|
Widan el Faras
|
|
The Widan el Faras basalts (nearby of the Fayoun oasis) are to be found between
the Oligocene Qatari Formation (below) and the Miocene Khashab Formation (above).
The thickness of the basalts was measured between 20 and 35 m. The type locality
of the Widan el Faras basalts is located at the Widan el Faras hills (upper
area of the Gebel Qatrani). Petrographical and chemical investigations prove,
that the basaltic flood originate from a tholeiitic magma (saturated with
silica). This magma is climbed-up along a fissure during the Oligocene age.
The basalt has a consequence of three different floods. The both first floods
are lenses - like. The third flood is massive and freshly preserved. It forms
an edge at the uppermost area of the Qatrani steep slope.
Further areas of flood basalts in north- and middle-Egypt are distributed.
They are concentrated in the region of Cairo, are found however also in the
Bahariya depression
and western to southwestern of it. |
|
Geomorhological structure
The
Widan el Faras basalt quarries, 20 km southwest of Umm es Sawan, are considered
the source of stone used on the mortuary temple floors and walls of 4 th and
5 th Dynasty (c. 2575 – 2323 BC) pyramid complexes.
|
Fayoum flood basalt area from space
|
|
Stratigraphical positions
|
|
|
|
|
Down slidden basalt blocks
|
dito
|
| |
|
|
Map of all basalt floods in the northern
part of Egypt
|
Remarkable is the age of all
basalt flows. The dates fluctuate between
32 and 23.5 Ma in the Oligocene age. It agrees with the dating of other subvolcanic
and orthomagmatic-hydrovolcanic structures in the Gilf Kebir,
in the White and Black
Desert as well as the Libyan
Desert Glass location. All structures are placed on a line, which proceeds
from southwest to northeast. Can we suppose here a connection between continental
drifting and a Hot Spot? |
