Geograph - photograph every grid square

For context, see NS3679 : Carman Quarry, in which this large stone appears below the centre of the image.

The upper part of the stone, displaying this unusual pattern, measures about 1.3 metres from side to side, and about 1 metre from its lower to its upper end. Its surface here would originally have been smooth, as in the lower left section of the photograph, but some layers have fallen off, exposing a network of ridges.

This rock was formed by the deposition of sand on mud cracks; it has therefore preserved, in the form of a natural cast, the shape of those cracks. A larger and more impressive example can be seen, lying flat, not far away: see NS3678 : Traces of ancient mud cracks.

I have not encountered any reports of these features elsewhere, but they are an interesting geological curiosity.