The Geology of North Africa

A summary of the geology of North Africa is given in this introduction. North Africa stands in a peculiar position that has enabled the record of a protracted history since the Archean. After the Proterozoic assembly of different cratonic nuclei, the newly formed supercontinent Gondwana underwent a Paleozoic–Mesozoic story that repeatedly weakened and dismembered its northern margin. Before Phanerozoic, the end of Neoproterozoic undoubtedly affected the northern Gondwana margin, but the extent of the Cadomian crustal reworking remains to be ascertained. Paleozoic cycles of Rheic and Paleo-Tethys openings rhythmed the deformation of this Gondwana margin until the opening of the Tethys (Maghrebian Tethys to the west or Neo-Tethys further east). Although the associated 3D plate kinematics of these paleo-configurations have been refined for a decade and provide significant constraints, unambiguous evidence is still lacking on many points. For instance: (1) the Variscan model for NW Africa is still debated on how it correlates with the Variscan-Alleghanian belt; (2) the age of Paleo-Tethys opening remains a matter of debate; (3) the Maghrebian/Neo-Tethys crustal natures and space extensions are still poorly known. These are a few of the questions that are still pending regarding this rich and fascinating geological story recorded in North Africa that will still provide exciting and stimulating works for decades to come. We hope that this short introduction will interest and stimulate the readers curious about this part of the world where there is still a lot to do.

This chapter provides insight and understanding into the upper mantle and lower crust of North Africa. Much study, throughout the last few decades, has been conducted on the deep structures and upper mantle of Africa. The continent’s geology is complicated, with multiple rift valleys, mountain ranges, and volcanic provinces. According to seismic investigations, the African continent possesses a thick lithosphere, which is thought to be a relic of ancient cratons that have remained constant for billions of eons. Recent seismic tomography research papers have revealed new details about the structure and behavior of the African mantle. Many mantle plumes, including the well-known African Superplume, have been discovered under the continent as a finding of this research. These plumes are believed to have played a significant and affected role in the creation of the continent’s massive igneous provinces and rift systems. In addition to mantle plumes, the African mantle has a variety of mantle domains with contrasting temperature and compositional properties. These domains are thought to have acted an essential role in the creation and evolution of the continent’s lithosphere, as well as in determining mineral resource distribution. Generally, Africa’s deep structure and upper mantle are distinguished by a complex and dynamic geology that has played an important role in defining the continent’s history and development. Continuing study provides fresh insights into the processes that have produced this interesting area, advancing our identification of the structure and dynamics of the Earth’s mantle.

The 3,000 km long and 2,000 km wide West African Craton exposed as the Leo-Man Shield in the south and the Reguibat Shield in the north, covered by Taoudeni, Iullemeden, and Volta basins, represents one of the largest outcrops of Precambrian orogens worldwide. Based on a review of published geophysical, petrological, geochemical, geochronological, structural, metamorphic, and metallogenic data, we propose an evolving geodynamic scenario covering the period from the Archean (~3.5 Ga) until the Mesozoic (~90 Ma). The Archean domains of both the Leo-Man and Reguibat shield (~3.5–2.6 Ga) are predominantly built of high-grade gneisses and magmatic rocks interpreted as resulting from hot-Earth geodynamic processes. The Paleoproterozoic domains (~2.35–1.9 Ga) are built of juvenile volcanic rocks with some zones (e.g., eastern Ghana, boundaries between the Archean and Paleoproterozoic domains), which show isotopic and geophysical signatures of reworked Archean crust. A large amount of data suggest a transitional plate tectonics setting characterized by volcanic arcs, cold metamorphic gradients, and rapid burial and exhumation of supracrustal rocks, important changes in orientation of stress field during the Eburnean orogeny as well as the occurrence of metal deposits characteristic for volcanic arc settings. However, some characteristics of hot orogens documenting the transitional character were also revealed: the greenstone-tonalite-trondhjemite-granodiorite-like granitoid domains, deep-seated subvertical craton-scale network of shear zones post-dating the principal accretion period, or the absence of ultrahigh-pressure metamorphism. The Pan-African orogenic belts (~0.8–0.58 Ga) surrounding the West African Craton show clear evidence of subduction/continental collision geodynamic setting. After the Pan-African orogeny, only local mantle-derived magmatism crosscutting older crust was reported in a form of doleritic dykes, kimberlite diatremes, and alkaline intrusions with no evidence for tectonic reworking of the Precambrian crust.

