秦岭地区城口—房县断裂带变形特征及ESR定年

现代地质 ›› 2005, Vol. 19 ›› Issue (1): 127-132.

秦岭地区城口—房县断裂带变形特征及ESR定年

徐亚军. 杨坤光. 马昌前.

中国地质大学地球科学学院，湖北武汉430074

收稿日期:2004-07-14 修回日期:2004-09-25 出版日期:2005-01-20 发布日期:2005-01-20
作者简介:徐亚军，男，硕士研究生，1978年出生，构造地质学专业，主要从事应用构造方面的研究工作。
基金资助:
国家重点自然科学基金（40334037）

Deformation Characteristics and the ESR Dating of Chengkou-Fangxian Fault Zone in the Qinling area

XU Ya-jun， YANG Kun-guang， MA Chang-qian

Faculty of Earth Sciences，China University of Geosciences， Wuhan， Hubei430074，China

Received:2004-07-14 Revised:2004-09-25 Online:2005-01-20 Published:2005-01-20

摘要/Abstract

摘要：

秦岭城口—房县断裂带是秦岭造山带和扬子板块的分界断裂带，平面上呈向南西突出的弧形，构成大巴山弧。断裂带的宏观构造组合显示了断裂带由北向南强烈逆冲，断层岩的宏观特征和显微构造特征表明断裂带以浅层脆性变形为特点，对断层岩的有限应变测量得出岩石发生了中等到较弱的变形。由断裂带石英脉电子自旋共振（ESR）定年，测得11个石英脉的年龄集中在3个年龄段（240～230 Ma，165～130 Ma，70～60 Ma），其中7个样品的年龄集中在165～130 Ma之间，由此推断断裂带活动于中晚侏罗世（165～130 Ma）达到其构造变形最强烈时期。

关键词: 城口—房县断裂带, 变形特征, ESR定年

Abstract:

The Chengkou-Fangxian fault zone is on the boundary of the Qinling Orogen and Yangtze Plate.The fault zone shows an arc-structure extruding towards SW, which composed the Dabashan tectonic arc. The macrostructures show that this fault zone thrusts strongly from north to south.The macrostructures and microstructures of these fault rocks reveal that the deformation mechanism of this fault zone is characterized by its brittle shallow. The finite strain measurements show that these rocks suffered a low-middle intensity deformation. Eleven quartz veins in the fault zone are dated by the Electron Spin Resonance(ESR), and their ages are distributed in the three stages (240-230 Ma,165-130 Ma,70- 60 Ma). Seven of them have ages from 165Ma to 130 Ma, indicating that the climax activity of this fault zone takes place at the Middle to Late Jurassic(165-130Ma).

Key words: Chengkou-Fangxian fault zone, the deformation characteristic, ESR dating

中图分类号:

P542

徐亚军. 杨坤光. 马昌前.. 秦岭地区城口—房县断裂带变形特征及ESR定年[J]. 现代地质, 2005, 19(1): 127-132.

XU Ya-jun,YANG Kun-guang,MA Chang-qian. Deformation Characteristics and the ESR Dating of Chengkou-Fangxian Fault Zone in the Qinling area[J]. Geoscience, 2005, 19(1): 127-132.

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