EKU Faculty and Staff Scholarship
 

Author ORCID Identifier

ORCID 0000-0001-5107-6847

Document Type

Article

Publication Date

10-2020

Abstract

Crystallization experiments on two pantellerites from Pantelleria, Italy, provide new evidence for the relation-ships between mineral phases in pantelleritic rocks as well as the influence of temperature and redox conditionson mineral assemblages. Experiments were performed at 1 kbar with temperature ranging between 750–900°C,andfluid saturation conditions with XH2O (=H2O/H2O+CO2) between 0 and 1. Redox conditions werefixed at,or slightly below, the FMQ buffer. Results show that at temperature of 900 °C pantelleritic magmas are well abovethe liquidus regardless their water content; we also observed a decrease in liquidus temperature (800°C) withincreasingly reducing conditions. Mineral assemblages of the natural rocks have been successfully reproduced,particularly the relationship between fayalite and aenigmatite, which appear to be strongly controlled by meltperalkalinity, temperature and redox conditions. This is thefirst time that fayalitic olivine have been synthetizedin experimental studies on pantellerites, which was found to be stable only for temperatures≥750°C while am-phibole can be stable at temperatures as high as 800°C at highfF2. Experimentalresults have been compared withthe composition of mineral phases as well as with the results obtained from mineral equilibrium,geothermometry, and oxygen barometry studies on pantelleritic lava and tuffs from Pantelleria (Italy), Eburru(Kenya) and Menengai (Kenya). Petrological characteristics appear similar at different locations worldwide,with typical assemblages of anorthoclase and sodian clinopyroxene with variable fayalite, aenigmatite, Fe-Ti ox-ides and amphibole.

Journal Title

Lithos

Romano et al 2020 Supplementary Table 1.xlsx (51 kB)
Supplementary Table 1

Share

COinS