Geodynamik und Vulkanismus im tropischen/subtropischen Atlantik (Koordinatorantrag M64)

调查的总体目标是：（1）深入了解缓慢扩张的大西洋中脊的火山和构造动态以及活跃热液喷口地区的地球化学和生物过程，重点是时间和空间的变化;（2）将热液过程与轴线上的火山活动联系起来。南纬4 ° ~ 11°之间的MAR在形态、熔体生成和岩浆成分上变化很大，是研究岩浆在壳幔中的运移和火山喷发过程的理想地区。将研究裂谷扩展、岩脉侵入和火山活动的演变，这将为了解热液喷口的形成和演变以及相关的生物过程提供基础。南部MAR的地质和生物学研究远不如北方MAR。然而，已发现热液和富含气体的流体的热液喷发的迹象。在这些数据的基础上，我们的研究小组将选择两个热液活动地点，并从火山学、地球化学和生物学方面对其进行表征。流体地球化学和微生物学的离散目标是与北方MAR系统进行比较，并研究与相关微生物和动物群相关的流体的水深依赖性相分离。从动物学的角度来看，南部MAR作为印度洋和太平洋之间可能的联系，在地理学和热液动物群演化方面的作用特别令人感兴趣。该项目的跨学科方法将提供新的见解耦合过程和动态上的一个缓慢传播的轴。 M64/2（FL Villinger）这次巡航调查是2004年在大西洋中脊北纬15度开始的方案（M60/3号巡航和有关建议）的继续。2004年的考察是在北纬15度的Logatchev油田进行基本的地球化学和生物学研究，2005年考察的重点是在选定的热液喷口地点进行流体射气、流体温度和化学、微生物活动和相关动物的时间变化。为了评估Logatchev热液田热液活动的长期变化，将安装一些环境监测站，这些监测站将于2006年恢复。2004年在Logatchev油田取样的流体可能是超临界（>300 bar，>400°C）来源的，显示铁、甲烷和氢的浓度很高，但硫化物含量很低，因此为热液生境提供了一个非常特殊的环境。2005年的研究重点将是不同喷口射气地点的地球化学变化及其对热液生态系统的影响。由于迄今对复杂热液系统的中期变化知之甚少，计划在今后几年继续进行这些随时间变化的研究。这个跨学科项目的优势在于地球化学、生物学和微生物学的不同工作组之间的密切互动，这些工作组处理热液生态系统的不同层面（从流体的无机物质到不同的生命形式）以及这些层面之间的界面。

M64/1 (FL Haase) The overall goals of the investigation are (1) to obtain insight into the volcanic and tectonic dynamics of the slow-spreading Mid-Atlantic Ridge (MAR) and geochemical and biological processes at active hydrothermal vent areas with emphasis on variations in time and space, and (2) to link the hydrothermal processes to the volcanic activity on the axis. The MAR between 4 and 11°S is highly variable in morphology, melt production and magma composition and an ideal region to study magma transport in the crust and mantle as well as volcanic eruption processes. The evolution of rift propagation, dyke intrusion, and volcanic activity will be investigated which will provide a basis to understand the formation and evolution of the hydrothermal vents and associated biological processes. The southern MAR is geologically and biologically much less well investigated than the northern MAR. However, indications for the occurrence of hydrothermal venting of hot and gas-rich fluids have been found. On the basis of these data, our research group will select two hydrothermally active sites and characterize them volcanologically, geochemically and biologically. Discrete aims for the fluid geochemistry and microbiology are the comparison with northern MAR systems and the investigation of water-depth dependant phase separation of the fluids in relation to the associated microorganisms and fauna. From the zoological perspective, the role of the southern MAR for biogeography and evolution of hydrothermal fauna as a possible link between the Indian and Pacific Ocean is of special interest. The interdisciplinary approach of this project will provide new insight into the coupled processes and dynamics on a slow-spreading axis. M64/2 (FL Villinger) The investigations of this cruise are a continuation of the program started at 15°N on the Mid-Atlantic Ridge in 2004 (cruise M60/3 and respective proposals). While in the 2004 cruise basic geochemical and biological studies were carried out in the Logatchev field at 15°N, the emphasis of the 2005 cruise lies on the temporal variability of fluid emanations, fluid temperature and chemistry, microbial activities and associated fauna at selected hydrothermal vent sites. In order to assess longterm variations in hydrothermal activity of the Logatchev Hydrothermal Field, a number of environmental monitoring stations will be installed which will be recovered in 2006. The fluids sampled at the Logatchev field in 2004 are probably of supercritical (>300 bar, >400°C) origin, showed high iron, methane and hydrogen concentrations, but low sulfide contents, thus providing a very special environment for hydrothermal habitats. The geochemical changes at different vent emanation sites and their consequences for the hydrothermal ecosystem will be in the focus of the studies in 2005. As little is known so far about the medium-term variability of complex hydrothermal systems, it is planned to continue these time-dependant studies in the following years. The strength of this interdisciplinary project is the intense interaction of the different working groups of geochemistry, biology and microbiology, which address the different levels of the hydrothermal ecosystem (from the inorganic material of the fluids to the different life forms) and the interfaces between these levels.