Tonstein Bands in the Coalfields of the East Midlands

Abstract
Kaolinite-mudstone bands, widely recoginzed in the Carboniferous of Western Europe, where they are known as tonsteins, are also represented in Britain. On the basis of the probable correlation eight such bands have so far been found in the Coal Measures of the East Midlands. Laterally two of these bands are thought to pass into rocks intermediate in type between tonstein and more normal Coal Measures mudstones.