• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Geochemistry, geophysics, geosystems >Along-Strike Variation in the Magmatic Tempo of the Coast Mountains Batholith, British Columbia, and Implications for Processes Controlling Episodicity in Arcs
【24h】

Along-Strike Variation in the Magmatic Tempo of the Coast Mountains Batholith, British Columbia, and Implications for Processes Controlling Episodicity in Arcs

机译：沿着海岸山山谷，不列颠哥伦比亚省山谷的岩石速度的变化以及控制弧中的流域的过程的影响

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 growth of the Coast Mountains batholith has been documented as episodic through time, and it has become a type example of a continental arc system that developed through non-steady-state magmatism. The magmatic record, however, is not well known along the length of the arc, hindering evaluation of the processes controlling the tempo and patterns of batholith growth. A new, robust geochronologic database (485 U-Pb zircon and titanite ages, 120 of which are newly presented herein) covering nearly 1,000 km of arc length reveals significant along-strike variation in the tempo of batholith emplacement, the timing of arc cessation, and the arc cooling history. Zircon ages range from ~180 to 40 Ma along the length of the arc and overlap with titanite ages, with the exception of parts of the central batholith where Eocene extension and exhumation of lower crustal rocks led to a more complex history. New analysis of zircon ages reveals significant along-strike differences in the timing of high flux magmatic events. Small-scale (150 km) intra-arc variations in magmatic tempo suggest that small-scale processes, likely operating within the arc system, appear to have driven the episodic growth of the Coast Mountains batholith. In contrast, rates of Cretaceous-Paleogene eastward arc migration are consistently ~2.5 km/Myr along the length of the arc. These rates are similar to those documented in North American arc systems, which suggests that arc migration has an external, plate-scale driver and/or is an intrinsic, self-modulating feature of most continental arcs. Summary Earth's exterior is composed of tectonic plates that move relative to one another. When two plates converge, the denser of the two is forced down below the other, lighter one. That process causes rocks in the upper of the two plates to partially melt, forming an arcuate welt of new igneous rocks (a batholith) resulting from cooling and crystallization of the melts. Although plate convergence can occur co
机译：海岸山地浴池的成长已被记录为整个时间，它已成为通过非稳态岩浆制定的大陆弧系统的类型示例。然而，岩浆记录沿电弧长度缺乏众所周知的，妨碍了控制浴池生长的速度的过程的评估。一种新的强大的地形学数据库（485 U-PB锆石和二氧化钛年龄，其中120岁以下）覆盖了近1,000公里的弧长弧形长度显着沿着浴池施加的速度下的速度变化，即弧停止的时机，和电弧冷却历史。锆部年龄的距离〜180至40 mA沿电弧长度和标题年龄的重叠，除了中央浴池的部分外，占领较低的地壳岩石的突出和挖掘导致更复杂的历史。对锆石年龄的新分析揭示了高通量岩浆事件的时序中的显着响应差异。小尺寸（＆lt 19 km）Magmatic Tempo的AR电弧变化表明，可能在弧系统内运行的小规模过程似乎推动了海岸山地山上的北部的生长。相比之下，白垩纪 - 古雄东弧迁移的速率沿着弧形的长度一致〜2.5 km / myr。这些利率类似于北美弧系统中记录的那些，这表明弧形迁移具有外部，板级驱动器和/或是大多数大陆弧的内在自我调制特征。摘要地球的外部由构造板组成，该板材相对于彼此移动。当两个板融合时，两者的密集被迫低于另一个较轻的。该过程导致两个板的上部岩石部分熔化，形成由熔体的冷却和结晶导致的新的火成岩（浴质岩）的弧形贴合。虽然板融合可以发生有限公司

著录项

相似文献

  • 外文文献
  • 中文文献
  • 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