There is general agreement that the Neoproterozoic Pan-African Orogeny played a significant role in the formation of the Greater Gondwana (Pannotia or Vendian Supercontinent). At the end of this orogeny (~540 Ma) several ocean basins closed during convergence and collision between cratons, microcontinents, and island arc terranes, yielding several complex transcontinental deformation belts between the cratons. These deformation belts are well-represented in the >3000 km-long Trans-Saharan Orogenic Belt (TSOB), which separates the West African Craton (WAC) from the Saharan Metacraton (SMC) in West Gondwana. Two major collages of multiply deformed polymetamorphic cratonic, intermediate, and juvenile crust span the full width of the TSOB. These are the Tuareg Shield of Algeria-Niger-Mali, and Nigerian-Benin Shield to its south. Detailed studies of these two shield areas have revealed the numerous stages and processes involved in the 750–550 Ma collision between the WAC and SMC. The main topic of this chapter is a review of the Tuareg Shield, with summaries of the many terranes that compose it, and of the sequence of events that formed it. These facts are compiled in a discussion of the origins and significance of the TSOB.

In Northeast Africa, a greenschist to lower amphibolite facies dominated collisional Pan-African belt extends along the Western flank of the Red Sea. The belt is known as the Egyptian Nubian Shield (ENS) in Egypt. The ENS represents the northern tip of the Arabian-Nubian Shield (ANS) and exhibits most of the essential lithological/structural features of the Midyan terrane exposed in western Saudi Arabia. The low-grade ANS was regarded as the upper crustal equivalent of the high granulite facies-dominated Mozambique Belt (MB), with both forming the N–S oriented East African Orogen (EAO), which formed during a ~200 Ma prolonged stage of closure of the Pacific-sized Mozambique Ocean, and convergence of East and West Gondwana that culminated in arc suturing and terrane accretion. The main objective of the present chapter is to introduce the ENS belt exposed in Northeast Africa. The Neoproterozoic ENS litho-units are typically juvenile and experienced a polyphase deformation history. Following this introduction, the setting of the ANS in Northeast Africa, the broad relations of the ANS with the EAO, and the tectonic components of the ANS will be addressed with reference to their lithotectonic associations, geochemistry and geochronology, and structural and tectonic framework. The chapter provides an opportunity to review the magmatic-metamorphic-tectonic history of the Pan-African belt in Northeast Africa.

This chapter is dedicated to the Variscan belt segment that is outcropping in NW Africa, covering Morocco, NW Algeria and NW of Mauritania. The NW Africa Variscan belt is considered an intraplate orogen, whose emplacement is largely due to the oceanic closure between Gondwana and Laurentia mainly from Carboniferous to Permian. This chapter re-examines the knowledge we have of this segment of the Variscan belt, reviewing the story over the time period spanning Devonian to Cisuralian and considering the up-to-date pending questions. A tectono-stratigraphical summary of the different domains of the belt is given and detailed for this time period. The “intraplate” character of the belt has been well-evidenced in northern Morocco and NW Algeria. Separated by the South (or Sub-) Meseta Zone, the Meseta and the Anti-Atlas and associated Carboniferous basins compose this northern part of the belt which shows a nice intraplate appendix to the southeast, in the Ougarta belt. Toward the southwest, the NW Africa Variscan belt shows a major extension in the Souttoufides belt, that fringes Gondwana from Western Anti-Atlas to the Morocco-Mauritania boundary along what is now the Atlantic coast. There, the opposite vergences of the Souttoufides, on one hand, and the Appalachian-Alleghanian belt, on the other hand, suggest a more classical double-verging orogen, where researchers are still looking for the past oceanic suture, probably lost in the Central Atlantic opening. The intraplate characteristics of northern Morocco/NW Algeria are now undisputed but the timing of Variscan deformation remains to be firmly established, regarding the initiation of the Variscan compression there. In this sense, we question the meaning of the precocious Eovariscan tectonic phase in NW Africa (Late Devonian(?)-Tournaisian/Early Visean) and propose a working alternative by considering this phase to represent a pre-orogenic stage, mainly extensional. As for the Souttoufides belt, knowledge is still poor about its Late Paleozoic story and its proper integration into the general Late Paleozoic framework. A state of the art is presented, that will likely be refined with the important geochronological and petrographical research that has been undertaken and that keeps going on for more than a decade. We try as much as we can to offer a modern view of the NW Africa Variscan belt by emphasizing the scientific questions that still await answers.

