%0 Journal Article %T Neoproterozoic crustal evolution in Southern Chad: Pan-African ocean basin closing, arc accretion and late- to post-orogenic granitic intrusion. %+ Institut des Sciences de la Terre d'Orléans (ISTO) %+ Département des Sciences de la Terre [Univ Ngaoundéré] (UN-FS) %A Pouclet, André %A Vidal, Max %A Doumnang, J.C. %A Vicat, Jean-Paul %A Tchameni, Rigobert %< avec comité de lecture %@ 1464-343X %J Journal of African Earth Sciences %I Elsevier %V 44 %P 543-560 %8 2006 %D 2006 %R 10.1016/j.jafrearsci.2005.11.019 %K Chad %K Pan-African orogen %K Volcanic arc %K Post-orogenic granites %K Neoproterozoic %Z Sciences of the Universe [physics]/Earth Sciences/Applied geologyJournal articles %X In the Lake Léré region, southern Chad, Neoproterozoic terrains are distributed in four lithostructural groups that reveal the geotectonic evolution of a part of the Pan-African orogenic domain. The first group includes basaltic volcanic rocks and fine-grained detrital sedimentary rocks of pre-tectonic basins that were emplaced in an extensional regime, close to a volcanic arc. The second and third groups include calc-alkaline gabbroic intrusions emplaced at an upper crustal level and a midcrustal tonalite, respectively, that are interpreted to be the roots of an active margin volcanic arc. These first three groups experienced WNW to ESE compression, and may belong to a fore-arc basic—volcanic arc—back-arc basin system that was accreted eastward to the Palaeoproterozoic Adamaoua-Yadé Block. The fourth group includes post-tectonic granite plutons invading the older groups. This paper documents the accretion processes in the southern margin of the Saharan Metacraton. %G English %2 https://insu.hal.science/hal-00073651/document %2 https://insu.hal.science/hal-00073651/file/Pouclet-JAfricEarthScience-2006.pdf %L hal-00073651 %U https://insu.hal.science/hal-00073651 %~ INSU %~ AFRIQ %~ CNRS %~ UNIV-ORLEANS %~ ISTO %~ OSUC %~ GIP-BE