Structural Controls on Magma Transport and Vertical Coupling in the Continental Lithosphere

在新西兰菲奥德兰举行的一个国际实地论坛(2003年4月26日至5月6日)为固体地球科学界的成员提供了一个机会，以研究岩浆通过大陆地壳产生、分离和输送的机制，以及这些过程如何影响岩石圈的机械演化。菲奥德兰的位置很重要，因为很少有野外地点允许地球科学家直接研究同时在下地壳大片区域内演化的构造和岩浆特征。菲奥德兰含有罕见的高压混合岩和下地壳构造特征的暴露，形成于白垩纪山系的异常深部(古深度25-50公里)。该遗址壮观的地貌保存激发了新的想法，并为评估熔体产生和从下地壳逃逸的过程以及迁移的岩浆如何与岩石圈规模的变形相互作用提供了基础。所讨论的具体问题包括：1)下地壳快速演化的热和构造制度的证据及其对岩石圈演化的影响；2)流体和熔体来源的证据和岩浆通过下地壳分凝和运移的变化机制；3)地壳熔融、麻粒岩相变质和变形之间的反馈机制；4)地壳熔融和岩浆作用对岩石圈内垂直耦合/脱钩过程的影响；5)天然下地壳剪切带中的流动模式及其与变形和岩浆输送过程的关系；6)对下地壳变形分凝和应变局部化过程的时空控制。菲奥德兰独特的地质环境允许30名地球科学家交流当前的知识和新思想，这些知识和新思想很好地表达了特定野外地点的地质学。该项目还部分支持5-8名学生和一名博士后助理参加会议。青年科学家的参与为学生提供了机会，让他们认识在相同或相似的感兴趣领域进行研究的其他地球科学家，但他们拥有不同的专业知识。它还允许他们与成熟的科学家互动，并有机会研究一些引人注目的暴露出来的地壳深部过程。

An international field forum in Fiordland, New Zealand (April 26 to May 6, 2003) is providing members of the Solid Earth Science community with an opportunity to examine the mechanisms by which magma is generated, segregated and transported through continental crust and how these processes affect the mechanical evolution of the lithosphere. The Fiordland location is significant because few field sites allow geoscientists to examine directly structural and magmatic features that evolved simultaneously within large sections of the lower crust. Fiordland contains rare exposures of high-pressure migmatite and lower crustal structural features that formed at unusually deep levels of a Cretaceous mountain system (25-50 km paleodepths). The spectacular preservation of features at this site are stimulating new ideas and are providing a basis for evaluating the processes of melt generation and escape from the lower crust and how migrating magma interacts with deformation at the lithospheric scale. Specific issues addressed include: 1) evidence of rapidly evolving thermal and structural regimes in the lower crust and effects on lithosphere evolution; 2) evidence of fluid and melt sources and changing mechanisms of magma segregation and transport through the lower crust; 3) feedback mechanisms among crustal melting, granulite facies metamorphism and deformation; 4) effects of crustal melting and magmatism on vertical coupling/decoupling processes within the lithosphere; 5) flow patterns in natural lower crustal shear zones and their relationship to deformation and magma transport processes; 6) space-time controls on deformation partitioning and strain localization processes in the lower crust. The unique geologic setting of Fiordland allows 30 geoscientists to exchange current knowledge and new ideas that are well expressed by the geology of specific field sites. This project also partially supports 5-8 students and a post-doctoral associate to attend the meeting. The participation of young scientists provides opportunities for students to meet other geoscientists conducting research in the same or similar fields of interest, but with different expertise. It also allows them to interact with mature scientists and an opportunity to study some spectacularly exposed deep crustal processes.