1. Geomorphometry-based detection of enhanced erosional signal in polygenetic medium-altitude mountain relief and its tectonic interpretation, the Sudetes (Central Europe).
- Author
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Szymanowski, Mariusz, Jancewicz, Kacper, Różycka, Milena, and Migoń, Piotr
- Subjects
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GEOLOGIC hot spots , *GEOLOGY , *PRINCIPAL components analysis , *PETROLOGY , *MATERIAL erosion , *MOUNTAINS , *MORPHOTECTONICS - Abstract
We explore the assumption that uplift drives erosion and hence, more dissected (eroded) terrains may indicate areas subject to more intense uplift than others, especially if other factors such as elevation and geology can be demonstrated as inconsistent with the spatial pattern of dissection. Geomorphometry and statistics are employed to recognize the enhanced erosional signal within a medium-altitude mountain terrain of the Sudetes in Central Europe, considered as a representative for moderately uplifted areas of complex bedrock diversity. This signal is understood as a meso-scale reflection of relief properties, whereas the recognition of homogeneous terrain units, different in terms of strength of erosional signal, is carried out by means of multi-criteria terrain classification, involving Principal Component Analysis and k-means grouping. Four groups covering 45% of the area have been identified. They were quantitatively compared with independent variables of altitude, lithology, structural units and rock strength, and also assessed in relation to rainfall pattern. It is concluded that their dependence on altitude and geology is only partial. Then, three types of dissected terrain are distinguished and interpreted in terms of uplift intensity, rock strength as a factor modulating erosional response to uplift and timescale. The spatial distribution of these types of terrain indicates several isolated 'hot spots' of erosional dissection on predominantly strong rocks, linked by less elevated areas, underlain by rocks of variable strength. The former are considered as having longer history of uplift and dissection, dated back to the late Palaeogene, whereas the latter record more recent history of endo -exogenic interactions, possibly since the late Miocene. The presence of canyon-like valleys incised into planar or gently sloping relief may indicate the most recent pulse of relief rejuvenation. The procedure proposed in the paper is suitable to be used in various settings, given that good quality topographic data are available. • Areas highly dissected by erosion identified through multi-variate relief classification. • Altitude, lithology and rock strength only partially explain the spatial pattern of dissection. • Different timing of uplift inferred from patterns of erosional dissection. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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