Evolution of Landforms Over the Nilgiri, South India

Two relict levels of erosion over the Nilgiri are recognised within a polycyclic and polygenetic planar Nilgiri surface. Landform study suggests a pediment cycle for the Ootacamund landforms, the younger of the two relict landforms. The older Dodabetta landforms now stand as vestiges of the original ground at higher elevations. Climate might have been less humid over a major part of this region during the period of pedimentation (post-Miocene) compared to earlier and later times. The Quaternary lowering of temperature in Pleistocene and subsequent warming up of climate are likely to have resulted in the formation of swampy courses, alluvial tracts and peaty subsoils along certain streams over the Nilgiri.