Mesozoic history of the Fairway-Aotea Basin: Implications for the early stages of Gondwana fragmentation
|Author(s)||Collot Julien1, Herzer R.2, Lafoy Y.3, Geli Louis1|
|Affiliation(s)||1 : IFREMER, Ctr Brest, Dept Geodynam & Geophys, F-29280 Plouzane, France.
2 : GNS Sci, Lower Hutt, New Zealand.
3 : Geol Survey New Caledonia, Direct Ind Mines & Energie Nouvelle Caledonie, F-98845 Noumea, New Caledonia.
|Source||Geochemistry Geophysics Geosystems - G3 (1525-2027) (American Geophysical Union), 2009-12 , Vol. 10 , N. 12 , P. 1-24|
|WOS© Times Cited||38|
|Keyword(s)||Aotea Basin, Fairway Basin, southwest Pacific|
|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 NESW 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 postEarly Cretaceous fragmentation of the eastern Gondwana margin in a slab retreat process.|