Split and cracked blocks and slabs - Landforms and Geology of Granite Terrains - page 266

(a)

(b)

Figure 11.11. (a) Plan of Wudinna Hill, Eyre Peninsula, South Australia, showing major fractures (heavy-

postulated, light-mapped) and location of A-tents and related forms. (b) Plots showing orien-
tation of crests of A-tents at two sites on northwestern Eyre Peninsula, and for all of the area.

11.3.2 Overlapping slabs
On the northwestern midslope of Wudinna Hill there is an overlapping slab consisting of a plate of
granite, the upper end of which is raised and overlaps another that forms the adjacent upslope sec-
tion of the hillside by about 300 mm ( Fig. 11.14). The two irregular edges of the raised and the flat
slabs are disposed roughly normal to the surface and match perfectly, suggesting that they were
once juxtaposed.

11.3.3 Displaced slabs
Perhaps the most spectacular example of a displaced slab is developed on Little Wudinna Hill,
near Wudinna, northwestern Eyre Peninsula, South Australia (Twidale, Schubert and Campbell,
1991). Here, a triangular sheet some 410 mm thick and 9 m long has slipped some 8.5 m down
a 16° slope, coming to rest against the steepened and flared lower slope of the hill ( Fig. 11.15a).