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FIELD TRIP IN GHANA (5th IGCP638 meeting, 2022) [more details are available in the 2nd cicrular]

The post-conference field trip will be held in the north of Accra from  6th to 9th Dec., 2022 as follows:

3 days field trip along various transects of the Precambrian formations of Ghana. Related themes associated with the conference include but not limited to Geological mapping, Geochemistry, Geophysics, Mineral exploration and Mining, Geochronology, Environmental management.

The merger of both meetings will help (i) establish relations between industry partners, students, academics and other professionals for further scientific collaborations, through research programs and  (ii) build capacity in understanding the Birimian of West Africa in terms of its Geology, Geodynamics and its metallogenic enrichment.

  • Two field trips will be held concurrently from the 6th to the 9th December 2022:
  1. The first one will be a cross-section of Paleoproterozoic Birimian rocks in Southern Ghana [Tentative names of facilitators: Prof. Johnson Manu, Prof. Bruce Banoeng-Yakubo, Prof. Thomas Mba Akabzaa, Prof. Patrick Sakyi, Dr. Prince Ofori Amponsah, Prof. Frank Nyame. Florence Akontoh will assist anyone who will be confirmed as facilitator(s)]
  2. The second one will be within the Voltaian, Pan-African and the Younger sedimentary basins in Ghana [Tentative names of facilitators: Prof. Daniel Asiedu, Prof. Prosper Nude, Prof. Bruce Baneong-Yakubo, Dr. Chris Anani, Prof. David Atta-Peters, Dr. Marian Sapah. Joyce Duku will assist anyone who will be confirmed as facilitator(s)]

For both trips we need a total of 30 people. It is on a first come first served basis.

  • The cost of the field trip will include transport, hotel accommodation, lunches and dinners.
  • The cost of the field trip is given within the 1st circular.


Summary Geology and mineral resources of Ghana

Based on lithology, age, structural and tectonic data the geology of Ghana has been divided into five broad domains. Covering the western half of the country is the Paleoproterozoic Birimian terrane which doubles up as the eastern margin of the West African Craton and is bounded to the east by the Neoproterozoic to Pan-African age Voltaian sediments. The south-eastern portion of the country is defined by the Pan-African Dahomeyide mobile belts. At the Coast of the country are the Paleozoic to Mesozoic coastal sediments. Most of these geological formations are covered with Tertiary and recent deposits of unconsolidated clays and sands mainly deposited in lagoons, littoral and deltaic environments.

The Paleoproterozoic Birimian Geology of Ghana

The Birimian terrane in Ghana forms the eastern edge of the Paleoproterozoic domain of the West African Craton (WAC) and covers the western part of Ghana (Fig. 1). The architecture of the Birimian in Ghana consists of five northeast-southwest trending and one north-south trending greenstone belts with intervening sedimentary basins. From south to north, the greenstone belts in Ghana are the Kibi-Winneba, Ashanti, Sefwi, Bui, Bole-Navrongo and Wa-Lawra. Interpretation of gravity and magnetic data showed north-easterly extension of these greenstone belts below the Neoproterozoic/Palaeozoic Voltaian sediments and in adjoining countries, thus reaching some 100 kilometres in length. These belts are 15-40 km wide and 60-90 km apart. They trend northeast-southwest and decrease in width north-westward across the country with intervening sedimentary basins. These basins and belts have been intruded by various granitoids. Four types of Paleoproterozoic granitoids suites are present in Ghana known as the Winneba, Cape Coast, Dixcove and Bongo granitoids. The Birimian terrane is highly eroded, therefore giving the terrane a general flat topography. By way of lithology the Birimian in Ghana is composed of volcanosedimentary rocks (volcaniclastic rocks, turbidity related greywackes, argillitic rocks and chemical sediments), volcanics (characterized by tholeiitic and alkaline compositional varieties with the tholeiitic basalt predating the calcalkaline series with reported ages of 2162 ± 6 Ma and 2266 ± 2 Ma and plutonic rocks (granitoids). The Birimian units in Ghana were formed between 2250 and 1980 Ma. Overlying all of this are the younger molassic sediments of the Tarkwaian. The Tarkwaian is composed of sandstones, phyllites, conglomerates and quartzites. The structural evolution of the Birimian terrane has been described by many workers as polycyclic events.


Fig. 1. Geological map of mineral resources of Ghana representing the main ore deposits

Two major phases of deformation with varying intensities have been described in the Birimian of Ghana: the Pre-Tarkwaian (D1) and Post-Tarkwaian (D2). Thus a low strain and high strain phases of deformation occurred. In the low strain phase, the rocks developed northeast-trending subvertical foliation (S1). This is sub-parallel, or at a small angle, to bedding and contain a subhorizontal intersection lineation (L1). Rocks belonging to the high strain phase occur predominantly along the north-western margins of the volcanic belts and are characterized by the presence of a penetrative north-eastern trending foliation (S2) and a south-west plunging stretching lineation.

Voltaian sediments (Volta Basin) Geology in Ghana

The final architecture of the Neoproterozoic to Lower Paleozoic Voltaian basin is that of a foreland basin and occupies an area size of >115,000 km2. The sedimentary basin forms at the margin of the WAC and along the nappe stacked Dahomeyide orogenic belt. The Volta Basin is composed of 5 to 7 km succession of flat lying Neoproterozoic to Paleozoic mega sequences of sandstones, siltstones and mudstones with subordinate proportions of limestones. The basin outcrops mostly in Ghana and in minor areas in Togo, Niger, Burkina Faso and Benin. The Basin unconformably overlies the deformed Paleoproterozoic Birimian rocks. Sedimentation of early sandstone in the basin syncline began around 1035 Ma and ended with tillites sequences dated around 620 Ma. This basin represents a subsidence on the south-eastern flank of the WAC and is partly up-thrust westward onto the Man shield. The sediments in the basin show an evolution from a cratonic to an epicontinental basin (with marine transgressional features), to that of a passive margin and finally to a foreland basin formed during the Pan African orogeny. In Ghana, the Volta Basin has been subdivided into the Upper, Middle group and the Lower group.

  1. The Lower Voltaian sediments which consists of the Kwahu/ Kintampo/ Damongo/ Gambaga/ Bombouaka Supergroup,
  2. The Middle Voltaian sediments which consist of the Oti/ Afram/ Pendjari Supergroup, and
  3. Upper Voltaian megasequence which consists of the Tamale Supergroup.

