| 湖南NW向常德-安仁断裂的地质特征、活动历史及构造性质 |
| |
| 引用本文： | 柏道远,李银敏,钟响,李彬,黄乐清,伍贵华,李超,姜文.湖南NW向常德-安仁断裂的地质特征、活动历史及构造性质[J].地球科学,2018,43(7):2496-2517. |
| |
| 作者姓名： | 柏道远 李银敏 钟响 李彬 黄乐清 伍贵华 李超 姜文 |
| |
| 作者单位： | 湖南省地质调查院, 湖南长沙 410016 |
| |
| 基金项目： | 中国地质调查局项目DD20160031 |
| |
| 摘 要： | 常德-安仁断裂是湖南东部一条NW向大断裂，关于其地质特征、活动历史及构造性质等尚缺乏系统研究.基于区域地质调查和基础地质研究资料，总结了常德-安仁断裂的总体特征，重塑了断裂的活动历史，探讨了断裂的构造性质和变形机制.主要认识如下:常德-安仁断裂走向NW330°，为一基底隐伏断裂，地质上表现为一NW向岩浆隆起带.该断裂为贯穿中、下地壳并切入岩石圈地幔的深大断裂，断裂倾向NE，倾角约54°.断裂具有长期活动历史:新元古代冷家溪期作为转换断层具走滑活动；冷家溪末期武陵（晋宁）运动中在区域S-N向挤压下右行走滑；板溪期早期和南华纪早期均具伸展活动并控制沉积相带的展布；加里东运动中在区域S-N向挤压下右行走滑；中三叠世晚期印支运动中在区域NW-NWW向挤压下左行走滑兼逆冲；晚三叠世-早侏罗世在区域S-N向挤压下右行走滑；中侏罗世晚期早燕山运动中在区域NWW向挤压下左行走滑；白垩纪-古近纪产生伸展活动.常德-安仁断裂在冷家溪期可能为一横切扬子陆块东南缘弧后盆地、岛弧和华南洋的转换断层.印支运动中断裂带因深部逆冲活动而构造隆升.该断裂具隐伏特征的原因可能与冷家溪期-南华纪同沉积活动、震旦系底部滑脱层发育、多条NE-NNE向大断裂的截切以及断裂沿线花岗岩体和断陷盆地的发育等有关.
|
| 关 键 词： | 常德-安仁断裂 隐伏断裂 岩浆隆起带 多期活动 转换断层 变形机制 构造 |
| 收稿时间： | 2017-11-20 |
Geological Features,Activity History and Tectonic Attribute of NW-Trending Changde-Anren Fault in Hunan |
| |
| Abstract: | Changde-Anren fault is a NW-trending deep fault in eastern Hunan, and its geological features, activity history and tectonic attributes have not been studied systematically. Based on regional geological survey and research data, the authors summarized the general features of the fault, analyzed the nature, genesis and forming ages of the secondary structures origined from the fault, and then reconstructed the activity history, probed in the tectonic attributes and deformation mechanisms of the fault. Main conclusions are as follows:Changde-Anren fault is a NW-trending (330°) basement hidden fault with outcropped fault only in part of north segment and appears as a NW-striking magma-uplift belt. It is a deep major fault breaking through the middle and lower crust and cutting into lithospheric mantle, and dipping northeast with dip angle of 54°. The fault experienced long-term activity as follows. It was a transform fault with strike-slip motion during Neoproterozoic Lengjiaxi Period, strike-slipped dextrally under regional S-N compression in Wuling Movement causing the clockwise rotation of the structural lineaments to the north of Taojiang, extended and controlled the sedimentary facies in Early Banxi Period and Early Nanhua, strike-slipped dextrally under regional S-N compression and fromed secondary NWW-trending thrust faults in Caledonian Movement, strike-slipped sinistrally with thrust and formed secondary NW-trending sinistral strike-slip fault and Anren "y"-type structure under regional NW to NWW compression in late Middle Triassic Indosinian Movement, strike-slipped dextrally under regional S-N compression and formed secondary NWW-trending thrust faults and uplifts during Late Trias-Early Jurassic, strike-slipped sinistrally under regional NWW compression and formed secondary NEE-trending dextral strike-slip fault in Middle Jurassic Early Yanshanian Movement, extended and formed small-scale NW-trending regulative faults controlling the boundary of the southwest end of NNE-trending faulted basins during Cretaceous-Paleogene. Changde-Anren fault was probably a transform fault crosscutting back-arc basin and island arc on the southeastern margin of Yangtze block and Huanan ocean. The uplift along Changde-Anren fault was formed in Indosinain Movement controlled by deep thrust, and rose further for large-scale granitic magmatism in Late Triassic. The hidden properties of the fault were provided by several facts such as follows:The fault developed in Lengjiaxi Group and Nanhua as synsedimentary fault but not in Sinian-Upper Paleozoic; there existed weak detachment layer of Jinjiadong Formation at the bottom of Sinian; NE to NNE-trending major faults cut Changde-Anren fault into several segments with relative independent motion; there occurred a large number of granitic bodies and Cretaceous-Paleogene basins. |
| |
| Keywords: | |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《地球科学》浏览原始摘要信息 |
| 点击此处可从《地球科学》下载免费的PDF全文 |
|