Following the Hercynian orogeny, all the continental blocks remained individualized from the Carboniferous to the Triassic periods. The dislocation of the Pangaea occurred in several stages along two major fractures: the Tethyan fracture and the Atlantic fracture. Morocco was, therefore, in a privileged position, and its history since 200 million years ago was influenced by the opening of the Atlantic Ocean and the birth of the Mediterranean. The Triassic transgression occurs over inherited terranes from the Hercynian and Permian periods. Except in specific regions and around the part of the Pangaea continent located at the intersection of future faults, the post-Hercynian paleotopography was not very pronounced. An open marine domain existed to the East, and the transgression during the upper Triassic period, mainly, was directed toward the West. In view of the Jurassic sedimentation, the Atlas domain differentiates and evolves into two distinct parts:1-A western part corresponding to an open basin to the Atlantic in the process of creation but is closed to the East by the ancient Massif ridge: this is the coastal domain (Essaouira, Agadir basins, etc.); 2-A central and eastern part, represented by the intracontinental basins of the central High Atlas and the eastern or Saharan Atlas, separated by the Tamlelt threshold. Together with the Middle Atlas basin to the north, they constitute the western extensions of the Tethys. In the Lower Cretaceous, the sea occupied restricted areas in Morocco (Rif zone, East of Oujda, and coastal basins). The first transgression occurred in the Valanginian to Aptian. Following the upper Aptian transgression, Morocco has seen a new regression marked by the evolution of continental and lagoon deposits in the Marrakesh region until the middle Cenomanian. In the upper Cenomanian, a major transgression occurred, covering extensive areas in Morocco. The Paleocene to Lutetian is composed of several third-order sequences, which represent successive ingressions followed by the withdrawal of the sea. The sector functioned as an Atlasic chain foreland basin from the Upper Eocene to Oligocene. The siliciclastic deposits of the Neogene and Quaternary fill in this basin called the Haouz of Marrakesh in the north and the Ouarzazate-Sous basin in the south, which is part of a tectonic depression. The basins are not homogeneous and made up of small units with specific sedimentary dynamics and contents. Thus in each one of these units, the deposits have their own organization (alluvial fans, fluvial, and lacustrine), and their distribution is controlled by the morpho-structural setting.

North Africa has a rich geological history and is enriched with different geological settings, as well as rich petroleum resources, including conventional and unconventional resources. This chapter will highlight the major tectonostratigraphic events and lithostratigraphy of the Phanerozoic Eon and Neoproterozoic Eon and major related basins, as well as major sedimentary basins in North Africa and their petroleum resources. North Africa's sedimentary basins are mostly composed of shallow marine and continental sediments of the Cambrian to Recent that mostly overlay the Precambrian basement. The interplay of tectonics, eustacy, erosions, uplift, and subsidence played a major role in the sedimentary record of the North African sedimentary basins, and therefore they formed a complex history of deposition. The organic-rich sediments of the Silurian and Cretaceous deposits play a major role in feeding the reservoirs with oil and gas across north Africa. The reservoir rocks have been recorded across the Paleozoic, Mesozoic, and Cenozoic successions; however, the Mesozoic and Cenozoic reservoirs are dominant. Both structural and stratigraphic entrapment styles were recorded across the hydrocarbon plays of North Africa. More attention can be directed to exploiting the unconventional resources that are still underexplored in the North African basins.