The Lower Voltaian sediments

The Lower supergroup (i.e. the Kwahu/ Kintampo/ Damongo/ Gambaga or Bombouaka Supergroup) is approximately 1000 m thick and comprises two mainly sandy groups which sandwich a third soft mudstone group.

Most of these rocks resulted from detrital, fine- to coarse-grained sediments deposited on an epicontinental to marine platform, along the edge of a peneplained basement, during a series of marine transgression-regression cycles related to a rifting event and a slow and variable subsidence.

The Middle Voltaian

The Oti/ Afram or Pendjari Supergroup lies, with an erosional and partly glacial unconformity, on different formations or groups of the lower Supergroup and, locally, directly on the Eburnean basement complex of the Man-Leo domain or uplift. It is 1500 – 4000 m thick and comprises the Kodjari or Buipe Group and the Porga/ Mango/ Bimbila or Sabare Group. The Kodjari or Buipe Group corresponds to a trilogy or “Triad “made up of glaciogenic deposits (tillites/ mictites), baryte-bearing dolomitic limestones (or cap carbonates), and thinly bedded siliceous shales or cherts defined as silexites. The Bimbila or Sabare (or Porga/ Mango) Group is composed of rhythmic shales and siltstones, with lenses of clayey limestones and various sandstones or greywackes. In total, the Oti/ Afram or Pendjari Supergroup is made up of mainly fine and immature materials deposited in a deep and very subsident marine environment. It is interpreted as a passive margin deposit or a sedimentary sequence related to the expansion of the ocean.

Upper Voltaian sediments

The Tamale Supergroup unconformably overlies the Oti/ Afram or Pendjari Supergroup. This is also subdivided into Yendi and Kebia Groups. The Yendi Group includes a lower polymictic micaceous and mainly sandy formation, overlain by a thick sequence of shales, impure limestones and siltstones. The Kebia Group is composed of various polymictic sandstones and conglomerates, with lenses of shale and siltstone.

The Tamale Supergroup corresponds to a molassic assemblage, derived from the Dahomeyide orogenic belt, and represents a foreland basin, deposited with a progressive erosional unconformity on the Oti/ Afram/ Pendjari Supergroup.

Pan-African Dahomeyide mobile belt

The Dahomeyide mobile belt is located in the southeast portion of Ghana. The Dahomiyide mobile belt can also be divided into three (3). These are:

  1. The Dahomeyan
  2. The Togo and
  3. The Buem units

The Dahomeyan

In Ghana, this 30 km wide belt can be traced from Fete, west of Accra the nation’s capital all the way to Agu in the republic of Togo and Beyond. Rocks found in this unit are mainly composed of felsic and mafic gneisses, believed to be reworked from Archean/ Precambrian basement during the Pan-African orogeny and recorded various polycyclic or episodic deformation. Regionally these rocks strike NE with moderate dips to the southeast. Based on tectonic and lithological data, this unit can be subdivided into three. These are:

  • quartzo-feldspathic and augen-gneiss referred to locally as the Ho gneiss
  • a suture zone of mafic and ultramafic rocks and granulites (Shai-Adaklu Hills)
  • a granitoid gneiss-migmatite assemblages east of the suture zone

The Togo units

This unit forms the Akwapim range in Ghana extends into northern Benin where it is called the Atacora Range. The Togo Unit is bordered to the west by the Cape Coast granitoid complex rocks, the Voltaian Basin and the Buem Unit. On the eastern section of the Togo Structural Unit are the Devonian Accraian rocks and Dahomeyan metamorphic basement rocks. The Togo Structural Unit consists of quartz sericite-schists, quartzites, phyllites and chlorite schist. Hornstones, jaspers and hematite quartz-schists occur as postdepositional rocks within the unit. The rocks in this unit are highly deformed with a general regional strike of NE with dips in the SE direction.

The Buem units

The Buem unit is juxtaposed to the south by the Dahomeyan unit and to the west by the Togo structural units. The Buem units can be divided into two domains, thus the eastern domain and the western domains. Rocks in the Buem are composed mainly of conglomerates, clastic sediments, volcanic rocks, variegated sandstones, limestones, jasperoids, gabbros and serpentinites. The volcanic rocks mainly consist of alkali basalt, basaltic andesites, trachytes, phonolites, volcanic breccias and pyroclastic materials. The contacts between the Togo structural units is marked by serpentinites. These serpentinites have massive to schistose textures. The serpentinites are mainly tectonically emplaced slices of a proto oceanic crust caught up during the suturing of the adjacent continental blocks of the Pan-African orogenic event. The rocks in the Buem generally strike NNE-SSW and are generally deformed.

Coastal sediments

The crustal evolution of Ghana in the Phanerozoic was characterized by development of a series of spatially restricted shallow, mostly marine coastal basins along the present-day Ghanaian coast. Occurrence probably along a zone of crustal weakness related to the opening of the Atlantic and proto-Atlantic Ocean. The sedimentation process started from Ordovician to Tertiary. During the Ordovician, the Sekondian group sediment deposited, followed by the Devonian Accrain rock, overlained by the Upper Jurassic Amissian Group to the Cretaceous Appollonian group. This was followed by the Tertiary and Quaternary sediments.The subsection will look at some of the groups.

The Palaeozoic Sekondian group

The non-continuous exposures (thus breaks in its strike extent) of the Paleozoic Sekondian group, occupies a total land area >500 km2 from Asemkaw to Pedu Townships in the western and central regions of Ghana respectively forms part of the West Africa Coastal basin province which is of great importance, as it provides a major play for hydrocarbons exploration. The 1,245 to 1,325 m thick Sekondi Group is composed of seven formations comprising of various successions of sandstones and shales which unconformably overlies the Birimian basement. At the base of this group is the glaciogenic intertidal to shallow marine or lacustrine deposit termed the Ajua shales which were deposited during the Late Ordovician period. Overlying the Ajua shales is the 300 m Elmina sandstone. This formation is mainly characterized by medium grained, indurated, cross bedded and well jointed feldspathic sandstone with limonitic cement. Lying above the glaciogenic Elmina sandstones is the fluviatile, deltaic and estuarine Takoradi beds (which includes the Takoradi shales and Takoradi sandstones). Biostratigraphy dating from brachiopods and pelecypods from the basal shales in this group yielded Late Devonian ages. This formation was followed by the aeolian to fluviatile deposited Efia Nkwanta beds. The topmost formations of this group are the Sekondi and Essikado sandstones. Prior to the post tectonic activities experienced by the group, minor Carboniferous and Jurassic igneous activity was experienced silicifying the Sekondi sandstone which it intrudes.

