MINERALOGICAL AND GEOCHEMICAL STUDY OF EVAPORITE SEDIMENTS FROM LAKE QUAROUN WATER UNDER VARIOUS CONDITIONS OF SALINE WATER CONCENTRATIONS (FAIYOUM - EGYPT)

Abstract

ABSTRACT MINERALOGICAL AND GEOCHEMICAL STUDY ON EVAPORITE SEDIMENTS OF LAKE QUAROUN WATER UNDER VARIOUS CONDITIONS OF SALINE WATER CONCENTRATIONS( FAIYOUM- EGYPT).

The present study deals with the mineralogical and geochemical studies of the evaporite sediments in the Faiyoum Depression (Quaroun Lake). The studied area lies between latitude 29" 26' ·29° 27 N and longitude 30 40', 30 41'E in the Western Desert , north of Faiyoum province at a distance of about 112 km south west of Cairo , in the southern coast of lake Quaroun. The area is hot and dry , rainfall is rare. Thirty three cores were collected from the sediments of the four

successive saline and hypersaline ponds , petrographical and mineralogical studies were undertaken using transmitted light microscopy , scanning electron microscopy and X- ray diffraction. The evaporite sediments of the first pond are characterized by presence of low magnesium calcite and gypsum: however non• evaporate minerals are aragonite, quartz and clay ( montimorllonite, kaolinite and illite). The evaporite sediments in the second pond are characterized by the presence of gypsum and carbonate mud. Carbonate mud is represented as low and high magnesium calcite, however non- evaporite minerals are aragonite, quartz and clay (montimorllonite, kaolinite and illite). In the third pond the evaporite sediments are characterized mainly by the presence of gypsum halite and minor quantities of glouberite, and traces of magnesium