Geology of the Wolverhampton and Telford district : sheet description of the British Geological Survey 1:50000 series sheet 153 (England & Wales)

This Sheet Description provides an account of the geology of the district covered by Geological Sheet 153 Wolverhampton. The district extends from the edge of the Black Country conurbation in the south-east, to Telford in the west, and includes a large tract of rural Green Belt on the Staffordshire–Shropshire borders. The solid rocks at outcrop range from Precambrian to Triassic in age. The oldest rocks, pyroclastic tuffs, originated in an island-arc setting in south polar latitudes; the youngest are continental red-beds that formed in inland sabkha environments, when Britain lay just north of the equator. Although the geological record spans about 560 Ma, the modern landscape has been shaped largely by geological processes that operated during the last two million years. Successive glaciations have modified the landscape, and the superficial deposits of till and glacial outwash that blanket much of the district are the product of a Late Devensian glaciation. The Ironbridge Gorge and other meltwater channels also date from this period. Since the ice retreated about 13 000 years ago, the postglacial history has been one of drainage development, valley incision and terrace aggradation. The district has a long industrial heritage dependent, until recently, on the mineral wealth of the Carboniferous rocks exposed in the South Staffordshire and Coalbrookdale coalfields. During the 18th and 19th centuries, settlements grew and prospered as industries were established, founded on a plentiful supply of coal, clay, ironstone and limestone. The relicts of these industries have left parts of the district with a legacy of difficult ground conditions, aspects of which are described in the applied section of this report. Today, mineral extraction is of less importance but brickclay, fireclay and some opencast coal are still produced, and the Triassic conglomerates are an important source of aggregate. The Permo–Triassic rocks of the Stafford Basin hold important groundwater resources from which large volumes of water are abstracted for public supply.