Paragenesis
in carbonate intercalations within Phosphorite sequence, Kharga-Dakhla Oases, Egypt
Samir A. Awad and H. H.
AlOtaib1
Geology Dept., Fac. Sciences, Ain Shams Univ., Cairo, Egypt, 1Khalid
Academy, Arriyadh. |
The carbonate units intercalating the main phosphatic sequence in Kharga-Dakhla Oases are
of six lithofacies. They indicate inner and outer neritic to lacustrine, drained swamps
and shallow near shore marine environments. Calcite, dolomite and siderite are the main
carbonate minerals identified in these rock types. Diagenetic processes in the phosphorite
carbonate units include: Fossil cavity fillings, pore and mold fillings, grumeleuse
texture, compaction, ferroan calcite veinlets, brown and colorless silica replacement and
dolomitizatloin. The time relationships of these processes are also discussed.
|
|