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

本建议书旨在对IODP第317次考察（新西兰坎特伯雷盆地）期间获得的样本进行巡航后分析并处理数据集。第317次考察的目的是了解全球海平面变化与当地构造和沉积过程在控制大陆边缘沉积旋回方面的相对重要性。19个区域性层序边界不整合面，知道从高频层序地层学，调查了晚中新世到现代陆棚斜坡样带的四个钻孔地点。首先，船上的结果表明，不整合的解释是有问题的，因为由间断和/或钻井过程引起的缺失层段的厚度是未知的。这些信息的获取对于进一步的研究，如年龄-深度估计、岩性层序对比、二维回剥等都是至关重要的。一个有利的方法是，通过对不整合面上下区域的56个全方位样品进行土工测量（固结仪和沉积物强度测试），确定压实和脱水特性，在此基础上重建“缺失地层”。第二个目标是回答这样一个问题，即沉积物压实历史是否可以在水平方向上穿过陆棚-斜坡样带并在垂直方向上向下追踪到980米以上的沉积物深度。物性、井下测井和沉积学船载资料的研究结果和补充分析将为坎特伯雷盆地沉降和海平面变化的定量分析提供支持。

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.