Icecap / Ice sheet 4 - East Greenland

As the ice-cap moves down the slope and melts, there are significant amounts of rock particles carried on the surface that accumulate on the lowest slopes. Here you are looking at ice covered in a layer of fine ground rock, the pyramid and ridge-shaped structures are also made of this ground rock and are around a meter high, why they should form liked this puzzled me at least, there was no obvious reason though I'm sure a glaciologist would be able to explain.