Models of landscape evolution and the survival of Palaeoforms
- Autores: C. R. Twidale
- Localización: Cadernos do Laboratorio Xeolóxico de Laxe: Revista de xeoloxía galega e do hercínico peninsular, ISSN 0213-4497, Nº 22, 1997, págs. 151-182
- Idioma: inglés
- Títulos paralelos:
- Los modelos de evolución del paisaje y la supervivencia de paleoformas
- Enlaces
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Resumen
Qne of the factots rnitigating against the recognition and acceptance of very old palaeosurfaces was, and in sorne rneasure rernains, the tacit acceptance of some of the better known rnodels of landscape evolution. Thus both the steady state and peneplanation rnodels imply virtual contemporaneity of surface, and though scarp retreat allows for a greater age, the rnaxirnurn is deterrnined by the duration of a cycle, probably of the order of 33 Ma; rnuch younger than rnany firmly dated epigene surfaces.
Basically landforrn and landscape persistence involves the stability, or only slow rate of change, of surfaces (divides) of bounding scarps, or both. Such slow rates of change are induced by such factors as resistant bedrock: hence the preservation of rnany palaeoforrns on quartzites, etc. In addition, several rnechanisms, such as uplift, through drainage, and consequent local "aridity"; incision and unequal activity; and reinforcernent or positive feedback rnechanisrns, enhance the persistence of surfaces.
