We report the 3D microstructure analyses of natural gas hydrates sampled from Gulf of Mexico. The samples were characterized by synchrotron radiation X‐ray cryo‐tomographic microscopy (SRXCTM) using the ‘TOMCAT’ beam line at the Swiss Light Source (SLS). The SRXCTM demonstrates its applicability to unlock some microscopic features of the marine hydrates, in particular of crystallite size and grain boundary network. The gas hydrate domains are surrounded by a network of pores of typically a few micrometers, which are largely due to decomposition. Out of the SRXCTM data, the porosity, total volume of the voids, the void surface area and number of the total gas‐filled voids have been calculated. The results reveal the capability of SRXCTM to access the 3D microstructure which is of fundamental importance to model the petrophysical properties of natural gas hydrates.

Field mapping of fluvial terraces, aerial photographs, ground penetrating radar and seismic data from gas and oil exploration were used at four different locations to detect young tectonic and halokinetic movements in the North-German-Basin.i) The course of the Rivers Weser and Aller follow precisely a shallow Tertiary graben on the northwestern flank of the Verden salt diapir. Recent local depressions and vegetation anomalies on the alluvial plain have the same orientation as the strike direction of the faults at subsurface depth. Apparently, the river follows tectonic lines, and thus the river sediments can be used for the interpretation of recent crustal movements.ii) The Wedehof diapir, in contrast, is topped by a local topographic high which follows exactly the shape of the underlying salt. Either the diapir formed an obstacle for the advance of the continental glaciers or one has to assume halokinetic uplift of more than 50 m during the post-Saalian Pleistocene. Either way, the Wedehof diapir shows control of the modern surface morphology by halokinesis.iii) The course of the river Hunte, in contrast, outside the area of salt diapirism, shows anomalies of incision and terrace width over a local updoming caused by tectonic inversion of distinct blocks in the basin. The confluence of several tributaries of the Hunte lies exactly over the updoming of Barnstorf. Thus, the rivers do not avoid the local high, but focus in this area, which is characterised by a graben on top of the domestructure, as visible in seismic profiles. Again, tectonism controls river development.iv) The last case study is from Lake Plön, where seismic profiles reveal that linear shorelines of the lake parallel the flanks of two local graben structures of Tertiary age. It is apparent that the Weichselian glaciers that formed the lake and the surrounding moraines interacted with the existing grabens.The Tertiary morphology in the North German basin was apparently draped by Quaternary glacial deposits, but rivers and lakes that dominate the topography of the modern landscape still reflect the geodynamic centers of Tertiary tectonism and halokinesis. Faults from the depth of the Tertiary penetrate the Quaternary strata and allow upward fluid migration, which becomes visible on aerial photographs as linear vegetation anomalies.

The catchment basin of the River Hunte (Lower Saxony, NW-German Basin) was studied on a mesoscale (length of $90 km) to investigate the influence of the geological subground on modern morphology. A Geo Information System (GIS) was used to calculate linear correlation coefficients between the depth of geological strata (Base Zechstein to Base Quaternary) and the height of the modern landscape (Holocene Alluvial Plain, Lower Weichselian Terrace, catchment basin and watershed). High linear correlation coefficients between the Base of Tertiary and the height of the modern topography (catchment basin [r 2 =0.87], Lower Weichselian Terrace [r 2 =0.95] and Holocene Alluvial Plain [r 2 =0.95]) indicate control of the modern topography by the depth of the geological subsurface via tilting of the entire basin. Most likely northward tilting of the NW-German Basin forces the River Hunte to flow in a northerly direction by relative uplift of the hinterland (Wiehengebirge, Rhenish Massif) and subsidence of the North Sea area.

1applications of a nanoscope in the set-up of hard X-ray optical data read-out device (e.g. see [1]). Other applications, for example, are envisaged in hard X-ray advanced nanolithography (chip fabrication) and in cell biology to view structural details of living cells in 3D and real time, at a previously unobtainable resolution. A set-up of grazing-angle incidence hard X-ray nanoscope (GIXN) is presented appropriate for the non-destructive high-resolution investigations of the various kinds of non-diffracting subsurface nanosize inclusions based on the grazing-angle incidence X-ray backscattering diffraction (GIXB) technique [2, 3], which takes place in the conditions of specular vacuum wave suppression phenomenon [4]. GIXN analyser is an asymmetrically cut single crystal, which is operating like an image magnifier. High-resolution X-ray diffractive optical lens (zone plate) and spatially resolving detector (CCD camera) are arranged like in classical schemes of the X-ray imaging microscopy. Keywords: X-ray imaging, grazing X-ray diffraction, X-ray back reflection P01.07.40 Acta Cryst. (2008). A64, C183Application of synchrotron X-ray micro tomographic microscopy at low temperature We report the application of synchrotron X-ray cryo-micro tomographic microscopy (SRXCTM) provided by the 'TOMCAT' beam line at the Swiss Light Source (SLS) for studying the substances such as ice and gas hydrate at low temperatures down to 150 K. Description of the precarious handling of the samples within their thermodynamic stabilities, polyamide sample holder, experimental setup, cryo-stage coupled with cooling setup, and data acquisitions were addressed. The monochromatized X-ray beam was modified by a slit system to a profile as small as of 1.4 mm 2 to confine the irradiation to the region of interest (ROI). The beam energy was optimized to enhance the contrast among the constituents of specimens. The X-ray beams were converted into visible light with a thin scintillator screen. Further magnifications of the projection images were done by microscope optics, which were digitalized using a high resolution CCD camera. Post processing of the reconstructed raw data was carried out using 'MATLAB'. The 3D visualization of the post processed datasets was performed with the software 'Amira' which facilitated to separate the cylindrical ROI from the raw dataset to eliminate the non reconstructed regions. Out of the SRXCTM dataset, both of ice and gas hydrate, parameters like porosity, surface area and volumes were calculated for the whole dataset as well as a single object. The imagery demonstrated the well suited applicability of SRXCTM revealing some salient microscopic features preserved in marine hydrates and atmospheric ice.Keywords: synchrotron X -ray tomography, ice, gas hydrate P01.07.41 Acta Cryst. (2008). A64, C183Imaging and structural analysis of heterogeneous diluted materials by diffraction tomography We evidence the potential of coupling pencil beam tomography with X-ray diffraction to examine unidentified phases in heterog...