MAJOR CONTROLS OF METALS’ DISTRIBUTION IN SEDIMENTS OFF THE NILE DELTA, EGYPT

MAJOR CONTROLS OF METALS’ DISTRIBUTION IN
SEDIMENTS OFF THE NILE DELTA, EGYPT
RIFAAT A.E.
National Institute of Oceanography & Fisheries, Alexandria, Egypt.
Keywords: Nile Delta- Sediment – Metals – Factor Analysis
ABSTRACT
The sediment samples that are collected during R/V CHAIN 1975 cruise to the
southeastern Mediterranean have been used to determine the major controls of metals’
distribution. The sediment samples were analysed mineralogically, chemically and
texturally. The parameters measured included carbonate minerals, total carbonate, organic
carbon, iron, manganese, copper, zinc, chromium, lead, nickel, cobalt, vanadium, calcium,
magnesium, strontium, sand, silt and clay. The statistical analysis of data showed that four
major factors control the distribution of metals in sediments of the Nile cone; These are:
Factor 1 terrigenous mud-calcareous sand; Factor 2 Aragonite mud-terrigenous sand; Factor
3 Algal sand; and Factor 4 Aragonite. The percentages of terrigenous sand, mud and
calcareous components of the Nile cone sediments greatly affect the elements spatial
distribution. In addition to that, minor controls such as precipitation and coprecipitation
may affect the elemental distribution. The distributions of iron, manganese, copper, zinc,
chromium, lead, nickel, cobalt, and vanadium are associated mainly with the terrigenous
mud fraction of the sediment whereas, calcium and strontium are mainly related to
calcareous sands. Iron, copper, cobalt, lead and vanadium are partially related to
montmorillonite. Lead is associated with acid feldspars and chromium is mainly controlled
by terrigenous sand. The distribution of calcium and strontium is controlled by the coarsecalcareous fraction of sediments. Magnesium and manganese are associate with algal sand.
The aragonite and calcite minerals are forming the majority of carbonate mud, which
controls partially the distribution of calcium, strontium, lead and copper.