| Title | The volcanic history of Pyrgousa - volcanism before the eruption of the Kos Plateau Tuff |
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| Author | Piper, D J W ;
Pe-Piper, G; Anastasakis, G; Reith, W |
| Source | Bulletin of Volcanology vol. 81, issue 5, 32, 2019 p. 1-15, https://doi.org/10.1007/s00445-019-1290-0 |
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| Year | 2019 |
| Alt Series | Natural Resources Canada, Contribution Series 20180267 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html |
| Area | Pyrgousa; Nisyros; Greece |
| Lat/Long WENS | 27.0250 27.0500 36.5958 36.5783 |
| Subjects | geochronology; geochemistry; mineralogy; igneous and metamorphic petrology; volcanology; Pleistocene; tectonic history; volcanism; magmatism; thermal history; intrusions; dykes; partial melting;
stratovolcanoes; bedrock geology; lithology; igneous rocks; volcanic rocks; andesites; tuffs; dacites; rhyolites; lava flows; breccias, volcanic; sedimentary rocks; limestones; structural features; domes; faults; stocks; petrogenesis; whole rock
geochemistry; barium geochemistry; strontium geochemistry; titanium geochemistry; zirconium geochemistry; radiometric dating; argon argon dating; biotite; magmas; provenance; mantle; thermal springs; textural analyses; mineralogical analyses;
phlogopite; amphibole; garnet; pyroxene; Kos Plateau Tuff; South Aegean Arc; Kefalos Tuff; Nisyros Tuff; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | location maps; geoscientific sketch maps; cross-sections, stratigraphic; photographs; photomicrographs; plots; tables; ternary diagrams; bar graphs |
| Program | GSC Atlantic Division |
| Released | 2019 04 24 |
| Abstract | The islet of Pyrgousa, 8 km west of Nisyros, has andesites overlain by proximal deposits of the Kos Plateau Tuff (KPT). These andesites record the evolution of the Kos-Nisyros volcanic centre prior to
the large KPT eruption at 161 ka. This precursory activity had previously been recorded only in dacites and rhyolites in the Kefalos Peninsula, farther from the volcanic centre. This study investigated the age, geochemistry, mineralogy, and
petrogenesis of the andesite domes, probable flows, and associated talus breccias on Pyrgousa. Analysed samples are basaltic andesite and andesite, with strong enrichment in Ba and Sr and low values of Ti and Zr. An 40Ar/39Ar date of 1.9 ± 0.1 Ma on
biotite is similar to dates from dacite and rhyolite stocks and domes in the Kefalos Peninsula, and like those dates is the maximum age due to excess 40Ar. There is no evidence on Pyrgousa for a stratovolcano precursor of the KPT eruption. The
andesite domes geochemically resemble Pliocene domes in Methana and Aegina that mark the onset of magmatism in the northwestern South Aegean Arc, with an important magma component derived from subcontinental lithospheric mantle. These early andesites
heated the upper crust, thus facilitating the growth of upper crustal magma chambers, which were filled by felsic crystal mush derived by differentiation of hydrous intermediate magmas with a more asthenospheric signature. |
| Summary | (Plain Language Summary, not published)
Study of precursor volcanism before a major explosive volcanic eruption. |
| GEOSCAN ID | 313027 |
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