| 造山带挤出构造 |
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| 引用本文： | 曾佐勋,杨巍然,刘立林,郭铁鹰,Franz Neubauer.造山带挤出构造[J].地质科技情报,2001,20(1):1-7. |
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| 作者姓名： | 曾佐勋 杨巍然 刘立林 郭铁鹰 Franz Neubauer |
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| 作者单位： | 1. 中国地质大学地球科学学院,
2. Institute of Geology and Paleontology,University of Salzburg,A-5020 Sa lzburg,Austria |
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| 基金项目： | 国家自然科学基金资助项目 !( 49772 14 7，49972 0 6 8)，国土资源部“九五”攻关课题! ( 95 -0 2 -0 0 2 -0 1)，湖北省地球表层系 |
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| 摘 要： | 挤出构造模式已经从二维变形进入三维变形研究，在喜马拉雅造山带，高喜马拉雅结晶地体沿北倾的主中央逆冲断层和北倾 的绒布寺正断层，表现为相对刚性体之间的韧性体的楔状挤出。非连续介质大变形有限元数值模拟结果为这一模式提供了力学依据。在前人工作的基础上，提出了东阿尔卑斯三维管状挤出模式，将上部脆性层划分出北部左行平移带，南部右行平移带和中部挤出楔，中部韧性层在南阿尔卑斯和欧洲前陆碰撞过程中，既有垂向挤出，也有侧向挤出，在平行缩短方向的剖面上，由箱状背形隆起演化成逆－逆断层组合的楔状挤出，形成三角断面的管状，在垂直缩短方向的剖面上，中部韧性层呈不均匀流动，形成管状层流－韧性层中心为纯剪切，上部和侧部为简单剪切，在陕甘川邻接区，由于祁连山－北秦岭加里东喧向南的推挤和川西前陆的刚性阻挡，造成西秦岭和东松潘－甘孜复合造山体的三维滑脱挤出，以北西西向玛曲－略阳滑脱逆冲断裂和北东向青川一茂县滑脱逆冲断裂为界，将陕甘川邻接区的三维滑脱挤出复合造山体划分为西秦岭滑脱挤出带，摩天岭0若尔盖滑脱挤出楔和龙门山滑脱挤出逆冲椎覆带，以近南北向岷江滑脱逆冲断裂为界将滑脱挤出楔进一步划分成摩天岭滑脱挤出体和苦尔盖滑脱挤出体，除了不同构造单元的不均匀隆升外，摩天岭还表现出向西的侧向挤出。
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| 关 键 词： | 挤出构造 造山带 喜马拉雅 阿尔卑斯 韧性体 数值模拟 |
| 文章编号： | 1000-7849(2001)01-0001-07 |
| 修稿时间： | 2000年10月18 |
EXTRUSION TECTONICS IN OROGENIC BELT |
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| Zeng Zuoxun,Yang Weiran,Liu Lilin,Guo Tieying,Franz Neubauer.EXTRUSION TECTONICS IN OROGENIC BELT[J].Geological Science and Technology Information,2001,20(1):1-7. |
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| Authors: | Zeng Zuoxun Yang Weiran Liu Lilin Guo Tieying Franz Neubauer |
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| Abstract: | The model of extrusion tectonics has been generalized to the research of three-dimensional extrusion from two-dimensional extrusion research.In the Himalaya orogenic belt,Higher Himalaya crystalline between the north dipping main central thrust fault and the north dipping Rongbushi normal fault (or Southern Tibet detachment system) yields ductile extrusion in wedge-shape.The finite element modeling with large deformation in noncontinuous media has proved that the normal and thrust faults dipping in the same direction can develop contemporarily under the same contraction regime.On the basis of works of previous researchers,the authors put forward a three-dimensional model of pipe-shaped extrusion for the eastern Alps.The upper brittle layer is divided into three parts,namely,the left-lateral strike-slip belt in the north part,the right-lateral strike-slip belt in the south part and the middle extrusion wedge.In the process of south Alps-Europe foreland collision,not only the vertical extrusion,but also the lateral extrusion develops.On the section parallel to the maximum shortening direction (MSD) the box-shaped anticline uplift revolved into wedge-shaped-extrusion with the combination of the thrust-thrust faults,forming the pipe with a triangular section.While on the section perpendicular to the MSD,the middle ductile layer flows inhomogeneously and form pipe-shaped laminar flows.It is put forward that a three dimensional decollement extrusion of a composite orogenic body exists in the adjoining area of Sichuan,Gansu and Shaanxi Provinces.It consists of the Western Qinling and Eastern Songpan-Garz orogenic belts and develops between the West Sichuan foreland and the rigid indenter of the Qilian-North Qinling Caledonian orogenic belt.It is divided into three first-order tectonic units,by the Maqu-Lueyang fault trending in NNW and the Qingchuan-Maoxian fault trending in NE.They are Western Qinling décollement-extrusion belt,Motianling-Zoig décollement-extrusion wedge and Longmenshan décollement-extr usion thrust belt.The wedge is further subdivided into Motianling décollement-extrusion body and Zoig décollement-extrusion body by the N-S trending Mingjiang fault.The Motianling presents westward lateral extrusion except the inhomogeneous uplift of the different tectonic units. |
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| Keywords: | extrusion tectonics orogenic belt Higher Himalaya Eastern Alps Western Qinling Songpan Garz |
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