| Titre | The volcanic history of Pyrgousa - volcanism before the eruption of the Kos Plateau Tuff |
| |
| Auteur | 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 |
| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180267 |
| Éditeur | Springer Nature |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1007/s00445-019-1290-0 |
| Media | papier; en ligne; numérique |
| Formats | pdf (Adobe® Reader®); html |
| Région | Pyrgousa; Nisyros |
| Lat/Long OENS | 27.0250 27.0500 36.5958 36.5783 |
| Sujets | vulcanologie; Pléistocène; antécédents tectoniques; volcanisme; magmatisme; antecedents thermiques; intrusions; filons rocheux; fusion partielle; strato-volcans; géologie du substratum rocheux;
lithologie; roches ignées; roches volcaniques; andésites; tufs volcaniques; dacites; rhyolites; coulées de lave; brèches volcaniques; roches sédimentaires; calcaires; caractéristiques structurales; dôme; failles; stocks; pétrogenèse; géochimie des
roches totales; géochimie du baryum; géochimie du strontium; géochimie du titane; géochimie du zirconium; datation radiométrique; datation argon-argon; biotite; magmas; origine; manteau terrestre; sources thermales; analyses de textures; analyses
minéralogiques; phlogopite; amphibole; grenat; pyroxene; Arc de South Aegean ; géochronologie; géochimie; minéralogie; pétrologie ignée et métamorphique; Phanérozoïque; Cénozoïque; Quaternaire |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; coupes transversales, stratigraphique; photographies; photomicrographies; graphiques; tableaux; diagrammes ternaires; graphique à
barres |
| Programme | Division de la CGC atlantique |
| Diffusé | 2019 04 24 |
| Résumé | (disponible en anglais seulement)
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. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Étude du volcanisme précurseur avant une éruption volcanique explosive majeure. |
| GEOSCAN ID | 313027 |
|
|