Reassessment of the Neoproterozoic evolution of the North Africa and the Arabian Peninsula revealed the presence of a single orogenic belt, the Saharides, starting from the West African Craton in the west to the eastern margin of Arabian Shield in the east. This orogenic event created a large subduction-accretion complex during the Tonian-Cambrian interval as a consequence of convergence between the West African and the Congo cratons. The Saharides are represented by Precambrian inliers such as Ahaggar (or Hoggar) Mountains in Algeria, the Tibesti Massif in Chad, Jebel Uweinat in the intersection of Egypt-Libya-Sudan, the Arabian Shield in the Arabian Peninsula, the Nubian Shield in Egypt, Sudan, Eritrea, Ethiopia, Kenya, and various massifs in Nigeria. Although the evolution of the region embracing the Saharides has been explained by multiple subduction zones and collisions of cratonic pieces involving reactivation of a ‘metacraton’, our analysis showed no continental collisions were involved until the very end of its history. The entire Sahara is shown to be underlain by a double orocline much like the Hercynian double orocline in western Europe and northwestern Africa.

The North African realm is one of the major oil and gas producing regions in the world, which contains several world-class basins. The petroleum systems of the Egyptian North Western Desert are mostly confined to the Mesozoic (Middle Jurassic, Lower Cretaceous, and Upper Cretaceous) sandstone reservoirs, which are charged from the Middle Jurassic and Lower Cretaceous shale source rocks and sealed with the Upper Jurassic and Lower and Upper Cretaceous shales and carbonates. In contrast, the Gulf of Suez contains multiple Paleozoic, Mesozoic, and Cenozoic carbonate and shale source rocks and sandstone and carbonate reservoir rocks, with the later units are sealed by Mesozoic (Upper Cretaceous) shales and Cenozoic (Paleocene, Lower and Upper Miocene) shale and evaporite deposits. The Nile Delta contains Cenozoic (Upper Miocene and Upper Pliocene) sandstone reservoirs, which are charged from the Cenozoic (Lower–Middle Miocene and Pliocene) shale source rocks. The petroleum traps vary between Late Cretaceous structural traps in the North Western Desert to younger Miocene syn-rift and Pliocene post-rift structural traps in the Gulf of Suez, and to much younger Pliocene and post-Pliocene combined structural–stratigraphic traps in the Nile Delta and the Eastern Mediterranean Exclusive Economic Zone of Egypt. The Libyan petroleum systems in Sirte Basin are comprised of Upper Mesozoic (Upper Cretaceous)–Lower Cenozoic (Paleocene–Eocene) carbonate reservoirs, which are charged from the Upper Cretaceous shales and sealed by the Paleocene carbonates and the Eocene evaporites. The western part of Libya shares the other Maghreb countries (Tunisia, Algeria, and Morocco) in having multiple petroleum systems that are restricted to the Paleozoic (Ordovician, Silurian, Devonian)–Triassic reservoirs and the Paleozoic (Lower Silurian, and Middle–Upper Devonian) hot shale source rocks. The Neoproterozoic Pan-African orogeny formed lineament and fault systems in the Maghreb countries. These structures were later reactivated by the Late Paleozoic and Mesozoic tectonic events and formed the structural traps and controlled the source rock maturation, petroleum expulsion, and developed the migration pathways of generated petroleum. The Uppermost Triassic–Lower Jurassic evaporites are regional sealing units of the Triassic reservoirs, while Paleozoic intraformational shales act as sealing units for the Paleozoic secondary reservoirs. Deposition of the Mesozoic and Cenozoic thick sedimentary sequences in eastern North Africa (Egypt and Libya) and thick Paleozoic sequences in the Maghreb countries (including Libya) provided essential overburden needed for the thermal maturation of the source rocks.

