Deep-seated fluid flow processes, seismic faulting and mud volcanisms in a mature collision zone; The backstop to the Mediterranean Ridge accretionary prism

成熟碰撞带的深层流体流动过程、地震断层和泥浆火山活动；

• 批准号: 172372746
• 负责人: Professor Dr. Achim Kopf
• 金额: --
• 依托单位: Zentrum für Marine Umweltwissenschaften (MARUM)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/172372746?language=en
• 关键词: Deep; seated; fluid; flow; processes

Convergent plate margins are important locations of mass transfer processes and tectonic activity. However, the so-called subduction factory has rarely been studied by scientific ocean drilling. It comprises (i) the small loop (where frontal accretionary prism is characterised by mostly dewatering), the intermediate loop several tens to hundreds of kilometres behind the toe (where out-of-sequence-faults and other pathways funnel deep-seated material to the ocean), and (iii) the big loop (where material is either recycled in the mantle, or emitted along the volcanic arc). The intermediate loop has never been drilled by DSDP, ODP or lODP, and only active proposal 555-full3 addresses this area in the Hellenic Subduction Zone (HSZ), Eastern Mediterranean. Three major faults south of Crete, all superbly imaged geophysically and one juxtaposed by an active mud volcano, provide evidence for fluid (and mud) ascent from several km depth in the backstop to the accretionary prism. To assist this 4* proposal in SPC ranking and OTF scheduling, and to test a number of critical hypothesis in subduction factory research linking hydrology and tectonics, we propose: - to carry out a research cruise (RV Poseidon) to deploy flow meters, take gravity cores and collect in situ pore pressure data at the proposed drill sites, - to use existing geotechnical as well geochemical data plus those collected during the cruise and from the fluxmeters to numerically model fluid flow at the boundary between the accretionary complex and its hinterland (i.e. the intermediate loop ofthe subduction factory between Eurasia and Africa), and - to relate physico-chemical processes along the active faults to be penetrated to the geochemical findings from hydrothermal experimenls and long-term deployments.

会聚板块边缘是物质传递过程和构造活动的重要场所。然而，所谓的俯冲工厂很少被科学的海洋钻探所研究。它包括（一）小环（在这里，正面的增生棱柱主要以脱水为特征），趾部后面几十到几百公里的中间环（在这里，不连续的断层和其他通道将深层物质漏斗到海洋中），以及（三）大环（在这里，物质要么在地幔中循环，要么沿着沿着火山弧排出）。DSDP、ODP或lODP从未钻探过中间环，只有现行的555-full 3提案涉及东地中海希腊俯冲带（HSZ）的这一区域。克里特岛南部的三个主要断层，都是极好的断层图像，其中一个由一个活跃的泥火山并列，提供了流体（和泥浆）从几公里深的逆止上升到增生棱镜的证据。为了帮助SPC排名和OTF调度中的这一4* 提案，并测试连接水文和构造的俯冲工厂研究中的一些关键假设，我们建议：- 进行研究航行（RV Poseidon）部署流量计，采集重力岩心，并在拟定钻探地点收集现场孔隙压力数据，- 利用现有的岩土工程和地球化学数据，加上航行期间收集的数据和从通量计收集的数据，对加积复合体与其腹地之间边界的流体流动进行数值模拟（即欧亚大陆与非洲大陆之间的俯冲工厂的中间环）;（2）将所要穿透的活动断裂沿着的物理化学过程与热液实验和长期部署的地球化学结果联系起来。