The poorly-studied Saharan Metacraton of North-Central Africa is located between the Arabian-Nubian Shield in the east, the Tuareg Shield in the west and the Central African Orogenic Belt in the south. The Republic of Chad, constrained within the Saharan Metacraton, comprises a Phanerozoic cover overlying Precambrian basement outcroppings in five distinct massifs: The Mayo Kebbi, Tibesti, Ouaddaï, Yadé and the Guéra. The Guéra Massif is the least studied of the five massifs but it likely preserves structures that were formed during the collision between Congo Craton and Saharan Metacraton. It is composed of diverse igneous rock types including granites, rhyolites, and gabbros. The first zircon U/Pb geochronology of the silicic rocks from the Guéra Massif yielded three main age groups: ~590 Ma, ~570 Ma, ~560 Ma, while a single gabbro yielded an age of ~580 Ma.
The ~590 Ma granites are metaluminous to peraluminous, alkali calcic to calc-alkalic and magnesian in composition. They are similar to granitic rocks typical of cordilleran or volcanic-arc settings (collisional rocks). The younger (≤ 570 Ma) granites and rhyolite are peraluminous to metaluminous, alkali calcic to calc-alkalic but ferroan and are similar in compositions to post-collisional granites (high K, calc-alkaline). Both magnesian and ferroan rocks show the enrichment in LREE with distinct negative Eu anomalies (Eu/Eu* = 0.04-0.88). The negative εNd(t) isotopes (εNd(t) = -14.5 to -0.2), variable ISr values (0.7037-0.7176), low TZr (~700oC) and abundant inherited zircons indicate the granitic rocks are derived primarily from crustal sources.
The ~580 Ma gabbro has a similar age and composition as a mafic, within-plate alkaline complex in West-Cameroon and matches the age of inherited zircons from different rock types around Lake Chad and Lake Fitri suggesting that there was a regional magmatic event at that time despite the dearth of rocks. The major and trace element geochemistry of the gabbro is similar to alkaline within-plate basalt suggesting that it was derived from a garnet-bearing mantle source. The enriched Sr-Nd isotopes (ISr = 0.7056, εNd(t) = -4.6) with the lack of crustal contamination indicates that it may originate from an enriched mantle (EMII) reservoir.
The geochronology and geochemical data indicate that there is a temporal evolution in the composition of rocks with the old, high εNd(t), magnesian collisional granites shifting to young, low εNd(t), ferroan post-collisional granites. The results suggest that the granites in the Guéra Massif were probably derived by the repeated melting of a single crustal source region, from an initially ‘fertile’ source to a ‘less fertile’ source at distinct intervals. The enriched isotopic composition of the Guéra Massif granites contrasts with the depleted compositions of the associated Neoproterozoic granites in southern Chad (Mayo Kebbi Massif, Lake Fitri inliers) indicates a thicker crustal root may exist under the Guéra Massif. The emplacement of different rock types in the Guéra Massif marks the tectonic regime transition from subduction and collision to post-collision within a span of ~40 million years.

Abdel-Monem, A.A., Hurley, P.M., 1979. U–Pb dating of zircon from psammitic gneisses, Wadi Abu Rosheid-Wadi Sikait area, Egypt. Institute of Applied Geology Bulletin, King Abdulaziz University Jeddah, Saudi Arabia 2, 165-170.
Abdelsalam, M.G., and Dawoud, A.S., 1991. The Kabus ophiolite melange, Sudan and its bearing on the western boundary of the Nubian Shield. Journal of the Geological Society 148, 83-92.
Abdelsalam, M.G., Gao, S.S., Liégeois, J.-P., 2011. Upper mantle structure of the Saharan Metacraton. Journal of African Earth Sciences 60, 328-336.
Abdelsalam, M.G., Liégeois, J.-P., Stern, R.J, 2002. The Saharan Metacraton. Journal of African Earth Sciences 34, 119-136.
Abdelsalam, M.G., Stern, R.J., 1996. Mapping Precambrian structures in the Sahara Desert with SIR-C/X-SAR Radar: The Neoproterozoic Keraf Suture, NE Sudan. Journal of Geophysical Research 101, 23063-23076.
Aldanmaz, E., Pearce, J.A., Thirlwall, M.F., Mitchell, J.G., 2000. Petrogenetic evolution of the late Cenozoic, post-collisional volcanism in western Anatolia, Turkey. Journal of Volcanology and Geothermal Research 102, 67-95.
Andersen, T., 2002. Correction of common lead in U-Pb analyses that do not report 204Pb. Chemical Geology 192, 59-79.
Ashwal, L.D., Burke, K., 1989. African lithospheric structure, volcanism and topography. Earth Planetary Science Letters 96, 8-14.
Barbarin, B., 1988. Field evidence for successive mixing and mingling between the Piolard Diorite and the Saint-Julien-la-Vêtre Monzogranite (Nord-Forez, Massif Central, France). Canadian Journal of Earth Sciences 25, 49-59.
Barbarin, B., 1999. A review of the relationships between granitoid types, their origins and their geodynamic environments. Lithos 46, 605-626.
Barbarin, B., Didier, J., 1992. Genesis and evolution of mafic microgranular enclaves through various types of interaction between coexisting felsic and mafic magmas. Earth and Environmental Science Transactions of the Royal Society of Edinburg 83, 145-153.
Bardintzeff, J.M., Liégeois, J.P., Bonin, B., Bellon, H., Rasamimanana, G., 2010. Madagascar volcanic provinces linked to the Gondwana break-up: Geochemical and isotopic evidence for contrasting mantle sources. Gondwana Research 18, 295-314.
Barth, H., Besang, C., Lenz, H., Meinhold, K.-D., 1983. Results of petrographical investigation and Rb/Sr age determinations on nonorogenic ring complexes in the Bayuda Desert, Sudan. Geological Jahrbuch 51, 3-34.
