Davisian Theory: The most popular theory of landform development was given by American geomorphologist William Morris Davis. His concept of geographical cycle or commonly known as cycle of erosion provided a genetic classification and systematic description of landforms. However, Prof. The main premises of Penckian model of landscape development are the following: 1. On the basis of morphological characteristics tectonic movements can be explained and their causal factors ascertained. Development of landscape is not time- dependent.
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Etchplanation involves 2 processes namely deep weathering followed by exhumation. Deep weathering refers to rapid chemical weathering and this causes rock paricles to further disintegrate into even smaller particles. This occurs when rainwater enters cracks and crevices in rocks thus exposing the rock to greater surface area of weathering.
This process of deep weathering occurs during the warm pliocene period and results in a deep layer of weather materials. Exhumation or removal of weathered materials happens during periglacial times due to flash floods or solifluction.
Hence, this can expose the basal surface of weathering the limit to weathering- from completely weathered rocks in the upper layers to unjointed basal suface. Outcrop in the basal surface that is exposed in the surface is formed as inselberg.
In places whereby there are orthogonal joints, tors may be formed after repeated process of etchplanation. This will exposed corestones that are more resistant to weathering due to more spacious jointing that stack on top of one another to form heaps of boulders m high. Spheroidal weathering may occur on the side of the corestones form of exfoliation resulting in the rounded nature of the core stone.
Etchplanation involves 2 processes namely deep weathering followed by exhumation. Deep weathering refers to rapid chemical weathering and this causes rock paricles to further disintegrate into even smaller particles. This occurs when rainwater enters cracks and crevices in rocks thus exposing the rock to greater surface area of weathering. This process of deep weathering occurs during the warm pliocene period and results in a deep layer of weather materials.
PEDIPLANATION THEORY EPUB
He explained the evolution of south African landscape through a cycle of erosion. He stared his study over the arid, semi arid and savana region of south Africa. This region is characterised by extensive plain area along with some uplifted landscape, scarp and eroded place, which he has given name as Pediplanation. Pediplanation refers to the remarkable surfaces of planation, surrounded by isolated hills and piles of boulders. Thus, L.
7 Major Geomorphic Theories of Landform Development
Mikree He tried to explain the formation of laccoliths resulting from vulcanicity during his field studies by applying the concept of tneory. The alternate freeze and thaw of moisture results in expansion and contraction which pediplanation theory disintegrates rocks along the joints. He clearly enjoyed working on the landscapes of the province of Natal as it then was and published journal articles pediplanation theory Pdiplanation and its coast, coastal Natal and on Durban, as pediplanation theory as his book, The Natal Monocline: Longitudinal dunes are separated by reg or hammada—sand-free bare surfaces. He formulated a set of cyclic models such as landscape cycle, epigene cycle, pediplanation cycle, hillslope cycle, etc. McKee categorised dunes as pediplanation theory dome dune, ii barchan, iii barchanoid, iv transverse dune, v parabolic dune, vi linear dune, vii reversing dune with two slip faces, and viii star dune. There is continuous migration retreat of hillslope and such retreat is always in the form of parallel retreat. This article about geography terminology is a stub.