SHROPSHIRE (Salop), a county of England on the Welsh border, bounded north by Cheshire and a detached portion of Flint, east by Staffordshire, south-east by Worcestershire, south by Herefordshire, south-west by Radnorshire, west by Mont gomeryshire and north-west by Denbighshire. The name Salop, in common use, comes from an early name of the county town of Shrewsbury (q.v.).
Towards the west Shropshire is hilly, while nearly all the county south of the Severn is upland. This comprises the Long Moun tain and a small part of the conspicuous Breidden group in the west, the Shelve hill lines, Longmynd (1,696 ft.), the Caradoc range, and Wenlock Edge (i,000 ft. to 1,200 ft.), with Clun Forest in the south-west, the Clee hills in the south-east, and the Wrekin (1,335 ft.). The Wrekin is an isolated hill north of the Severn. The pre-Cambrian series of rocks are represented here and in the adjoining Ercall hill (granitoid and gneissic rocks) and again in the line of "hog-backs" including Lawley and Caradoc running south-west. These consist of volcanic lavas and tuffs, and are, with the Wrekin, among the oldest hills in the British Isles. Next in point of age come the conglomerates, grits and shales of the Longmynd. The mass of these well consolidated rocks makes a flat-topped plateau of 4 or 5 sq.m., which faces the Caradoc hills across the Church Stretton valley. Cambrian rocks succeed hard quartzites and sandstones, with soft shales (Shineton Shale) which have been eaten out to form the hollow west of Longmynd. The Ordovician system is represented by the resistant quartzites of the Stiperstones, the volcanic ashes of Shelve Hill, the grits of Snailbeach, the sandstones of Hoaredge and a few intrusions of volcanic rocks.
Silurian rocks outcrop in the shape of a horseshoe around the mountain mass from Stiperstones to Caer Caradoc, being represented by mudstones in the smoothly contoured Long Moun tain, whose slopes, nevertheless, have deep hidden dingles, by sandstones and shales in the Clun Forest and by the mudstones of Wenlock and Ludlow, with the interstratified limestones of Wenlock and Aymestry which form an unbroken scarp for 17 m. in the remarkable Wenlock Edge. This is in reality a double
ridge made of two "edges," the higher and eastern of which is sometimes called View Edge. The steep scarps of both "edges" look to the north-west, and are densely clothed with woods of beech, oak, elm and hazel, while the gentler "dip-slopes" are arable and pasture.
Old Red Sandstone outcrops in the Clee hills (Titterstone Clee 1,749 ft. and Brown Clee 1,792 ft.) which stand so high because they are covered by layers of the next division of rocks, the Carboniferous, here protected in turn by a capping of hard igneous intrusive dolerite known locally as "Dhu-Stone." The Old Red Sandstone group also has extensive out-liers at Clun and Bettws-y-Crwyn among the Silurian rocks of the south-west of the county.
The Carboniferous Limestone and Millstone Grit of the Den bighshire coalfield enter the county near Oswestry in the north west lobe, and end in the conspicuous cliff of Llanymynech hill, overlooking the Vyrnwy and Severn flats. They also appear at Lilleshall and Coalbrookdale on the west border of the eastern coalfield, and include the little coalfield of Titterstone Clee.
Elsewhere in the Hanwood, Coalbrookdale and Forest of Wyre coalfields these lower rocks are absent, and the Coal-Measures rest directly on Silurian, Ordovician and Cambrian rocks. The Coal-Measures, with their coal seams and bands of ironstone, are of great economic importance. Triassic deposits, laid down in a lake whose south shore was not far from the present border of "the Upland," cover most of north Shropshire. An island of Longmyndian rock (Haughmond Hill) and a peninsula of coal measures (from Coalbrookdale to Lilleshall) outcrop from these sandstones, marls and conglomerates. Around Wem and Prees is a capping of Liassic clays, while outcropping conglomerates or breccias form the hills of Nesscliff, Pim Hill, Grinshill and Hawkstone. Over much of the plain, glacial deposits—boulder clay, gravel and sand—are spread. Some peat bogs in the drif t covered region towards the Cheshire border appear to occupy the sites of lakes, of the type of the meres of the Ellesmere district, in the irregular morainic material.