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

会聚板块边缘是质量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(i)小环（在这里，正面增生棱镜的特征主要是脱水），中间环在脚趾后面几十到几百公里（在这里，序外断层和其他途径将深层物质输送到海洋），以及（iii）大环（在这里，物质要么在地幔中循环，要么沿着火山弧排放）。中间环从未被DSDP、ODP或lODP钻探过，只有555-full3计划在东地中海希腊俯冲带（HSZ）的这一区域进行钻探。克里特岛南部的三个主要断层，都有很好的地球物理成像，其中一个与一个活跃的泥火山并在一起，提供了流体（和泥浆）从几公里深处上升到增生棱镜的证据。为了在SPC排序和OTF调度方面协助这一4*建议，并测试与水文和构造相关的俯冲工厂研究中的一些关键假设，我们提出：-进行一次研究巡航（RV Poseidon），部署流量计，取重力岩心，并在拟议的钻探地点收集原位孔隙压力数据；-利用现有的岩土和地球化学数据，加上巡航期间收集的数据，以及从通量计收集的数据，对沉积复合体及其腹地边界（即欧亚大陆和非洲之间的俯冲工厂的中间环）的流体流动进行数值模拟；并将沿活动断层的物理化学过程与热液实验和长期部署的地球化学发现联系起来。

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.