ABSTRACT
To some, deserts are simply barren areas, barely capable of supporting life forms. An important feature of the Great Indian Desert is the presence of the snow-fed Indus and its tributaries, both past and present. The discharge pattern is highly seasonal, and floods can be very destructive. Ancient river courses of different ages have been located, and the geomorphology of ancient Indus courses in the Thal doab (between Chenab and Indus) has been described elsewhere. Southern Arabia would have been influenced by the varying strength of the monsoons, and thus it shows a certain similarity of climatic trends to those observed in East Africa and the Thar. The impact of post-Tertiary climates can be appreciated only within the context of plate tectonics and continental drift. Around 50—60 million year BP, Australia began to drift apart from Antarctica, and it migrated northward, drifting to within 4 of its present latitude by the early Miocene.
