It has been suggested that in prehistoric times, there was a former forest cover in upland areas of Britain, the deliberate clearance of which led directly to blanket peat formation. However, recent investigations of blanket peats in the southern Pennines show numerous pine and birch fragments in the basal peat layers, and also widespread evidence of burning in the form of microscopic carbon particles. It is possible that these fires were deliberately started by the Mesolithic and Neolithic occupants of the area to clear the ground for hunting. Peat formation was advanced when the trees of the area were cut down. Pollen diagrams are included. -- AATA