Conglomerate, Suffolk

Conglomerate is a rock made up of pebbles that have been transported and rounded by water, either in fast-flowing rivers or on beaches near the high tide mark.

Whilst beach conglomerates tend to be mostly pebbles, those formed in rivers usually have more sand mixed in.

This example, from Suffolk, was deposited by meltwater rivers flowing from the edges of an Ice Sheet that covered northern Britain during the last Ice Age, that ended about 10,000 years ago. At that time, the climate of Suffolk would have been like that of northern Canada today. Some of the pebbles have travelled from as far away as Norway, transported first by ice, and then by water.