Geology, geochemistry, and mineralisation of a spilite-keratophyre association in Cretaceous flysch, East Cape area, New Zealand
- 1 May 1979
- journal article
- research article
- Published by Taylor & Francis in New Zealand Journal of Geology and Geophysics
- Vol. 22 (3), 307-328
- https://doi.org/10.1080/00288306.1979.10424101
Abstract
Geological, geochemical, and mineralogical studies were carried out during a programme of base metal mineral exploration on a band of volcanic rocks intercalated within a flysch sequence of Cretaceous age (Mokoiwi Formation). The volcanics occur in the Tapuaeroa Valley—Te Kumi area, East Cape, New Zealand. These studies led to the conclusion that the characteristics of the volcanic band conform to those of a spilite-keratophyre association. The volcanic rocks, which are represented by dolerite, basalt, and related pyroclastic products are here informally named Rip Volcanics. The pyroclastics have a typical bimodal composition which is exemplified by argillaceous vitric tuff beds and a highly sodic tuff (keratophyre). The Rip Volcanics form a tectonically disrupted lithosome emplaced in its present position by the decolle-ment of the Mokoiwi Formation rock mass to which the volcanics belong, from a provenance somewhere in the north or north-east. Small and economically insignificant pods of sulphide mineralisation consisting of pyrite and chalcopyrite occur at the western end of the volcanic band. This mineralisation is interpreted as being the tectonically broken remnants of a once continuous “distal” volcanogenic massive sulphide deposit.Keywords
This publication has 13 references indexed in Scilit:
- Densities, porosities, and seismic velocities of some rocks from Victoria Land, AntarcticaNew Zealand Journal of Geology and Geophysics, 1978
- Rare earth element and other trace element distribution, and the origin of the iblean magmasJournal of Volcanology and Geothermal Research, 1976
- The Dun Mountain ophiolite belt, New Zealand, its tectonic setting, constitution, and origin, with special reference to the southern portionAmerican Journal of Science, 1976
- Geology of Mt Taitai, Tapuaeroa valley, Raukumara PeninsulaNew Zealand Journal of Geology and Geophysics, 1976
- Metamorphic belt and volcanic arc migration in New ZealandNature, 1975
- Basalt geochemistry used to investigate past tectonic environments on CyprusTectonophysics, 1975
- New fossil localities in the Torlesse Supergroup, western Raukumara Peninsula, New ZealandNew Zealand Journal of Geology and Geophysics, 1972
- Glaciation and the Stones of StonehengeNature, 1971
- The Mesozoic of New Zealand: Chapters in the history of the Circum-Pacific Mobile BeltQuarterly Journal of the Geological Society, 1969
- A Lower Tertiary Décollement on the East Coast, North Island, New ZealandNew Zealand Journal of Geology and Geophysics, 1968