The Appollonian formation

This Cretaceous-Eocene formation can be found along the SW Ghana and SE Ivory Coast. The Ghanaian portion is known as the Tano Basin. Thus, this sediment occupies between the Tano River and the West of Ankobra and occupies an area size of 116550 km2.The formation is composed of sands, clay and fossiliferous limestone overlying unconformably of the Birimian Supergroup. The oldest rocks in the formation are greyish green sandy shale which is Aptian in age and the youngest members comprise recent sand and shaly clay deposits as seen in the stratigraphic succession of Table 1.



Thickness (m)



Loose sand, clay and shaly clay



 --------------------------------------------------------- Unconformity ---------------------------------------------------


Fossiliferous limestone and black clay





Sandstone, minor shale and limestone







  --------------------------------------------------------- Unconformity ---------------------------------------------------


Green-gray sandstone and minor shale




Black Carbonaceous shale



 --------------------------------------------------------- Unconformity ---------------------------------------------------


Siltstone, igneous and metamorphic rock pebbles




Grayish green sandstone and shale



Table 1. Table showing a summary stratigraphy of the Appollonian formation

The Keta basin

This basin is located in the south-eastern corner of the country and occupies and area of 375550 km2 with 220150 km2 on land and the rest in the offshore. Nearly 50% of its onshore coverage has been covered by laggons. The basin is mainly made up of clays, shales, siltstones and fossiliferous limestone. These rocks lie unconformably on the Dahomeyan units. The ages of the rocks have been dated from Devonian to recent



Ghana as a country is endowed with many natural resources and geotouristic sites. Notable natural resources associated with the nation’s geology include gold, alluvial diamond, manganese, bauxite, oil, limestone, kaolin, basalt and varieties of metamorphic and igneous rocks with good bearing capacities which are useful in many civil works.


FIELD TRIP IN ALGERIA (4th IGCP638 meeting, Oct. 28th - Nov. 2nd, 2019)

The post-conference field trip will be held in the northeast of Algeria from Oct. 30th  to Nov. 2nd 2019 as follows:

4 days field trip along with a transect on the Paleozoic-Mesozoic Formations, from Algiers to the Tunisian border (i.e. Algiers-Sétif-Guelma-Annaba), and several visits of mineralized outcrops and mines.

The main aim, with the help of some specialists of this area, is to allow the participants :

1- examine and discuss together some key outcrops for the understanding the lithology and the geodynamics in relationship with mineralizations,

2- visit operating mines within the area of Sétif : iron of Djebel Anini, lead-zinc deposits of Boukhdima, and Chaâbet El Hamra zinc mine. But while being at the vicinity of the rich Roman ruins and ancient roman city of Djemila (near Sétif), we will take this opportunity to make a detailed visit of ruins and examine the geological outcrops around [dinner and overnight at El Bachir Hotel, Sétif]

3- A visit to the archaeological site of Aïn Boucherit (near El Eulma and close to Ain Hanech site), called the Cradle of Humankind following the discovery of lithic tools in cut stones and fossil bones of animals going back 2.4 million years, could also be on the programme (see e.g. discussion) [dinner and overnight at Bouchahrine complex, Guelma]

4- discover a wide variety of geological facies of the mineralized rocks within basins, thermal places (Guelma area) related to recent tectonic activities where several ore deposits can be distinguished.

(a) The station of Hammam Debbagh thermal spring (Guelma area) will be visited. It shows an active thermal source on top of a faulting system, with output water temperatures ranging between 89°C and 98°C indicating a high thermal gradient. Such water contains sodium chloride and calcium sulfate, and may also contain very low amount of radon and arsenic. However the discussion will be open and will focus on the formation of travertines which are cross-cut by several faults and fractures oriented in close relationship with the stress regime changes of North Africa during Mio-Plio-Quaternary,

(b) Outcrops of the Kabyle Basement with its suite of metamorphic core complex, and numerous deposits of Paleozoic and Mesozoic ages within Annaba area will be visited [dinner and overnight at Bouchahrine complex, Guelma]

5- On the way back to Algiers before night, numerous deposits of Paleozoic and Mesozoic ages will be visited. The discussions may continue till Algiers.

Possible organization of a touristic day

Visit of Algiers and its surrounding area: Bay of Algiers, Bardo & National Fine Arts Museums, Casbah

Location Fig.1 Fig.2 Fig.3

Main Resources

The detailed programme will be posted soon. A tentative programme is given below.

Field guide-booklet

The guide-booklet in general presents the geology of Algeria and a more detailed way the sites of observation of the geological field trip. The transect areas to be described in detail are located in the Djurdjura Massif, the Guelma Basin and the areas of Sétif and Annaba .
We propose to write the guide-booklet in English and in French.

Notice that the field guidebook will be delivered to only participants of the field trip. The sampling of rocks is authorized.

Livret guide de terrain

Le livret guide présente en général la géologie de l'Algérie et de façon plus détaillée les sites d’observation de l’excursion géologique. Les régions à décrire en détail sont la coupe passant par les régions du massif du Djurdjura, le bassin de Guelma et les régions de Sétif et Annaba.

Nous proposons d’écrire le guide de terrain en anglais et en Français.

Notez que le livret-guide sera distribué seulement aux participants de l'excursion sur le terrain. L'échantillonnage des roches est autorisé.

Coordinators: M. Zerrouki (ASGA), M. Boutaleb (USTHB, Algiers), M. Chabou (Univ Sétif), M. Mouzaia (Ferphos Co.), and M. Laouar (Univ Annaba)

Participants Fees ($)




275 us$

The number of places is limited to 50.

Participation is on a first come, first served.

The fees will be adjusted in the final circular depending on sponsors financial support

NB : 1 € = 135,29 DA; 1 us$ = 120 DA


Geology of Algeria: an overview

Algeria, largest country of Africa and ninth in the world from its surface, of 2,381,741 km2, is an open-air geological museum. From its geographical location on the southern Mediterranean shore, in the northwestern part of North Africa, Algeria offers several natural areas, which are as many different geological provinces by their ages, lithological structures, contents and extents (e.g. Fabre et al, 1978):

  • In the North, the Tellian Atlas, high plateaus and the Saharan Atlas,
  • In the Center, the Saharan Platform,
  • In the Southwest, the Eglab massif, the Ougarta mounts, the Bechar, Tindouf and Taoudeni Basins,
  • In the South, the Hoggar and the Tassilis.


