After collecting images TOBI over 600 km and have 18 times the dredged slopes wrinkle elongated "smooth seafloor" we can provide some answers as to the nature seafloor in our first study area.
TOBI images show only very few volcanic edifices, mainly localized to the ends of these lines extended. Much of the two slopes of these lines shows surfaces, either very smooth or with a mottled texture, and very reflective (very bright images TOBI see 3D image). These highly reflective slopes are found both in the axial valley in the oldest parts of our study area where we expected however that the sediment cloud images, blurring TOBI at least partially landforms.
Many figures of erosion (such as scree slopes, magnifiers breakout etc. ..) are observed and show the instability of these slopes. Dredging on both sides of the elongated wrinkles have collected several hundreds of kilograms of rock almost exclusively of mantle peridotites, more or less altered (with veins of serpentine) and deformed. Some rock samples are covered with a crust of manganese, which gives them a rounded, black, almost shiny. Furthermore, initial analysis of water samples collected by CTD show abnormal levels of manganese near the bottom. These concentrations could be explained by hydrothermal alteration of mantle rocks. One of our hypotheses is that the presence of debris size pluricentimétrique covered with manganese crust could explain the highly reflective nature of the slopes of lines lying on the TOBI images. If no fault plane is observed directly, because too eroded, repeated observation of mantle peridotites in our dredges makes the presence of faults necessary to exhume the rocks on the seafloor.
Remains to explain the genesis and evolution of wrinkles elongated "smooth seafloor" by these fault systems verging opposite.
detailed analysis of the data (TOBI images, bathymetry, magnetic anomalies, water and rock samples dredged) that we will at land will be to propose a coherent model of implementation of the "smooth seafloor.
Many figures of erosion (such as scree slopes, magnifiers breakout etc. ..) are observed and show the instability of these slopes. Dredging on both sides of the elongated wrinkles have collected several hundreds of kilograms of rock almost exclusively of mantle peridotites, more or less altered (with veins of serpentine) and deformed. Some rock samples are covered with a crust of manganese, which gives them a rounded, black, almost shiny. Furthermore, initial analysis of water samples collected by CTD show abnormal levels of manganese near the bottom. These concentrations could be explained by hydrothermal alteration of mantle rocks. One of our hypotheses is that the presence of debris size pluricentimétrique covered with manganese crust could explain the highly reflective nature of the slopes of lines lying on the TOBI images. If no fault plane is observed directly, because too eroded, repeated observation of mantle peridotites in our dredges makes the presence of faults necessary to exhume the rocks on the seafloor.
Remains to explain the genesis and evolution of wrinkles elongated "smooth seafloor" by these fault systems verging opposite.
detailed analysis of the data (TOBI images, bathymetry, magnetic anomalies, water and rock samples dredged) that we will at land will be to propose a coherent model of implementation of the "smooth seafloor.
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