sentences:  This Westphalian succession includes a sequence with a thickness of more than 1800 m in the west.The Coal Measures were laid down on a low-lying waterlogged plain with peat mires immediately south of an ancient geological feature known as the Wales-London-Brabant High.From late Carboniferous times, through the Permian, South Wales lay on the northern margin of the Variscan orogen, an area affected by a complex continental collision taking place to the south.