Tomographic microstructures and fabrics of ODP Leg 204 gas hydrates in relation to formation conditions in marine sediments.

我们建议调查的深度和压力的依赖性的天然气水合物的微观结构和组构的天然气水合物在ODPLeg 204的核心。探讨气泡、沉积物性质与天然气水合物的关系。我们推测，水合物的结构是由上覆岩层压力的影响，而晶体的大小是由水合物晶体之间的物质传输，导致较大的晶体控制。一个关键的方法将是显微层析成像，探索（亚）微米范围内的水合物的三维结构。结合高分辨率同步辐射衍射技术、低温扫描电镜和拉曼光谱，我们有信心对不同深度的水合物沉淀进行表征。海瑟薇岭六个钻探点的50多个取样层段可供使用，覆盖整个水合物稳定区。因此，这些样本构成了一个独特的科学收藏，可以进行高分辨率和深度相关的分析。我们将把我们的结果与世界上其他水合物矿床的结果进行比较，并希望对水合物的微观结构有更深入的了解。

We propose to investigate the depth and pressure dependency of gas hydrates microstructure and fabric of gas hydrates in cores of ODP Leg 204. The relation of gas bubbles, sediment properties and gas hydrates will be explored. We hypothesize that the fabric of the hydrates is influenced by the overburden pressure, whereas the crystal size is controlled by material transport between hydrate crystals, leading to larger crystals. A key method will be micro-tomography, exploring the three dimensional architecture of hydrates on a (sub-) micrometer range. Combining this method together with high-resolution synchrotron diffraction techniques, cryo-SEM and Raman spectroscopy we are confident to characterize gas hydrate precipitates in various depth levels which were formed by different mechanisms. More than 50 sample intervals from six drill sites at Hydrate Ridge are available covering the entire hydrate stability zone. By that, the samples constitute a unique scientific collection allowing for both high-resolved and depth-related analyses. We will compare our results to those of other hydrate deposits in the world and hope to get a much deeper insight into the microfabrics of hydrates in general.