New Caledonia Ophiolite, Marginal Rifting to Fore‐arc Evolution - Archive ouverte HAL Access content directly
Conference Papers Acta Geologica Sinica Year : 2020

New Caledonia Ophiolite, Marginal Rifting to Fore‐arc Evolution

(1) , , , ,
1
Dominique Cluzel
  • Function : Author
  • PersonId : 1065693
Jonathan Aitchison
Arianna Secchiari
Alessandra Montanini
  • Function : Author
Delphine Bosch
  • Function : Author

Abstract

The New Caledonia Ophiolite (Peridotite Nappe), represents about one third of the island's surface (i.e. 5 500 km 2). The ophiolite is composed of harzburgites, dunites, lherzolites, minor mafic-ultramafic cumulates, and various dykes and sills. The mantle section underwent a polyphase evolution, which involved prominent depletion and re-fertilization. The oldest events are probably recorded by abyssal-type lherzolites of the northern massifs, which bear traces of moderate partial melting. Plagioclase lherzolites were formed by shallow entrapment of highly depleted MORB melt in residual spinel lherzolites. Nd isotope compositions are consistent with derivation from an asthenospheric mantle source that experienced a recent MORB-producing depletion. This evolution was most likely accomplished during the late Cretaceous breakup of the eastern Australian margin. The harzburgite-dunite association, which forms the bulk of Peridotite Nappe was probably formed through a multistage magma-producing process. Harzburgites composition may have be obtained by a first phase of ~15% dry fractional melting, followed by 15%-18% hydrous melting in a supra-subduction zone setting. Variable  Nd negatively correlate with 87 Sr/ 86 Sr,
Not file

Dates and versions

hal-03510823 , version 1 (30-01-2022)

Identifiers

Cite

Dominique Cluzel, Jonathan Aitchison, Arianna Secchiari, Alessandra Montanini, Delphine Bosch. New Caledonia Ophiolite, Marginal Rifting to Fore‐arc Evolution. IGCP 649 Diamonds and recycled mantle 5th workshop, Muscat, Oman, Nov 2019, Muscat, Oman. pp.9 - 10, ⟨10.1111/1755-6724.14431⟩. ⟨hal-03510823⟩

Collections

CNRS UNC
4 View
2 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More