Cotham Marble
Cotham Marble or Landscape Marble is a variety of Rhaetian stromatolitic limestone from the Penarth Group, found in south Wales and southwestern England in the area around Bristol, possibly extending to the south coast in east Devon. It is named after Cotham House in Cotham, Bristol. This limestone was used for ornamental purposes, particularly during the Victorian era. On cut and polished faces the stone has the appearance of a landscape, complete with ploughed fields, trees, and hedges.
Occurrence
The beds known as Cotham Marble form part of the Cotham Member of the Lilstock Formation, part of the Penarth Group. They occur as lenses within the upper part of the Cotham Member. The marble is widely but patchily developed within the Cotham Member in its outcrop that extends from Glamorgan in South Wales, through the Bristol area to the coast of southeast Devon.The lenses are typically between 3 and over 20 centimetres thick and are up to 3 metres across. Within each lens there is a basal convex upward layer from which the landscape rises. The 'hedge' layer is about 5 millimetres thick, marked at the top by many small bumps. The 'trees', arborescent structures, extend upwards from the hedge and are relatively constant in height at about 4–5 cm, although somewhat shorter near the lens edges. In most cases the lenses contain only a single layer of the landscape, but two, or exceptionally three layers may be developed, known as double and triple landscape marble respectively, each growing up from the crest of the underlying layer.