Stratigraphical correlation of the Triassic rocks of the British Isles

Abstract

Traditional ideas of the stratigraphical correlation of the British Triassic rocks are reviewed briefly. A revised scheme of stratigraphical correlation is proposed, mainly on the basis of sub-surface information from borings made after 1940. Six principal lithostratigraphical divisions are tentatively proposed. The base of the Bunter Pebble Beds is taken as the base of the Trias, and the top of the Rhaetic is considered to be the top of the Trias. The principal elements in this correlation are the recognition of two major lithostratigraphical units in the Keuper Marl, the recognition of the usefulness and widespread extent of the Waterstones Formation, and the re-interpretation of many borelogs of 'Bunter Sandstone' in terms of two lithostratigraphical units. The stratigraphical correlations suggested in this paper have important implications for the study of the palaeogeography of the Triassic period in Britain.