Due to aridity, shortage, and sporadic rainfall in North African countries, groundwater represents a potential source for drinking and irrigation purposes. The groundwater in North Africa is found in shallow and deep aquifers. The latter is considered “fossil” because of not being recharged by present “modern” rainfall. Fossil aquifers are being seriously depleted due to excessive pumping and overexploitation. The major deep fossil aquifers in North Africa typically cross the borders between countries and are referred to as transboundary aquifers. Such aquifers consist mainly of sandstone and have large thicknesses and extension areas with significant hydrogeological parameters such as the Nubian Sandstone Aquifer System and the Northwestern Sahara Aquifer System. Insufficient water supply to sustain the increasing population in North Africa and the Sahara Desert countries has spurred scientific research to better understand the nature, origin, and hydrogeologic setting of these aquifer systems in the region. This chapter presents a comprehensive analysis of the major transboundary aquifer systems located beneath the Sahara Desert, highlighting their potential and strategic role in addressing freshwater scarcity to expand agricultural and economic endeavors. Remote sensing data offer a cost-effective approach for monitoring and formulating sustainable management strategies for these systems. Results show that The Northwestern Sahara Aquifer System faces groundwater depletion, necessitating urgent integrated responses and management strategies to decrease extraction rates and encourage sustainable utilization, however specific areas within the Nubian Sandstone Aquifer System show promising groundwater resources. Further research is essential to examine the mechanisms and timing of recharge within these aquifer systems and understand the contemporary contributions to these systems. These scientific investigations are crucial for finding solutions to the urgent water supply challenges in this arid/hyper-arid region.

This chapter deals with some selected non-metallic ore deposits in North Africa that are hosted by a variety of rock lithologies with great diversity of type and age. Non-metallic ores in Africa north of the 18° N latitude were formed by a diverse variety of geological processes. These ores are hosted by different rocks that range in age from the Neoproterozoic (Nubian Shield in the east) until the Mesozoic (Atlas in the west). Also, some non-metallic ores are encountered in the Proterozoic rocks of the Mesozoic Atlas. The chapter provides an up-to-date review of new publications that dealt with a variety of non-metallic ores in igneous, metamorphic, and sedimentary host rocks from the Archean to recent. The chapter discusses the use of mineral fabrics, mineral chemistry, trace elements (including REEs), stable isotopes, fluid inclusions, paragenesis, and paragenetic sequence in order to decipher the ore genesis of some important non-metallic resources. They comprise a series of industrial minerals that are needed for the development of the North African countries in terms of modern technological applications, as well as to improve the state budgets and finally attain an acceptable standard of life in coherence with other developed parts of the world. The updated accounts include models of ore genesis for fluorite and barite ores that form either by igneous-related hydrothermal solutions or by sedimentary processes, including diagenesis and the effect of pedogenesis in terms of karst formation. The chapter also gives updates on new research of the important phosphate belt in North Africa, with an emphasis on the valuable content of by-products that are rich in radioactive elements and REEs. Other non-sedimentary resources of phosphates are also discussed, especially those occurring with alkaline felsic intrusions. Accounts of other representative non-metallic ores are also presented.

In this chapter, new data about selected metallic ore deposits in North Africa are presented. They concentrate on new researches in the post-2016 era that witnessed remarkable interest of North African and international researchers to characterize the mineralogy, geochemistry, and ore genesis of a variety of ores in different geological environments and host rocks after the textbook by Bouabdallah and Slack (2016). Also, the chapter sheds light on the most significant lithological and structural controls of mineralizations that range in age from Archean to late Cenozoic. New information up to 2021 are presented and they are based on combined field criteria, mineral chemistry, geochemistry, stable isotopes, fluid inclusions, and ore genetic models. Metallic ores discussed in the chapter are hosted by either igneous-metamorphic or sedimentary rocks that display significant roles of hydrothermal alterations viz. metasomatism and post-depositional processes such as diagenesis and karstification. For some specific ores, precise age determination based on modern techniques such as ion microprobe U–Pb is presented for the ore minerals or associated accessory minerals in the mineralized zones and in the unaltered host rocks as well.

