Mesozoic history of the Fairway‐Aotea Basin: Implications for the early stages of Gondwana fragmentation

Abstract

The Fairway Ridge is a buried continental structure that separates the Fairway Basin from the New Caledonia Basin. The proposed Cretaceous age of the Fairway Basin has remained highly hypothetical to date. Deep offshore petroleum exploration wells revealed well‐dated Mesozoic carbonaceous sedimentary rocks in the Taranaki Basin at the southern end of the Aotea Basin. In this paper we use geophysical data to confirm the continuity of the 2000 km long Fairway‐Aotea Basin connecting New Caledonia to New Zealand and prove its early Late Cretaceous age. Analysis of seismic reflection profiles together with newly compiled gravity and magnetic maps reveals Late Cretaceous NE–SW trending lineaments projecting northeastward from major Tasman Sea fracture zones and the Bellona Trough, which demonstrate that the opening of the Fairway‐Aotea Basin predates the opening of the Tasman Sea. This result combined with observations of the Mesozoic regional geology suggests that the Lord Howe, Fairway, and Norfolk ridges are part of a remnant late Early Cretaceous continental arc, which was fragmented into three pieces by the late Early to early Late Cretaceous. This event might be contemporaneous with a plate motion change between the Gondwana and Pacific plates and/or the arrival of the Hikurangi plateau in the subduction zone around 105 Ma, which caused the cessation of subduction along this plate boundary. We interpret either of those two events as being possible trigger events for the post–Early Cretaceous fragmentation of the eastern Gondwana margin in a slab retreat process.

Lithosphere delamination with foundering of lower crust and mantle caused permanent subsidence of New Caledonia Trough and transient uplift of Lord Howe Rise during Eocene and Oligocene initiation of Tonga-Kermadec subduction, western Pacific

“…We agree with previous analyses that sedimentary basins formed during Cretaceous rifting and were controlled approximately by the location of structures associated with the Gondwana fore arc, which is approximately along the line of the New Caledonia Trough [ Collot et al , 2009]. However, we find that the first hypothesis alone fails to explain a number of significant observations: (1) stratal geometries suggest that the New Caledonia Trough formed as a major physiographic feature, 200–300 km wide and 2000 km long, at the time of a prominent middle Eocene‐Oligocene unconformity and onlap surface; (2) stratal geometries do not indicate that the axis of the New Caledonia Trough in its current configuration precisely aligns with significant Late Cretaceous depocenters; (3) platform morphology on either side of New Caledonia Trough indicates a phase of Eocene‐Oligocene uplift to near sea level, followed by rapid Oligocene‐Miocene subsidence of ∼1100–1800 m; and (4) seismic reflection facies tied to boreholes suggest tectonic subsidence of 1800–2200 m at the southern end of New Caledonia Trough and possibly >3000 m in central parts of New Caledonia Trough since Eocene time.…”

“…The New Caledonia Trough is a NNW trending physiographic depression lying in 2000–3500 m water depth between the Lord Howe Rise (500–2000 m water depth) and Norfolk Ridge (0–2000 m water depth). We draw a clear distinction in this paper between the modern well‐defined physiography of the New Caledonia Trough (Figure 1) and the sedimentary basins beneath its axis and flanks, which have previously been referred to as the, e.g., New Caledonia Basin, Deepwater Taranaki Basin, Aotea Basin, Fairway Basin [ Collot et al , 2008, 2009; Uruski and Wood , 1991; Uruski , 2008]. The details of the sedimentary record are deduced from core and dredge samples and geophysical data, many of which have not previously been published.…”

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

“…130 Ma) and was initially associated with intraplate volcanism (Ewart et al, 1992;Bryan et al, 1997). Both rift-related extensional tectonics and magmatism migrated eastward from 130 to 85 Ma and affected New Zealand and the Lord Howe Rise during the 110-90 Ma interval (McDougall & Van Der Lingen, 1974;Tulloch et al, 2009;Collot et al, 2009;Higgins et al, in press) and New Caledonia at ca. 89-85 Ma .…”

Seafloor features and fluid migration in the Capel and Faust basins, offshore eastern Australia

“…Regional seismic interpretation indicates that major fault reactivation, regional uplift and erosion occurred during the Eocene in parts of the northern LHR and the northern Fairway Ridge van de Beuque et al, 2003;Collot et al, 2008Collot et al, , 2009). This compressional deformation is interpreted to be related to the obduction of the South Loyalty Basin over New Caledonia (Kroenke, 1984;Collot et al, 2008).…”