...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Earth and Planetary Science Letters: A Letter Journal Devoted to the Development in Time of the Earth and Planetary System >Lithium isotope fractionation in the southern Cascadia subduction zone
【24h】

Lithium isotope fractionation in the southern Cascadia subduction zone

机译：卡斯卡迪亚南部俯冲带锂同位素分馏

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

We present lithium (Li) abundances and isotope compositions for a suite of anhydrous olivine tholeiites (HAOTs) and hydrous basalt-andesitic (BA) lavas from the Mt. Shasta and Medicine Lake regions, California. The values of delta(7) Li vary from +0.9 parts per thousand to +6.4 parts per thousand and correlate inversely with distance from the trench. These data are consistent with continuous isotope fractionation of Li during dehydration of the subducted oceanic lithosphere, an interpretation corroborated by uniformly high pre-eruptive H2O contents in basaltic andesites accompanied by high Li, Rb, Sr, Ba and Pb abundances. The subduction-derived component that was added to these hydrous magmas is shown to be very similar beneath both Mt. Shasta and Medicine Lake volcanoes despite characteristically distinct Li isotope compositions in the magmas themselves. More evolved andesites and dacites from Mt. Shasta have delta(7) Li from +2.8 to +6.9 parts per thousand which is identical with the range obtained for HAOTs and BA lavas from Mt. Shasta. Therefore, Li isotopes do not provide evidence for any other crustal component admixed to Mt. Shasta andesites or dacites during magmatic differentiation and magma mixing in the crust., (c) 2006 Elsevier B.V. All rights reserved.
机译：我们介绍了来自山的一组无水橄榄石陶粒（HAOT）和含水玄武岩-安山岩（BA）熔岩的锂（Li）丰度和同位素组成。加利福尼亚的Shasta和Medicine Lake地区。 del（7）Li的值从+0.9千分之几到+6.4千分之几不等，并且与离沟槽的距离成反比。这些数据与俯冲海岩石圈脱水过程中Li的连续同位素分馏是一致的，这一解释得到了玄武质安山岩中均匀高的喷发前H2O含量以及高Li，Rb，Sr，Ba和Pb丰度的证实。在两个山下，俯冲派生的成分被添加到这些含水岩浆中。尽管岩浆本身具有独特的锂同位素组成，但沙斯塔火山和梅迪奇湖火山都是如此。更多来自山的演化安山岩和dacites。 Shasta的delta（7）Li从+2.8至+6.9千分之几，与从Mt. Mt.获得的HAOT和BA熔岩所获得的范围相同。沙斯塔。因此，Li同位素不能提供任何证据证明任何其他与Mt混合的地壳成分。地壳岩浆分化和岩浆混合过程中的Shasta安山岩或dacits。，（c）2006 Elsevier B.V.保留所有权利。

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