The Variscan belts of North Africa are renowned for their diversity and richness in ore deposits of significant economic potential. The Variscan mineral resources, of polymetallic character, are geologically controlled by complex and polyphase tectonic-magmatic events driven by the Variscan orogeny, dating back to the late Paleozoic times. The Variscan (Hercynian) vein-type mineralization, along the northern fringe of the West African Craton, is mainly hosted within amalgamated Precambrian and Paleozoic terranes of the Moroccan Meseta domain and Algerian-Moroccan Atlas system. The development of large ductile to brittle shear zones accompanied or not by plutonic magmatic bodies (mantle, mixed, or crustal) led to the deposition of the main sulfidic and oxidized metallic mineralization as hydrothermal veins during the late Variscan orogeny. Mineralization is predominantly antimony Pb, Sb, Zn, (As, Sn) sulfides and Ag sulfosalts with free or sulfide-trapped gold commonly associated with As quartz structures sheltered along E-W to NE-SW or NW-SE reactivated basement faults. Two mineralization process phases have been identified; the first one with Sn-W-Mo±Au (Be) is associated with the Hercynian calc-alkaline to monzonitic granitoid emplacement, dated at 320 to 280 Ma. The second one with Pb-Zn-Ag accompanied or not by the leucogranites setting resulted from the reactivation of the pre-existing rooted shear zones, concomitant to the uplift and the erosion of the crust during the late Permian–early Triassic. The formation of mineralizing hydrothermal fluids can be linked either to the direct influence of basal-crustal plutonic magma (calc-alkaline granitoids) to purely crustal magma (Leucogranites), or to the circulation of hydrothermal fluids, of metamorphic origin, coming from the base of the upper crust (supracrustal) through active shear zones during the late Permian transpression phase. Hydrothermal fluids can also be originated from the process of dehydration of sediments by compaction, from the initiation of regional metamorphism resulting from the effect of lithostatic and hydrostatic pressures, and the circulations of meteoric and seawater. These hydrothermal fluids infiltrate in-depth, heat up, and create a geothermal circuit which, while going up toward the surface, deposits the mineralization of tin, tungsten, native gold associated with arsenopyrite, gold-bearing pyrite, silver-bearing galena, sphalerite, in zones made permeable by brecciation and opening of the pre-existing fractured or newly created and faulted systems. Undoubtedly, the Tighza-Aouam (Pb, Zn, Ag) deposit is also rich in gold and tungsten, the El Hammam fluorite deposit, not metalliferous, and the Achemach Tin deposit are economically the most prominent Variscan ore deposits, exploited exclusively in the Hercynian Central Massif of Morocco; while those of neighboring Algeria correspond to the polymetallic veins of the Boukais massif, Ougarta belt (Cu-Pb±Zn±Ag and Au) and of the Beni Snouss district (Au, As) in the GharRouban massif.

