GEOMORPHOLOGICAL EVIDENCE FOR THE EXTENSION OF THE MEGA-KALAHARI INTO SOUTH-CENTRAL ANGOLA

Abstract

ABSTRACT Linear dune features in south-central Angola have been mapped using recently released Soviet General Staff topographical maps, satellite imagery, aerial photography and limited ground truthing along the Angolan/Northern Namibian border. Analysis indicates that there are a range of relict aeolian features extending as far as 14°E 15°S. In the wetter eastern sector, extensive relict linear dunes (in the order of 200 km in length) are highlighted by vegetation contrasts and a trellis drainage pattern, which feeds into the main southward flowing drainage. In the drier western sector, the linear features are less extensive and appear to have a more direct association with reworked fluvial deposits of the Cuvelai and Cunene drainage systems. These features provide evidence that linear dunes were present over a greater area of the western Mega Kalahari than previously thought (Thomas, 1984). Recent studies in the Caprivi Strip (Thomas et al., 2000) and western Zambia (O'Connor and Thomas, 1999) can be linked to the identified linear features which form a continuation of this northern dune sector, interrupted only by the main drainage channels of the Zambezi, Cuando, Cuito and Cubango Rivers.