AUC GEOGRAPHICA

AUC GEOGRAPHICA
AUC Geographica (Acta Universitatis Carolinae Geographica) is a scholarly academic journal published since 1966 that focuses on actual results of research from a wide range of the geographical sciences: physical geography and geo-ecology, regional, social, political and economic geography and regional development, cartography and geo-information, demography and geo-demography. The journal disseminates research results on geographical theory and methodology and also strives to help solve practical problems in Czech regional, socio-economic and demographical policy-making.

AUC GEOGRAPHICA, Vol 54 No 2 (2019), 129–151

Influence of neotectonics on land surface evolution in the upper part of the Blue Nile Basin (Ethiopia): findings from a DEM

Michal Kusák, Vít Vilímek, Jozef Minár

DOI: https://doi.org/10.14712/23361980.2019.13
announced: 26. 08. 2019

abstract

The morphometric analysis of lineaments, valleys and signs of erosion taken from a digital elevation model (DEM) made it possible to not only confirm most of the conclusions of the morphotectonic development of the Blue Nile Basin from the previously published results of structural, petrological, tectonic and geochronological analyses, but also to expand our knowledge by applying several new hypotheses. The relative age of the morpholineaments of particular directions was estimated from the character of topographic profiles. Faults, lineaments and valleys are predominantly oriented in a direction compatible to the published concepts of the tectonic development of the area. Overall, the most abundant NE-SW and NNE-SSW lines reflect a change of extension from a NW-SE to WNW-ESE direction during the Pliocene, in relation to the creation and development of the Main Ethiopian Rift (MER). This is confirmed by a more developed character of the valleys and less pronounced erosion activity of the NE-SW oriented valleys contrary to the deeper narrower NNE-SSW valleys characterised by downward and headward erosion in the second direction. The most pronounced morphological manifestations of the E-W extension of the MER and western Afar during the Quaternary are confined to the borders of the MER. The directions of the Pre-Neogene rift structures to the NW-SE and WNW-ESE are compatible with the oldest elements of the current landscape and with the relict fragments of the valley network on the SE boundary of the upper Blue Nile Basin, which could have been drained across current shoulders of the MER to the S and E before the Late Miocene.

keywords: landscape evolution; neotectonics; river piracy; lineaments; DEM; Main Ethiopian Rift; Ethiopian Highlands

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Influence of neotectonics on land surface evolution in the upper part of the Blue Nile Basin (Ethiopia): findings from a DEM is licensed under a Creative Commons Attribution 4.0 International License.

210 x 297 mm
published: 2 x per year
print price: 200 czk
ISSN: 0300-5402
E-ISSN: 2336-1980

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