Upper Cretaceous to Palaeogene successions of the Gouaro anticline: Deepwater sedimentary records of the tectonic events that led to obduction in New Caledonia (SW Pacific)

Type Article
Date 2021-04
Language English
Author(s) Bordenave Aurélien1, 2, 3, Etienne Samuel2, Collot Julien2, Razin Philippe3, Patriat MartinORCID4, Grélaud Carine3, Agnini Claudia5, Morgans Hugh6, Guillemaut Flora3, Moreau Armand3
Affiliation(s) 1 : ADECAL Technopole, 1bis rue Berthelot, BP 2384, 98845 Nouméa, New Caledonia
2 : Geological Survey of New Caledonia (DIMENC), BP465, 98845 Nouméa Cedex, New Caledonia
3 : Université Bordeaux Montaigne/EA 4592 Géoressources & Environnement, 1 allée Fernand Daguin, 33607 Pessac Cedex, France
4 : IFREMER - Centre Bretagne - ZI de la Pointe du Diable, CS 10070, 29280 Plouzané, France
5 : Department of Geosciences, University of Padova, Padova, Italy
6 : GNS Science, Lower Hutt, New Zealand
Source Sedimentary Geology (0037-0738) (Elsevier BV), 2021-04 , Vol. 415 , P. 105818 (25p.)
DOI 10.1016/j.sedgeo.2020.105818
WOS© Times Cited 4
Keyword(s) Zealandia, New Caledonia, Upper Cretaceous, Palaeogene, Turbidite, Obduction
Abstract

In New Caledonia, upper Cretaceous to Palaeogene sedimentary rocks record a regional tectonic shift from Cretaceous extension to Eocene compression, which led to the obduction of oceanic mantle onto the northeastern tip of the submerged Zealandia continent. This study provides new descriptions of these successions in the region of the Gouaro anticline, from outcrops and an extensively cored, 1.9 km long onshore petroleum well, CADART-1. Combined sedimentological, palaeontological and mineralogical data allow us to propose a revised lithostratigraphic framework and to discuss sedimentary sources, basin physiography and vertical tectonic motions. The base of the studied section comprises an upper Cretaceous transgressive syn- to post-rift siliciclastic succession (Gouaro Formation) culminating in deepwater silicified mudstones. Our biostratigraphic analysis suggests that the Palaeocene and Lower Eocene are not present in the studied section. During the middle Eocene, sedimentation is dominated by deepwater pelagic carbonates and calciturbidites (Adio Limestone). The middle to upper Eocene is marked by a 4 km thick, lithologically heterogeneous turbidite succession, the Bourail Flysch Group, divided into: (i) the Lutetian to Bartonian Lower Bourail Flysch Formation, comprising mixed siliciclastic - calcareous turbidites; (ii) the Bartonian to Priabonian Middle Bourail Flysch Formation, dominated by calcareous turbidites; and (iii) the uppermost Eocene (to Oligocene?) Upper Bourail Flysch Formation consisting of clinopyroxene-rich volcaniclastic turbidites and extraformational breccias. Two successive phases of clastic fluxes occurred, the former during the Lutetian-Bartonian and the latter during the uppermost Priabonian, separated by a period of drowning and/or subsidence during the Bartonian to Priabonian. These phases are likely controlled by vertical motions and we discuss their possible tectonic origin. Of particular note is that we believe that within the Bourail Basin, horizontal shortening and nappe emplacement are only recorded during the latest Eocene and possibly Oligocene. Indeed, the second phase of clastic flux is associated with debris flow breccia, possibly derived from a thrust front, yet we discuss alternative origins such as fault scarp erosion or intraslope failures.

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Corrigendum - 10.1016/j.sedgeo.2021.106008 4 2 MB Open access
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How to cite 

Bordenave Aurélien, Etienne Samuel, Collot Julien, Razin Philippe, Patriat Martin, Grélaud Carine, Agnini Claudia, Morgans Hugh, Guillemaut Flora, Moreau Armand (2021). Upper Cretaceous to Palaeogene successions of the Gouaro anticline: Deepwater sedimentary records of the tectonic events that led to obduction in New Caledonia (SW Pacific). Sedimentary Geology, 415, 105818 (25p.). Publisher's official version : https://doi.org/10.1016/j.sedgeo.2020.105818 , Open Access version : https://archimer.ifremer.fr/doc/00679/79082/