Batchelor, R.A., Bowden, P., 1985. Petrogenetic interpretation of granitoid rock series using multicationic parameters. Chemical Geology 48, 43-55.
Belin, J.M., 1988. Evolution des enclaves basiques et de leur matrice dans un granite. L’exemple du granite porphyroïde de Saint-Gervais d’Auvergnue (Massif Central français). Comptes rendus de l’Académie des sciences. Série 2, Mécanique, Physique, Chimie, Sciences de l'univers, Sciences de la Terre 307, 387-393.
Benkhelil, J., Dainelli, P., Ponsard, J.F., Popoff, M., Saugy, L., 1988. The Benue Trough: wrench-fault related basin on the border of the equatorial Atlantic. In: Manspeizer, W., Triassic-Jurassic rifting. Continental breakup and the origin of the Atlantic Ocean and passive margins. Elsevier, Amsterdam, 787-819.
Black, R., Girod, M., 1970. Late Paleozoic to Recent igneous activity in West Africa and its relationship to basement structure. African Magmatism and Tectonics, 185-210.
Black, R., Liégeois, J.P., 1993. Cratons, mobile belts, alkaline rocks and continental lithospheric mantle: the Pan-African testimony. Journal of the Geological Society 150, 89-98.
Black, R., Lameyre, J., Bonin, B., 1985. The structural setting of alkaline complexes. Journal of African Earth Sciences 3, 5-16.
Black, R., Liégeois, J.P., 1991. Pan-African plutonism of the Damagaram inlier, Niger Republic. Journal of African Earth Sciences 13, 471-482.
Boehnke, P., Watson, E.B., Trail, D., Harrison, T.M., Schmitt, A.K., 2013. Zircon saturation re-revisited. Chemical Geology 351, 324-334.
Bonin, B., 1990. From orogenic to anorogenic settings: evolution of granitoid suites after a major orogenesis. Geological Journal 25, 261-270.
Bonin, B., 2007. A-type granites and related rocks: evolution of a concept, problems and prospects. Lithos 97, 1-29.
Boullier, A.M., Liégeois, J.-P., Black, R., Fabre, J., Sauvage, M., Bertrand, J.M., 1986. Late Pan-African tectonics marking the transition from subduction-related calc-alkaline magmatism to within-plate alkaline granitoids (Adrar des Iforas, Mali). Tectonophysics 132, 233-246.
Bowen, N.L., 1922. The reaction principle in petrogenesis. The Journal of Geology 30, 177-198.
Brito-Neves, B.B., Campos-Neto, M.C., Fuck, R.A., 1999. From Rodinia to Western Gondwana: an approach to the Brasiliano-Pan African Cycle and orogenic collage. Episodes 22, 155-166.
Buiter, S.J., Torsvik, T.H., 2014. A review of Wilson Cycle plate margins: A role for mantle plumes in continental break-up along suture?. Gondwana Research 26, 627-653.
Bussy, F., 1990. The rapakivi texture of feldspars in a plutonic mixing environment: A dissolution-recrystallization process?. Geological Journal 25, 319-324.
Caby, R., Andreopoulos-Renaud, U., Pin, C., 1989. Late Proterozoic arc-continent and continent-continent collision in the Pan-African Trans-Saharan Belt of Mali. Canadian Journal of Earth Sciences 26, 1136-1146.
Chappell, B.W, White, A.J.R., 1974. Two contrasting granite types. Pacific Geology 8, 173-174.
Chappell, B.W., Stephens, W.E., 1988. Origin of infracrustal (I-type) granite magmas. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 79, 71-86.
Chiu, H.-Y., Chung, S.-L., Wu, F.-Y, Liu, D., Liang, Y.-H., Lin, I.J., Iizuka, Y., Xie, L.-W., Wang, Y., Chu, M.-F., 2009. Zircon U-Pb and Hf isotopic constraints from eastern Transhimalayan batholiths on the precollisional magmatic and tectonic evolution in southern Tibet. Tectonophysics 477, 3-19.
Clarke, D.B., 1996. Two centuries after Hutton’s ‘Theory of the Earth’: the status of granite science. In Brown, M., Candela, P.A., Peck, D.L., Stephens, W.E., Walker, R.J., Zen E-an, The Third Hutton Symposium on the origin of granites and related rocks. Geological Society of America 315.
Clarke, F.W., Washington, H.S., 1924. The composition of the Earth’s crust. USGS Professional Paper 127, 1-117.
Clemens, J.D., Holloway, J.R., White, A.J.R., 1986. Origin of an A-type granite: Experimental constraints: American Mineralogist 71, 317-324.
Clifford, T.N, 1967. The Damaran episode in the Upper Proterozoic-Lower Paleozoic structural history of southern Africa. Geological Society of America Special papers, 92-100.
Clifford, T.N., 1968. Radiometric dating and the pre-Silurian geology of Africa. In: Hamilton, E.I., and Farquhar, R.M., (eds.). Radiometric Dating for Geologists, Interscience, London, 299-416.
Cogley, J.G., 1984. Continental margins and the extent and number of the continents. Reviews of Geophysics and Space Physics 22, 101-122.
Collins, W.J., Beams, S.D., White, A.J.R, Chappell, B.W., 1982. Nature and origin of A-type granites with particular reference to southeastern Australia. Contributions to Mineralogy and Petrology 80, 189-200.
Collins, W.J., Huang, H.Q., Jian, X., 2016. Water-fluxed crustal melting produces Cordilleran batholiths. Geology 44, 143-146.
Cordani, U.G., Brito-Neves, B.B., D'Agrella-Filho, M.S., 2003. From Rodinia to Gondwana: a review of the available evidence from South America. Gondwana Research 6, 275-283.
Cox, K.G., Bell, J.D., Pankhurst, R.J., 1979. The interpretation of igneous rocks, George Allen and Unwin
Curtis, P., Lenz, H., 1985. Geologic and geochronological investigations of selected alkali ring igneous complexes in the Nuba Mountains, southern Kordofan, Sudan. Geological Jahrbuch 69, 3-24.
