Abstract In New Caledonia, the cover refers to the autochthonous Late Cretaceous to Paleogene sedimentary and volcanic formations unconformably overlying the basement rocks and underlying the allochthonous nappes. The first period of deposition, broadly from the Late Cretaceous to Paleocene ( c. 105–56 Ma) was controlled by extension and rifting. The second period, broadly the Eocene ( c. 56–34 Ma), was dominated by convergence and contraction. The Late Cretaceous part of the cover consists of synrift conglomerates and coal-bearing deposits with interlayered bimodal, subduction-related and intra-plate volcanic rocks. The post-rift deposits are deep water sedimentary rocks deposited under anoxic conditions with reduced terrigenous input. The Paleocene to Eocene formations, mainly carbonates, attest to profound palaeogeographical changes and a switch to a different geodynamic regime, linked to the onset of Eocene convergence. The Middle to Late Eocene formations are typically composed of turbidites and breccias. They were deposited in a typical flexural foreland basin context as an upwards-coarsening sequence topped by an olistostrome. They are associated with tectonic convergence and east-dipping subduction that led to the end-Eocene obduction of ophiolitic nappes. This two-fold evolution, extension then compression, can be integrated in the wider framework of the plate tectonic evolution of the SW Pacific.

Abstract New Caledonia is known as a global biodiversity hotspot. Like most Pacific islands, its modern biota is characterized by high levels of endemism and is notably lacking in some functional groups of biota. This is the result of its distinctive palaeobiogeographical history, which can be described in terms of three major episodes relating to Gondwana, Zealandia and New Caledonia. The geological record, the fossil record and the modern biota of the archipelago are all reviewed here. The geological record shows that the main island, Grande Terre, was submerged between 75 and 60 Ma. There is a 9 myr interval without any geological record between 34 and 25 Ma, immediately after the obduction of the Peridotite Nappe. Grande Terre may or may not have been submerged during this 9 myr interval. The ages given by molecular biology, independent of any geological calibration points, form a continuous spectrum from 60 Ma up to the present day. The derived lineage ages from molecular phylogenies all post-date 60 Ma, supporting the idea of the continuous availability of terrestrial environments since 60 Ma. Of the three common scenarios for the origin of the New Caledonia biota, long-distance dispersal is the most plausible, rather than vicariance or dispersal over short distances.

Abstract: The most extensive Permian tetrapod (amphibian and reptile) fossil records from the western USA (New Mexico to Texas) and South Africa have been used to define 11 land vertebrate faunachrons (LVFs). These are, in ascending order, the Coyotean, Seymouran, Mitchellcreekian, Redtankian, Littlecrotonian, Kapteinskraalian, Gamkan, Hoedemakeran, Steilkransian, Platbergian and Lootsbergian. These faunachrons provide a biochronological framework with which to assign ages to, and correlate, Permian tetrapod fossil assemblages. Intercalated marine strata, radioisotopic ages and magnetostratigraphy were used to correlate the Permian LVFs to the standard global chronostratigraphic scale with varying degrees of precision. Such correlations identified the following significant events in Permian tetrapod evolution: a Coyotean chronofaunal event (end Coyotean); Redtankian events (Mitchellcreekian–Littlecrotonian); Olson’s gap (late Littlecrotonian); a therapsid event (Kapteinskraalian); a dinocephalian extinction event (end Gamkan); and a latest Permian extinction event (Platbergian–Lootsbergian boundary). Problems of incompleteness, endemism and taxonomy, and the relative lack of non-biochronological age control continue to hinder the refinement and correlation of a Permian timescale based on tetrapod biochronology. Nevertheless, the global Permian timescale based on tetrapod biochronology is a robust tool for both global and regional age assignment and correlation. Advances in Permian tetrapod biochronology will come from new fossil discoveries, more detailed biostratigraphy and additional alpha taxonomic studies based on sound evolutionary taxonomic principles.