3358 x 5036 px | 28,4 x 42,6 cm | 11,2 x 16,8 inches | 300dpi
Data acquisizione:
agosto 2005
Ubicazione:
Cleveland uk
Altre informazioni:
Cleveland Ironstone consists of a seriese of deposits varying in thickness and depth below ground. These seams can be found beneath much of East Cleveland and at one time there were dozens of working mines at places like Eston, Upleatham, Skelton and Liverton. The topmost deposit of Ironstone can outcrop on the surface and is known as the "top steam" or "dogger seam". This tends to be extreamly viable in quality an thickness. Beneath this at a depth of around 70 meters is the "main seam", the most reliable and consistent deposit which can be up to 4 meters thick. Just below this lies the "pecten" or "shelly " seam named after the amount of fossils found in the stone. This is a more minor seam at approximatly 1.5 meters thick. At a short distance beneath this is the "two foot seam" which was often confused with the pecten seam. The deepest level worked was the "avicula seam", named after a characteristic fossil. This was mainly exploited at the south of the ore field in the Grosmont area where the main deposit is interspersed with bands of shale making it uneconomic to extract.