Water Release from the Base of Active Glaciers

The four experiments described consisted of mixing ground-up till with varying amounts of water and then measuring the alignment of the particles in the present Earth's magnetic field. The laboratory results are compared with those obtained from the Port Stanley Till. It has been determined that, at the time of deposition of the Port Stanley Till, the material under the ice consisted of a slurry composed of rock and mineral particles with about 28 percent to 47 percent water by weight.

It has also been determined that the long axes of the coarse magnetite (>37µ) retain an alignment which was developed by ice movement either englacially or in the slurry at the ice-till interface. The fine magnetite fraction (<37µ) is free to rotate during deposition, and it is this fraction which gives rise to the RM_c of the till.

It is suggested that the slurry at the base of the ice acts as a lubricant and substantiates the concept of basal sliding of glaciers caused by continuous release of water from the base of active glaciers.