Sedimentological and mineralogical characteristics of khors sediments, Lake Nasser, Egypt

Sedimentological and mineralogical characteristics of khors sediments,
Lake Nasser, Egypt
Nazeh Naguib Gindy
National Institute of Oceanography and Fisheries, Aswan, Egypt
Abstract
Thirty-two surface sediment samples were collected from eight major khors (El-Ramla, Kalabsha, WadiAbyad, El-Allaqi, Singari, Korosko, Tushka and Or) along Lake Nasser to study the sedimentological and
mineralogical characteristics of the northern, middle and southern khors sediments. The observed lateral variations
in grain size characteristics and its parameters are attributed mainly to the characteristics and the nature of source
rocks surrounding the studied khors. Sand fractions (63 – 125 μm) were separated from the studied sediments. The
heavy minerals content reflects a deficiency in pyroxenes and an enrichment of epidotes and amphiboles. This may
confirm the effect of local contribution of these minerals from the surrounding country rocks. The insignificant
lateral and seasonal variations in the calculated hydraulic fractionation indices, induced by the predominance of a
provenance factor rather than a hydraulic fractionation factor. The observed variations in the transportation indices
values, attributed mainly to the effect of local source from the surroundings of the studied khors. The clay minerals
are mainly represented by kaolinite, smectite and traceable amounts of illite. The formation of clay minerals in the
studied khors sediments is due to the weathering of the local country rocks.
Keywords: Lake Nasser, khors sediments, heavy minerals, clay minerals