Slice of Cotham Marble

Description Slice of Cotham Marble  This section of Cotham Marble measures 16.5 cm x 8cm and has been polished on one side, unpolished on the other. The wavy ‘botryoidal’ lines and unique patterns and markings are in a variety of shades of brown, black and also grey. Cotham Marble comes from the Bristol area in Southern England. It was formed during the Triassic period 205 million years ago. The patterns in Cotham Marble were created by Stromatolites in the mud and silt of what was then a shallow sea. At this time, 205 million years ago, Southern England sat close to the equator. Cotham marble is sometimes known as ‘landscape marble’ however technically it isn’t a marble, it is a limestone. Stromatolites are found in layered sedimentary formations. These incredible formations were formed by colonies micro-organisms. They are regarded as the oldest known life form, with the oldest ones billions of years old.  The remarkable patterns are actually the fossilised remains of Stromatolites, they were created over thousands of years. Bacteria such as cyanobacteria getting trapped in the sediment in shallow seas. Some of the oldest examples in Great Britain are in Scotland near Lochinver in the Northwest Highlands. These ones can be seen in the Precambrian-age Torridonian Rocks, these ones are 1200 Million years old. Return to UK Minerals                 Return To Minerals A-Z