Dall'Agnol, R., Oliveira, D.C., 2007. Oxidized, magnetite-series, rapakivi-type granites of Carajás, Brazil: implications for classification and petrogenesis of A-type granites. Lithos 93, 215–233.
Daly, J.C., Chorowicz, J., Fairhead, J.D, 1989. Rift basin evolution in Africa: the influence of reactivated steep basement shear zones. In Cooper, M.A. and Williams, G.D., Inversion tectonics: Geological Society Special Publication 44, 308-334.
Davidson, J.P., Wilson, I.R., 1989. Evolution of the alkali basalt-trachyte suite from Jebel Marra volcano, Sudan, through assimilation and fractional crystallization. Earth Planetary Science Letters 95, 141-160.
Dawaï, D., Bouchez, J. L., Paquette, J. L., Tchameni, R., 2013. The Pan-African quartz-syenite of Guider (north-Cameroon): magnetic fabric and U–Pb dating of a late-orogenic emplacement. Precambrian Research, 236, 132-144.
Dawson, J.B., 1984. Contrasting types of upper-mantle metasomatism? In: Kornprobst, J. (Ed.), Kimberlites II: The Mantle and Crust-mantle Relationships. Elsevier, Amsterdam, 289–294.
De La Roche, H., Leterrier, J. T., Grandclaude, P., Marchal, M., 1980. A classification of volcanic and plutonic rocks using R1 R2-diagram and major-element analyses-its relationships with current nomenclature. Chemical Geology 29, 183-210.
Dickin, A.P., 2005. Radiogenic isotope geology. Cambridge University Press.
Didier, J., Barbarian, B., 1991. The outstanding contributions of Alfred Labroid to the study of enclaves in magmatic rocks. In: Enclave and Granite Petrology. Elsevier, Amsterdam, 25-32.
Dixon, T.H., 1981. Age and chemical characteristics of some pre-Pan-African rocks in the Egyptian Shield. Precambrian Research 14, 119-133.
D'Lemos, R.S., 1996. Mixing between granitic and dioritic crystal mushes, Guernsey, Channel Islands, UK. Lithos 38, 233-257.
Dodge, F.C.W., Kistler, R.W., 1990. Some additional observations on inclusions in the granitic rocks of the Sierra Nevada. Journal of Geophysical Research: Solid Earth 95, 17841-17848.
Dostal, J., Owen, J.V., Shellnutt, J.G., Keppie, J.D., Gerel, O., Corney, R., 2015. Petrogenesis of the Triassic Bayan-Ulan alkaline granitic pluton in the North Gobi rift of central Mongolia: implications for the evolution of the Early Mesozoic granitoid magmatism in the Central Asian Orogenic Belt. Journal of Asian Earth Science 109, 50-62.
Douce, A.E.P., 1999. What do experiments tell us about the relative contributions of crust and mantle to the origin of granitic magmas? Geological Society, London, Special Publications 168, 55-75.
Duchesne, J.C., Wilmart, E., 1997. Igneous charnockites and related rocks from the Bjerkreim–Sokndal layered intrusion (Southwest Norway): a jotunite (hypersthene monzodiorite)-derived A-type granitoid suite. Journal of Petrology 38, 337-369.
Dupré, B., Allègre, C. J., 1983. Pb–Sr isotope variation in Indian Ocean basalts and mixing phenomena. Nature 303, 142-146.
Eby, G.N., 1990. The A-type granitoids: a review of their occurrence and chemical characteristics and speculations on their petrogenesis. Lithos 26, 115-134.
El Makkrouf, A.A., 1988. Tectonic interpretation of Jabal Eghei area and its regional application to Tibesti orogenic belt, south central Libya (SPLAJ). Journal of African Earth Sciences (and the Middle East) 7, 945-967.
Faure, G., 1977. Principles of isotope geology.
Fernandez, A., Barbarin, B., 1991. Relative rheology of coeval mafic and felsic magmas: nature of resulting interaction processes and shape and mineral fabrics of mafic microgranular enclaves. Enclaves and granite petrology, 263-275.
Ferré, E., Gleizes, G., Caby, R. 2002. Obliquely convergent tectonics and granite emplacement in the Trans-Saharan belt of Eastern Nigeria: a synthesis. Precambrian Research 114, 199–219.
Ferré, E., Déléris, J., Bouchez, J.L., Lar, A.U., Peucat, J.-J., 1996. The Pan-African reactivation of Eburnean and Archaean provinces in Nigeria: structural and isotopic data. Journal of the Geological Society of London 153, 719–728.
Floyd, P.A., Winchester, J.A, 1975. Magma type and tectonic setting discrimination using immobile elements. Earth and Planetary science letters 27, 211-218.
Fezaa, N., Liégeois, J.-P., Abdallah, N., Cherfouh, E.H., De Waele, B., Bruguier, O., Ouabadi, A., 2010. Late Ediacaran geological evolution (575–555 Ma) of the Djanet terrane, eastern Hoggar, Algeria, evidence for a Murzukian intracontinental episode. Precambrian Research 180, 299–327.
Foster, D.A., Hyndman, D.W., 1990. Magma mixing and mingling between synplutonic mafic dikes and granite in the Idaho-Bitterroot batholith. Geological Society of America Memoirs 174, 347-358.
Fourcade, S., Javoy, M., 1991. Sr-Nd-O isotopic features of mafic microgranular enclaves and host granitoids from the Pyrenees, France: evidence for their hybrid nature and inference on their origin. In: Didier, J., Barbarin, B. (eds.) Enclaves and Granite Petrology. Elsevier, Amsterdam, 345-364.
