Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Journal of the Geological Society

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Whattam, S. A. Articles by Smith, I. E. M. Search for Related Content GeoRef GeoRef Citation

Formation and emplacement of the Northland ophiolite, northern New Zealand: SW Pacific tectonic implications

^{1 1}Department of Earth Sciences, University of Hong Kong, Pokfulam Road, Hong Kong, China (e-mail: sawhatta@graduate.hku.hk)
^{2 2}Department of Geosciences, National Taiwan University, 245 Chousan Road, Taipei 106, Taiwan
^{3 3}Department of Geology, University of Auckland, Private Bag 92019, Auckland, New Zealand
*Present address: School of Earth and Environmental Sciences, Seoul National University, Seoul, 151–747, Korea

Petrological, geochemical, geochronological and palaeomagnetic data for rocks of the Northland ophiolite terrane of northern New Zealand suggest that it formed in a suprasubduction-zone setting between c. 29 and 26 Ma, at c. 35°S, close to its Late Oligocene obduction site. Cretaceous igneous rocks formerly considered to be part of the ophiolite probably represent the basement upon which the ophiolite was emplaced, and are probably part of the Mount Camel arc-related terrane. The ophiolite is believed to have been generated in the southeastern South Fiji Basin, close to a NW–SE-oriented transform fault located to the SW of the Vening Meinesz Fracture Zone, and was probably emplaced in response to the collision of the Hikurangi Plateau with eastern New Zealand at the end of the Oligocene. This collision would have involved a major adjustment on the transform fault, thereby allowing a portion of the upper-crustal section of the southern South Fiji Basin to be emplaced southwestward onto northern New Zealand as well as the coeval emplacement of the East Cape Allochthon to the south. Concomitant subduction of the lower crust–mantle section led to the initiation of arc volcanism that resulted in the Northland Lower Miocene volcanic–plutonic suite.

KEYWORDS: SW Pacific, Northland ophiolite, tectonics, palaeomagnetism, absolute age