The Algerian-Tunisian phosphorites, from Paleocene-Eocene, were mainly deposited around “Kasserine Island” into three main basins as a result of the large Tethyan phosphogenesis. This chapter reviews the main characteristics of the most representative phosphorite deposits with the aim of comparing their lithostratigraphy, petrography, mineralogy, and geochemical features (major and trace elements, and isotopes), in order to summarize the current state of knowledge of their depositional environments. The phosphorites while sharing similar characteristics in terms of lithology and petrography, also show significant variations in thickness and vertical configuration mostly related to the depth of local basins and depositional facies. Phosphorites are often made up of a complex carbonate fluorapatite (CFA) mineral phase that arises from a microbial-driven phosphatization process of former particles (pellets, coprolites, and bioclasts). The mineral exo-gangue is mainly represented by dolomite, calcite, quartz, gypsum, heulandite-clinoptilolite, and Opal-CT in addition to some accessory minerals. P₂O₅ contents range from 17.97 wt% to 35.00 wt% (median = 26.5 ± 3.59 wt%), and consequently the values of other oxides fluctuate in different phosphorites facies. Contents of trace elements and rare earth elements (REE) vary significantly through the deposits (e.g. ~0.8 ppm < Cd >  ~172 ppm; ~101 ppm < Cr >  ~374 ppm; ~2 ppm < Cu >  ~44 ppm; ~16 ppm < U >  ~126 ppm; ~125 ppm < ∑REE >  ~1018 ppm). REE + Y-geochemistry shows that the northern deposits formed under oxic conditions, while the eastern and southern deposits formed in sub-reduced to sub-oxic environments. There, a little detrital input and slight paleoproductivity occurred, as revealed by detrital and paleoproductivity geochemical proxies. This realm, associated with the δ¹³C, δ¹⁸O, and ⁸⁷Sr/⁸⁶Sr isotopic records, contrasts with the occurrence of the Paleocene Eocene Thermal Maximum (PETM) global warming event during the phosphorite formation.

This study presents an overview of the geothermal footprint of north Africa, with a focus on Algeria and Egypt which have medium-to-high geothermal potential. This study aims to calculate Curie depths, geothermal gradients, and heat flow maps for north Africa, in addition to estimating the stored geothermal power at three sites with high geothermal potential in Algeria and Egypt. Evaluation of terranes for geothermal energy potential makes use of key geothermal parameters. These include Curie depth, geothermal gradient, and heat flow. In this study, these parameters are estimated for north African countries using a variety of geophysical techniques. The Curie depth, calculated from power spectra of aeromagnetic data, ranges from 16 to 33 km. The present day temperature gradient varies between 18 to 34 °C/km and heat flow values lie between 54 and 102 mW/m². A stochastic Monte Carlo simulation was performed to estimate the geothermal energy stored in the three North African geothermal fields (Hammam Faraun in Egypt and Hammam Bouhdjar and Maskhoutine in Algeria) for 25 years and 50 years. The geothermal electricity potential at Hammam Faraun is ~2.57 MWe and ~1.28 MWe for 25 and 50 years, respectively. The electricity potential for Hammam Bouhdjar is ~4.39 MWe for 25 years, and ~2.19 MWe for 50 years. The electricity potential for Hammam Maskhoutine is ~7.82 MWe for 25 years, and ~3.91 MWe for 50 years. Densely spaced geophysical surveys (e.g., magnetotelluric, gravity, magnetic) should be used to estimate the extent and thickness of geothermal reservoirs, and data from deep geothermal testing wells should be used to evaluate subsurface porosity and density to enhance estimates of geothermal power in the studied regions. Based on the estimates presented here, north African countries (especially northern Algeria and eastern Egypt) can benefit from the utilization of geothermal renewable energy sources.

Oil shale and rare earth elements (REE) are examples of the strategic resources in North Africa. Oil shale is considered as a major oil and/or gas-prone source rock. The Lower Silurian organic-rich shales account for 80–90% of all Paleozoic hydrocarbon sources in North Africa. However, due to Egypt's palaeohigh at the time, the Silurian organic-rich sediments were not deposited there, but Upper Cretaceous-Paleogene oil shale can be found. In the last decades, the interest and mandate for valuable resources and elements (REE) are continually increasing due to their critical role in several fields of activity such as technology and industry. Rare earth elements are generally associated with phosphorite deposits as they contain large quantities of REE. The current chapter covers five North African countries, i.e., Egypt, Libya, Tunisia, Algeria, and Morocco.