Frey, F.A., Garcia, M.O., Wise, W.S., Kennedy, A., Gurriet, P., Albarede, F., 1991. The evolution of Mauna Kea volcano, Hawaii: petrogenesis of tholeiitic and alkalic basalts. Journal Geophysical Research 96, 14347–14375.
Frost, B.R., Barnes, C.G., Collins, W.J., Arculus, R.J., Ellis, D.J., Frost, C.D., 2001. A geochemical classification for granitic rocks. Journal of Petrology, 42, 2033-2048.
Frost, C.D., Frost, B.R., 2011. On the ferroan (A-type) granitoids: their compositional variability and modes of origin. Journal of Petrology 52, 39-53.
Fujimaki H., Tatsumoto, M., Ki Aoki, 1984. Partion coefficients of Hf, Zr, and REE between phenocrysts and groundmasses. Journal of Geophysics Research 89, 662-672.
Gao, S., Rudnick, R.L., Yuan, H.L., Liu, X.M., Liu, Y.S., Xu, W.L., Ling, W.L., Ayers, J., Wang, X.C. and Wang, Q. H., 2004. Recycling lower continental crust in the North China craton. Nature 432, 892-897.
Genik, G.J., 1992. Regional framework, structural and petroleum aspects of rift basins in Niger, Chad and the Central African Republic (CAR). Tectonophysics 213, 169-185.
Genik, G.J., 1993. Petroleum geology of Cretaceous-Tertiary rift basins in Niger, Chad, and Central African Republic. AAPG Bulletin 77, 1405-1434.
Ghuma, M.A., Rogers, J.J., 1978. Geology, geochemistry, and tectonic setting of the Ben Ghnema batholith, Tibesti massif, southern Libya. Geological Society of America Bulletin, 89, 1351-1358.
Gill, R., Ramsey, M.H., 1997. What a geochemical analysis means. Modern analytical chemistry: an introduction to quantitative chemical analysis techniques for earth, environmental and materials scientists, 1-11.
Gourgaud, A., 1991. Comagmatic enclaves in lavas from the Mont-Dore composite volcano, Massif Central, France. In: Didier, J. and Barbarin, B. (eds.), Enclaves and Granite Petrology. Elsevier, Amsterdam, 221-233.
Gourgaud, A., Vincent, P.M., 2004. Petrology of two continental alkaline intraplate series at Emi Koussi volcano, Tibesti, Chad. Journal of volcanology and geothermal research 129, 261-290.
Green, T., Blundy, J., Adam, J., Yaxley, G., 2000. SIMS determination of trace element partition coefficients between garnet, clinopyroxene and hydrous basaltic liquids at 2-7.5 Gpa and 1080-1200oC. Lithos 53, 165-187
Guiraud, R., Maurin, J.C., 1992. Early Cretaceous rifts of Western and Central Africa: an overview. Tectonophysics, 213, 153-168.
Hanchar, J.M., Watson, E.B., 2003. Zircon saturation thermometry. Reviews in mineralogy and geochemistry 53, 89-112.
Harker, A., 1909. The natural history of igneous rocks. Macmillam.
Harms, U., Darbyshire, D.P.F., Denkler, T., Hengst, M., Schandelmeier, H., 1994. Evolution of the Neoproterozoic Delgo sutures zone and crustal growth in northern Sudan: geochemical and radiogenic isotope constrains. Geological Rundschau 83, 591–603.
Harms, U., Schandelmeier, H., Darbyshire, D.P.F., 1990. Pan-African reworked early/middle Proterozoic crust in NE Africa W of the Nile: Sr and Nd isotope evidence. Journal of Geological Society, London 147, 859–872.
Harris, N.B.W., Hawkesworth, C.J., Ries, A.C., 1984. Crustal evolution in NE and E Africa from model Nd ages. Nature 309, 773–776.
Henry, B., Liégeois, J.-P., Nouar, O., Derder, M.E.M., Bayou, B., Bruguier, O., Ouabadi, A., Belhai, D., Amenna, M., Hemmi, A., Ayache, M., 2009. Repeated granitoid intrusions during the Neoproterozoic along the western boundary of the Saharan Metacraton, eastern Hoggar, Tuareg shield, Algeria: an AMS and U-Pb zircon age study. Tectonophysics 474, 417–434.
Huppert, H.E., Sparks, R.S., Turner, J.S., 1984. Some effects of viscosity on the dynamics of replenished magma chambers. Journal of Geophysical Research 89, 6857-6877.
Irving, A.J, Frey, F.A., 1978. Distribution of trace elements between garnet megacrysts and host volcanic liquids of kimberlitic to rhyolitic composition. Geochemica et Cosmochimica Acta 42, 771-787.
Isseini, M., Andre-Mayer, A.S., Vanderhaegh, O., Barbey, P., Deloule, E., 2012. A-type granites from the Pan-African orogenic belt in southwestern Chad constrained using geochemistry, Sr-Nd isotopes and U-Pb geochronology. Lithos 153, 39-52.
Isseini, M., Hamit, A., Abderamane, M., 2013. The tectonic and geological framework of the Mongo area, a segment of the Pan-African Guera Massif in Central Chad: evidences from field observations and remote sensing. Revue Scientifique du Tchad 1, 4-12.
Johnson, K.T.M., 1998. Experimental determination of partition coefficients for rare earth and high-field-strength elements between clinopyroxene, garnet, and basaltic melt at high pressures. Contributions to Mneralogy and Petrology 133, 60-68
Johnson, P.R., Woldehaimanot, B., 2003. Development of the Arabian-Nubian Shield: perspectives on accretion and deformation in the northern East African Orogen and the assembly of Gondwana. Geological Society, London, Special Publications, 206, 289-325.
Jung, S., Mezger, K., Hoernes, S., 1998. Petrology and geochemistry of syn- to post-collisional metaluminous A-type granites-a major and trace element and Nd-Sr-Pb-O-isotope study from the Proterozoic Damara Belt, Namibia. Lithos 45, 147-175.
