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Neoproterozoic magmatic evolution of the southern Ouaddaï Massif (Chad)

Djerossem, Félix; Berger, Julien; Vanderhaeghe, Olivier; Isseini, Moussa; Ganne, Jérôme; Zeh, Armin 1
1 Institut für Angewandte Geowissenschaften (AGW), Karlsruher Institut für Technologie (KIT)


This paper presents new petrological, geochemical, isotopic (Nd) and geochronological data on magmatic rocks from the poorly known southern Ouaddaï massif, located at the southern edge of the so-called Saharan metacraton. This area is made of greenschist to amphibolite facies metasediments intruded by large pre- to syn-tectonic batholiths of leucogranites and an association of monzonite, granodiorite and biotite granite forming a late tectonic high-K calc-alkaline suite. U-Pb zircon dating yields ages of 635 ± 3 Ma and 613 ± 8 Ma on a peraluminous biotite-leucogranite (containing numerous inherited Archean and Paleoproterozoic zircon cores) and a muscovite-leucogranite, respectively. Geochemical fingerprints are very similar to some evolved Himalayan leucogranites suggesting their parental magmas were formed after muscovite and biotite dehydration melting of metasedimentary rocks. A biotite-granite sample belonging to the late tectonic high-K to shoshonitic suite contains zircon rims that yield an age of 540 ± 5 Ma with concordant inherited cores crystallized around 1050 Ma. Given the high-Mg# (59) andesitic composition of the intermediate pyroxene-monzonite, the very similar trace-element signature between the different rock types and the unradiogenic isotopic signature for Nd, the late-kinematic high-K to shoshonitic rocks formed after melting of the enriched mantle and further differentiation in the crust. ... mehr

Verlagsausgabe §
DOI: 10.5445/IR/1000129747
Veröffentlicht am 16.02.2021
DOI: 10.1051/bsgf/2020032
Zitationen: 5
Web of Science
Zitationen: 5
Zitationen: 6
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Geowissenschaften (AGW)
KIT-Zentrum Klima und Umwelt (ZKU)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2020
Sprache Englisch
Identifikator ISSN: 1777-5817
KITopen-ID: 1000129747
Erschienen in Bulletin de la Société Géologique de France
Verlag EDP Open
Band 191
Seiten 34
Vorab online veröffentlicht am 24.11.2020
Nachgewiesen in Scopus
Web of Science
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