Other granitic residuals and uplands - Landforms and Geology of Granite Terrains - page 162

Figure 7.14. General view of Labrador Plateau, north of Schefferville, Province of Québec, Canada, show-

ing scoured granite surface with rounded, part-buried, boulders.

Figure 7.15. Serra do Gerês, northern Portugal/southern Galicia, Spain.

that the region is known as the lake plateau. Nival processes have resulted in such features as alti-
planation benches and patterned ground. But the granitic character of the bedrock finds expression
in unspectacular yet typical granite forms.
The Serra do Gerês, in southern Galicia/northern Portugal, is a massif of Hercynian granites.
Differential weathering of fracture zones has been exploited by Late Pleistocene glaciers, as well
as by Holocene frost and river action. All of the major morphological features are two-stage fea-
tures initiated by subsurface weathering but exposed and brought into relief by glaciers, nival
activity and running water. The straight valleys of the massif reflect major fracture zones, and the
medas or conical residuals also stand in rows in zones of compression ( Fig. 7.10a). Castellated
forms or borrageiros occur in zones of greater fracture density (Fig. 7.15). Roches moutonnées are