Carbonate geochemistry and mineralogy of short cores, Gulf of Suez, Egypt

Abstract

The present paper deals primarily with the mineralogical, geochemical and isotopic characteristics of some modern carbonate sediments recovered from four short cores from the Gulf of Suez off Sukhna. These cores lie between 32° 44′ and 32° 48′ E and 28° 58′ and 29° 16′ N. The paper aims to figure out the various controls on the minerals accumulation in the Gulf of Suez and to evaluate the chemical and isotopic variations in these sediments. Mineralogical investigations reveal the presence of Mg-calcite and aragonite as the dominant minerals with subordinate amounts of calcite and dolomite. The Sraragomite values calculated for the studied cores suggest the mixed origin of aragonite, i.e. it is derived from mixtures of skeletal (mollusks and corals) and nonskeletal. Both Mg and Mn favor the incorporation into the embryonic forms of the biotic and abiotic calcite and Mg-calcite crystals The vertical distribution profiles of Ca, Mg, Sr, Fe, Mn and Ba and also oxygen and carbon stable isotopes in the studied cores exhibit significant relations with the mineralogy. Both elemental values and isotopic signatures of the investigated samples are in accord with the significant role played by biological processes in the production of carbonate sediments in the Gulf of Suez.