Algoma-, Superior-, and oolitic-type iron deposits of the Islamic Republic of Mauritania (phase V, deliverable 83)

High-grade hematitic iron ores (or HIF, containing 60–65 percent Fe) have been mined in Mauritania from Superior-type iron deposits since 1952. Depletion of the high grade ores in recent years has resulted in a number of new projects focused on lower grade magnetite ores in Algoma-type banded iron formation (or BIF, containing approximately 35 percent Fe). Large deposits of oolitic-type iron ores are also present in Phanerozoic sedimentary rocks in Mauritania. According to recent U.S. Geological Survey figures, Mauritania is the fifteenth largest iron producer in the World and currently has about 1.1 billion tonnes of crude iron ore reserves (USGS, 2012).

The main hosts for Algoma-type iron ore are BIF in: (1) the Mesoarchean rocks of the Tiris Complex and (2) Amsaga Complex, (3) the Mesoarchean Lebzenia Group in the greenstone belts of the Tasiast-Tijirit terrane, and (4) the Saouda Group of the Inchiri district. Neoarchean Algoma-type BIF is present in the (5) Eizzene and Oumachouema Groups of the Inchiri district, (6) the Ijibbitene Group of the Ijibbitene massif, and (7) the Guenieba and Gadel Groups of the Gorgol Noir Complex in the southern Mauritanides. Superior-type iron ores are restricted to the allochthonous Paleoproterozoic sequences of the Kediat Ijil and Guelb El Mhaoudat, which overlie the Tiris Complex. Paleoproterozoic BIF are present in the Sfariat belt, which hosts at least three known occurrences, and at Guelb Zednes, all of which are interpreted as fragments of Superior-type iron formation that have been either imbricated with or allochthonously deposited on the Mesoarchean-Paleoproterozoic suture zone during the Birimian orogeny.

Phanerozoic oolitic ironstones are hosted in the upper Silurian and lower Devonian rocks of the Gara Bouya Ali Group and the Zemmour Group in the Tindouf Basin in northern Mauritania and in the end Ordovician Tichit Group, the Silurian Oued Chig Group, and the lower Devonian Tenemouj Group in the Taoudeni Basin near Tidjikja. These rock groups define 11 permissive tracts for Algoma-, Superior-, and oolitic-type iron deposits in Mauritania.