New Mills - Geography

Geography

New Mills is approximately 182 miles (293 km) NNW of London and 8 miles (13 km) south-east of Stockport. It borders on Disley, in Cheshire, and Marple, in the Stockport Metropolitan Borough in Greater Manchester. The town is on the north-western edge of the Peak District, but only a small part of it is included within the boundaries of the National Park. The town includes the hamlets of Thornsett, Hague Bar, Rowarth, Brookbottom, Gowhole, and most of Birch Vale.

At its lowest point the parish is about 120m above sea level, but the valley sides rise to 370m at the highest points above Rowarth. The watercourses to the north, particularly the Rowarth Brook, drain the southward slopes of Mellor Moor, Cown Edge and Lantern Pike. The Sett and its tributary the Kinder drain much of the plateau of Kinder Scout; the Sett flows through Hayfield before passing through Birch Vale to the Torrs and the River Goyt. The Goyt rises on the moors of Axe Edge, near the River Dane and the Cat and Fiddle Inn between Buxton and Macclesfield. It passes through Whaley Bridge, where it is joined by the Todd Brook and the Black Brook from Chapel-en-le-Frith. The sides of the Goyt valley have been used to carry two railway lines, the Peak Forest Canal and the A6 trunk road from London to Carlisle via Manchester; these all pass through New Mills.

Geologically speaking, New Mills lies in the north–south-orientated syncline known as the Goyt Trough. The base rocks are from the Carboniferous period, with underlying Namurian gritstone sandstones, from 333 M a.to 313 M a. Above there are coal measures present (Langsettian from 312 M a.). This was folded in the Variscan orogeny into the Goyt Trough syncline. Coal has been mined at over 30 locations in the area, including Pingot Pit. There are three narrow seams of coal present: the Red Ash, Little Mine and the Yard Seam. The Yard Coal is so named because that is the average thickness of the seam; it is the lowest seam and rests on Woodhead Hill Sandstone. In these seams lead ore has also been extracted. Beardmoor Colliery, Ollersett or Burnt Edge Colliery and Lee or New Mills Colliery all worked the 3 foot (0.91 m) seam. 1 cubic yard (0.76 m3) of coal weighs about half an imperial ton, and the Yard Seam would produce 4500 tons per acre. Bigrave Edge or Broadmoor Edge Colliery worked the Red Ash seam, which was only 18 inches (460 mm) thick.

The syncline was buried in younger rocks of the Tertiary Period. These were eroded, not least by the scouring of the Ice Age ice sheets and the pressures of the meltwaters when temperatures rose. New Mills was on the margins of glaciation, and the meltwaters sought additional routes under the ice for run off. They exploited faults and crevices in the underlying rock. In the Torrs Gorge, the Rivers Goyt and Sett cut a new channel into the strata of the Woodhead Hill Sandstone which forms the centre of New Mills. A mantle of glacial sediment, principally gravels, covered the whole of the braided valleys. In the Pleistocene period, of 12.9 k a to 11.6 k a, the rivers re-formed into single channels, and meanders were formed. These became very distorted above the constrictions of the gorges. Down cutting occurred, exposing previous layers, creating terraces that were covered with silty clay alluvium.