The geology of Benin in West Africa includes the north-northeast trending
Proterozoic
The Proterozoic () is a geological eon spanning the time interval from 2500 to 538.8million years ago. It is the most recent part of the Precambrian "supereon". It is also the longest eon of the Earth's geologic time scale, and it is subdivided ...
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
to
Holocene
The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s in the south, separated very closely by the 7th latitude.
Neogene
The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...
alluvial deposits
Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...
extend across
Benin
Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north ...
’s northeastern border with
Niger
)
, official_languages =
, languages_type = National languages
Economic geology
In northwestern Benin, gold is mineralized in conglomerates of quartzite of the Togo Group. In addition to
artisanal
An artisan (from french: artisan, it, artigiano) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art ...
gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
mining, geological materials for industry and construction are mined. In Goumpere, nickel, copper, chromium, and cobalt have been detected by the observance of geochemical anomalies. Additionally, 123 million tons of limestone have been observed in the Oueme district which could be used for cement and lime. There is also 33 million tons of sandstone available that could be used for ballast. Uranium and iron ore have been discovered in the region as well.
Benin has been extracting crude oil since the 1990s, the majority of which comes from the Seme Field. More onshore exploration continues. There is an estimated 1.09 Mt of crude petroleum and 1.1 billion m3 of natural gas.