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The sediment stratigraphy of a flood event: An example from the Sabie River, South Africa

Author:
Knight, Jasper, Evans, Mary
Source:
Catena 2017 v.151 pp. 87-97
ISSN:
0341-8162
Subject:
floods, national parks, organic horizons, rivers, sediments, stratigraphy, South Africa
Abstract:
The geomorphic effects of river floods in various climatic settings worldwide have been extensively described, but there is little information on sedimentary processes during and immediately following flood peaks. Here we reconstruct sedimentary processes and patterns of the 2012 flood on the Sabie River in Kruger National Park, South Africa, from the preserved geomorphic and sedimentary signature of this event. Based on a combination of geomorphic and sedimentary evidence, the maximal and waning flow stages of the flood event are identified, shown by cut and fill and fining up sequences within aggradational bars, and organic horizons, which may be buried, that correspond to the period of flood peak recession. The presence of organic horizons suggests a strongly seasonal flow regime typical of semi-arid South African rivers. It also provides an exemplar of a flood event stratigraphy that is usually poorly preserved in the geologic record.
Agid:
6109648