الفهرس 
Mineralogic and Petrorraphic Studies of the Evaporite and non-Evaporite Sediments from Saline and Hypersaline PondsOnly 14 pages are availabe for public view
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Abstract
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” 261 · 29° 27’ N and
longitude 30° 401 , 30° 411 E in the Western Desert, north ofFaiyoum 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
haractcrizcd 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 traces of magnesium calcite, however non- evaporite minerals arc quartz and clay ( montimorllonite,
kaolinite and illite). The fourth pond evaporite sediments are characterized by the presence of
glouberite, thenardite and halite mainly, gypsum , allenite and leonhardrite as minor. However non-
evaporite minerals are quartz and clay ( montimorllonite, kaolinite and illite).
Chemical analyses of lake Quaroun water , and the various saline and
hypersaline ponds understudy were analyzed and discussed. The present study revealed
that the average salinity values of the successive solar ponds water increase from
60.7 g./1. In the first pond to maximum value in the fourth pond which attains to 357g./l., the
average salinity value is of about 123 g./1. and 244g./l. respectively in
the second and the third pond.
The values of the ion concentrations and molecular ratios reflected
2
the type of mineral precipitation. Such these ratios , mMg+
2
/mCa+ ,
CI”/S04-2 and niNa•/Mg•2• the postulated flow diagram revealed that the la!<e Quaroun water and
type of the brine of the fourth pond are
Cl , Na, Mg and S04 brine.
The behaviour of the major ions in the studied brine such as , cr ,
2
ca•2 , S04-2 , HC03-& C03-
and pH were discussed.
Parameters affecting forming evaporite of artificial saline and hypersaline ponds also
discussed.