Erosion Surfaces

Abstract

SINCE Ramsay recognised in 1878 that the even skyline of South Wales represented a plain of marine denudation, uplifted and dissected, upland surfaces of low relief have been recognised in all parts of the world, and their probable relation to the great unconformities of the stratified rock succession has been discussed. Some, following W. M. Davis, have preferred to regard them as sub-aerial peneplains rather than marine features, but few certain criteria exist for distinguishing sub-aerial from submarine surfaces, after uplift and dissection, and each case must be judged on its merits. Recent years have witnessed a concentration of interest upon such features, commonly known as ‘platforms'. In America, the work of the late Joseph Barrell, and of D. W. Johnson, has emphasised the importance of this line of study. A committee of the International Geographical Congress, on which Prof. A. G. Ogilvie is the British representative, is at present seeking to organise the work of mapping erosion surfaces in Europe, using an agreed, though tentative, scheme of symbols. Interest has also been fostered by the publication of Prof. Baulig's recent monograph1 in which high-level platforms are discussed in the context of the daring theory of major eustatic changes of sea-level.