From its geographical position, Algeria is attached at the same time to Europe by the recent history of its northern part known as “Alpine” and to Africa by the ancient history of its southern part under the Saharan Atlas.

From the North towards the South, one may distinguish two large Alpine and African parts (Figs. 1, 2).

 Carte principaux gites et gisem

 Fig. 1. Global map of mineral resources of Algeria representing the main ore deposits within the main massifs


resources DZ

Fig. 2. Geological map of Algeria showing the main mineral resources

The Alpine part gathers:

- The Tellian Atlas, comprising the Northern Tell (old Kabylie, Chenoua massifs and the Meso-Cenozoic calcareous dorsal) and the Southern Tell (Bibans and Ouarsenis Mounts),

- The High plains (Oranian Meseta and Mole Constantine),

- The Saharan Atlas (Aurès, Ouled Naïl, Djebel Amour and Ksour Monts).


The African part comprises:

- The Saharan platform including western and eastern Grand Ergs, plateaus of Tademaït and Tinhert, and Bechar, Taoudenni and Tindouf Basins.

- The Ougarta and Eglab located at the western limit of the Saharan platform. The Eglab represents the northern outcrop of the West African Craton (WAC). The crystalline Hoggar massif or the Targui Shield, located at the South of the Saharan platform belongs to the Panafrican chain.


Geological characteristics of the various domains and the mineral resources

The Tellian Atlas

The Tellian Atlas (or Tellian domain) is integrated with the Saharan Atlas (or preSaharan domain) in the chain known as Alpine which extends from Spain and the Rif in Morocco to the Himalayas. The Tellian Field comprises in the South, the Southern Tell is constituted by the Ouarsenis, Bibans and Babors massifs and in the North, Northern Tell with the Petite and Grande Kabylie and the calcareous chain.


The Northern Tell

It comprises the “old massifs” and the “calcareous chain”:

- The old massifs are Paleozoic in age, located in the Edough at Annaba, in Kabylie, in Algiers and in the Chenoua. They are made of crystallophyllian series which include at the base, a gneissic complex on top of which outcrop sericitic, calcareous schists, arkoses and conglomerates dated from Devonian to Permian. The age of the metamorphism is polyphase.

- The calcareous chain is a set of limestones membered, of Mesozoic-Cenozoic age, which border the old massifs of Paleozoic age. From East to West, one finds them north of Constantine until the South of Annaba, area of Bouira, Djurdjura, areas of Algiers and Cherchell-Cape Tenes.


The Southern Tell

One may distinguish there autochthonous or reduced extensional zones and an allocthonous cover (Tellian thrusts and flyschs/Turbidites).

The autochthonous or parautochthonous zones appear in windows under the thrusts, affected by a light metamorphism and deformations prior to the emplacement of thrusts since the Lower Miocene.
- The allocthonous cover (Tellian thrusts and flyschs/turbidites) is made of a marly-carbonated and detrital material, that was deposited by gravity. The allochthonous zones are located north of the old massifs and south of the calcareous chain.

In the Tellian Atlas, mineralizations are related to Alpine and Hercynian orogeneses, thus one may distinguish:
in the old massifs: mineralizations of iron, base metals (lead, zinc, and copper) and gold indices;
in the Tellian nappes: base metal mineralizations (lead, zinc, and copper) as well as silver, mercury, barytine and sulphur.


The High plains

It is an autochthonous zone which comprises from West to East: the Oranian Meseta, the Algiers High Plains and the Constantine High plateaus. The Mesozoic formations (Jurassic calcaro-dolomitic formations with detrital contribution at the Cretaceous) are transgressive on a primary basement which levels in the mounts of Saïda and the area of Tiaret, westwards.

One meets mineralizations out of base metals, lead, zinc and sometimes copper within the High plains.


The Saharan Atlas

Both the Saharan Atlas and the High plains belong to the northern margin of North-African Craton involved in the history of the Alpine chain. It develops north of the relatively stable Saharan platform and from which it is separated by the southern Atlasic accident. The northern limit of the Saharan Atlas is marked by the southern Mesetian accident.

The outcropping formations are Meso-Cenozoic in age: saliferous at the Trias, carbonated at the Upper-Middle Jurassic, detrital at the Upper Jurassic - Lower Cretaceous, and carbonated at the Upper Cretaceous and Cenozoic pro parte.

The Saharan Atlas is characterized by the iron and phosphate layers in its eastern part.


The Saharan platform

It is located at the South of the Alpine domain of Algeria, which contains great hydrocarbon potentialities. It is characterized by its flat relief from where its name. It comprises a Precambrian basement on top of which a powerful sedimentary cover very little deformed lays unconformably.


The Ougarta

The Ougarta chain, located in the western part of the Saharan platform, is consisting in volcano-sedimentary (tuffs and greywackes) and volcanic (ignimbrites, andesites, dacites and rhyolites) formations attributed to Neoproterozoic, on top of which a powerful folded Paleozoic series lays in unconformity.

The Ougarta and the Saharan platform are both characterized by the large oil and gas fields, the layers of iron (Gara Djebilet and Mecheri Abdelaziz) and of the diamond indices, manganese and copper-silver indices.


The Eglab massif

It belongs to the Reguibat dorsal and represents the northern outcrop of the West African Craton (WAC), in the southwestern part of Algeria. It constitutes a stable basement since the Eburnean event (~2 Ga).

It is characterized by several lithological series:

- Granitoids (Neoarchean to Paleoproterozoic) and volcano-sediments with flysch/turbidite character (Paleoproterozoic), which are cross-cut by mafic and felsic complexes (diorites and granites) and are covered by an important volcanic formation, called the Eglab volcanism (ignimbrites, rhyolites and rhyodacites).

-  Volcano-sediments (arkoses, conglomerates and felsic neutrals interstratified volcanites and their tuffs (Paleoproterozoic).
-  Limestones with stromatolites and sandstones, a series of platform (Neoproterozoic), uncomformable on the whole structure.

