...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Contributions to Mineralogy and Petrology >Supra-subduction and abyssal mantle peridotites of the Coast Range ophiolite, California
【24h】

Supra-subduction and abyssal mantle peridotites of the Coast Range ophiolite, California

机译：加利福尼亚海岸山脉蛇绿岩的超俯冲和深渊地幔橄榄岩

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 Coast Range ophiolite (CRO) of California is one of the most extensive tracts of oceanic crust preserved in the North American Cordillera, but its origin has long remained controversial. We present here new data on mineral compositions in mantle peridotites that underlie crustal sections of the ophiolite, and show that these are dominantly refractory harzburgites related to high apparent melting in a supra-subduction zone (SSZ) setting. Abyssal peridotite (characterized by high-Al spinels and relatively high Ti, Na, Nd, Sm, Lu, and Hf in pyroxene) occurs at one location where it is associated with SSZ mantle peridotite and volcanic rocks with both oceanic and arc-like geochemistry. SSZ mantle peridotites (characterized by intermediate-Cr/Al or high-Cr spinels, and by extremely low Ti, Na, Nd, Sm, Lu, and Hf in pyroxenes) are associated with crustal sections containing arc-related volcanic rocks, including boninites. This convergence between conclusions based on crustal lithologies and their underlying mantle sections confirms previous proposals that link the CRO to SSZ processes, and seriously undermines hypotheses that invoke formation of the ophiolite at a mid-ocean ridge spreading center.
机译：加利福尼亚的海岸蛇绿岩（CRO）是保存在北美山脉中最广泛的洋壳之一，但其起源长期以来一直存在争议。我们在此提供有关蛇绿岩地壳剖面下地幔橄榄岩中矿物成分的新数据，并显示这些是与超俯冲带（SSZ）高度融化有关的主要难熔哈氏岩。深海橄榄岩（由高铝尖晶石和辉石中较高的Ti，Na，Nd，Sm，Lu和Hf表征）发生在与SSZ幔橄榄岩和火山岩相关的一个位置，具有海洋和弧状地球化学特征。 SSZ幔橄榄岩（特征为中等Cr / Al或高Cr尖晶石，以及辉石中极低的Ti，Na，Nd，Sm，Lu和Hf）与包含弧相关火山岩（包括邦尼石）的地壳剖面有关。基于地壳岩性的结论及其下伏的地幔剖面之间的这种融合，证实了先前将CRO与SSZ过程联系起来的提议，并严重破坏了在中洋脊扩散中心引起蛇绿岩形成的假说。

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