sentences:  Now the Wilmslow Formation (part of the Sherwood Sandstone Group), the lower Triassic was previously a threefold division, the Lower Mottled Sandstone, The Pebble Beds and the Upper Mottled Sandstone (only the later is seen at Alderley), which merged into the Conglomerates of the upper Triassic.The Upper Mottled Sandstone – now the lower Wilmslow Member – is a medium- to coarse-grained friable false-bedded sandstone with abrupt colour changes from bright red to white.It is composed mainly of rounded grains but sub-angular grains also occur.