Denudation Surfaces

Denudation Surfaces

 

(surfaces of denudation planation), level or slightly undulating surfaces that were smoothed out by exogenous processes during a period of the protracted stabilization of the denudation base and that cut rocks of varying ages to the same level. A necessary condition for the formation of denudation surfaces is the compensation of tectonic manifestations by processes of denudation and aggradation. In mountainous regions where there have been repeated changes in the denudation base, several denudation surfaces of varying ages may be formed, which can often be reconstructed only from fragments such as mountain peaks and crests of uniform elevation. The denudation surfaces are always younger than the latest rocks, in terms of the period of their formation, cut by the given surface. Denudation surfaces include peneplains, pediplains, and equiplains.

References in periodicals archive ?
According to recent speleothem datings, the oldest denudation surfaces in the Tatras cannot predate the latest Miocene (Glazek, 1996).
This paper uses the elevation-relief ratio to constrain the horizontal and vertical extent of sub-horizontal denudation surfaces in Wales, United Kingdom.
Key words: sub-horizontal denudation surfaces, elevation-relief ratio, SRTM data, ESRI ArcMap, Wales.
Many such studies are underpinned by the identification and correlation of sub-horizontal denudation surfaces, despite numerous controversies surrounding this field of research (e.g.
The overall aim of the present paper is to demonstrate the value of the elevation-relief ratio as a geomorphological tool, which is able to analytically identify sub-horizontal denudation surfaces within heavily dissected landscapes; therefore, the elevation-relief ratio may be applied in a diverse range of geological and tectonic settings beyond the passive continental margin of northwest Europe.
Elevation-relief ratio values generally range between 0.15 and 0.85, with clustering between 0.40 and 0.60 (Pike & Wilson 1971); therefore, in this paper it is considered that elevation-relief ratio values between 0.00-0.40 and 0.60-1.00 both represent sub-horizontal surfaces, but that only those values between 0.60-1.00 represent sub-horizontal denudation surfaces as it is these that are characterized by a generally convex morphology.
those areas with elevation-relief ratio values of d"0.40 and e"0.60), whilst the maps presented in column (ii) depict only the areas defined as sub-horizontal denudation surfaces through the application of the elevation-relief ratio (i.e.
In order to constrain the vertical extent of any sub-horizontal denudation surfaces, altitude-frequency histograms have been constructed (Figure 7).
Despite the differences in horizontal surface area described in the previous section, changing the size of the circular neighbourhood does not have a marked influence on the altitudinal range occupied by sub-horizontal denudation surfaces; however, such surfaces do become progressively more pronounced as the size of the circular neighbourhood increases.
In this study four sub-horizontal denudation surfaces are shown at lower elevations in the altitude-frequency histograms; the prominence of these surfaces decreases with elevation.
The overall aim of this paper was to demonstrate the value of the elevation-relief ratio as a geomorphological tool, which is able to analytically identify sub-horizontal denudation surfaces within the heavily dissected landscape of Wales.
It is very difficult to reconcile the results described here with the tripartite classification of Brown (1960); in that study, evidence was presented for the existence of three widespread sub-horizontal denudation surfaces at between 210-330 m asl, 365-485 m asl, and 515-575 m asl.