The Eglab massif shows gold indices, associated copper and molybdenum, and REE


The Hoggar

The crystalline massif of the Hoggar which outcrops on more than 300,000 km2, stable since the Cambrian, belongs to the Panafrican chain. It is subdivided into three large different submeridian compartments (western, central and eastern) limited by two NS lithospheric shears (4°50’ and 8°30’).
- Within the Western Hoggar, the “pharusian” chain outcrops and is made up of two branches (western and eastern) separated by the granulitic from the mole In Ouzzal, Archaean in age. It consists of two thick Neoproterozoic volcano-sedimentary series (lower and upper Pharusian) intruded by a very developed orogenetic plutonism.

- The Central Hoggar is known as polycyclic where the whole Lower Paleoproterozoic gneissic formations are dominant, covered in discordance by the Pharusian volcano-sedimenatry series.

- The Eastern Hoggar is characterized by two different domains:

- a detrital series (pelites and conglomerates) lengthened along the 8°30’ shear zone,
- a large number of orogenetic granitoid batholites intrusive in meta-sedimentary sequences.

The Hoggar is characterized mainly by gold-bearing ore deposits, wolfram-tin, uranium and indices of REE, rare metals, iron, manganese, talc and graphite.


Outline on the mineral resources of Algeria

  • precious metals: gold, silver
  • precious and semi-precious stones: diamond, topaz, beryl
  • base metals: zinc, lead, copper,
  • elements of the platinum group (PGE)(Platinum, palladium, iridium, ruthenium, rhodium, osmium) and nickel-cobalt
  • rare metals: wolfram, tin, tantalum, niobium, beryllium,
  • industrial minerals: baryta, bentonite diatomite, magnesite, pearlite, pozzolana, decorative stones, talc, gypsum, siliceous sands


  newTentative programme of the field trip (Oct. 30th - Nov. 2nd, 2019)

Coordinators: M. Zerrouki (ASGA), M. Boutaleb (USTHB, Algiers), M. Chabou (Univ Sétif), M. Mouzaia (Ferphos Co.), and M. Laouar (Univ Annaba)

Algiers-Sétif-Guelma-Annaba-Algiers  [A maximum of 50 participants + ASGA organizing committee]

 Download the field trip programme: field trip

 Notice that the field guidebook will be delivered to only participants of the field trip.

Oct. 30th, 2019: Departure from Algiers to Sétif (300 km), where a visit of iron, lead-zinc and zinc deposits within Djebel Anini, Boukhdima, and Chaâbet El Hamra Mine, is scheduled, respectively [dinner and overnight at El Bachir Hotel, Sétif]

Oct. 31st, 2019: Visit of the roman ruins and roman city of Djemila (close to Sétif), then departure to Guelma. A visit to the archaeological site of Aïn Boucherit (near El Eulma and close to Ain Hanech site), called the Cradle of Humankind following the discovery of lithic tools in cut stones and fossil bones of animals going back 2.4 million years, could also be on the programme (see e.g. reference below) [dinner and overnight at Bouchahrine complex, Guelma]

Nov. 1st, 2019: (i) Visit of Hammam Debbagh thermal spring with the travertine outcrops (see e.g. references below) and antimony deposits, (ii) Departure to Annaba, outcrop of the Kabyle Basement with its suite of metamorphic core complex, and numerous deposits of Paleozoic and Mesozoic ages within Annaba area [dinner and overnight at Bouchahrine complex, Guelma]

Nov. 2nd, 2019:  On the way back to Algiers before night, numerous deposits of Paleozoic and Mesozoic ages will be visited. The discussions may continue till Algiers.


Some related references to field trip:

Benamara A, Kherici-Bousnoubra H, Bouabdallah F., 2017. Thermo-mineral waters of Hammam Meskoutine (north-east Algeria): composition and origin of mineralization. J. Water Land Dev., 34, 47–57.

Bouaicha F.,  Dib H., Belkhiri L., Manchar N.,Chabour N., 2017. Hydrogeochemistry and geothermometry of thermal springs from the Guelma region, Algeria. J. Geol. Soc. India, 90, 226–232.

Bouaicha F.,  Dib H., Bouteraa O., Manchar N., Boufaa K., Chabour N., Demdoum A., 2019. Geochemical assessment, mixing behavior and environmental impact of thermal waters in the Guelma geothermal system, Algeria, Acta Geochimica,

Dib, H., 2008. Guide pratique des sources thermales de l’Est algérien. Mémoires du Service Géologique national, Editions du Service Géologique national, Alger, 106p.

Djemmal S., Menani M.R., Chamekh K., Baali F., 2017. The contribution of fracturations in the emergence of the thermal springs in Setif city, Eastern Algeria. Carbonates Evaporites, 12, 141.

Issaad M., A. Boutaleb, O. Kolli, M. Edahbi, M. Benzaazoua, R. Hakkou, 2019. Environmental characterization of mine waste at the Pb–Zn Sidi Kamber abandoned mine (NE Algeria). Rendiconti Lincei. Scienze Fisiche e Naturali, in press.

Maouche S., Abtout A., Merabet N.-E., Aïfa T., Lamali A., Bouyahiaoui B., Bougchiche S., Ayache M., 2013. Tectonic and hydrothermal activities in Debagh, Guelma Basin (Algeria). J. Geol. Res., 1–13.

Nait Amara, B., Aissa, D.E., Maouche, S., Braham, M., Machane, D., Guessoum, N., 2019. Hydrothermal alteration mapping and structural features in the Guelma basin (Northeastern Algeria): contribution of Landsat-8 data. Arabian Journal of Geosciences, 12, 94.

Sahnouni M., J.M. Parés, M. Duval, I. Cáceres, Z. Harichane, J. van der Made, A. Pérez-González, S. Abdessadok, N. Kandi, A. Derradji, M. Medig, K. Boulaghraif, S. Semaw, 2018. 1.9-million- and 2.4-million-year-old artifacts and stone tool–cutmarked bones from Ain Boucherit, Algeria. Science , 362(6420), 1297-1301, 

Ysbaa, S., Haddouche, O., Boutaleb, A., Chemam, M., Sadaoui, M., 2019. Mineral deposits of northeastern Algeria (southern Medjerda mounts and diapiric zone): regional-scale structural controls, spatial distribution, and importance of geophysical lineaments. Arabian Journal of Geosciences, 12, 482.





FIELD TRIP IN CÔTE D'IVOIRE (3rd IGCP638 meeting, Oct. 15-20th, 2018)

The post-conference field trip will be held in the southwest of Côte d'Ivoire from 17 to 20 October 2018 as follows:

4 days field trip along with a transect on the Precambrian Formations, in the area of San Pedro, southwest Côte d'Ivoire, and several visits of mineralized outcrops and mines.

