Flared slopes revisited

Flared slopes are smooth concavities caused by subsurface moisture-generated weathering in the scarp-foot zone of hillslopes or boulders. They are well represented in granitic terrains but also developed in other massive materials such as limestone, sandstone, dacite, rhyolite, and basalt, as well as other plutonic rocks. Notches, cliff-foot caves, and swamp slots are congeners of flared slopes. Though a few bedrock flares are conceivably caused by nivation or by a combination of coastal processes, most are two-stage or etch forms. Appreciation of the origin of these forms has permitted their use in the identification and measurement of recent soil erosion and an explanation of natural bridges. Their mode of development is also germane to the origin of the host inselberg or bornhardt and, indeed, to general theories of landscape evolution. But certain discrepancies have been noted concerning the distribution and detailed morphology of flared slopes. Such anomalies are a result of structural factors (sensu lato), of variations in size of catchment and in degree of exposure, and of several protective factors. Notwithstanding, the original explanation of flared slopes stands, as do their wider implications. © 1998 by V. H. Winston & Son, Inc. All rights reserved

The study of desert dunes in Australia

AbstractMost of the early explorers were bewildered by the features they encountered in the Australian deserts, but Sturt's observations led him to speculate on the origin of the sand ridges that were so much a part of his desert experience. Scientific investigations of the dunes, however, awaited the twentieth century. In the 1930s Madigan made signal contributions to the understanding of the features, but he also raised as many problems as he resolved. Post-war investigations by King and those due to Wopfner, initially related but incidental to the search of oil and gas, have done much to clarify the dynamics of dune development. More recently, luminescence dating has allowed the sand ridges, as well as periods of lake fill and alluviation, to be dated with some confidence. Chronological research has been extended to include the major palaeodunefields of southern Australia.C. R. Twidal