地学前缘 ›› 2010, Vol. 17 ›› Issue (4): 185-196.

• 论文 • 上一篇    下一篇

造山带挤出构造与高压-超高压岩石剥露机制:以大别山为例

刘鑫,李三忠,索艳慧,周均太,焦倩,徐磊,赵峰梅   

  1. 1中国海洋大学 海洋地球科学学院, 山东 青岛 266100
    2海底科学与探测技术教育部重点实验室, 山东 青岛 266100
  • 收稿日期:2010-04-08 修回日期:2010-04-28 出版日期:2010-07-01 发布日期:2010-07-01
  • 作者简介:刘鑫(1985—),男,硕士研究生,构造地质学专业。Email: lxn0532@126.com
  • 基金资助:

    国家重点基础研究发展计划“973”项目(2009CB825006);国土资源大调查项目(1212010711812);S863重点项目(2009AA093401)

Orogenic extrusion tectonics and exhumation of high/ultrahighpressure rocks: A case study from the Dabie Orogen.

 LIU  Xin, LI  San-Zhong, SUO  Yan-Hui, ZHOU  Jun-Ta, JIAO  Qian, XU  Lei, DIAO   

  1. 1College of Marine Geosciences, Ocean University of China, Qingdao 266100, China
    2Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Qingdao 266100, China
  • Received:2010-04-08 Revised:2010-04-28 Online:2010-07-01 Published:2010-07-01

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摘要：

造山带挤出构造阐述了被边界断裂所围限的造山带深变质块体,在造山带内部垂向和(或)侧向应力的作用下折返变形的过程。研究主要集中在挤出块体的几何形态及其内部变形样式、边界断裂特征、挤出路径以及挤出动力来源等4个方面,其研究目的主要是为了解决造山带深变质岩石折返剥露的机制问题。依据挤出块体的挤出方向与造山带主体走向之间的关系,在三维球形坐标系LxLyLz中,将造山带挤出构造大致分为7个端员类型(Ⅰ型～Ⅶ型)。其中Lx为造山带或俯冲带的主体走向;Ly呈水平方向并与Lx相垂直;Lz垂直于Lx和Ly所构成的平面。这些基本端员类型的组合及其之间的过渡类型可以详尽地诠释大别山印支期高压超高压岩石的挤出过程。其中榴辉岩相挤出阶段介于Ⅳ型与Ⅶ型挤出构造之间,角闪岩相挤出阶段介于Ⅱ型与Ⅵ型挤出构造之间并可能具有渠道流挤出模式,而绿片岩相挤出阶段类似于Ⅴ型挤出构造。

关键词: 挤出构造, 剥露机制, 大别山, 高压超高压岩石, 构造变形

Abstract:

Orogenic extrusion tectonics is referred to a process that faultbounded deepseated metamorphic complexes returned and deformed under orogenic vertical and/or lateral stress. The previous researches generally focused on geometry and deformation style of extrusion blocks, bounding faults, paths of extrusion and dynamics, the purpose of which was to try to explain the exhumation of deepseated metamorphic complexes in an orogen. Based on the relationship between the movement direction of extrusion block and the strike of orogenic belt, the orogenic extrusion tectonics are divided into seven endmember types (type Ⅰtype Ⅶ) in threedimensional spherical coordinate system, LxLyLz. Lx represents the strike of an orogen or a subduction zone, and Ly is horizontal and perpendicular to Lx, and Lz is perpendicular to a plane composed by Lx and Ly. The combination of these endmembers and transition types can provide a detailed interpretation of extrusion of the Dabie high/ultrahighpressure rocks. Eclogitefacies extrusion ranges from  type  Ⅳ to  type  Ⅶ extrusion, and amphibolitefacies extrusion varies from  type Ⅱ to  type Ⅵ extrusion, which probably indicates that there was possibility of channel flow during this stage. And  type Ⅴ extrusion could be suitable for greenschistfacies extrusion in the Dabie Orogen.

Key words:  extrusion, exhumation, Dabie Shan, high/ultrahighpressure rocks, deformation

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