Kasser, M.Y., 1995. Evolution précambrienne de la région du Mayo Kebbi (Tchad). Un segment de la Chaîne Panafricaine. Thèse de Doctorat, Muséum d'Histoire Naturelle de Paris, France, 217 pp.
Kennedy, W.Q., 1964. The structural differentiation of Africa in the Pan-African (±500 Ma) tectonic episode. Research Institute of African Geology, University of Leeds, 8th Annual Report, 48-49.
Key, R.M., Charsley, T.J., Hackman, T.J., Wilkinson, A.F., Rundle, C.C., 1989. Superimposed upper Proterozoic collision controlled orogenies in the Mozambique Orogenic belt of Kenya. Precambrian Research 44, 197–225.
King, P.L., White, A.J.R., Chappell, B.W., Allen, C.M., 1997. Characterization of origin of aluminous A-type granites from the Lachlan fold belt, Southeastern Australia. Journal of Petrology 38, 391-391.
Klerkx, J., Deutsch, S., 1977. Resultats preliminaires obtenus par la methode Rb/Sr sur l’age des formations Precambriennes de la region d’Uweinat (Libye). Musee Royal de l’Afrique Centrale. Déepartement Géeologie Minéeralogie Rapport Annuel, 83-94.
Koyaguchi, T., Blake, S., 1991. Origin of mafic enclaves: constraints on the magma mixing model from fluid dynamic experiments. In: Didier, J. and Barbarin, B. (eds.), Enclaves in Granite petrology. Elsevier, Amsterdam, 415-429.
Kröner, A., 1979. Pan-African mobile belts as evidence for a transitional tectonic regime from intraplate orogeny to plate margin orogeny. In Tahoun, S.A., Evolution and mineralization of the Arabian-Nubian shield. Pergamon Press, Oxford 1, 21-37.
Kröner, A., 1980. Pan African crustal evolution. Episodes 2, 3-8.
Kröner, A., 1982. Rb-Sr geochronology and tectonic evolution of the Pan-African Damara belt of Namibia, southwestern Africa. American Journal of Science 282, 1471-1507.
Kröner, A., 2004. Pan-African Orogeny. Encyclopedia of Geology 1, 1-12.
Kröner, A., Stern, R.J., Dawoud, A.S., Compston, W., Reischmann, T., 1987. The Pan-African continental margin in NE Africa: evidence from a geochronological study of granulites at Sabaloka, Sudan. Earth Planetary Science Letters 85, 91–104.
Kröner, A., Todt, W., Hussein, I.M., Mansour, M., Rashwan, A.A., 1992. Dating of late Proterozoic ophiolites in Egypt and the Sudan using the single grain zircon evaporation technique. Precambrian Research 59, 15–32.
Kusnir, I., Moutaye, H. A., 1997. Ressources minérales du Tchad: une revue. Journal of African Earth Sciences 24, 549-562.
Küster, D., Liégeois, J.-P., 2001. Sr-Nd isotopes and geochemistry of the Bayuda Desert high-grade metamorphic basement (Sudan): an early Pan-African oceanic convergent margin, not the edge of the East Saharan ghost craton? Precambrian Research 109, 1-23.
Kwékam, M., Affaton, P., Bruguier, O., Liégeois, J. P., Hartmann, G., Njonfang, E., 2013. The Pan-African Kekem gabbro-norite (West-Cameroon), U–Pb zircon age, geochemistry and Sr–Nd isotopes: Geodynamical implication for the evolution of the Central African fold belt. Journal of African Earth Sciences 84, 70-88.
Kwékam, M., Liégeois, J.P., Njonfang, E., Affaton, P., Hartmann, G., Tchoua, F., 2010. Nature, origin and significance of the Fomopéa Pan-African high-K calc-alkaline plutonic complex in the Central African fold belt (Cameroon). Journal of African Earth Sciences 57, 79-95.
Latourrette, T.Z., Kennedy, A.K., Wasserburg, G.J., 1993. Thorium-Uanium fractionation by garnet -Evidence for a deep source and rapid rise of oceanic basalts. Science 261, 739-742.
LeMaitre, R.W., Bateman, P., Dudek, A., Keller, J., Lameyre, J., Le Bas, M.J., Sabine, P.A., Schmid, R., Sorensen, H., Streckeisen, A., Woolley, A.R., Zanettin, B., 1989. A classification of igneous rocks and glossary of terms. Blackwell Scientific Publications, Oxford, pp. 193.
Li, Z.X., Powell, C.M., 2001. An outline of the palaeogeographic evolution of the Australasian region since the beginning of the Neoproterozoic. Earth-Science Reviews 53, 237-277.
Li, Z.X., Zhang, L., Powell, C.M., 1995. South China in Rodinia: part of the missing link between Australia–East Antarctica and Laurentia? Geology 23, 407-410.
Liégeois, J.P., 1998. Some words on the post-collisional magmatism. Lithos 45, 15-18.
Liégeois, J.P., Abdelsalam, M.G., Ennih, N., Ouabadi A., 2013. Metacraton: Nature, genesis and behavior. Gondwana Research 23, 220-237.
Liégeois, J.P., Black, R., 1987. Alkaline magmatism subsequent to collision in the Pan-African belt of the Adrar des Iforas (Mali). Geological Society, London, Special Publications 30, 381-401.
Liégeois, J.P., Black, R., Klerkx, J., Michot, J., 1984. Pétrographie et géochronologie Rb-Sr de la transition calco-alcaline-alcaline fini-panafricaine dans l'Adrar des Iforas (Mali): accrétion crustale au Précambrien supérieur. Géologie africaine-African Geology, 115-146.
Liégeois, J.P., Black, R., Navez, J., Latouche, L., 1994. Early and late Pan-African orogenies in the Air assembly of terranes (Tuareg Shield, Niger). Precambrian Research 67, 59-88.
