Geological structure and mineral resources of Algeria The hydrocarbon System Ourd Mya is located in the Sahara Basin. It is one of the producing basins in Algeria. The stratigraphic section consists of Paleozoic and Mesosoic, it is about 5000 m thick. In the eastern part, the basin is limited by the Hassi-Messaoud high zone which is a giant oil field produced from the Cambrian sands. The western part is limited by Hassi R`mel which is one of the biggest gas field in the world, it is produced from the triassic sands. The Mesozoic section lays on the lower Devonian and in the eastern part, on the Cambrian. The main source rock is Silurian shale with an average thickness of 50 m and a total organic matter of 6 % (14 % in some cases). Results of maturation modeling indicate that the lower Silurian source is in the oil window. The Ordovician shales are also a source rock but in a second order. Clastic reservoirs are in the Triassic sequence which is mainly fluvial deposit with complex alluvial channels, it is the main target in the basin. Clastic reservoirs within the lower Devonian section have a good hydrocarbon potential in the east of the basin through a southwest-northeast orientation. The late Triassic-Early Jurassic evaporites overlie the Triassic clastic interval and extend over the entire Oued Mya Basin. This is considered as a super-seal evaporate package, which consists predominantly of anhydrite and halite. For Paleozoic targets, a large number of potential seals exist within the stratigraphic column.
Geological map on:http://www.mem-algeria.org/hydrocarbons/fig4.htm
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Mining activity is secular in Algeria and more than 30 minerals have been identified. The well known deposits are of iron, salt, zinc, lead, barite, marble,...in addition to other deposits discovered like gold, wolfram-tin, who constitute a mining potential to exploit or explore in the future, and promising indices for diamond, rare earths, precious and semi-precious stones.
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Algerian mining potential comprises the following substances:
1 - DIAMOND
Prospection was carried out in Reggane area where a placer was find with 1500 grains of diamond. Exploration and surveying works are undertaken in this area and aim to find the primary source especially in the West African craton.
2 - IRON.
The big potential is located in the South-west part of the country and has 3.5 milliard tons of reserves grading 57% Fe. The deposits are Mecheri Abdelaziz and Gara Djebilet located at 250 km Eastward Tindouf.
The potential of the Northern part of the country is valued at 70 million tons, 60 million tons in Ouenza and Boukhadra areas and 12 million tons in Djebel Hanini-Setif area grading 60% Fe.
3 -. GOLD
Gold deposits are basically located in the southern part of Algeria in the Hoggar area.
- Tirek deposit located at 400 km from Tamanrasset city, geological reserves are evaluated at more than 730,000 tons grading 18 g/t.
- Amessmessa deposit located at 460 km west of Tamanrasset, geological reserves are estimated at 3.38 million tons with an average grade of 18 g/t.
- Tiririne-Hanane deposit located at 450 km East of Tamanrasset, geological reserves are appraised at 481,000 tons with an average grade of 17 g/t.
- In Abegui deposit in stockwork forms with reserves of 2,807,000 tons and grade of 3.59 g/t.
The reserves highlighted are about 100 tons.
As for the total potential, it is estimated at more than 200 tons.
4 - DECORATIVE STONES AND FURTHER
The identified decorative stones areas are:
- Oued Madakh serpentine deposit (Oran region),
- Hassi Ghala travertine and limestone deposit (A"in Témouchent region),
- Tén`es limestone deposit (Chlef region),
- Dhar El Mendjel black limestone deposit(A"in Témouchent region),
- Djebel Dyr nummulitic limestone and flint deposits (Tébessa region),
- Djebel Def black limestone (Tébessa region),
- Gypsum flower and silicified wood (Gharda"ia, Ouargla and Béchar region).
These deposits are characterised by a variety of colours, a homogeneous habitus, a shiny polish, and are easily accessible from the county town; mining conditions are favourable for an open cast method.
For semi-precious and precious stones, an inventory has been listed in the Hoggar in 1993 and 1996 by ORGM (National Bureau for Geological and Mining Research). This surveying showed 60 indicators comprising beryl, corundum, topaz, zircon, turquoise, piezo-quartz, kyanite, fluorite and decorative stones (agate, chalcedony).
