Typology of Natural Granite Landscapes

There are two major recurrent themes in geomorphological research into granite landscapes. On the one hand, there is a recognition of the extraordinary diversity of landforms supported by granitic rocks, on a variety of scales, from microrelief on exposed rock surfaces to regional landscape types. On the other hand, there are striking geomorphic similarities between basement regions across the world, noted again at the scale of individual, almost omnipresent landforms, as well as in larger landform assemblages. To account for both diversity and similarity, various attempts have been made to produce a typology of granite landscapes. One of the early systematic approaches was that presented by Wilhelmy (1958) in his Klimamorphologie der Massengesteine. In line with the dominant paradigm in German geomorphology, he was an advocate of strong climatic control on the development of landforms and, accordingly, used climatic zonation of the globe as a basis for his classification system. Seven major morphoclimatic zones with allegedly distinctive phenomena of granite weathering and denudation have been distinguished. In addition, Wilhelmy emphasized climate-controlled change in landform inventories with altitude, citing examples from Corsica, the Sinai Peninsula, and Korea. Following Lautensach (1950), he specifically mentions mountain ranges in the Korean Peninsula, where a dissected landscape typified by deep ferruginous weathering gradually gives way to assemblages typical of harsh periglacial environments as altitude increases. The problem with the climatic approach is the likely co-existence of landforms and weathering patterns of different ages, hence formed in different environmental conditions, especially in middle and high latitudes. In fairness, it has to be said that inherited components have been recognized by Wilhelmy, but the evidence for inheritance is not always conclusive. Selected controversial examples have been presented in the previous chapters. These difficulties also raise a wider methodological issue, if climatic zonation of the globe is to be an appropriate framework to analyse granite landforms. Stoddart (1969) and more recently Twidale and Lageat (1994) offered insightful reviews in this respect, concluding that the uncertainties and limitations of climatic geomorphology are far too many to make it a preferred paradigm. Thomas (1974) adopted a different approach, a morphological one, attempting to identify characteristic granite landform systems.