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Detailed Reference Information |
Smith, I.E.M., Okada, T., Itaya, T. and Black, P.M. (1993). Age relationships and tectonic implications of late Cenozoic basaltic volcanism in Northland, New Zealand. New Zealand Journal of Geology and Geophysics 36(3): 385-393. |
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An episode of late Miocene-Recent essentially basaltic volcanism is the latest in a sequence of magmatic events recognised in the tectonically complex geological development of the Northland Peninsula. New K-Ar dates together with an extensive collection of new major and trace element chemical analyses prompt a reassessment of the significance of these late Cenozoic basalts. The main time/space groupings recognised are Tertiary volcanics in the Kaikohe-Bay of Islands, Puhipuhi, Ti Point, and Stony Batter areas and Quaternary basalts in the Kaikohe-Bay of Islands and Whangarei areas and at Tara. Basalts in the Kaikohe-Bay of Islands area are transitional to alkalic in character, while those in the south are transitional to tholeiitic, with the Ti Point and Stony Batter rocks being geochemically distinct. A consistent model for these observations is that the magmas originate from different levels of a layered mantle source in which the upper part carries a geochemical signature inherited from an earlier subduction event. |
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BACKGROUND DATA FILES |
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Abstract |
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Abstract |
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Table 1b |
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Table 1b |
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Table 1a |
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Table 1a |
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Dating Methods |
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Keywords
absolute age; Ar/Ar; Australasia; basalts; Cenozoic; dates;, evolution; geochemistry; igneous rocks; K/Ar; Kerikeri Volcanics;, New Zealand; North Island; Northland New Zealand; ophiolite;, tectonics; upper Cenozoic; volcanic rocks; volcanism; volcanology, 05A, Igneous and metamorphic petrology |
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Publisher
The Royal Society of New Zealand |
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