• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Geology Review >Episodic Volcanism in the Buck Creek Complex (Central British Columbia. Canada): A History of Magmatism and Mantle Evolution from the Jurassic to the Early Tertiary
【24h】

Episodic Volcanism in the Buck Creek Complex (Central British Columbia. Canada): A History of Magmatism and Mantle Evolution from the Jurassic to the Early Tertiary

机译：巴克克里克综合体（加拿大不列颠哥伦比亚中部）的间歇性火山作用：从侏罗纪到第三纪的岩浆作用和地幔演化历史

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 Buck Creek volcanic complex of the Intermontane Superterrane of the Canadian Cordillera records a long history of volcanic activity from the Cretaceous through to the Eocene, when mag-matic activity peaked, to the Miocene. Its basement includes primitive continental arc volcanic rocks of the Jurassic Hazelton Group (approx 200 Ma; mainly basalt and andesites) emplaced prior to the accretion of Stikinia during the Mesozoic. In contrast, in the post-accretionary volcanic complex, the major pulse of volcanism started with the extrusion of continental margin calc-alkaline rocks (basaltic andesites to rhyolites) of the Cretaceous Tip Top Hill Formation (approx 85 Ma). Their Nd-Sr isotopic compositions resemble those of the pre-accretionary Hazelton Group. However, this post-accretionary Cretaceous arc was more evolved and its crust was significantly thicker than the Hazelton. Mafic rocks of both the Hazelton and Tip Top Hill suites were generated from a spinel-bearing mantle source. The Eocene volcanics (approx 50 Ma) evolved from typical high-K calc-alkaline mafic/intermediate rocks to flows that resemble intraplate tholeiitic basalts. Collectively, the Eocene rocks had a common (and comparatively deep) source, likely garnet-bearing subcontinental lithosphere. These compositional variations are probably related, in part, to an increase in the degree of partial melting. They record a gradual change from a compressional to an extensional tectonic environment, and overall represent an arc setting that matured and thickened over ca. 35 m.y., culminating in Eocene extension coincident with the cessation of compression in the foreland fold-and-thrust belt. Overlying intraplate alkali basaltic rocks of Miocene age appear to represent the final stage of this transition, as subduction-modified lithospheric mantle was replaced by a new asthenospheric mantle source. The association of Cretaceous, Eocene, and Miocene volcanic rocks in the Buck Creek complex is widespread in the region, suggesting that this model of tectono-magmatic evolution can be applied elsewhere in central British Columbia.
机译：加拿大山脉山脉上山间地带的巴克溪火山综合体记录了从白垩纪一直到始新世（当岩浆活动达到顶峰）到中新世的火山活动的悠久历史。它的基底包括侏罗纪Hazelton组的原始大陆弧火山岩（约200 Ma;主要是玄武岩和安山岩），在中生代Stikinia增生之前就已被置入。相反，在增生后的火山岩中，主要的火山作用始于白垩纪尖顶山地层（约85 Ma）的大陆边缘钙碱性岩（从玄武岩到流纹岩）的挤压。它们的Nd-Sr同位素组成类似于增生前的Hazelton组。但是，这种增生后的白垩纪弧比黑泽尔顿演化得更多，其壳明显更厚。 Hazelton和Tip Top Hill套件的镁铁质岩石均来自尖晶石地幔源。始新世的火山（约50 Ma）从典型的高K钙碱性镁铁质/中间岩石演化成类似于板内张统玄武岩的流动。总的来说，始新世岩石有一个共同的（且相对较深）来源，可能是含石榴石的次大陆岩石圈。这些成分变化可能部分与部分熔融程度的增加有关。他们记录了从压缩构造环境到伸展构造环境的逐渐变化，总体上代表了一个弧形背景，该弧形背景在ca左右逐渐成熟并变厚。下午35时，始新世伸展达到顶峰，同时前陆褶皱和冲断带停止压缩。俯冲改造的岩石圈地幔被新的软流圈地幔源所取代，中新世时期上覆的板内碱性玄武岩似乎代表了这一转变的最后阶段。巴克克里克（Buck Creek）复合体中的白垩纪，始新世和中新世火山岩协会在该地区广泛存在，这表明这种构造-岩浆演化模型可以在不列颠哥伦比亚省中部的其他地方应用。

著录项

相似文献

  • 外文文献
  • 中文文献
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