Geotechnical and sediment physical characterization of glacial-interglacial cycles on a late Miocene to Holocene shelf-slope transect (Canterbury Basin, New Zealand)

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This proposal is designed for postcruise analyses of samples and processing of data sets gained during IODP Expedition 317 (Canterbury Basin, New Zealand). Expedition 317 was aimed to understand the relative importance of global sea level changes versus local tectonic and sedimentary processes in controlling continental margin sedimentary cycles. Nineteen regional sequence-bounding unconformities, know from high-frequency sequence stratigraphy, were investigated on four drill sites of a late Miocene to recent continental shelfslope transect. First onboard results show that the interpretation of the unconformities is problematical because the thicknesses of the missing intervals, caused by hiatuses and/or the drilling process, are unknown. For further investigations, e.g. age-depth estimation, lithological sequence correlation, two dimensional backstripping, it is crucial to get these information. An auspicious approach is the reconstruct of the “missing strata” on the basis of the determination of compaction and dewatering properties via geotechnical measurements (oedometer and sediment strength tests) on 56 whole-round samples from areas above and below the unconformities. A second goal is to respond to the question if the sediment compaction history can be traced horizontally across a shelf-slope transect and vertically down to a sediment depth of more than 980 m. The results and additional analyses of physical property, down-hole logging and sedimentological shipboard data will support the quantitative analysis of subsidence and sea level change in Canterbury Basin.