dc.contributor.author |
Lindsay, J.M. |
en |
dc.contributor.author |
Worthington, T.J. |
en |
dc.contributor.author |
Smith, I.E.M. |
en |
dc.contributor.author |
Black, P.M. |
en |
dc.date.accessioned |
2009-08-25T06:02:30Z |
en |
dc.date.available |
2009-08-25T06:02:30Z |
en |
dc.date.issued |
1999 |
en |
dc.identifier.citation |
New Zealand Journal of Geology and Geophysics 42 (2), 155-168. 1999 |
en |
dc.identifier.issn |
0028-8306 |
en |
dc.identifier.other |
eid=2-s2.0-0033149853 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/4863 |
en |
dc.description |
An open access copy of this article is available from the publishers website. |
en |
dc.description.abstract |
Little Barrier Island is the emergent part of a large, isolated, dacite-rhyodacite volcano in the active Hauraki Rift, 80 km northeast of Auckland. Two volcanic episodes are recognised: Waimaomao Formation was emplaced as a rhyodacite dome at 3 Ma, whereas the more extensive dacitic lavas of Haowhenua Formation were erupted between 1.2 and 1.6 Ma. All Little Barrier lavas are strongly porphyritic and contain phenocrysts of plagioclase, orthopyroxene, and hornblende. Geochemically, they are subduction related and distinct from the older lavas of the Coromandel Volcanic Group, being Zr rich but Rb and Ba poor. Their Sr and Nd isotope ratios are similar to those of the Tonga-Kermadec arc volcanoes. Modelling of the dacite supports petrographic evidence that recharge and mixing were important in the magmatic system. Little Barrier and two dacite domes of similar age and composition near Whangarei form a northwest-trending lineament subparallel to the Alexandra Volcanics and the Vening Meinesz Fracture Zone. |
en |
dc.publisher |
Royal Society Of New Zealand |
en |
dc.relation.ispartofseries |
New Zealand Journal of Geology and Geophysics |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from http://www.sherpa.ac.uk/romeo/issn/0028-8306/ |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.source.uri |
http://www.royalsociety.org.nz/publications/journals/nzjg/1999/011 |
en |
dc.title |
Geology, petrology, and petrogenesis of Little Barrier Island, Hauraki Gulf, New Zealand |
en |
dc.type |
Journal Article |
en |
dc.subject.marsden |
Fields of Research::260000 Earth Sciences::260100 Geology |
en |
pubs.issue |
2 |
en |
pubs.begin-page |
155 |
en |
pubs.volume |
42 |
en |
dc.rights.holder |
Copyright: Royal Society of New Zealand |
en |
pubs.end-page |
168 |
en |