Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 89-108 |
| Seitenumfang | 20 |
| Fachzeitschrift | Mineralogy and Petrology |
| Jahrgang | 86 |
| Ausgabenummer | 1-2 |
| Publikationsstatus | Veröffentlicht - Jan. 2006 |
Abstract
Pyroclastites erupted from the Upper Pollara magma chamber (13 ka, Salina Island, Aeolian Archipelago) resulted from mingling and mixing of rhyolitic and andesitic magmas. An experimental study has been conducted on the rhyolitic end-member to constrain the pre-eruptive conditions of the magma. In order to check for the role of mixing on the equilibrium phase assemblage, three different starting compositions, corresponding to three different mixing degrees, have been used. The crystallization experiments were conducted at two different oxygen fugacities and at variable temperature and fluid contents. The results indicate that the natural mineralogical assemblage can only be reproduced from a composition showing a certain degree of mixing. Assuming a pressure of 200 MPa (generally accepted for the Aeolian Islands), the pre-eruptive temperature of the magmas is estimated between 755 and 800°C and the water content of the melt was higher than 4-4.5 wt.%. The Upper Pollara magma crystallized at relatively high fO2 (ΔlogfO2 = Ni-NiO + 1 log unit), compared to rhyolitic magmas from Lipari and Vulcano. As this difference has not been observed for the most primitive magmas the difference in fO2 could be related to different degassing processes operating in Salina and Lipari - Vulcano magmas.
ASJC Scopus Sachgebiete
- Erdkunde und Planetologie (insg.)
- Geophysik
- Erdkunde und Planetologie (insg.)
- Geochemie und Petrologie
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in: Mineralogy and Petrology, Jahrgang 86, Nr. 1-2, 01.2006, S. 89-108.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Crystallization conditions in the Upper Pollara magma chamber, Salina Island, Southern Tyrrhenian Sea
AU - Donato, P.
AU - Behrens, Harald
AU - De Rosa, R.
AU - Holtz, Francois
AU - Parat, F.
N1 - Copyright: Copyright 2006 Elsevier B.V., All rights reserved.
PY - 2006/1
Y1 - 2006/1
N2 - Pyroclastites erupted from the Upper Pollara magma chamber (13 ka, Salina Island, Aeolian Archipelago) resulted from mingling and mixing of rhyolitic and andesitic magmas. An experimental study has been conducted on the rhyolitic end-member to constrain the pre-eruptive conditions of the magma. In order to check for the role of mixing on the equilibrium phase assemblage, three different starting compositions, corresponding to three different mixing degrees, have been used. The crystallization experiments were conducted at two different oxygen fugacities and at variable temperature and fluid contents. The results indicate that the natural mineralogical assemblage can only be reproduced from a composition showing a certain degree of mixing. Assuming a pressure of 200 MPa (generally accepted for the Aeolian Islands), the pre-eruptive temperature of the magmas is estimated between 755 and 800°C and the water content of the melt was higher than 4-4.5 wt.%. The Upper Pollara magma crystallized at relatively high fO2 (ΔlogfO2 = Ni-NiO + 1 log unit), compared to rhyolitic magmas from Lipari and Vulcano. As this difference has not been observed for the most primitive magmas the difference in fO2 could be related to different degassing processes operating in Salina and Lipari - Vulcano magmas.
AB - Pyroclastites erupted from the Upper Pollara magma chamber (13 ka, Salina Island, Aeolian Archipelago) resulted from mingling and mixing of rhyolitic and andesitic magmas. An experimental study has been conducted on the rhyolitic end-member to constrain the pre-eruptive conditions of the magma. In order to check for the role of mixing on the equilibrium phase assemblage, three different starting compositions, corresponding to three different mixing degrees, have been used. The crystallization experiments were conducted at two different oxygen fugacities and at variable temperature and fluid contents. The results indicate that the natural mineralogical assemblage can only be reproduced from a composition showing a certain degree of mixing. Assuming a pressure of 200 MPa (generally accepted for the Aeolian Islands), the pre-eruptive temperature of the magmas is estimated between 755 and 800°C and the water content of the melt was higher than 4-4.5 wt.%. The Upper Pollara magma crystallized at relatively high fO2 (ΔlogfO2 = Ni-NiO + 1 log unit), compared to rhyolitic magmas from Lipari and Vulcano. As this difference has not been observed for the most primitive magmas the difference in fO2 could be related to different degassing processes operating in Salina and Lipari - Vulcano magmas.
UR - http://www.scopus.com/inward/record.url?scp=31044439535&partnerID=8YFLogxK
U2 - 10.1007/s00710-005-0105-5
DO - 10.1007/s00710-005-0105-5
M3 - Article
AN - SCOPUS:31044439535
VL - 86
SP - 89
EP - 108
JO - Mineralogy and Petrology
JF - Mineralogy and Petrology
SN - 0930-0708
IS - 1-2
ER -