• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Dextral strike-slip faulting history of the Mid-Cretaceous d'Abbadie fault zone, Pelly Mountains, south-central Yukon, Canada.
【24h】

Dextral strike-slip faulting history of the Mid-Cretaceous d'Abbadie fault zone, Pelly Mountains, south-central Yukon, Canada.

机译：加拿大育空地区中南部佩利山白垩纪中部阿布巴迪断裂带的右旋走滑断层历史。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The d'Abbadie fault zone is located in south-central Yukon, northeast of the Teslin fault. It is a north-striking, steeply dipping strike-slip fault with a strike length of 70 km. There is a complex deformation and metamorphic history that predated the d'Abbadie fault zone where Paleozoic supracrustal rocks of the Last Peak succession, in the Yukon-Tanana terrane, were polydeformed and metamorphosed under greenschist facies conditions in the Permo-Triassic, and cooled in the Early Jurassic. This study focuses on history of a transect of the d'Abbadie fault zone, in the northeast portion of Livingstone Creek area (NTS 105E/8).;The ca. 96 Ma Last Peak granite is a NW-SE striking, steeply dipping, variably foliated and mylonitic leucogranite that lies within the central part of the study area. Petrological and kinematic studies of the S-C mylonites show that the development and discrete distribution of the mylonites to the granite was facilitated by the heat of the pluton itself while it was intruding. Such heat made the rocks weak, which therefore made them susceptible to deform in a ductile manner under cold upper crustal conditions.;The Last Peak granite was syntectonic with the displacement of the d'Abbadie fault zone. Evidence includes the discrete distribution of the mylonitic rocks to within the pluton, cross cutting contacts, contact aureole, and the presence of an eastward ductile strain gradient within the Last Peak granite towards the centre of the d'Abbadie fault zone.;Sense of shear indicators that are preserved in both the cataclastic and mylonitic fault rocks provide the foundation for a kinematic analysis of the fault movement of the d'Abbadie fault zone. Structures and microstructures in mylonitic rocks in the syntectonic Last Peak granite and the relative motion on brittle shear fracture planes throughout the fault zone indicate that the d'Abbadie fault zone is a dextral strike-slip fault.;Geological mapping and structural analysis indicate that the d'Abbadie fault zone constitutes a 2 km-wide zone of primarily anastomosing brittle dextral strike-slip faults, and a localized 200-500 m-wide strand of dextral S-C mylonites in the Last Peak granite. The brittle faults are filled with 2-30 m-wide cataclasites and 1 mm to 40 cm-wide cataclasite zones that are distributed in variably sized strands along the faults. The cataclastic rocks form three domains: the Cataclasite, Mixed and Fracture domains. The S-C mylonites form three domains: the Protomylonite, Mylonite and Ultramylonite domains.;Timing of the deformation along the d'Abbadie fault is in part constrained by syntectonic emplacement of the ca. 96 Ma Last Peak granite within the fault zone. Localized cataclasite zones, slickenlines on fault polished surfaces, and fractures overprint the S-C mylonites in the Last Peak granite. These crosscutting relationships suggest that brittle faulting outlasted cooling of the granite and ductile deformation. Metamorphic conditions of the brittle and ductile rocks are confined to the greenschist facies. This is based on chlorite along fault surfaces and in strain shadows of K-feldspar porphyroclasts in mylonites in the syntectonic Last Peak granite.;The major deformation mechanism responsible for the formation of the cataclastic and brittle rocks include: cataclastic flow in and between grains, frictional grain-boundary sliding, and stress-induced solution transfer. Such mechanisms are consistent with a brittle deformation regime and are indicative of the rheology of a brittle crust. Therefore, the syntectonic depth-temperature conditions for the d'Abbadie fault zone are best estimated between 5-10 km and 250 °C.;The d'Abbadie fault zone is made of coherent fault rocks that are consistently distributed. This suggests that it has not undergone any significant reactivation and that it was a short-lived structure whose motion was restricted to the mid-Cretaceous, at ca. 96 Ma.
机译：d'Abbadie断裂带位于Teslin断裂东北部的育空中南部。这是一个向北的，陡峭的走滑断层，走向长度为70 km。早在d'Abbadie断层带之前就有一个复杂的变形和变质史，育空地区-塔纳那地层中末峰演替的古生代上壳岩在绿泥岩相条件下在二叠纪-三叠纪经历了多变形和变质作用，并在侏罗纪早期。这项研究的重点是利文斯通克里克地区东北部（NTS 105E / 8）的d'Abbadie断层带的断面历史。 96 Ma Last Peak花岗岩是位于研究区中部的NW-SE撞击，陡峭倾斜，叶状和斜长的白垩纪花岗岩。对S-C斑岩的岩石学和运动学研究表明，在侵入过程中，岩体本身的热量促进了褐斑岩向花岗岩的发育和离散分布。这样的热量使岩石变弱，因此使它们易于在寒冷的上地壳条件下以延性方式变形。最后峰花岗岩与d'Abbadie断层带的位移是共形的。证据包括髓系岩石在岩体内部的离散分布，横切接触，接触金针以及在最后一个山顶花岗岩中朝着d'Abbadie断裂带中心的向东延性应变梯度的存在。断裂碎屑岩和mylonitic断层岩中保存的指示剂为d'Abbadie断层带断层运动的运动学分析提供了基础。构造上Last Peak花岗岩中的镁铁质岩石的结构和微结构以及整个断裂带在脆性剪切断裂面上的相对运动表明d'Abbadie断裂带是右旋走滑断裂。地质图和结构分析表明d'Abbadie断层带构成了一个2 km宽的区域，主要吻合了脆性右旋走滑断裂，并在Last Peak花岗岩中形成了一个局部的200-500 m宽的右旋SC柱状带。脆性断层中充满了2-30 m宽的裂殖质和1 mm至40 cm宽的裂变质带，这些带沿断层以不同大小的股线分布。碎裂碎屑岩形成三个区域：碎裂岩，混合和断裂区域。 S-C镍铁矿形成三个区域：原生质岩，Mylonite和Ultramylonite区域;沿着d'Abbadie断层的变形时间部分受ca的共面构造约束。断裂带内的96 Ma Last Peak花岗岩。最终的花岗岩区，断裂抛光表面上的光滑线和裂缝覆盖了Last Peak花岗岩中的S-C镍铁矿。这些横切关系表明，脆性断层使花岗岩的冷却持续时间太长，并且韧性变形。脆性和韧性岩石的变质条件仅限于绿岩相。这是基于沿断裂面的绿泥石和在上构造峰顶花岗岩中的钾长石卟啉岩的应变阴影。导致碎裂和脆性岩石形成的主要变形机制包括：晶粒内和晶粒间的碎裂流，摩擦晶界滑动和应力引起的固溶传递。这样的机制与脆性变形状态一致，并且指示了脆性壳的流变学。因此，d'Abbadie断层带的构造深度温度条件最好在5-10 km和<250°C之间进行估算; d'Abbadie断层带由一致分布的相干断层岩构成。这表明它没有经历任何重大的再活化，并且是一个短暂的结构，其运动被限制在白垩纪中期。 96毫安。

著录项

  • 作者

    Mercier, Melanie.;

  • 作者单位

    Carleton University (Canada).;

  • 授予单位 Carleton University (Canada).;
  • 学科 Geology.
  • 学位 M.Sc.
  • 年度 2011
  • 页码 148 p.
  • 总页数 148
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号