Tectono-magmatic controls on hydrothermal activity at the Mid-Atlantic Ridge vent fields Logatchev and 5°S

这项拟议的工作旨在了解缓慢扩张山脊的构造-岩浆作用与热液喷发的起源和性质之间的关系。特别是，我们将测试离轴喷发是否是构造阶段海底扩张的自然结果，而轴上喷发是在岩浆主导阶段发生的。超镁铁质赋存的洛加切夫油田位于构造活动的脊段上，而玄武岩赋存的5°S系位于最近岩浆活动的脊段的轴线上。这些对比鲜明的热液喷口风格使它们成为实现我们目标的理想自然实验室。在DFG“S优先计划1144”“从地幔到海洋”期间获得的大量背景数据和知识的基础上，我们现在准备使用最先进的数值模型来检验我们的主要假设。作为对大型构造控制热液喷发的研究的补充，我们还将探讨流体动力学对流体路径和化学的控制。通过这一综合办法，拟议的工作将使我们能够更紧密地将地表观测与深处的远程物理化学过程联系起来。

The proposed work aims at understanding the relationships between tectono-magmatic processes at slow spreading ridges and the origin and nature of hydrothermal venting. In particular, we will test if off-axis venting is a natural consequence of seafloor spreading in a tectonic phase, while on-axis venting occurs during magmatic dominated phases. The ultramafic hosted Logatchev field is located off-axis on a tectonically active ridge segment, while the basaltic hosted 5°S system is situated on the axis of a ridge segment with recent magmatic activity. These contrasting styles of hydrothermal venting make them ideal natural laboratories for our objectives. Building on the extensive background data and knowledge acquired during DFG‟s Priority Program 1144 “From Mantle to Ocean”, we are now poised to test our main hypothesis using state-of-the-art numerical models. As a complement to studies of large-scale tectonic controls on hydrothermal venting, we will also explore the fluid-dynamic controls on fluid pathways and chemistry. By this integrated approach, the proposed work will allow us to more closely link surface observations with remote physicochemical processes at depth.