Sedimentary
and chemical nature of Recent sabkhas, central part of Red Sea coastal zone, Egypt
Mahmoud M. Hassaan, I
Hassanein1, A. Abu ElEzz1 and A. Mousa1
Geology Dept., Fac. Sciences, EIAzhar Univ., Cairo,
and 1Exploration Dept., Petroleum Research Inst., Cairo, Egypt. |
Sedimentary, heavy mineral and geochemical studies were carried out on the recent coastal
sabkha sediments at Marsa Urn Tunduba, Marsa Sefein, Wadi Abu Dabbab and Wadi Homra in the
central part of the Red Sea coastal zone, Egypt.
The sediments are chiefly calcareous sandstones, argillaceous sandstones, calcareous
claystone and claystone. Gypsum and anhydrite are present in the basal parts of the
successions while halite encrustations mostly occur in the topmost part.
The heavy mineral assemblages and the relative abundance of ultrastable minerals indicate
that these minerals were derived from sedimentary (Upper Cretaceous to Pleistocene),
igneous rocks (basic to acidic), and metamorphic rocks.
The vertical distribution of the major elements oxides and trace elements is controlled by
the abundance of the clastic, clay, carbonate and evaporate minerals. Regarding the total
organic carbon amount, they are impoverished except in the topmost halitic bed of Marsa
Sefien sabkha. Moreover, the organic carbon amount in each sabkha is related to the amount
of clay and evaporite minerals which reflect various degrees of sabkhaization of the
studied recent examples. A model of hydrodynamic processes forming these evaporite sabkhas
shows the effect of both sea water and meteoric water in developing these sabkhas.
|
|