Environmental Engineering Reference
In-Depth Information
Plate 15.5
Large-scale abraded rock surfaces alongside the
Findelen glacier, Switzerland (top left), with typical abrading
tools during (top right) and after (bottom) extended abrasion.
Photos: Ken Addison.
Small tools abrade semi-continuous grooves until they wear out. Larger tools may,
through their weight, be held less firmly over small bedrock concavities and strike
intermittent chips or
chatter marks
out of the substrate (Plate 15.6). Surface abrasion
lowering rates of 1-4 mm a
−1
(the low range of which exceeds that of fluvial abrasion)