Liégeois, J.P., Latouche, L., Boughrara, M., Navez, J., Guiraud, M., 2003. The LATEA metacraton (Central Hoggar, Tuareg shield, Algeria): behaviour of an old passive margin during the Pan-African orogeny. Journal of African Earth Sciences 37, 161-190
Liégeois, J.P., Navez, J., Hertogen, J., Black, R., 1998. Contrasting origin of post-collisional high-K calc-alkaline and shoshonitic versus alkaline and peralkaline granitoids. The use of sliding normalization. Lithos 45, 1-28.
Loiselle, M.C., Wones D., 1979. Characteristics and origin of anorogenic granites. Geological Society of America, Abstracts with Programs 11, 468.
Ludwig, K.R., 2003. Isoplot/Ex, version 3: a geochronological toolkit for Microsoft excel: Berkeley. California, Geochronology Center Berkeley.
Maniar, P.D., Piccoli, P.M., 1989. Tectonic discrimination of granitoids. Geological society of America bulletin 101, 635-643.
McKenzie, D.A.N., Onions, R.K., 1991. Partial melt distributions from inversion of rare earth element concentrations. Journal of Petrology 32, 1021-1091.
Medlicott, H.B., Blanford, W.T., 1879. A Manual of the Geology of India. Geological Survey of India, Calcutta.
Meert, J.G., 2003. A synopsis of events related to the assembly of eastern Gondwana. Tectonophysics 362, 1-40.
Meert, J.G., Torsvik, T.H., 2003. The making and unmaking of a supercontinent: Rodinia revisited. Tectonophysics 375, 261-288.
Meinhold, K.D., 1979. The Precambrian basement complex of Bayuda Desert, northern Sudan. Review Geology, Geographical Physics 21, 359-401.
Middlemost, E.A., 1985. Magmas and magmatic rocks: an introduction to igneous petrology. Longman, London, pp. 266.
Miller, C.F., McDowell, S.M., Mapes, R.W., 2003. Hot and cold granites? Implications of zircon saturation temperatures and preservation of inheritance. Geology 31, 529-532.
Moreau, C., Demaiffe, D., Bellion, Y., Boullier, A.M., 1994. A tectonic model for the location of Palaeozoic ring complexes in Air (Niger, West Africa). Tectonophysics 234, 129-146.
Murphy, J.B., Shellnutt, J.G., Collins, W.J., 2017. Late Neoproterozoic to Carboniferous genesis of A-type magmas in Avalonia of northern Nova Scotia: repeated partial melting of anhydrous lower crust in contrasting tectonic environments. International Journal of Earth Sciences, 1-13.
Nardi, L.V., Bonin, B., 1991. Post-orogenic and non-orogenic alkaline granite associations: the Saibro intrusive suite, southern Brazil-a case study. Chemical Geology 92, 197-211.
Ngako, V., Affaton, P., Njonfang, E., 2008. Pan-African tectonics in northwestern Cameroon: implication for the history of western Gondwana. Gondwana Research 14, 509-522.
Njanko, T., Nédélec, A., Affaton, P., 2006. Synkinematic high-K calc-alkaline plutons associated with the Pan-African Central Cameroon shear zone (W-Tibati area): petrology and geodynamic significance. Journal of African Earth Sciences 44, 494-510.
Nomo, E.N., Tchameni, R., Vanderhaeghe, O., Sun, F., Barbey, P., Tekoum, L., Tchunte, P.M.F, Eglinger, A., Fouotsa, N.A.S., 2017. Structure and LA-ICP-MS zircon U–Pb dating of syntectonic plutons emplaced in the Pan-African Banyo-Tcholliré shear zone (central north Cameroon). Journal of African Earth Sciences 131, 251-271.
Nzenti, J.P., Barbey, P., Macaudiere, J., Soba, D., 1988. Origin and evolution of the late Precambrian high-grade Yaounde gneisses (Cameroon). Precambrian Research 38, 91-109.
Oliveira, D.C., Dall'Agnol, R., Barros, C.E.M., Oliveira, M.A., 2009. Geology, geochemistry and magmatic evolution of the Paleoproterozoic, anorogenic oxidized A-type Redenção granite of the Jamon Suite, eastern Amazonian Craton, Brazil. The Canadian Mineralogist 47, 1441–1468.
Patchett, P.J., Chase, C.G., 2002. Role of transform continental margins in major crustal growth episodes. Geology 30, 39-42.
Pearce, J.A., Gale, G.H., 1977. Identification of ore-deposition environment from trace-element geochemistry of associated igneous host rocks. Geological Society, London, Special Publications 7, 14-24.
Pearce, J.A., Harris, N.B., Tindle, A. G., 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology 25, 956-983.
Pegram, W.J., Register, J.K., Fullagar, P.D., Ghuma, M.A., Rogers, J.J.W., 1976. Pan-African ages from a Tibesti massif batholith, southern Libya. Earth and Planetary Scientific Letters 30, 123-128.
Penaye, J., Kroner, A., Toteu, S.F., Van Schmus, W.R., Doumnang, J.C., 2006. Evolution of the Mayo Kebbi region as reveal by zircon dating: an early (ca. 740 Ma) Pan-African magmatic arc in south-western Chad. Journal of African Earth Sciences 44, 530-542.
Pin, C., 1991. Sr-Nd isotopic study of igneous and metasedimentary enclaves in some Hercynian granitoids from the Massif Central, France. In: Didier, J. and Barbarin, B. (eds.), Enclaves and Granite Petrology. Elsevier, Amsterdam, 333-343.
Pin, C., Binon, M., Belin, J.M., Barbarin, B., Clemens, J.D., 1990. Origin of microgranular enclaves in granitoids: Equivocal Sr‐Nd Evidence from Hercynian Rocks in the Massif Central (France). Journal of Geophysical Research: Solid Earth 95, 17821-17828.