The North Africa region extends from the Red Sea and Gulf of Aqaba in the East to the Atlantic Ocean in the West, including five countries: Egypt, Libya, Tunisia, Algeria, and Morocco. The earthquake record demonstrates that this region suffers from earthquakes with considerable level of hazard due to the complex convergent plate boundary along the African continental plate near to the comparative movements of tectonic microplates from the Mediterranean Sea in the North and the Red Sea in the East. Additionally, the inland tectonic activities induce local seismic sources inside the African plate in its North African segment. Furthermore, local site effects, vulnerability of the built environment, and the dramatic increase of concentration of population within hazardous areas, alongside the nature of the sociocultural in North Africa in respect to natural disasters, all these factors can significantly increase the damage posed by earthquakes in this region. Several researchers studied the seismicity of North Africa and gained valuable results; however, their studies commonly focused on a particular region or subject. Therefore, the authors of this article are hopeful to introduce a piece of simple and informative material to the reader about the region of North Africa by compiling earthquake data from several sources and by a systematic literature review. In this chapter, the reader can find information about location, seismotectonic setting, seismic sources, and historical and instrumental earthquakes with a brief description of the devastating events, earthquake recording history, and seismic networks of each country in North Africa.

In the last few years, exploration interest in discovering new hydrocarbon resources in North Africa’s various concessions has resulted in many new and important oil and gas reservoirs being found. However, tight reservoirs in different regions of the North African region are distinguished by their complexity and heterogeneity. Therefore, there are many challenges to reducing exploration costs and risk in order to identify those target zones with economically productive sand reservoirs of onshore and especially offshore hydrocarbon exploration in deep marine regions in North Africa and the Mediterranean. Hence, this chapter introduces several modern frameworks and methodologies based on using new and various modern techniques to improve the imaging of the gas channels, chimneys, and various features to reduce the exploration cost and risk. Examples are several classes of post-stack seismic attributes, partial-stack attributes through the Amplitude Variation with Offset (AVO) analysis, and various Machine Learning (ML) techniques such as supervised and unsupervised Artificial Neural Networks (ANNs). Furthermore, the methodology in its application to different basins with similar geological settings in the North African region.

The arid to semi-arid climate of northern African countries is an asset for the preservation of meteorites and impact structures. The Sahara, the largest hot desert in the world, is considered the most productive region for the recovery of meteorites on Earth after Antarctica. In contrast, North Africa, like the rest of the African continent, remains relatively unexplored for impact structures. This chapter presents current knowledge of the impact cratering record and meteorite falls and finds in North Africa (Algeria, Egypt, Libya, Morocco, Sudan, and Tunisia). It provides a comprehensive literature review and data set (including aerial imagery and topography) of confirmed impact structures, including (in alphabetical order) Agoudal, Amguid, B.P. Structure, Kamil, Ouarkziz, Oasis, Talemzane and Tin Bider. A subsection includes a discussion about the unresolved enigma of the source of Libyan Desert Glass. This is followed by a presentation of current knowledge and hypotheses on eight non or partially elucidated circular structures, which aims to stimulate field exploration and further research. Circular structures once regarded as potential impact structures and now elucidated are briefly described in a subsection entitled “discarded impact structures”. The section on meteorites highlights a selection of the most remarkable objects discovered in this region and the relationship between meteorites and ancient civilizations in Egypt, revealing on of the most ancient pieces of evidence of the interest of humankind for these objects.

North Africa has a rich geological history that spans from the Archean to the Quaternary period, which is well reflected in its varied geological and geomorphological landscapes. This region has provided a diverse record of ancient life, including fossils from numerous geological periods. Noteworthy geological features, like the Alpine High Atlas Mountains and the Precambrian West African Craton, traverse multiple North African countries. While these landscapes provide valuable insights into Earth’s history and have significant educational potential, they are largely unknown to the public due to limited research on geoheritage, geoconservation, and geotourism. There has been no comprehensive geoheritage inventory in North Africa, with sporadic local efforts often driven by academic entities. Even though North African nations have legislation to protect cultural and natural heritages, the establishment of geoheritage inventory and protection is nascent. This chapter aligned with the goals of the African Geoparks Network, seeks to highlight the existing knowledge on North African geoheritage and promotes the potential of geosites for socio-economic development via geotourism and geoparks.