Geology Reference
In-Depth Information
Fig. 7 a
and
b
The balconies of Ghou
with villages on the cliffs
above the oasis
With satellite imagery, one of the most wonderful struc-
tures to be observed are the Saharan Atlas mountains that are
a Tertiary intracontinental chain trending NE-SW and
bounded by two major fault lines: the North and South Atlas
Faults. The Saharan Atlas mountains consist of Mesozoic
sequences which are of 3
4 km thick, exceeding 6 km in
some places. This chain is characterized by large folded
anticlines and synclines. The structures are elongated in a
NE-SW direction in the western part and E-W in the eastern
part (Bettahar
2009
). These structures are both spectacular
and educational. Furthermore, the Saharan Atlas is very rich
in geosites of considerable interest, but relatively few are
known in detail. Some of the geosites are described brie
-
Fig. 8 a
and
b
The Djelfa Salt mountain (scale is given by the
geologist in the photo
a
)
fl
y
below.
The Rhou
d), located in the Aures
Massif, is a region with an interesting stratigraphic sequence
from Jurassic to Quaternary (6,000 m thick) in age. The El-
Abiod wadi has carved a spectacular canyon and its cliffs
provide a beautiful view of the small oasis. The terraces of
Ghou
balcony (Fig.
7
a
-
a national heritage site in 1928 and in 2005. The Salt
mountains, which are three mountains composed entirely of
salt, are located in the Saharan Atlas (Gautier
1914
): El
Outaya rock between El Kantara and Biskra is considered to
be the most important one in North Africa (6 km long, 3 km
wide and 300 m high); the Djelfa rock salt (1,500 m in
diameter, Fig.
8
a
, cut into the rock waterfalls, is a location offering an
unusual vista; on each terrace is perched an uninhabited
village which was built 4 centuries ago; the site was declared
d) situated 25 km north of Djelfa, and
Metlili rock (less than 500 m in diameter) located 30 km
-