Pin, C., Poidevin, J.L., 1987. U–Pb zircon evidence for a Pan-African granulite facies metamorphism in the Central African Republic. A new interpretation of the high-grade series of the northern border of the Congo Craton. Precambrian Research 36, 303–312.
Pinna, P., Calvez, J.Y., Abessolo, A., Angel, J.M., Mekoulou-Mekoulou, T., Mananga, G., Vernhet, Y. 1994. Neoproterozoic events in the Tcholliré area: Pan-African crustal growth and geodynamics in central-northern Cameroon (Adamawa and North Provinces). Journal of African Earth Sciences,18, 347–353.
Pitcher, W.S., 1997. The Nature and Origin of Granite, Chapman and Hall, London.
Pouclet, A., Vidal, M., Doumnang, J.-C., Vicat, J.P., Tchameni, R., 2006. Neoproterozoic crustal evolution in Southern Chad: Pan-African ocean basin closing, arc accretion and late- to post-orogenic granitic intrusion. Journal of African Earth Sciences 44, 543–560.
Pupin, J.P., 1980. Zircon and granite petrology. Contributions to Mineralogy and Petrology 73, 207-220.
Radain, A.A., Ali, S., Nasseef, A.O., Abdel-Monem, A.A., 1987. Rb-Sr geochronology and geochemistry of plutonic rocks from the Wadi Shuqub quadrangle, west-central Arabian Shield. Journal of African Earth Sciences 6, 553-568.
Rapela, C.W., Heaman, L.M., McNutt, R.H., 1982. Rb-Sr geochronology of granitoid rocks from the Pampean Ranges, Argentina. Journal of Geology 90, 574-582.
Ries, A.C., Shackleton, R.M., Dawoud, A.S., 1985. Geochronology, geochemistry and tectonics of the NE Bayuda Desert in northern Sudan: Implication for the western margin of the late Proterozoic fold belt of NE Africa. Precambrian Research 30, 43–62.
Riley, T.R., Knight, K.B., 2001. Age of pre-break-up Gondwana magmatism. Antarctic Science 13, 99-110.
Rollinson, H.R., 2014. Using geochemical data: evaluation, presentation, interpretation. Routledge.
Ruiz, C., Fernández-Leyva, C., Locutura, J., 2008. Geochemistry, geochronology and mineralisation potential of the granites in the Central Iberian Zone: The Jalama batholith. Chemie der Erde-Geochemistry 68, 413-429.
Rudnick, R.L., Gao, S., 2003. Composition of the Continental crust. Treatise on Geochemistry 3, 1-64.
Saleh, M.A., 1994. Bibliographie Géologique du Tchad 1903–1994. CIFEG Publication Occasionelle 30. I–XXIV, 1–181.
Schandelmeier, H., Darbyshire, D.P.F., Harms, U., Richter, A., 1988. The E Saharan craton: evidence for pre-Pan-African crust in NE Africa W of the Nile. In: El Gaby, S., Greiling, R.O. (Eds.), The Pan-African belts of NE Africa and Adjacent areas. Friedr Vieweg and Sohn, pp. 69–94.
Schluter, T., 2008. Geological Atlas of Africa. Springer-Verlag, Berlin, pp. 307.
Schmitt, A.K., Simon, J.I., 2004. Boron isotopic variation in hydrous rhyolitic melts: a case study from Long Valley, California. Contributions to Mineralogy and Petrology 146, 590-605.
Seguem, N., Alexandre, G.A..A, Klötzli, U., Kepnamou, A.D., Emmanuel, E.G., 2014. Petrography and geochemistry of Precambrian basement straddling the Cameroon-Chad border: The Touboro Baïkokoum area. International Journal of Geosciences 5, 418-431.
Shand, S.J., 1943. Eruptive rocks: their genesis, composition, classification, and their relation to ore deposits with a chapter on meteorites. T. Murby and Co., London.
Shang, C.K., Satir, M., Morteani, G., Taubald, H., 2010. Zircon and titanite age evidence for coeval granitization and migmatization of the early Middle and early Late Proterozoic Saharan Metacraton; example from the central North Sudan basement. Journal of African Earth Sciences 57, 492-524.
Shellnutt, J.G., Lee, T.Y., Yang, C.C., Hu, S.T., Wu, J.C., Wang, K.L., and Lo, C.H., 2015. Late Permian mafic rocks identified within the Doba basin of southern Chad and their relationship to the boundary of the Saharan Metacraton. Geological Magazine 152, 1073-1084.
Shellnutt, J.G., Lee, T.Y., Torng, P.K., Yang, C.C., and Lee, Y.H., 2016. Late Cretaceous intraplate silicic volcanic rocks from the Lake Chad region: An extension of the Cameroon volcanic line? Geochemistry, Geophysics, Geosystems 17, 2803-2824.
Shellnutt, J.G., Pham, N.H.T., Denyszyn, S.W., Yeh, M.-W., Lee, T.-Y., 2017a. Timing of collisional and post-collisional Pan-African Orogeny silicic magmatism in south-central Chad. Precambrian Research 301, 113-123.
Shellnutt, J.G., Yeh, M.W, Lee, T.Y, Iizuka, Y., Pham, N.H.T, Yang, C.C, 2018. The formation of post-collisional granites by lithospheric delamination along the Chad Lineament, Saharan Metacraton, South-Central Chad. Lithos, in press.
Shervais, J.W., 1982. Ti-V plots and the petrogenesis of modern and ophiolitic lavas. Earth and Planetary Science Letters 59, 101-118.
Stern, R.J., 1994. Arc assembly and continental collision in the Neoproterozoic E African Orogen: implication for the consolidation of Gondwanaland. Annual Reviews of Earth Planetary Sciences 22, 319–351.
Stern, R.J., Johnson, P.R., Kröner, A., Yibas, B., 2004. Neoproterozoic ophiolites of the Arabian-Nubian shield. Developments in Precambrian Geology, 13, 95-128.