The main aim is to allow the particpants with some specialists of this area (Man-Leo rise) part of the West African Craton (WAC):

- discover a wide variety of geological facies of the Birimian Formations and the transition of the Archean Formations as well, 

- examine and discuss together some key outcrops for the understanding the lithology and the geodynamics in relationship with mineralizations,

- visit an operating mine within the sector, probably gold mine of Angovia (Perseus) in the Yaouré at 25 km west of Yamoussoukro or gold mine ofAgbaou (Endeavour)

Location Fig.1 Fig.2 Fig.3

Main Resources

Mineral Industry (2011, 2012) Rough Diamond (2013) Petroleum Systems (2006)

Gold Resources: RedRock IronRidge Taruga


Noter que le programme de l'excursion de terrain a été modifié pour la raison suivante:

L'excursion géologique est réduite d'une journée car nous n'irons pas à San-Pédro dans le Sud-Ouest. Le voyage est assez long et nous aurons juste une journée d'observation des sites, ce qui est court. De plus, les accès aux principaux affleurements (notamment Monogaga) sont difficiles (pistes non entretenues). Le lendemain (dimanche) nous aurons une journée entière de voyage (10 à 11 heures de route). En résumé, le voyage à San-Pédro est assez long pour seulement une journée de travail; ce qui n'est pas très rentable. Il est donc annulé...

As the geological field trip will take place in the volcanosedimentary trough of Fêtèkro, to ~200 km of Abidjan, instead of San Pedro, we will also visit either one of the goldmines (Agbaou, Endeavour) of this trough, or a mine located at ~50 km NW in the Yaouré unit, the mine of Angovia (Perseus).

Note that the field trip programme has been modified for the following reason:

The geological field trip is reduced one day because we will not go to San-Pédro, southwestwards. The travel is rather long and we will have just one day observation of sites, which is short. Moreover, accesses to the main outcrops (in particular Monogaga) are difficult (tracks not maintained). The next day (sunday) we will have a full day  travel (10 to 11 hours drive). In summary, the travel to San-Pédro is long enough for only one work day; which is not very profitable. It is thus canceled...

Comme l'excursion géologique se déroulera dans le sillon volcanosédimentaire de Fêtèkro, à ~200 km d'Abidjan, à la place de San Pedro, nous visiterons aussi soit l'une des mines d'or (Agbaou, Endeavour) de ce sillon; soit une mine située à ~50 km au nord-ouest dans l'unité du Yaouré, la mine d'Angovia (Perseus).

Details of the field trip programme

Wednesday October 17th, 2018

7h00: field trip departure (breakfast at 7h30)

8h30: major unconformity of the Paleozoic basin on Birimian Formations

9h30: granites (Birimian) in the Comoé Basin (#Hydroelectric dam of Taabo#)?

11h30: beginning of the Anikro cross-section with the pillow lavas

13h00: volcanic ashes (cinerites)

13h30-14h00: lunch break in the field

14h30: the gabbros and country rocks (schists)

15h15: Yamoussoukro with the visit of the Basilica until 16h30

16h45: refreshment break

17h15: stay at a hotel

19h00: dinner

Départ pour le terrain à 7h00 (petit déjeuner à 7h30), discordance majeure du bassin paléozoïque sur le Birimien à 08h30, granites (Birimien) dans le bassin de la Comoé à 9h30, (#Barrage hydroélectrique de Taabo#) ? Début de la coupe d’Anikro avec les pillow lava à 11h30, les cinérites à 13h00, déjeuner sur le terrain de 13h30 à 14h00, les gabbros et schistes encaissants à 14h30, Yamoussoukro à 15h15 avec la visite de la Basilique jusqu’à 16h30, pause rafraichissement à 16h45, hôtel à 17h15 et déjeuner à 19h00.

Thursday October 18th,  2018

8h00: field trip departure

8h30-13h00: continuing the exploration of the Anikro cross-section with details on the basin, the ignimbrites and the periclinal termination

13h00-13h30: lunch break in the field

14h30-16h30: visit of the Mine of Angovia

17h00: back to Yamoussoukro

Départ pour le terrain à 8h00 pour finir la coupe d’Anikro avec les détails sur le bassin, les ignimbrites et la terminaison périclinale jusqu’à 13h00, déjeuner sur le terrain de 13h00 à 13h30, visite de la Mine d’Angovia de 14h30 à 16h30, retour à Yamoussoukro à 17h00.

Friday October 19th, 2018

8h00: departure from Yamoussoukro to San-Pedro

13h00: stop at Soubré to visit the hydroelectric dam

17h30: arrival at San-Pedro

Départ de Yamoussoukro à 8h00 pour San-Pedro, arrêt à Soubré pour voir le barrage hydroélectrique (vers 13h), arrivée à San-Pedro à 17h30.

Saturday October 20th, 2018

8h00: departure to Monogaga and Kounoukou

17h30: back to San-Pedro

Départ à 8h00 pour Monogaga et Kounoukou, retour à San-Pedro à 17h30.

Sunday October 21st, 2018

8h00: departure to Bay of the Sirens (Large-Béréby), with a stop at Adjaméné. The main outcrops of Gbowé and Bay of the Sirens will be visited and possible discussions with participants on the local geology and global geology.

10h30: arrival at Bay of the Sirens

13h30-14h00: departure from Bay of the Sirens

15h30: arrival at San-Pedro

17h00: departure to Abidjan

Départ à 8h00 pour la Baie des Sirènes (Grand-Béréby), arrivée à 10h30. Avant la Baie des Sirènes, on fera un arrêt à Adjaméné. Tous les affleurements de Gbowé et de la Baie des Sirènes seront observés. Départ de la Baie des Sirènes entre 13h30 et 14h00. Arrivée à San-Pedro à 15h30 et départ pour Abidjan à 17h.

The program of the field trip could undergo modifications according to the difficulties of access of certain sites, of which Monogaga for example.

Le programme de l’excursion pourrait subir des modifications en fonction des difficultés d’accès de certains sites, dont Monogaga par exemple.

Field guide-booklet

The guide-booklet in general presents the geology of the Ivory Coast and a more detailed way the sites of observation of the geological field trip. The two areas to be described in detail are the Fetékro through and the SASCA (south-west of the Ivory Coast) domain.
We propose to write the guide-booklet in English and in French.

Notice that the field guidebook will be delivered to only participants of the field trip. The sampling of rocks is authorized.

