The Intermontane and Insular Coalfields of British Columbia also contain deposits of Cretaceous bituminous coal. Coal mined in the South Yorkshire coalfields was brought by rail and exported through Grimsby. The opening of the coalfields made N&W prosperous and Pocahontas bituminous coal world-famous. Most of the coal produced from Northern Coalfields Limited is dispatched to pithead power plants. Most of the coal from the East Kootenay coalfields is exported to Japan and Korea. The South Wales Valleys hosted Britain's only mountainous coalfields. Bituminous coal is present in most of Britain's coalfields and is 86% to 88% carbon. Following Japanese industrialization additional coalfields were discovered northern Japan. Bilaspur is also the headquarters of South Eastern Coalfields Limited. ONGC is doing exploration work in South Karanpura Coalfields for CBM. The violence-prone areas of Ireland corresponded to areas of violence in the Pennsylvania coalfields. Throughout the entire county there are vast and important coalfields. Many coalfields were developed in the industrial revolution. Large shovels were built for the Ohio open pit coalfields. This brought the route into proximity with enough coalfields to provide a regular profit.