Stern, R.J., Kröner, A., Reischmann, T., Bender, R., Dawoud, A.S., 1994. Precambrian basement around Wadi Halfa: a new perspective on the evolution of the Central Saharan Ghost craton. Geologische Rundschau 83, 564–577.
Storey, B.C., 1995. The role of mantle plumes in continental breakup: case histories from Gondwanaland. Nature 377, 301-308.
Streckeisen, A., 1974. Classification and nomenclature of plutonic rocks recommendations of the IUGS subcommission on the systematics of igneous rocks. Geologische Rundschau 63, 773-786.
Suayah, I.B., Miller, J.S., Miller, B.V., Bayer, T.M., Rogers, J.J., 2006. Tectonic significance of Late Neoproterozoic granites from the Tibesti massif in southern Libya inferred from Sr and Nd isotopes and U–Pb zircon data. Journal of African Earth Sciences 44, 561-570.
Sultan, M., Tucker, R.D., El Alfy, Z., Attia, R., Ragab, A.G., 1994. U–Pb (zircon) ages for the gneissic terrane west of the Nile, southern Egypt. Geologische Rundschau 83, 514–522.
Sun, S.S., McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders, A.D., Norry, M.J. (eds.), Magmatism in the Ocean Basins. Geological Society of London Special Publication 42, 313-435.
Taylor, P.N, Jones, N.W, Moorbath, S., 1984. Isotopic assessment of relative contributions from crust and mantle sources to magma genesis of Precambrian granitoid rocks. Philosophical Transactions of the Royal Society of London A310, 605-625.
Taylor, S.R., McLennan, S.M., 1995. The geochemical evolution of the continental crust. Reviews of Geophysics 33, 241-265.
Tchameni, R., Pouclet, A., Penaye, J., Ganwa, A.A., Toteu, S.F., 2006. Petrography and geochemistry of the Ngaoundéré Pan-African granitoids in Central North Cameroon: implications for their sources and geological setting. Journal of African Earth Sciences 44, 511-529.
Tindle, A.G., 1991. Trace element behaviour in microgranular enclaves from granitic rocks. In: Didier, J. and Barbarin, B. (eds.), Enclaves and Granite Petrology. Elsevier, Amsterdam, 313-332.
Torsvik, T.H., Cocks, L.R., 2013. Gondwana form top to base in space and time. Gondwana Research 24, 999-1030.
Toteu, S.F., Fouateu, R.Y., Penaye, J., Tchakounte, J., Mouangue, A.C.S., Van Schumus, W.R., Deloule, E., Stendal, H., 2006b. U–Pb dating of plutonic rocks involved in the nappe tectonic in southern Cameroon: consequence for the Pan-African orogenic evolution of the central African fold belt. Journal of African Earth Sciences 44, 479-493.
Toteu, S.F., Penaye, J., Djomani, Y.H.P., 2004. Geodynamic evolution of the Pan-African belt in central Africa with special reference to Cameroon. Canadian Journal of Earth Sciences 41, 73-85.
Toteu, S.F., Van Schmus, R.W., Penaye, J., Nyobe, J.B., 1994. U-Pb and Sm-Nd evidence for Eburnian and Pan-African high-grade metamorphism in cratonic rocks of southern Cameroon. Precambrian Research 67, 321-347.
Toteu, S.F., Van Schumus, W.R., Penaye, J., Michard, A., 2001. New U-Pb and Sm-Nd data from North-central Cameroon and its bearing on the pre-Pan-African history of Central Africa. Precambrian Research 108, 45-73.
Unrug, R., 1997. Rodinia to Gondwana: the geodynamic map of Gondwana supercontinent assembly. GSA Today 7, 1–6.
Vail, J.R., 1985. Pan-African (late Precambrian) tectonic terrains and the reconstruction of the Arabian-Nubian Shield. Geology 13, 839-842.
Veevers, J.J., 2003. Pan-African is Pan-Gondwanaland: oblique convergence drives rotation during 650–500 Ma assembly. Geology 31, 501-504.
Vernon, R.H., 1984. Microgranitoid enclaves in granites-globules of hybrid magma quenched in a plutonic environment. Nature 309, 438-439.
Vernon, R.H., 1990. Crystallization and hybridism in microgranitoid enclave magmas: microstructural evidence. Journal of Geophysical Research: Solid Earth 95, 17849-17859.
Watson, E.B., Harrison, T.M., 1983. Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types. Earth and Planetary Science Letters 64, 295-304.
White, A.J.R., 1979. Sources of granite magmas. Geological Society of America Abstracts with Programs 11, no 7, 539.
White, A.J.R., Chappell, B.W., 1988. Some supracrustal (S-type) granites of the Lachlan Fold Belt. Earth and Environmental Science Transactions of The Royal Society of Edinburgh, 79, 169-181.
Wiebe, R.A., Smith, D., Sturm, M., King, E.M., Seckler, M.S., 1997. Enclaves in the Cadillac Mountain granite (coastal Maine): samples of hybrid magma from the base of the chamber. Journal of Petrology 38, 393-423.
Winchester, J.A., Floyd, P.A., 1976. Geochemical magma type discrimination: application to altered and metamorphosed basic igneous rocks. Earth and Planetary Science Letters 28, 459-469.
Windley, B.F., 1984. The evolving continents, 2nd edition. John Wiley and Sons, New York, 399.
Winter, J.D. 2010. An introduction to igneous and metamorphic petrology. Prentice Hall, New York.
Wolff, J.P., 1964. Carte géologique de la Republique du Tchad, Echelle 1:1,500,000. Bureau de Recherche Géologique Minière.
Wyllie, P.J., Cox, K.G., Biggar, G.M., 1962. The habit of apatite in synthetic systems and igneous rocks. Journal of Petrology 3, 238-243.
Zindler, A., Hart, S., 1986. Chemical geodynamics. Annual Review of Earth and Planetary Sciences 14, 493-571.