Detrital zircon records of Late Cretaceous syn-rift sedimentary sequences of New Caledonia: an Australian provenance questioned

Dominique Cluzel (1, 2) , Christopher J. Adams (3) , Pierre Maurizot (4) , Sébastien Meffre (5)

1 ISTO - Institut des Sciences de la Terre d'Orléans
2 PPME - Pôle Pluridisciplinaire de la Matière et de l'Environnement
3 Dunedin Research Centre
4 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
5 CODES - ARC Centre of Excellence in Ore Deposits

The Late Cretaceous clastic coastal sediments of New Caledonia are contemporaneous with the latest stages of the eastern Australian marginal rifting. As such, they record the erosion of basement terranes located on uplifted and tilted blocks and a contemporaneous volcanic activity. Detrital zircon populations contain two major components, the younger of which is Early Cretaceous, and the older Early Paleozoic and Precambrian. Following recent advances in the knowledge of detrital zircon content of basement terranes, and at variance with previous interpretations, that hypothesised a possible direct Australian provenance for Precambrian zircons, the detrital zircon record of these syn-rift sediments allows a local recycled provenance to be established. In consequence, this new evidence confirms that New Caledonia was already isolated from Australia as early as Coniacian time (ca. 89-85 Ma) a fact consistent with the development of faunal and floral endemism at that period. The prominent abundance of Early Cretaceous detrital zircons also establishes the importance of a previously unrecorded Early Cretaceous magmatism in the area.

Keywords: Southwest Pacific; New Caledonia; Late Cretaceous; U-Pb geochronology; provenance; detrital zircon; endemism

Domains: Tectonics; Global Changes

Dominique Cluzel, Christopher J. Adams, Pierre Maurizot, Sébastien Meffre. Detrital zircon records of Late Cretaceous syn-rift sedimentary sequences of New Caledonia: an Australian provenance questioned. Tectonophysics, 2011, 501 (1-4), pp.17-27. ⟨10.1016/j.tecto.2011.01.007⟩. ⟨insu-00557057⟩