The 2012 Olympic flame will travel through Dudley Canal Tunnel on 30th June as it travels around the UK. The Shropshire town of Much Wenlock is sometimes credited with inspiring the modern Olympic movement, so as the flame travels through the tunnel, there will be a less obvious geological connection to be made as well.

The canal tunnels in Dudley were originally dug to extract limestone which could be used in industry. Eventually scientists realised that the limestone in Dudley was similar to that found at Much Wenlock, and contained the same fossils. This further led them to suggest that the rocks formed in the same conditions and at the same time, probably a shallow, warm sea with coral reefs present. Eventually these rocks came to be known as the Much Wenlock Limestone Formation, regardless of where they were found. To a geologist’s eye, Much Wenlock Limestone is very distinctive in appearance.

Favosites - a typical coral from the Much Wenlock Limestone Formation

By searching out occurrences of these same rocks, we can build up a picture of the extent of the sea in which the rocks were laid down – for instance, as well as making up Wenlock Edge, we see Much Wenlock Limestone in Dudley, as far east as the edge of Birmingham, and on the edges of the Malvern Hills. Further east, there was a land mass, and across the Welsh border, the sea became deeper. It was only in the relatively small area between the two where conditions were right to encourage the abundance of life that we see fossilised today.