Moradi Formation | |
---|---|
Stratigraphic range: Lopingian ~ | |
Type | Geological formation |
Unit of | Izégouandane Group |
Sub-units | Lower, Middle and Upper Units |
Underlies | Teloua 1 Formation |
Overlies | Tamamaït Formation |
Thickness | 100 metres (330 ft) |
Lithology | |
Primary | Mudstone, siltstone |
Other | Sandstone, conglomerate |
Location | |
Coordinates | 18°48′N7°12′E / 18.8°N 7.2°E |
Approximate paleocoordinates | 16°36′S8°12′E / 16.6°S 8.2°E |
Region | Agadez Region |
Country | Niger |
Extent | Iullemmeden Basin |
The Moradi Formation is a geological formation in Niger. It is of Late Permian age. It is informally divided into three subunits. The lower portion of the formation consists of red mudstone, with muddy calcareous sandstone and quartz-granlule conglomerate present as lenses. The middle portion consists of muddy siltstone in thick beds interbedded with red argillaceous sandstone. The lower two thirds of the upper portion of the formation consist of red siltstone intercalated with channel lag intraformational conglomerates, while the upper third consists of barchanoid shaped lenses of conglomeratic sandstone with ventifacts. [1] These facies are indicatived of deposition under arid conditions, with less than 300 millimetres (12 in) of annual rainfall in the Central Pangean desert, with annual temperatures of 30 to 35 °C (86 to 95 °F), but with ephemeral water presence including lakes. [2]
The formation is known for its fossils, including the temnospondyls Nigerpeton [3] and Saharastega, [4] [5] the pareiasaur Bunostegos, [6] the captorhinid Moradisaurus , [7] as well as a large indeterminate gorgonopsid. [8] Dicynodonts, widespread in other contemporary deposits, appear to be absent, with previous reports being in error. [8] The flora of the formation includes indeterminate voltzian conifers. [9]