Geology Reference
In-Depth Information
8
Minor forms developed on steep slopes
Inselbergs are characteristically steep-sided. In large measure, this reflects the high dip of the
orthogonal fractures that delineate the forms and of the sheeting joints that plunge steeply near the
margins of compartments. In addition, however, the basal slopes of many bornhardts have been
oversteepened by weathering and erosion. In particular, flared slopes and related forms are well-
developed, and many steep slopes are also grooved or fluted.
8.1
FLARED SLOPES
8.1.1
Description and characteristics
Flared slopes are concavities shaped in steeply inclined rock walls. They most commonly occur at
the bases or lower margins of hills and boulders, but are also found high on the slopes of bornhardts
(see Chapter 6). They are up to 12 m high, though most are less than 4 m (Fig. 8.1a). Some of the con-
cavities are so pronounced that the slopes are overhanging (
Fig. 8.2a)
.
In places the concavity is not
simple, but consists of two or three minor flares superimposed on the overall concavity (Figs 8.1a
(a)
Figure 8.1.
(a) Flared slope, some 14 m high, and known as Wave Rock, on northern flank of Hyden Rock,
southern Yilgarn of Western Australia.
