TITLE:
New U-Pb Zircon Evidence for Paleoarchean Crustal Inheritance in the Kenema-Man Domain, Western Côte d’Ivoire
AUTHORS:
Wilfried Digbeu, Alain Nicaise Kouamelan, Koffi Alexis N’Dri, Ziandjêdé Hervé Siagné, Gnagnon Stéphane Raymond Koffi, Zié Ouattara
KEYWORDS:
Kenema-Man, Paleoarchean, U-Pb Zircon, Gneiss, Crustal Evolution, WAC
JOURNAL NAME:
International Journal of Geosciences,
Vol.17 No.9,
September
18,
2026
ABSTRACT: The Archean evolution of the Kenema-Man Domain remains a key issue for understanding the early growth of the West African Craton (WAC), particularly in western Côte d’Ivoire where the oldest crustal components remain poorly constrained. This study presents new in situ zircon U-Pb LA-ICP-MS geochronological data from two Archean gneisses (NID-1 paragneiss and TRO-4 anatectic orthogneiss) collected in the Man region, with the aim of refining the timing of early crustal evolution and subsequent tectono-metamorphic events. Zircons from the NID-1 paragneiss define several Archean age components. Older ages between ca. 3164 ± 41 Ma and 3089 ± 23 Ma are interpreted primarily as inherited and/or detrital zircon components derived from older crustal sources. Younger ages between ca. 2895 ± 18 Ma and 2820 ± 30 Ma occur in both zircon rims and cores; they may therefore record a composite signal involving late Archean zircon growth or recrystallization as well as inherited or detrital input. In the TRO-4 anatectic orthogneiss, seven analyses previously grouped at 3320 ± 47 Ma yield a MSWD of 6.11, indicating significant excess scatter and showing that this group does not represent a single statistically homogeneous crystallization event. Nevertheless, the oldest individual analysis yields 3342 ± 18 Ma and documents the preservation of Paleoarchean zircon components in western Côte d’Ivoire. Additional zircon populations at ca. 3.20 and 3.08 Ga record younger Archean components. Zircon Th/U ratios, together with cathodoluminescence textures, indicate predominantly magmatic zircon crystallization with variable later modification. These new data strengthen the evidence for Paleoarchean crustal inheritance in the Man region and document a prolonged history of Archean crustal growth and reworking within the Kenema-Man Domain.