... Group, the Akouta uranium deposit is hosted by the Guezouman Formation, which is composed of fluvio-deltaic sandstones, in particular, organic-rich channel formations ( Forbes 1989 ; Cavellec 2006 ). The Arlit deposit is found in the Tarat Formation of the Tagora Group, which contains fluvial...

... ). The Tagora unit consists of four fluvial sandstone formations: the Guezouman, Tarat, Madaouela and Arlit formations. The Guezouman and Tarat formations are separated by the thin Tchinezogue formation formed during a marine transgression event. Both the Guezouman and Tarat formations host uranium deposits...

... of about 1200 m and hosts several world-class deposits of uranium. They are located in the Visean Guezouman Formation for the deposits mined underground by Cominak near Arlit (44 000 tonnes U), and in the Namurian Tarat Formation, mined by open pit by Somaïr near Akokan (50 000 tonnes U), 50 km...

...Thierry Sempere; Bernard Beaudoin GeoRef, Copyright 2013, American Geosciences Institute. 1984 Africa Arlit Niger Arlit Unit Carboniferous depositional environment lithostratigraphy Middle Mississippian Mississippian Namurian Niger paleoclimatology paleoenvironment Paleozoic...

... ) on all continents. Distal tectonic events induced the migration of diagenetic fluids within the basins or the infiltration of meteoric waters. Deposits of this style that are hosted by Carboniferous strata, such as the tectonolithologic deposits of the Arlit district in Niger, have Mesozoic to Cenozoic U...

... high grade of the Arlit district deposits with more than 100,000 t U at about 0.3%. For the Lodève hydrothermal-diagenetic deposit of tectonolithologic type, in France, Ahmadach et al. [1993 ] have also determined the parent magma chemistry and initial U content of the volcanics ash layers which...

...% of these dollars ( Energy Information Administration, 1989 ). Included in these expenditures was 3.01 million ft of drilling. Exploration drilling in search of new deposits or extensions of known deposits was 43% of the total. Development drilling, which defines the size, shape, and grade of deposits and provides...

... (2005) and Z aouia (2007) identified salt crystals (gypsum and halite) in the calcarenite pores, revealing atmospheric pollution, mineral deposition, soil moisture, the groundwater, runoff, and irrigation return through capillary suction all being influences that contribute to degradation processes...

... total deposits known; IAEA, 2016 ) and represent a group that is closely linked to the introduction of land plants in the Silurian Period worldwide (e.g., Lodeve, France; Akouta and Arlit, Niger; Wyoming, USA).The Domiasiat-Wakhyn deposits of Meghalaya, India belong to this group with substantial...

...Figure 6 Composition of chloroform extracts from different uranium deposits. ‘Polars’ and ‘Aromatics’ are more oxidized than ‘Saturates’. Pipes- breccia pipes, Grand Canyon Area, Arizona, Lodeve- Lodeve, France. Arlit- Arlit-Akouta, Niger. Utah- Temple Mountain, Utah. Vosges- Vosges, France...

... the existence of a continuous sedimentary realm until the Early Carboniferous ( Bertrand-Sarfati et al. 1991 ; Legrand-Blain & Perret-Mirouse 2000 ). On top of the Palaeozoic formations, unconformable horizontal Mesozoic–Cenozoic formations are observed. The oldest Mesozoic deposits are Early Cretaceous...

... original minimal extent of sedimentary deposits beyond their present-day erosional limits. Mapping is based on a compilation of published original data on the stratigraphy and depositional environments of sediments, structures, magmatism, and low-temperature thermochonology, as well...

.... The mineralization is primarily controlled by sedimentologic features which define the flat-shaped mineralized bodies. The deposit is however quite different from the Colorado Plateau-type mineralizations (absence of vanadium, more proximal setting), and more similar to the Arlit district deposits in Niger (similar...

... SUDAN (DRC) of Democratic Republic of Congo (DRC) s exports in the years leading up to independence in 1960. The country possesses a wide range of minerals, the most important of which are copper, cobalt, diamonds, and gold. Signi cant deposits of zinc, germanium, tin, tungsten, columbium-tantalum...