| 河南省西峡—内乡北部元古界与古生界间的构造边界 |
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| 引用本文： | 索书田,钟增球.河南省西峡—内乡北部元古界与古生界间的构造边界[J].地质科学,1990,0(1):12-21. |
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| 作者姓名： | 索书田 钟增球 |
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| 作者单位： | 武汉地质学院 |
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| 摘 要： | 构造制图和详细的构造解析,在东秦岭造山带核部识别出一个原先未曾注意的元古代变质岩区与古生代变质岩区间的构造边界——军马河-马蹄湾断裂带。实际上,这个构造边界是一个底部韧性变形带,带内发育构造混杂岩、糜棱岩和强直片麻岩。本文阐述了各种几何学特征,它们表明变形是发生在一个缓倾斜的剪切带之上。大量的运动学标志指出,在中生代花岗岩类岩体就位前,再造的元古代变质岩区沿着构造边界向北逆冲于古生代变质岩区之上。
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| 关 键 词： | 构造边界 糜棱岩 逆冲断层 构造混杂岩 |
| 收稿时间： | 1987-05-01 |
| 修稿时间： | 1987-05-01; |
TECTONIC BOUNDARY BETWEEN PROTEROZOIC AND PALEOZOIC TERRAINS IN THE NORTHERN PART OF THE XIXIA AND NEIXIANG, HENAN PROVINCE |
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| Suo Shutian Zhong Zengqiu Hu Yuhua.TECTONIC BOUNDARY BETWEEN PROTEROZOIC AND PALEOZOIC TERRAINS IN THE NORTHERN PART OF THE XIXIA AND NEIXIANG, HENAN PROVINCE[J].Chinese Journal of Geology,1990,0(1):12-21. |
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| Authors: | Suo Shutian Zhong Zengqiu Hu Yuhua |
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| Institution: | Wuhan College of Geology |
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| Abstract: | Structural mapping and special structural analysis allow the recognition of a previously unidentified tectonic boundary between two distinct metamorphic terrains in the eastern Qinling mountains. The boundary crops out in the northern part of the Xixia and Neixiang, Henan Province in a WNW-trending zone roughly 100 km long and 2 km wide that narrows to wards northwest. The Proterozoic Qinling Group gneisses and marbles are separated from the Paleozoic lowmetamorphic volcanic rocks and turbidite sequence by the boundary. The boundary which can be called the Junmahe-Matiwan Fault Belt is a major ductile thrust zone. It is marked by mylonitic rocks and straight gneisses. Thick marble units in this zone invaribly have the form of tectonic melange, full of rotated and flattened blocks or fragments of various types of granites, silicalites, dolomites, etc. in a mylonitic matrix. The mylonitic foliation within this zone dips gently to the south. It is folded and truncated by younger ductile or brittle shear zones. The kinematic evidence afforded by the major ductile shear zone leads to a model for development of the eastern Qinling mountains through a process of stacking of crustal segments, with translation northward along lo-wangle ductile shear zones originating at considerable depth. The boundary is actually a basal ductile defomation zone, along which the reworked Proterozoic metamorphic belt has been thrusted to the north on the Paleozoic metamorphic belt before emplacement of the Mesozoic granitoids. Thus these new data are clearly favorable to the intracontinental shearing model. |
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| Keywords: | boundary mylonite thrust tectonic melange |
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