5- LEAD-ZINC.
Lead-zinc potential is evaluated at 150 million tons of ore mainly situated in the North. Perspectives are oriented for developing Oued Amizour lead and zinc deposit (11% Zn and 3.2 % Pb with an average thickness of 49 m).
6- BARITE.
It is found essentially in the atlasic areas, some deposits are developed and other are in production with an annual output of 40,000 tons, primarily for drilling.
7 - BENTONITE.
It comes from the volcanic basins of tertiary formations in the western part, in Maghnia and Mostaganem areas; these occurrences are located near port and are accessible by road or by train. Bentonite production covers widely drilling needs. Some amounts are exported to the oil countries. The country possesses many potentialities for industrial development.
8 - SALT.
Salt reserves are important and are represented by :
- Salt rocks evaluated at 1 milliard tonne.
- Laguna salt with reserves of 1.5 milliard tons in annual renewable drifts in South-East Algerian salt pans.
These reserves can be enhanced by development of salt industry in terms of production and processing.
Big amounts can be intended to exportation.
9 - KAOLIN.
Four economic deposits have been identified in Tamazert, Sidi Ali Bounab, Chekfa and Djebel Debbagh areas. The production is limited and the exploitation of this substance can be improved.
10- PHOSPHATE.
Actual reserves are evaluated at 2 milliards tons, localized in Djebel Onk phosphated basin (Tebessa) and can be developed by open cast way with a maximum stripping ratio of 1/4.
These reserves represent only a part of the phosphate basin.
11 - DIATOMITE.
Many deposits exist near Mohammadia and Mostaganem towns. Their production is limited and can be developed.
12- DOLOMITES.
The country possesses a great number of deposits of this substance.
13 - FELDSPAR.
A"in Barbar deposit reserves are of 7 million tons. The exploitation of this deposit is imminent.
14 - FLUORITE.
Many indicators are located in the North in gangue form in the metallic substances deposits but the output is not important.
In the Hoggar, two districts have been defined:
- A"it Oklan deposit at 150 km from Tamanrasset with 1,220,000 tons of ore grading 30%. Total reserves are appraised at 226,500 tons,
- Dehine indicator, 150 km from Tamanrasset with preliminary results giving 2000 tons of fluorite.
15 - WOLFRAM-TIN.
The potential is estimated at 123.6 tons of wolfram and 36.6 tons of tin, located in the Hoggar massif.
16- URANIUM.
An important potential has been located in the Hoggar massif.
17 - RARE EARTHS (Niobium, Tantalum, Rubidium).
The potential is estimated at :
- 13,76 tons of ore grading 0,02 % Tantalum,
- 4,12 tons of ore grading 0,006 % Niobium ,
- 133 tons of ore grading `a 0,187 % of Rubidium.
18 - GRANITES.
The granite potential for decorative stones is widespread in Algeria. Colors varied, the possibilities of exploitation of this substance exist.
19 - GYPSUM.
The country possesses a big potential of gypsum suitable for building materials (plaster), delay cement, and agricultural applications. The most important deposits are Dahra (Chellif area), Djebel Chegga, Mostaganem, Arzew, Sidi Bel abb`es, Habouch (Mina Mountains) and Babors areas. Available informations are poor but gypsum is a common mineral in the Mediterranean area.
20- PERLITE.
It exists in the volcanic and sedimentary rocks near Maghnia area. It can be exported from local ports. Deposits are located near road and railway networks and can be exploited by open cast mining.
21- TALC.
Indicators are located in the East of the country, The hypothetical reserves vary from 200.000 to 600.000 tons for each index.
More on:http://www.mem-algeria.org/english/index.php?page=geologie-des-provinces-petroliere-en-algerie
http://www.mem-algeria.org/english/index.php?page=potentialites
ZDROJ: Ministére de l´énergie et des Mines de l´Algérie, leccos.com, citeseerx.ist.psu.edu
