Original paper
Inselbergs - exhumed and exposed
Twidale, C. R.
Zeitschrift für Geomorphologie Volume 25 Issue 2 (1981), p. 219 - 221
24 references
published: Jul 15, 1981
ArtNo. ESP022002502007, Price: 29.00 €
Abstract
Granite inselbergs are of several morphological types but it can plausibly be argued that the dome or bornhardt is the fundamental form from which others such as nubbins and koppies are derived (Twidale 1981a). Though bornhardts originate in various ways the field evidence strongly suggests that many, perhaps most, evolve in two stages, the first involving fracture-controlled differential compartment weathering in the subsurface, the second the preferential erosion of the weathered compartments (see Twidale 1980, 1981b, c). The two-stage development of residual boulders has been appreciated for almost two centuries (Hassenfratz 1791; see also Twidale 1978). As regards inselbergs, Mennell (1904) was fully aware of the importance of fractures in their formation, and Falconer (1911: 245-246) gave a succinct exposition of the two-stage concept long before such workers as Linton (1955) and Büdel (1957) rigorously examined and established it in the modern scientific literature.
Keywords
inselberg • granite • bornhardts • weathering • subsurface