The Talasea peninsula, located on the north coast of New Britain island, is composed of a chain of Quaternary composite volcanoes and a caldera, with rock types ranging from basalt to rhyolite.
The andesites of Talasea are typically porphyritic, with phenocrysts of plagioclase, clinopyroxene, orthopyroxene and titanomagnetite, in a groundmass of the same minerals and glass. The acid rocks have a similar mineralogy but also contain quartz, amphibole, biotite and ilmenite, while the basalts lack orthopyroxene and titanomagnetite phcnocrysts, but contain olivine.
References:
- Lowder, G.G. (1970): The Volcanoes and Caldera of Talasea, New Britain: Mineralogy. Contributions to Mineralogy and Petrology 26, 324-340.
Mineral List:17 entries listed. 10 valid minerals.
The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database!