Livret guide de terrain

Le livret guide présente en général la géologie de la Côte d’Ivoire et de façon plus détaillée les sites d’observation de l’excursion géologique. Les deux régions à décrire en détail sont le sillon de Fetékro et le domaine SASCA (Sud-Ouest de la Côte d’Ivoire).

Nous proposons d’écrire le guide de terrain en anglais et en Français.

Notez que le livret-guide sera distribué seulement aux participants de l'excursion sur le terrain. L'échantillonnage des roches est autorisé.

Coordinators: Dr. A. Kouamelan, Pr. Y. Coulibaly


Participants Fees ( / FCFA)




225 / 150 000

115 / 75 000

450 / 300 000

The number of places is limited to 30.

Participation is on a first come, first served.

1 ~ 655.957 FCFA




FIELD TRIP IN MOROCCO (2nd IGCP638 meeting, Nov. 7-12th, 2017)

Coordinators: Pr. Omar Saddiqui, Pr. Lahssen Baidder, Pr. Hassan Ouanaimi

The post-conference field trip will be held in the south of Morocco from 9 to 12 November 2017. as follows:

4 days field trip along with a transect on the Anti-Atlas Paleoproterozoic Formations, with a possible quick cross along the High-Atlas, and several visits of mineralized outcrops and mines.

Participants Fees () Remarks







The number of places is limited to 20.

Participation is on a first come, first served.

 Post Congress FIELD TRIP

November 9-12, 2017

guided by

O. Saddiqi, L. Baidder (University Hassan II of Casablanca), H. Ouanaimi (University of Marrakech)

 Summary: South of Morocco is one of the most attractive tourist areas with diversified landscapes of mountains covered with snow towards the desert plains. The High-Atlas with its 3000 to 4000 meters constitutes a major climatic barrier with the disturbances of the Atlantic, which represent the arid climate of the sub-Saharan field of the Anti-Atlas in the south of the chain. These areas are occupied by Berber populations which have a long tradition of hospitality. The route of the excursion follows most tourist roads marked by exceptional outcrops illustrating a transect through the High-Atlas and the central Anti-Atlas mountain ranges (Figure 1), which corresponds to the external domain of the Hercynian chain (Variscan, Alleghanian), and which also includes broad inliers dominated by Panafrican terranes. The High-Atlas was formed during the Cenozoic one to the detriment of an aborted Triassic-Jurassic fracture. Consequently, three superimposed wilsonian cycles can be illustrated during this field trip. The route will make it possible to illustrate the complex geological history of these zones. Our objective is to present and discuss the various regional characteristics and sets of themes (sedimentological, structural, magmatic, metamorphic, metallogenic,…), which allowed the recording of the principal geodynamic events during this long geological history. Splendid minerals (erhytrite, vanadinite,…) and fossils (trilobites, goniatites,…) can be bought at several places. During this excursion, the loop Ouarzazate - Bou Azzer - Tazenakht - Ouarzazate makes it possible to the participants to discover the Panafrican chain (domain of external platform, the ophiolitic suture zone of Bou Azzer, the early volcanoclastic cover sequence [late Neoproterozoic] and the folded Paleozoic sediments [Cambrian and Ordovician]). 

A detailed guide-booklet will be provided with GPS positioning of each stop. The sampling of rocks is authorized.


 Structural evolution of the High Atlas/Anti-Atlas Domains: an overview

Paleoproterozoic and Eburnean orogeny

Neoproterozoic and Pan-African orogeny

Paleozoic and Variscan orogeny

Mesozoic and the Central Atlantic opening

Cenozoic and Atlasic deformation

Itinerary and Stops


Day 1 (J1): Casablanca-Marrakech: The coastal block with the phosphates plateaus and Hercynian massifs of Rehamna and Jebilet. Visit of Guemassa polymetallic mine (MANAGEM Group)

Day 2 (J2): Marrakech-Ouarzazate via Tizi n’Tichka: The Marrakech High Atlas (Ouzellarh Block)

Stop J2.1: The North Sub-Atlasic zone at Aït Ourir; Triassic basalts Liassic-Turonian series

Stop J2.2: North Sub-Atlasic zone (continuation); the Cretaceous-Eocene sequence

Stop J2.3: Oued Rdat overall panorama; Triassic Oukaimeden sandstones

Stop J2.4: Tazlida Precambrian basement

Stop J2.5: “Ouarzazate 97 km”: Ordovician slump beds and Bou Ourhioul panorama

Stop J2.6: Agdal Tichka: Middle Cambrian unconformity upon Upper Neoproterozoic rhyolites

Stop J2.7: Tichka Pass panorama

Stop J2.8: Telouet crossroad; South Atlas Fault, Mesozoic-Cenozoic cover

Stop J2.9: Aguelmous-Agouim: the Tiourjdal basalt sequence

Stop J2.10: Imini fault-ramp fold, Cretaceous transgression and Mn mine       

Day 3 (J3): Ouarzazate-Tazenakht-Ouarzazate: Proterozoic basement and Paleozoic cover of the Central Anti-Atlas

Stop J3.1: Panorama High Atlas/Anti-Atlas; Late Proterozoic ignimbrite (Ouarzazate Group OG)

Stop J3.2: Contact Adoudounien/OG

Stop J3.3: Quartzites saghro Group (SG); Pan-African deformation

Stop J3.4: Zenaga Paleoproterozoic schists

Stop J3.5: Tazenakht 2 Ga old granite; OG/Eburnean unconformity

Stop J3.6: Transgression Adoudounian limestones/OG

Stop J3.7: Quartz-diorite SG west of Bou Azzer; Adoudounian unconformity

Stop J3.8: Bou Azzer ophiolite complex

Stop J3.9: Foum Zguid 200 Ma old dolerite mega-dyke

Stop J3.10: Bleida 580 Ma old granodiorite

Day 4 (J4): Ouarzazate-Demnate-Casablanca: High-Atlas crossing and its Precambrian basement

Stop J4.1: The road to the north offers a gorgeous panorama on the South Atlas Front

Stop J4.2: The Skoura inlier with post-Pan-African angular unconformity

Stop J4.3: Landscapes on the Mesozoic cover (CAMP basalts and Liassic carbonates). The Ait Tamlil village is built on allochthonous Devonian shales and limestones

Stop J4.4: A thick Visean turbiditic complex associated with the Devonian nappes

Stop J4.5: The folded/faulted Mesozoic cover offers a famous site with dinosaur foot prints

Stop J4.6: The Imi n'Ifri touristic waterfalls overhang the Demnat town.

