Red sandstone, Shropshire

To left, red sandstone hand specimen. The image below shows red sandstone in close up, with the constituent grains clearly visible.

Red sandstones like this are found in several parts of England. They are made of small, rounded sand grains, and frequently show slanting beds (cross-bedding), like the ones in the photograph below. The wind-blown dunes in deserts like the modern Sahara have rounded grains and large scale cross bedding just like this.

When these sands were deposited 250 to 200 million years ago (Permian and Triassic times), Britain must have had a hot desert climate.

The porous red sandstones of the Midlands are an important source of groundwater, especially for brewing beer! The red colour is due to iron oxide cementing the grains together.