Equatorial Guinea is a small nation of 1.2 million located on the west coast of Central Africa which gained independence from Spain in 1968. Thanks to the discovery and exploitation of significant oil reserves in the 1990s, it enjoys a purchasing power parity GDP per capita of more than US$38,699 which is as of 2016 the highest in Africa and the 31st highest in the world. However, the country has been ranked only 138th out of 188 countries on the United Nations Human Development Index in 2015. After the oil price collapsed in 2014, the economy has gone into a free for all which has put growth in a downwards spiral from around 15% to −10%.
The geology of the Falkland Islands is described in several publications. The Falkland Islands are located on a projection of the Patagonian continental shelf. In ancient geological time this shelf was part of Gondwana, which around 400 million years ago broke from what is now Africa and drifted westwards relative to Africa. Studies of the seabed surrounding the islands indicated the possibility of oil. Intensive exploration began in 1996, although there had been some earlier seismic surveys in the region.
The geology of Egypt includes rocks from Archaean - early Proterozoic times onwards. These oldest rocks are found as inliers in Egypt’s Western Desert. In contrast, the rocks of the Eastern Desert are largely late Proterozoic in age. Throughout the country this older basement is overlain by Palaeozoic sedimentary rocks. Cretaceous rocks occur commonly whilst sediments indicative of repeated marine transgression and regression are characteristic of the Cenozoic Era.
The geology of Djibouti consists largely of volcanic rocks from the Miocene to Holocene epochs. There are more recent alluvial deposits with coral on the coast, as well as Cenozoic sedimentary. Amba Aradam Sandstones from the Jurassic Period are found in the southeast of the country.
The geology of Algeria is diverse; the country divides into three different tectono-stratigraphic domains. In the south and west is the West African Craton which consists of Precambrian granitic basement and surrounding Neoproterozoic mobile belts. Further south the Tuareg Shield comprises the Hoggar, Adrar des Iforas and Air sub-shields which have each been affected by tectono-thermal events touching much of the continent. In the north are the Alpine chain mountains with a succession of folded and over-thrusted strata.
The geology of Angola includes large areas of Precambrian age rocks. The west of the country is characterized by meta-sedimentary rocks of Proterozoic age including tillites assigned to the Bembe System. Overlying these are a thick pile of limestones and other marine sediments laid down during the Mesozoic and Cenozoic eras. Amidst the Proterozoic sequence are areas of crystalline basement dating from the Archaean. More Archaean basement rocks form the Kasai Craton in northeastern Angola. In the north, within the Cassanje Graben are clastic sediments and volcanic rocks of the Karoo Supergroup. Kimberlites and carbonatites resulting from magmatic activity during the Karoo period are found along a northeast-southwest line through the country. Continental sediments of the Kalahari Group are widespread in eastern Angola.
The geology of Benin in West Africa includes the north-northeast trending Proterozoic Dahomeyide orogen in the north and a range of Cretaceous to Holocene sedimentary rocks in the south, separated very closely by the 7th latitude. Neogene alluvial deposits extend across Benin’s northeastern border with Niger. In the Togo and Benin regions, the following rock types have been identified: metasandstones, schists, metasilexites, metasiltstones, metaconglomerates, metatillites, carbonate rocks or marbles, ultramafic rocks, metajaspillites, metahematites, quartzites, quartz schists, micaschists, gneisses, migmatites, amphibolites, granites, charnockites, eclogites, metabasalts, calc-silicate rocks and pyroxenites.
The geology of Burkina Faso is dominated by Precambrian rocks of the Guinea Rise, a dome of Archaean rocks, composed largely of migmatites, gneisses and amphibolites, over which lie the greenstone belts of the early Proterozoic age. The latter are metasediments and metavolcanics assigned largely to the Birimian Supergroup, a suite of rocks in which economically significant mineralization occurs. Pre-Birimian migmatites, gneisses, and amphibolites, located under the Birimian rocks, are the oldest rocks in the country. The Birimian deposits in the southwestern part of the country are typically divided between clastic and volcano-clastic formations.
The geology of Eritrea in east Africa broadly consists of Precambrian rocks in the west, Paleozoic glacial sedimentary rocks in the South and Cenozoic sediments and volcanics along the coastal zone adjoining the Red Sea. The Precambrian rocks been involved with the orogeny process, which is when a section of the Earth's crust is deformed to form a mountain range. Mesozoic sediments in the Danakil and Aysha horsts, which are raised blocks of the Earth's crust that have been lifted, were deformed. The older rocks include meta-sediments and older gneissic basement belonging to different Proterozoic terranes. Mesozoic sediments of marine origin occur in the coastal area along the Red Sea. A number of thin Miocene age basalt flows occur within the sediments of this zone whilst the basalts of the Aden Series date from Pliocene to Holocene times, some being extruded at the time of a major phase of uplift and rifting during the Pleistocene.
The geology of Rwanda comprises Mesoproterozoic metasediments, largely quartzites, sandstones, and shales of the Burundian Supergroup which are locally intruded by granite. There are four types of granite in the Kibaran Belt. In eastern Rwanda are the “older granites” along with granitic-gneisses and migmatites of Palaeoproterozoic age. In the northwest and southwest are Neogene volcanics, ranging in age from Cenozoic to recent. Some of the volcanoes in the area are highly alkaline. Alluvium and lake sediments of Quaternary age occur in parts of the Western Rift and along rivers and lakes.
