Stoney Furlong and Chedworth Valley Geology and Landscape Trail isbn 9781904530107 The old quarry and railway cutting known as Stony Furlong exposes part of the White Limestone (Great Oolite Group), and Chedworth Valley is one of many deeply incised valleys of the Cotswolds, fed by springs emanating from the limestones in the valley sides. The trail explores the uses of local stone, from building and roofing, to aggregate and walling.