| Title | Quantitative tectonic reconstructions of Zealandia based on crustal thickness estimates |
| Author | Grobys, J.W.G.; Gohl, K.; Eagles, G. |
| Author Affil | Grobys, J.W.G., Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Federal Republic of Germany |
| Source | Geochemistry, Geophysics, Geosystems - G3, 9(1), Citation Q01005. Publisher: American Geophysical Union and The Geochemical Society, United States. ISSN: 1525-2027 |
| Publication Date | 2008 |
| Notes | In English. 59 refs. GeoRef Acc. No: 288088 |
| Index Terms | Antarctica; Australia; Pacific Ocean-- Campbell Plateau; Pacific Ocean--Great South Basin; Pacific Ocean--New Caledonia Basin; New Zealand; Australasia; Bounty Trough; Campbell Plateau; crust; Gondwana; Great South Basin; kinematics; lithosphere; New Caledonia Basin; Pacific Ocean; plate tectonics; plates; quantitative analysis; reconstruction; South Pacific; Southwest Pacific; tectonics; tectonophysics; thickness; West Pacific |
| Abstract | Zealandia is a key piece in the plate reconstruction of Gondwana. The positions of its submarine plateaus are major constraints on the best fit and breakup involving New Zealand, Australia, Antarctica, and associated microplates. As the submarine plateaus surrounding New Zealand consist of extended and highly extended continental crust, classic plate tectonic reconstructions assuming rigid plates and narrow plate boundaries fail to reconstruct these areas correctly. However, if the early breakup history shall be reconstructed, it is crucial to consider crustal stretching in a plate- tectonic reconstruction. We present a reconstruction of the basins around New Zealand (Great South Basin, Bounty Trough, and New Caledonia Basin) based on crustal balancing, an approach that takes into account the rifting and thinning processes affecting continental crust. In a first step, we computed a crustal thickness map of Zealandia using seismic, seismological, and gravity data. The crustal thickness map shows the submarine plateaus to have a uniform crustal thickness of 20-24 km and the basins to have a thickness of 12-16 km. We assumed that a reconstruction of Zealandia should close the basins and lead to a most uniform crustal thickness. We used the standard deviation of the reconstructed crustal thickness as a measure of uniformity. The reconstruction of the Campbell Plateau area shows that the amount of extension in the Bounty Trough and the Great South Basin is far smaller than previously thought. Our results indicate that the extension of the Bounty Trough and Great South Basin occurred simultaneously. |
| URL | http://hdl.handle.net/10.1029/2007GC001691 |
| Publication Type | journal article |
| Record ID | 85015 |