Open Access Repository

Fluid inclusion evidence of second immiscibility within magmatic fluids (79AD eruption of Mt. Vesuvius)


Downloads per month over past year

Fulignati, P, Kamenetsky, VS, Marianelli, P and Sbrana, A 2005 , 'Fluid inclusion evidence of second immiscibility within magmatic fluids (79AD eruption of Mt. Vesuvius)' , Periodico di Mineralogia, vol. LXXIV , pp. 43-54 .

PeriodMiner-200...pdf | Download (692kB)
Available under University of Tasmania Standard License.

| Preview


Foid-bearing syenite cognate xenoliths represent fragments of the upper peripheral parts of the K-phonolitic portions of the 79 AD magma chamber, wrenched during the explosive eruption. Abundant multiphase fluid inclusions are hosted within K-feldspar and coexist with rare silicate melt inclusions. This gives evidence to the exsolution of a magmatic volatile-rich phase from the peripheral parts of the silicate magma chamber. The characterization of daughter mineral assemblage of these fluid inclusions, by SEM-EDS and Raman spectroscopy, indicates two ubiquitous main components: Na-K chlorides (halite + sylvite) and Na-Ca carbonates (calcite plus/minus nahcolite). Microthermometric experiments indicate nearly magmatic trapping temperatures (760 degrees C to 830 degrees C) of the homogeneous chloride-carbonate liquid. Cooling of such liquid produces two immiscible melt phases (chlorides and carbonates) at 455-435 degrees C. This suggests that a hypersaline-carbonate fluid, exsolved from the silicate magma, can further experience another unmixing event that would occur in essentially 'post-magmatic' environment.

Item Type: Article
Authors/Creators:Fulignati, P and Kamenetsky, VS and Marianelli, P and Sbrana, A
Keywords: Vesuvius, foid-bearing syenites, fluid inclusions, immiscibility, exsolution
Journal or Publication Title: Periodico di Mineralogia
ISSN: 0369-8963
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page