...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Asian earth sciences >Chemical geodynamics of mafic magmatism above subduction zones
【24h】

Chemical geodynamics of mafic magmatism above subduction zones

机译：俯冲区镁岩岩浆岩岩的化学地质动力学

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 geochemical signatures of subducting crust have been identified in various types of mafic igneous rocks at convergent plate boundaries, where island arc basalts (IAB) and continental arc andesite are accepted as the typical products of subduction zone magmatism. These crustal signatures are commonly represented not only by enrichment in large ion lithophile elements (LILE) and light rare earth elements (LREE) relative to normal midocean ridge basalts (MORB), but also by enrichment in radiogenic Sr isotopes but depletion in radiogenic Nd isotopes relative to the primitive mantle. Such enriched signatures also occur in oceanic island basalts (OIB) and their continental counterparts, but their origin has been controversial in igneous petrology. The present review focuses on the origin of enriched signatures in mafic igneous rocks above subduction zones. Although these mafic rocks are distributed in both interplate and intraplate areas, they are generally categorized into two series according to their trace element distribution patterns in the primitive mantle-normalized diagram. One is IABlike series, showing enrichment in LILE, Pb and LREE but depletion in high field strength elements (HFSE) such as Nb and Ta relative to heavy rare earth elements (HREE). The other is OIB-like series, exhibiting enrichment in LILE and LREE, enrichment or non-depletion in HFSE but depletion in Pb relative to HREE. In either series, these mafic igneous rocks show enhanced enrichment of LILE and LREE with increasing their incompatibility relative to normal MORB, indicating the presence of crustal materials in these mafic igneous rocks. Inspection of the mass balance in major and trace elements between source and product indicates that subducting crustal rocks were not directly incorporated into the mantle sources of both series. Instead, they underwent metamorphic dehydration and partial melting at different depths to produce liquid phases, which dominate the budget of fluid- to melt-mobile elements and their pertinent radiogenic isotopes in the mantle sources. As a consequence, the composition of liquid phases is a key to the geochemical composition of both series. Therefore, the crustal materials are transferred by the liquid phases via metasomatic reactions into the mantle sources at the slabmantle interface in subduction channels. As such, the difference in the geochemical transfer from the subducting crust into the mantle can account for the difference in the composition between the interplate IAB-like and intraplate OIB-like series. This provides a holistic model for the origin of both IAB- and OIB-like series mafic igneous rocks above subduction zones.
机译：已经在收敛板边界的各种类型的MAFIC IGNEE岩石中鉴定了桥面地壳的地球化学签名，其中岛弧玄武岩（IAB）和大陆弧安嵌段被认为是俯冲区岩浆岩的典型产品。这些地壳签名通常不仅代表了相对于正常的Midocal脊玄武岩（Morb）中的大离子型绞合元件（含量）和轻质稀土元素（LREE），而且还通过富集在辐射性SR同位素中富集，但在辐射性ND同位素中耗尽相对于原始地幔。这种丰富的签名也发生在海洋岛屿基础（OIB）及其大陆同行中出现，但他们的起源在导致的岩画中一直存在争议。本综述重点介绍丘草区上方MAFIC IGNES岩石中丰富签名的起源。虽然这些MAFIC岩石在两者和腔内区域分布，但它们通常根据原始地幔标准化图中的痕量元素分布模式分为两个系列。一个是Iablike系列，在乳液，Pb和lee中显示富集，但在高场强元件（HFSE）中耗尽，例如Nb和Ta相对于重稀土元素（HREE）。另一个是Oib样系列，在HFSE中展示含有肥料和嗜睡，富集或非枯竭，但在PB相对于HREE耗尽。在任一系列中，这些乳房的火岩岩石展示了增强的肥料和lee，随着相对于正常Morb的不相容性而增加，表明这些乳头火岩中的地壳材料存在。检查源和产品之间的主要和微量元素的质量平衡表明，底层地壳岩石不直接纳入两种系列的地幔源。相反，它们在不同深度下进行了变质脱水和部分熔化以产生液相，其在地幔源中占据流体至熔融 - 移动元件的预算和它们的相关辐射同位素。结果，液相的组成是两种系列的地球化学组合物的关键。因此，在俯冲通道中通过液相通过液相通过液相转移到地幔源中的地壳材料在俯冲通道中的裂缝界面转移。因此，从桥面壳体进入地幔的地球化学转移的差异可以考虑IAB样和内部内板状系列的interplate Iab样和内部液体的组成的差异。这为IAB和OIB样系列MAFIC IGNEES岩石的起源提供了整体模型。

著录项

  • 来源
    《Journal of Asian earth sciences》 |2020年第1期|104185.1-104185.32|共32页
  • 作者

    Zheng Yong-Fei; Xu Zheng; Chen Long; Dai Li-Qun; Zhao Zi-Fu;

  • 作者单位

    Univ Sci & Technol China Sch Earth & Space Sci CAS Key Lab Crust Mantle Mat & Environm Hefei 230026 Peoples R China;

    Univ Sci & Technol China Sch Earth & Space Sci CAS Key Lab Crust Mantle Mat & Environm Hefei 230026 Peoples R China;

    Univ Sci & Technol China Sch Earth & Space Sci CAS Key Lab Crust Mantle Mat & Environm Hefei 230026 Peoples R China;

    Univ Sci & Technol China Sch Earth & Space Sci CAS Key Lab Crust Mantle Mat & Environm Hefei 230026 Peoples R China;

    Univ Sci & Technol China Sch Earth & Space Sci CAS Key Lab Crust Mantle Mat & Environm Hefei 230026 Peoples R China;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Subduction zone; Mafic magmatism; Geochemical transfer; Crustal metasomatism; Crustal recycling; Mantle wedge;

    机译：俯冲区;迈克斯·岩浆作用;地球化学转移;地壳偏见主义;地壳回收;地幔楔形;

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