Correlation of the younger Triassic rocks across eastern England

The younger Triassic rocks of eastern England, traditionally called the Keuper Series, have been correlated in boreholes between Tetney Lock, on the Lincolnshire coast, and the South Nottinghamshire outcrop. In addition the correlation has been extended to Burton-upon-Stather in North Lincolnshire. Wire-line geophysical logs have been the chief means of correlation. The log markers are sub-parallel to the base of the Rhaetic and, excepting the onlapping Keuper-Bunter contact, they are believed to be close approximations to synchronous horizons. The Keuper Sandstone ( Sherlock 1947 ) of the Nottingham area dies out toward the north-east and it is markedly diachronous. A dolomitic facies in more north-easterly boreholes pinches out toward the outcrop and it also is diachronous. The Muschelkalk time-equivalent recognized by Geiger & Hopping (1968) in the Tetney Lock borehole correlates with at least the upper part of the Waterstones, the Radcliffe and the lower half of the Carlton Formations at outcrop • Thus the lowermost beds of the British Keuper Series—the Woodthorpe Formation and possibly part of the Waterstones Formation—are the correlatives of the upper Buntsandstein of Germany, whilst the correlative of the German Keuper is restricted to that part of the British Keuper Series above the middle of the Carlton Formation. A new rock-stratigraphical unit, the Nottingham Group, is proposed to replace the name Keuper Series in eastern England.