Back way to Casablanca

MinesAnti Atlas

Location of the main ore deposits in the Anti-Atlas Belt. The calc-alkaline magmatism of the Ediacaran, late Pan-African metacratonic period was associated with large-scale base metal and gold mineralization. Metallogenic activity was greatest during the final extensional stage, at the Precambrian-Cambrian boundary. It is characterized by world-class precious metal deposits, base-metal porphyry and SEDEX-type occurrences (Gasquet et al., 2005).

Structural map and reliable U-Pb radiometric ages (new and previous) of the Neoproterozoic plutonic and volcanic rocks in the Anti-Atlas and a proposed timetable. Western Anti-Atlas data are from Hassenforder (1987), Aït Malek et al. (1998), Gasquet et al. (2001), Walsh et al. (2002); Central Anti-Atlas from Ducrot and Lancelot (1977), Leblanc and Lancelot (1980), Mifdal and Peucat (1985), Thomas et al. (2002), Samson et al. (2003), Inglis et al. (2004); Thomas et al. (2004); Eastern Anti-Atlas from Magaritz et al. (1991), Landing et al. (1998), Levresse (2001), Cheilletz et al. (2002). International stratigraphic ages (left, in red) are after Amthor et al. (2003) and Gradstein et al. (2004). In bold the three studied inliers (Gasquet et al., 2005).

Anti Atlas Mines

 The Moroccan Anti-Atlas showing the Proterozoic inliers with the numerous polymetallic ore deposits (As, Au, Ag, Co, Cu, Ni, Zn, Pb).

 Download the field trip programme: field trip

 Notice that the field guidebook will be delivered to only participants of the field trip.




FIELD TRIP IN SENEGAL (1st IGCP638 meeting, Dec. 5-10th, 2016)

A guide booklet of the field trip area will be available with the route map and the main stops

Map of Senegal


The post-conference field trip (December 7-10th, 2016) will be held according to the program below:

(1) the Precambrian of the West African Craton of Kedougou, about 700 km from Dakar: Geological cross section from the Greenstone Belts of Mako to the Diale sedimentary basin (Paleoproterozoic/Neoproterozoic).

Tourism: Visits of the Dindefelo falls and the Niokolo Koba National Park

(2) Senegalo-mauritanian Basin : Tertiary and Quaternary volcanism of Dakar and Mbour

Tourism : Geotourism, geoparks and parks (Hann and/or Bandia)

List and route of field trips

Field trip Route Coordinators Fees ($ US) Remarks
Kedougou: Precambrian formations

Geo-cross section:

Niemenike - Mako -Bafoundou - Lame / Diale (Bandafassi-Ibele-Landiene)

Tourism : Dindefelo falls / Niokolo-Koba park

M. Gueye

M. Dabo

Academic    300

Student          50

Professional 600

The number of places is limited.

Participation is on a first come, first served.

Dakar: Tertiary-Quaternary Volcanism & Geosites Mamelles / Ouakam / Cap Manuel / Goree islands

Academic    150

Student          50

The number of places is limited.

Participation is on a first come, first served.

Mbour: Tertiary Volcanism & Geosites Popoguine cliff / Dayane pipe / Bandia park

Academic    150

Student          50

The number of places is limited.

Participation is on a first come, first served.


Field trip Programme to Kédougou

7 Décembre 2016

  6h : Départ de Dakar

12h : Arrivée à Kaolack (Pause déjeuner de 30 mn)

18h : Arrivée à Kédougou (repas et nuitée hôtel)

8 Décembre 2016

6h30 : Départ de Kédougou

    7h : Arrivée à Mako

Station 1 : Basaltes en pillow-lavas de Badian (7h-8h30)

Station 2 : UB Manssarintana, andésite, dolérite, tufs andésitiques, tufs rhyolitiques (8h30-11h30)

Station 3 : Carrière de basaltes de Mako (12h -13h)

              - Pause déjeuner (13-14h30)

Station 4 : Granodiorite, gabbro et shear zone de Andar (14h30-16h)

Station 5 : Granodiorite bananeraie, granite et rhyolite de Niéméniké (16h-17h)

Station 6 : Mine de Torogold (17h-18h)

9 Décembre 2016

Départ 6h arrivée 7h

Station 7 : Contact Birimien Néoprotérozoïque à Landiéné (7h-9h)

Station 8 : Bandafassi- Calcaires à assises siliceux, et sills de dolérite du Paléozoïque dont le métamorphisme thermique occasionne la formation de scapolite sur le calcaire. Déformation : plissement disharmonique (10h-11h)

Station 9 : Schistes graphiteux de Débou-Inda, Déformation : shear zone et plissement (11h30)

Station 10 : Calcaire conglomératique d’Ibel, filons de dolérite et de lamprophyre du Paléozoïque, Déformation : Plissement dysharmonique, déformation des filons, cisaillement (12h-13h)

       - Pause déjeuner (13-14h30)

Station 11 : Visite des chutes de Dindéfelo (14h30-15h30)

17h: Retour à Kédougou et départ pour le parc.

10 Décembre 2016

  7h: Petit déjeuner et Début visite du Parc

12h: Fin visite et déjeuner

14h: Départ retour sur Dakar

23h: Arrivée à Dakar


Carte de localisation des sites à visiter durant l’excursion.


Répartition des grandes séries du Birimien et des Mauritanides (d’après Bassot (1966), modifiée). (1) Supergroupe de Mako, (2) Supergroupe de Dialé-Daléma, (3) Batholite de Badon-Kakadian, (4) Batholite de Saraya, (5) Granitoïde de Gamaye, (6) Granitoïde de Boboti, (7) Granitoïde de type Diombaloye, (8) Granitoïde de type Bondoukou, (9) Série de Falémé, (10) Série de Ségou-Madina kouta, (11) Série de Younkounkou, (12) Série du Mali, (13) Granitoïde du Niokolo Koba, (14) Série de Bakel, (15) Zone de cisaillement. MTZ : Zone transcurente majeure ; SMF : Accident Sénégalo-Malien.


Carte géologique de la boutonnière de Kédougou-Kéniéba (d’après Pons et al., 1992, modifiée par Dabo et al., 2015). Gm : Granite de Gamaye. MTZ : Zone transcurente majeure ; SMF : Accident Sénégalo-Malien. Encadrés : zones à visiter durant l’excursion.