Probing the Chilean subduction zone at mantle depths:Insights from Patagonian High-Pressure rocks

探测地幔深处的智利俯冲带：来自巴塔哥尼亚高压岩石的见解

• 批准号: 266332247
• 负责人: Professor Dr. Samuel Angiboust, Ph.D.
• 金额: --
• 依托单位: Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum (GFZ)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/266332247?language=en
• 关键词: Probing; Chilean; subduction; zone; mantle

Even though documented by numerous geophysical studies over the last 30 years, the Chilean subduction zone structure and dynamics at depths greater than 40 km remains poorly resolved. We herein propose to study the only high-pressure metamorphic terrane from the Chilean margin exhumed from blueschist-to-eclogite facies (40-50 km depth) on the Diego de Almagro Island (Patagonia, Chile), to highlight accretionary and fluid-rock interaction processes in the deep (40-50 km) Chilean subduction zone. The internal structure of the Island, which is apparently constituted by material from various origins and metamorphic histories, needs further characterization of its geological history. The field campaign will permit (i) to realize a widespread sampling and structural measurements throughout the Island (ii) to realize the first geological cross-section across the island and (iii) to perform detailed pressure-temperature-time-deformation paths for the various sub-units building up the island. The strength of our approach is to combine modern thermobarometric tools with in situ Ar-Ar geochronological constrains and Rb-Sr deformation ages. These results will be of importance to improve our vision of the lithological composition and structure of the Chilean subduction channel as well as of deformation processes rooted at the base of the seismogenic zone. The results will also shed light on subduction interface dynamics at Moho depths and will therefore be of importance of the geophysicists community.

尽管在过去30年中进行了大量的地球物理研究，但智利俯冲带的结构和动力学在40公里以上的深度仍然很难解决。我们在此建议研究唯一的高压变质岩石从智利边缘挖出蓝片岩榴辉岩相（40 - 50公里深）的迭戈德阿尔马格罗岛（巴塔哥尼亚，智利），突出增生和流体-岩石相互作用过程中深（40 - 50公里）智利俯冲带。该岛的内部结构显然是由各种来源和变质历史的物质构成的，需要进一步确定其地质历史。现场活动将允许（i）在整个岛屿实现广泛的采样和结构测量（ii）实现整个岛屿的第一个地质横截面和（iii）为建造岛屿的各个子单元执行详细的压力-温度-时间-变形路径。我们的方法的优势是结合现代温压工具与原位Ar-Ar年代学约束和Rb-Sr变形年龄。这些结果将是重要的，以提高我们的视野的岩性组成和结构的智利俯冲通道，以及变形过程植根于基地的孕震区。结果也将揭示在莫霍面深度的俯冲界面动力学，因此将是重要的地球化学家社区。

项目成果

Hot subduction in the middle Jurassic and partial melting of oceanic crust in Chilean Patagonia

• DOI: 10.1016/j.gr.2016.10.007
• 发表时间: 2017-02
• 期刊: Gondwana Research
• 影响因子: 6.1
• 作者: S. Angiboust;T. Hyppolito;J. Glodny;A. Cambeses;A. Garcia‐Casco;Mauricio Calderón Nettle;Caetano Juliani

Eclogite-, amphibolite- and blueschist-facies rocks from Diego de Almagro Island (Patagonia): Episodic accretion and thermal evolution of the Chilean subduction interface during the Cretaceous

迭戈德阿尔马格罗岛（巴塔哥尼亚）的榴辉岩、角闪岩和蓝片岩相岩石：白垩纪期间智利俯冲界面的幕式增生和热演化

• DOI: 10.1016/j.lithos.2016.09.001
• 发表时间: 2016
• 期刊: Lithos
• 影响因子: 3.5
• 作者: Hyppolito;Angiboust;Juliani;Glodny;Garcia-Casco;Calderon;Chopin
• 通讯作者: Chopin