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Shoulder uplift of the Western Ghats passive margin, India: a denudational model
Author(s) -
Gunnell Y.,
Fleitout L.
Publication year - 1998
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/(sici)1096-9837(199805)23:5<391::aid-esp853>3.0.co;2-5
Subject(s) - geology , escarpment , denudation , rift , lithosphere , craton , geomorphology , continental margin , paleontology , structural basin , tectonics
The paper presents a denudational rift flank uplift model of the Western Ghats of Karnataka, India. The Cenozoic denudation of the Deccan plateau was constrained by relative dating of regional planation surface levels, in combination with preliminary apatite fission track results. The denudational history of the Western Ghats escarpment coastal foreland was constrained both by onshore fission track and offshore sediment data. Methods are briefly described. Results were used as reference data to elaborate a computer simulation model of both flexural rift flank upwarp and escarpment retreat from the K/T boundary to the present. Depending on the assumptions concerning the attributes of the thin elastic lithospheric sheet (infinite or semi‐infinite), the shape and elevation of the initial Deccan topography (flat‐lying, or affected by lithospheric updoming due to the Reunion mantle plume) and the position of the continental divide upon rifting, the flexural response to denudational unloading is shown to yield either a concave‐up flexure of the Dharwar craton, or a convex, monoclinal downwarp of the margin. The relative merits of each model are discussed in the light of auxiliary field evidence, particularly from the neighbouring Deccan traps. However, the diverse assumptions on boundary conditions fail to entirely avoid geomorphological equifinality. © 1998 John Wiley & Sons, Ltd.