Minor forms developed on gentle slopes - Landforms and Geology of Granite Terrains - page 208

(a)

(b)

Figure 9.3. (a) Subaerial differential weathering of minerals of the side wall of a pit developed on granodior-

ite from Monte Louro (Galicia, northwestern Spain), showing pitted surface (see pp. 71-73).
(b) Shallow saucer-shaped pan on Yarwondutta Rock, northwestern Eyre Peninsula, South
Australia, showing large fragments remaining in pool after being released by the weathering of
the surrounding granite to form grus or granite sand.

along wavy planes of dislocation, and with results similar to those induced by rock plastification
and consequent late weathering (Vidal Romaní, 1989).
Many basins have formed along or at the intersection of fractures and fissures, and some are
elongated along the fracture plane ( Figs 9.5a and b; also Fig. 9.2a) . Others, developed in structurally
complex country rock, have irregular outlines as a result of the exploitation of various fractures
(Fig. 9.5c). The original depression may be irregular in shape, but moisture attack tends to produce
rounded forms of considerable perfection because of the concentration of weathering, whether by
water or by frost action, on projections of rock.