Geology Reference
In-Depth Information
Fig. 7
The remains of mining and the Jerissa village
3.8
Jebel Jerissa Mine (G8, Fig.
2
)
many quarries limestone is being extracted, as in Jebel
Houd, or used for establishing industries such as cement
manufacture in Oum El Klil in the Tajerouine area.
The Jebel Jerissa is an iron ore mine and is an example of
mineralization related in large part to a fossil reef facies
where the palaeogeographical factors have contributed to
controlling mineralization and the development of the mine.
The iron ore has been exploited since 1907. At the begin-
ning, the exploitation was of surface materials but since
1960 ore has been mined from quarries or from under-
ground. Since 1974, the Jebel Jerissa mine is the most
important quarry operating in Tunisia.
The hematite of the iron ore has replaced the carbonates
in the bioclastic limestones of the Serdj Formation that are
composed of fragments of rudists, orbitolines, molluscs and
algae alternating with oolitic layers.
The rocks hosting the mineralization are intersected by a
NE-SW oriented zone of transverse faults along which there
has been replacement of marl limestone by iron minerals.
The mineralization is in lenticular clusters. From 1908 to
1974, clusters of goethite, siderite and oligiste (hematite)
have been exploited, after which the siderite beneath the
hydrostatic level was worked. Other deposits of El Kef area
were exploited to provide ores of lead and zinc as the
deposits of Sakiet-Sidi-Youssef, Touiref, Nebeur, Bou Grine
(blende, galena, calamine, barite,
4
Discussion and Conclusions
El Kef region, located in the northwest of Tunisia, has a rich
and varied geological, palaeontological and cultural heritage.
The geology of the area contains sedimentary formations
deposited on the southern fringe of the Tethys Ocean. These
rocks, most of which are fossiliferous, cover a time period
from the Triassic to the Pleistocene.
The economic aspects of this area deriving from the
applied geology, thermal springs and mineral waters,
dams, mining, phosphate ore mining, and other economic
materials, make it an economically viable region. The
region also re
ects a unique relationship between the
geological, natural, and cultural heritages as it tells a story
of the settlement of men on this site since prehistoric
times, e.g., the Sidi Zin Paleolithic site and Neolithic caves
of Sidi Mansour.
The geological heritage, the landscapes, and the rocks and
fossils are an attraction for tourists and can serve as a basis
for development of scienti
fl
uorite, smithsonite)
(Sainfeld
1952
). Jebel Slata consists also of iron ores in
which a new mineral species, the cesarolite (lead manga-
nate), was rst discovered. The remains of mining and the
Jerissa village are now an industrial archaeological Park
(Fig.
7
). This heritage site has already been largely surveyed
and assessed, and a geo-mining circuit can be established.
The region also has deposits of phosphates in the lower
Eocene (Ypresian) as at Kalaat Khasba or Sra Ouertane. In
fl
c and cultural tourism activities.
Offering geotours, along the cited geosites, will provide a
framework for the development of an eco-sustainable tour-
ism and will be a signi
cant added value to the socio-eco-
nomic infrastructure of the region.
Acknowledgements
The authors thank warmly Dr. Saloua Jeddi
(Entreprise Tunisienne d
'
Activit
é
sP
é
troli
è
res) for her contribution to
the English version and for the reviewers who improved the paper to
make it publishable.
