Publication Date:
2017-04-04
Description:
New experimental data of Ar and Ne solubility at pressures up to 360 MPa in alkali-basaltic (Mt. Etna, Italy)
and rhyolitic (Vulcano Island, Italy) melts are presented. Solubility experiments have been conducted in
internally heated pressure vessels at 1200 °C under nominally anhydrous conditions. Ar and Ne contents
dissolved in the experimental glasses were then measured by quadrupole mass spectrometry. Over the
pressure range investigated, Ar and Ne solubilities vary linearly with Ar and Ne pressures and can be described
by Henry's constant (kAr,Ne=PAr, Ne /xAr, Ne, where PAr, Ne is the partial pressure of Ar or Ne and xAr, Ne is the
molar fraction of Ar or Ne in the melt) of 7.6±0.8×105 and 1.9±0.4×105 MPa, respectively for Ar and Ne in
the basaltic melt and 1.5±0.2×105 and 3.8±0.2×104 MPa, respectively for Ar and Ne in the rhyolitic melt. In
accordance with existing models, rhyolitic melts show higher noble gas solubilities than basaltic melts, Ne
solubility being higher than that of Ar in a given composition. We propose a semi-empirical model of noble gas
(Ar, Ne and He) solubility calibrated on a very large set of measurements in natural and synthetic silicate
melts. The model expands the concept of ionic porosity in terms of porosity accessible for noble gas
dissolution in melt, taking into account the large-scale structural effects of cations, as well as temperature and
pressure. The model is valid over a wide range of temperatures (800–1600 °C), pressures (up to 3 GPa) and
compositions, being useful for both geological and physico-chemical studies.
Description:
Published
Description:
145-157
Description:
1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
Description:
JCR Journal
Description:
restricted
Keywords:
Noble gas solubility
;
silicate melt
;
04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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