Physical properties of the AND-1B core, ANDRILL McMurdo Ice Shelf Project, Antartica
Whole-core physical properties of the AND-1B sediment core were determined on site for initial core characterisation and correlation with seismic modelling to predict target-reflector depth. This was accomplished by the application of a GEOTEK MSCL (multisensor core logger) from which detected parameters were converted to wet bulk density (WBD), P-wave velocity (Vp), and magnetic susceptibility (MS). Due to difficulties in terms of sensor drift, non-contact resistivity (NCR) data were not processed on site. Standards were logged together with the cores throughout the entire depth range to monitor data quality and demonstrate that no systematic offsets occurred between different core diameters of the AND-1B core (PQ-liner, PQ, HQ, and NQ). Physical properties exhibit a large range of values, reflecting the different nature of the various lithologies including clasts, effects of cementation, and overall downcore gradients in WBD and Vp as a result of compaction. Generally, the boundaries of the major stratigraphic units are in good agreement with changes in the pattern of the physical properties. WBD, Vp, and MS exhibit remarkable cyclicities in particular in the upper part of the core down to about 600 metres below seafloor (mbsf).