II.—Conglomerate at the Base of the Lower Keuper

Abstract

Recent excavations for buildings on the east side of Nottingham have afforded opportunities for observing the true character and development of the conglomerate at the base of the Lower Keuper, which did not exist when this district was visited by the Government Geological Survey. The fact that no fair equivalent of the Muschelkalk of Germany has been met with in England lends an interest to the beds at the junction of the Lower Keuper and the Upper Bunter which they would probably not otherwise possess. Thus the Geological Survey paid special attention to the scanty exposures of this junction that happened to exist twenty years ago in this part. The best section to be seen at that time, near Nottingham, was in a lane leading from the Mansfield turnpike road, a mile north of the town, to the Mapperley Hills, and is thus described by Mr. Aveline in his memoir on the Nottingham district (Sheet 71, N.E.):—“Near the bottom of the lane there are beds of coarse sandstone [Upper Bunter] slightly consolidated, with pebbles of various coloured quartz, quartz-rock, and other sandstones. There is no good bedding visible in this conglomerate, and lying on it there are thin and regularly-bedded fine sandstones of a red colour. This is the bottom of the Lower Keuper beds, and the line between the two formations is well marked, there being an apparent unconformity. There is about twelve feet of this red sandstone, and above it three to four feet of soft red loam, then a thin bed of coarse light sandstone, above this a bed of sand and marl, with some small pebbles of quartz, then alternations of dark and light-brown soft sandstone of various thickness, and red marly shale, which pass up into the Upper Keuper red marly shale with thin beds of white sandstone.”