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Climatic Geomorphology
Most texts differentiate two overall categories for glacial erosion modelling, dividing
them into smaller and larger forms. This distinction is, however, not very realistic due to
the wide dimensional interval occupied by some of them.
2.1. Striations, grooves and glacial polishing
Friction of particles at the glacial base during movement over the rocky bed produces
erosive actions on it that become apparent as scratches, grooved forms and polishing of the
rocky substrate surface. This action implies extraction of particles from the rocky bottom
that incorporates them into the glacier.
One of the most common forms are striations or straie (Fig. 3.3), which are fine aligned
grooves generally not much more than a metre long and a few millimetres wide and deep.
Striations develop more easily in fine grained rocks and disappear when being exposed for
long to weathering agents. In limestones this disappearance is very fast due to dissolution.
So, on the slopes of the limestone pavement of Ingleborough in northern England,
striations cropping out by removal of a glacial till are removed after about 10 years
Figure 3.3. Glacial striations. Santa Elena Fort, Head of G~illego River, Aragonese Pyrenees.
Climatic Geomorphology
Most texts differentiate two overall categories for glacial erosion modelling, dividing
them into smaller and larger forms. This distinction is, however, not very realistic due to
the wide dimensional interval occupied by some of them.
2.1. Striations, grooves and glacial polishing
Friction of particles at the glacial base during movement over the rocky bed produces
erosive actions on it that become apparent as scratches, grooved forms and polishing of the
rocky substrate surface. This action implies extraction of particles from the rocky bottom
that incorporates them into the glacier.
One of the most common forms are striations or straie (Fig. 3.3), which are fine aligned
grooves generally not much more than a metre long and a few millimetres wide and deep.
Striations develop more easily in fine grained rocks and disappear when being exposed for
long to weathering agents. In limestones this disappearance is very fast due to dissolution.
So, on the slopes of the limestone pavement of Ingleborough in northern England,
striations cropping out by removal of a glacial till are removed after about 10 years
Figure 3.3. Glacial striations. Santa Elena Fort, Head of G~illego River, Aragonese Pyrenees.