大象传媒

The deflation of the upland limestone landscape by slow solution weathering is demonstrated at Norber in the Yorkshire Dales. Limestone is dissolved very slowly over a period of time. Erratics at Norber are boulders of gritstone standing on a plinth of limestone. The boulders protect the limestone from chemical weathering. The depth of the limestone indicates how long the weathering has taken. Thanks to Ordnance Survey.