Page:Cornwall; Cambridge county geographies.djvu/28

 12 CORNWALL geological structure. Granite formation, slate rock, sand- stone, limestone, chalk all have their special characters, unmistakable. When we are among the granites in the west of England we expect a tent-like shape of hill with a tor of rock at the summit ; the sides strewn with a St Keyne's Well, Liskeard "clatter" of fallen rock, and clothed in heather and furze. When we come to the slates, and the overlying cold clays, we expect little except in the gorges and valleys cut through the strata by the streams. Of sandstone, or of chalk, form- ing breezy rolling downs, there is none in Cornwall, nor of limestone with its bold scars, such as are met with in