The geology of Burundi consists largely of metamorphic rocks of Proterozoic age with inliers of basement rocks of Archaean age. The former are metasediments of the Burundian and Malagaarasian Supergroups which are of Meso- and Neoproterozoic age, respectively. Granites intrude the rocks from the Burndian Supergroup along a 350 km zone of mafic and ultramafic intrusions. Just like Tanzania, the Malagarasian Supergroup has Neoproterozoic rocks. The top of this group contains the Kibago Group, which consists of sandstones, quartzites, shales, and a basal conglomerate.
The geology of Madagascar comprises a variety of rocks of Precambrian age which make up the larger part of the east and centre of the island. They are intruded by basalts and rhyolites of Mesozoic to Cenozoic age. In contrast, the western part of the island is formed from sedimentary rocks of Carboniferous to Quaternary age. Archean rocks occur from the northeast portion of the island down to the south in the Ranotsara shear zone. Rocks in the northern portion of Madagascar are greenstone belts, from the Archean or Paleoproterozoic age.
The geology of the Republic of the Congo, also known as Congo-Brazzaville, to differentiate from the Democratic Republic of the Congo, formerly Zaire, includes extensive igneous and metamorphic basement rock, some up to two billion years old and sedimentary rocks formed within the past 250 million years. Much of the country's geology is hidden by sediments formed in the past 2.5 million years of the Quaternary.
São Tomé and Príncipe both formed within the past 30 million years due to volcanic activity in deep water along the Cameroon line. Long-running interactions with seawater and different eruption periods have generated a wide variety of different igneous and volcanic rocks on the islands with complex mineral assemblages.
The geology of Cameroon is almost universally Precambrian metamorphic and igneous basement rock, formed in the Archean as part of the Congo Craton and the Central African Mobile Zone and covered in laterite, recent sediments and soils. Some parts of the country have sequences of sedimentary rocks from the Paleozoic, Mesozoic and Cenozoic as well as volcanic rock produced by the 1600 kilometer Cameroon Volcanic Line, which includes the still-active Mount Cameroon. The country is notable for gold, diamonds and some onshore and offshore oil and gas.
The geology of Ivory Coast is almost entirely extremely ancient metamorphic and igneous crystalline basement rock between 2.1 and more than 3.5 billion years old, comprising part of the stable continental crust of the West African Craton. Near the surface, these ancient rocks have weathered into sediments and soils 20 to 45 meters thick on average, which holds much of Ivory Coast's groundwater. More recent sedimentary rocks are found along the coast. The country has extensive mineral resources such as gold, diamonds, nickel and bauxite as well as offshore oil and gas.
The geology of South Sudan is founded on Precambrian igneous and metamorphic rocks, that cover 40 percent of the country's surface and underlie other rock units. The region was affected by the Pan-African orogeny in the Neoproterozoic and extensional tectonics in the Mesozoic that deposited very thick oil-bearing sedimentary sequences in rift basins. Younger basalts, sandstones and sediments formed in the last 66 million years of the Cenozoic. The discovery of oil in 1975 was a major factor in the Second Sudanese Civil War, leading up to independence in 2011. The country also has gold, copper, cobalt, zinc, iron, marble, limestone and dolomite.
The geology of Eswatini formed beginning 3.6 billion years ago, in the Archean Eon of the Precambrian. Eswatini is the only country entirely underlain by the Kaapvaal Craton, one of the oldest pieces of stable continental crust and the only craton regarded as "pristine" by geologists, other than the Yilgarn Craton in Australia. As such, the country has very ancient granite, gneiss and in some cases sedimentary rocks from the Archean into the Proterozoic, overlain by sedimentary rocks and igneous rocks formed during the last 541 million years of the Phanerozoic as part of the Karoo Supergroup. Intensive weathering has created thick zones of saprolite and heavily weathered soils.
The geology of Sudan formed primarily in the Precambrian, as igneous and metamorphic crystalline basement rock. Ancient terranes and inliers were intruded with granites, granitoids as well as volcanic rocks. Units of all types were deformed, reactivated, intruded and metamorphosed during the Proterozoic Pan-African orogeny. Dramatic sheet flow erosion prevented almost any sedimentary rocks from forming during the Paleozoic and Mesozoic. From the Mesozoic into the Cenozoic the formation of the Red Sea depression and complex faulting led to massive sediment deposition in some locations and regional volcanism. Sudan has petroleum, chromite, salt, gold, limestone and other natural resources.
The geology of Nigeria formed beginning in the Archean and Proterozoic eons of the Precambrian. The country forms the Nigerian Province and more than half of its surface is igneous and metamorphic crystalline basement rock from the Precambrian. Between 2.9 billion and 500 million years ago, Nigeria was affected by three major orogeny mountain-building events and related igneous intrusions. Following the Pan-African orogeny, in the Cambrian at the time that multi-cellular life proliferated, Nigeria began to experience regional sedimentation and witnessed new igneous intrusions. By the Cretaceous period of the late Mesozoic, massive sedimentation was underway in different basins, due to a large marine transgression. By the Eocene, in the Cenozoic, the region returned to terrestrial conditions.
