, and kinematic features of the Wanggezhuang ductile shear zone, showing that: the shear zone strikes N-S with several dipping directions(W, SW, and NW). Most of the foliation dips to the west at a low dipping angle, mineral stretching lineations plunge to W at low plunge angle;Asymmetric rotational porphyroclast and S-C fabrics indicate a top-to-west shearing.Integrating evidence of half-graben extensional basin matched with extensional structure from the west of the shear zone: we presented that the extensional event was produced by the retreat of the Paleo-pacific plate, that is, huge extensional structural result in crustal thinning in North China Craton.

关 键 词：低角度韧性剪切带 伸展构造 锆石U-PB定年 苏鲁构造混杂带 板块后撤 

分 类 号：P542[天文地球—构造地质学] P597.3[天文地球—地质学]