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)

The Norfolk Ridge: A Proximal Record of the Tonga‐Kermadec Subduction Initiation

“…Direct and compelling evidence for contractional deformation of unit NR1 (or equivalents to the north or south) is restricted to the northern (folds on Figures 7 and 8, this paper) and southern (Bache et al, 2012;Stratford et al, 2022) terminations of the main north-south section of Norfolk Ridge. This is consistent with Eocene deformation in New Caledonia (Bordenave et al, 2021;Maurizot, Bordenave, et al, 2020;Maurizot, Cluzel, Patriat, et al, 2020), and regional observations of TECTA deformation farther west, which are mostly south of the main section of Norfolk Ridge (Stratford et al, 2022;Sutherland et al, 2017), and in Reinga Basin (Orr et al, 2020). Convergent plate motion during the interval 45-25 Ma was substantial (>1,000 km) in the vicinity of Norfolk Ridge (Bache et al, 2012;Gurnis et al, 2004).…”

“…The inference of rapid late Eocene to early Oligocene subduction initiation along the Norfolk Ridge is backed up by the timing of the succession of events at the scale of northern Zealandia. Indeed, the compressional events in the area south of Norfolk Ridge (e.g., Reinga Basin, southern NCT) are dated between 40 and 30 Ma (Bache et al., 2012; Etienne et al., 2018; Orr et al., 2020; Stratford et al., 2022; Sutherland et al., 2017) which overlaps with timing of compressional events in New Caledonia that are dated 45‐35 Ma (Bordenave et al., 2021; Collot et al., 2008; Dallanave et al., 2020; Maurizot, Bordenave, et al., 2020). In contrast, the earliest signs of subduction initiation in New Caledonia are dated around 55 Ma (Cluzel et al., 2006, 2012, 2016) and it was not until 24–20 Ma that subduction initiated beneath the northern tip of New Zealand (Herzer, 1995; Rait, 2000; Rait et al., 1991).…”

“…In New Caledonia, the Uitoé limestone is overlain by nappes of Cretaceous to Eocene sedimentary rocks that include syn‐tectonic Eocene flysch and post‐rift cover (Bordenave, 2019; Espirat, 1989; Maurizot, 2011; Paris, 1977). The development of these shallow‐water platforms is interpreted in NC and NZ as recording the drowning of a forebulge associated with progression of the nappes (Bordenave et al., 2021; Maurizot, 2011; Maurizot, Bordenave, et al., 2020). On Norfolk Ridge, nappes are not observed except locally beneath the eastern flank on line VESPA19, where an imbricated wedge that is likely composed of unit NR1 overthrusts the UNR surface toward the west (Figure 7).…”

“…Onshore New Caledonia and Northland, New Zealand, shallow-water carbonates of late Eocene (Uitoé limestones, (Maurizot, 2014;Maurizot, Bordenave, et al, 2020)) and Oligocene (Te Kuiti limestones, (Barrett, 1967;Edbrooke et al, 1998;Isaac, 1996)) age sit unconformably on sedimentary basement terranes of Mesozoic age (respectively Teremba Terrane in NC and Waipapa Terrane in NZ); and contemporaneous calciturbidites in deepwater basins contain detrital products from these carbonate platforms (Bordenave et al, 2021;Maurizot & Cluzel, 2014;Sutherland et al, 2019bSutherland et al, , 2019c. Hence, we infer that transient uplift occurred sometime between the Eocene and Oligocene along the entire length of the Norfolk Ridge from New Caledonia to northern New Zealand, though it may be slightly younger in the south.…”

Absolute Paleolatitude of Northern Zealandia From the Middle Eocene to the Early Miocene

“…However, during the early to middle Eocene and after cessation of Tasman seafloor spreading, T‐K subduction initiated proximal to Norfolk Ridge (Gurnis et al., 2004), the northernmost part of which emerges as New Caledonia (Cluzel et al., 2012; Collot et al., 2020; Sutherland et al., 2020). Marked variations in the lithology and accumulation rates of Paleogene sediments presently exposed in New Zealand and New Caledonia reveal that significant tectonic change occurred around 46–44 Ma (Bordenave et al., 2021; Dallanave, Agnini, et al., 2018; Dallanave et al., 2015, 2020; Maurizot, 2011; Maurizot & Cluzel, 2014), attributed to early T‐K subduction and uplift of northern Zealandia (Dallanave et al., 2020).…”