The role of mixing processes in andesite genesis - deep sediment recycling versus shallow crustal contamination

混合过程在安山岩成因中的作用 - 深层沉积物回收与浅层地壳污染

• 批准号: 288974582
• 负责人: Professor Dr. Karsten Matthias Haase
• 金额: --
• 依托单位: GeoZentrum Nordbayern
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/288974582?language=en
• 关键词: role; mixing; processes; andesite; genesis

Andesites are the typical volcanic rocks at active continental margins and the average continental crust has an andesitic composition. Many andesitic magmas form by complex mixing processes involving sedimentary material that is either subducted into the mantle wedge or may be assimilated in the crust by the ascending magma. The Aegean arc represents the subduction zone with one of the highest sediment recycling rates on Earth and the magmas show whole-rock geochemical evidence of a significant sediment contribution. In order to define the depths of the magma sources and the mixing processes we suggest to study the major and trace element as well as Sr-Nd-Hf-Pb-O isotope composition of minerals like olivine, amphibole, clinopyroxene, and plagioclase and potential glass inclusions in lavas from the Methana/Aegina volcanoes in the Aegean arc. The mineral phases allow insights into the mixing processes of different end-members at different depths that can be determined by thermo-barometry. The Methana/Aegina lavas are well-suited for such a case study because they are geochemically well-described and variable with extreme compositions of the mixing end-members and they contain abundant mineral phases.

安德山矿是活跃大陆边缘处的典型火山岩，平均大陆壳具有安第斯山脉的组成。许多安第斯山岩岩浆通过涉及沉积材料的复杂混合过程形成，这些过程要么俯冲到地幔楔中，要么可以被上升的岩浆在地壳中吸收。爱琴海弧代表俯冲带，地球上最高的沉积物回收率之一，岩浆显示出明显的沉积物贡献的全岩地球化学证据。 In order to define the depths of the magma sources and the mixing processes we suggest to study the major and trace element as well as Sr-Nd-Hf-Pb-O isotope composition of minerals like olivine, amphibole, clinopyroxene, and plagioclase and potential glass inclusions in lavas from the Methana/Aegina volcanoes in the Aegean arc.矿物相允许在不同深度的不同端成员的混合过程中进行深入了解，而这些深度可以通过热气压来确定。 Methana/Aegina熔岩非常适合这种案例研究，因为它们在地球化学上描述了且可变，并具有混合端会员的极端组成，并且包含丰富的矿物相。