Distribution, petrography, and chemistry of Kiwitahi and Maungatautari volcanics, North Island, New Zealand

Autor:	Jim Cole
Rok vydání:	1978
Předmět:	Basalt geography Olivine geography.geographical_feature_category Andesite Geochemistry Geology Pyroxene engineering.material Volcanic rock Porphyritic Geophysics Earth and Planetary Sciences (miscellaneous) engineering Petrology Hornblende Labradorite
Zdroj:	New Zealand Journal of Geology and Geophysics. 21:143-153
ISSN:	1175-8791 0028-8306
Popis:	The ‘Kiwitahi Volcanics’ form a chain on the west side of the Hauraki Depression. Individual cones and flows occur at Waiheke Island, Miranda, Pukekarnaka, Tahuna, Maungatapu, Kiwitahi, Maungakawa, and Te Tapui. Maungatautari is a volcanic complex 8 km SE of Cambridge which is surrounded by a lahar ‘ring-plain’. The lahars overlie ignimbrites of the Pakaumanu Group, but because they probably represent slope wash from Maungatautari formed soon after deposition of the ignimbrite, they cannot be used to date activity within the Complex. Petrographically, all lavas are porphyritic, the Kiwitahi Volcanics comprising olivine low-Si andesite, pyroxene low-Si andesite, labradorite-pyroxene andesite and low-Si andesite, and hornblende andesite. Maungatautari lavas comprise olivine basalt, labradorite andesite, and hornblende andesite. Major and trace element analyses of the Kiwitahi Volcanics and Maungatautari Volcanic Complex differ, Maungatautari lavas having higher K,O, Zr, V, and Sc than Kiwitahi Volc...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::85613cf6d206756f81ea00d1185a874f https://doi.org/10.1080/00288306.1978.10424046 Zobrazit plný text záznamu