Details
| Original language | English |
|---|---|
| Pages (from-to) | 187-196 |
| Number of pages | 10 |
| Journal | Chemical geology |
| Volume | 213 |
| Issue number | 1-3 |
| Early online date | 6 Nov 2004 |
| Publication status | Published - 15 Dec 2004 |
Abstract
New data on water solubility in trachytic melts at pressures from 20 to 200 MPa and 850 °C are reported. Three trachytes, which differ mainly in Na/K ratio, were studied. The glasses obtained from water saturated experiments were analysed using both infrared spectroscopy (FTIR) and Karl Fischer Titration (KFT). The independent KFT data on total water contents were used to calculate linear molar absorptivity values for infrared bands at ∼4500 cm-1 (hydroxyl groups) and ∼5200 cm-1 (molecular water). Water contents in the three trachytic melts studied are higher than those observed in rhyolitic melts at similar pressures and approach 8 wt.% H2O at 200 MPa. Increasing Na2O content in the trachyte compositions investigated is found to correlate positively with melt water content, similar to the effect of Na2O in haplogranitic systems. The new solubility data, when compared with two theoretical models for water solubility [Papale, P., 1997. Thermodynamic modeling of the solubility of H2O and CO2 in silicate liquids. Contrib. Mineral. Petrol. 126, 237-251; Moore, G., Vennemann, T., Carmichael, I.S.E., 1998. An empirical model for the solubility of H2O in magmas to 3 kilobars. Am. Mineral. 83, 36-42], show that these models tend to systematically underestimate water solubilities in trachytic melts, probably because much of the available solubility data concern relatively alkali-poor, calc-alkaline melt compositions.
Keywords
- FTIR, Molar absorptivity, Solubility model, Trachytic melts, Water solubility
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Chemical geology, Vol. 213, No. 1-3, 15.12.2004, p. 187-196.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Water solubility in trachytic melts
AU - Di Matteo, V.
AU - Carroll, M. R.
AU - Behrens, H.
AU - Vetere, F.
AU - Brooker, R. A.
N1 - Funding Information: We thanks Prof. Leo Melluso and Prof. Enzo Morra for the samples and the XRF analysis; Prof. Giancarlo della Ventura for the use of FTIR; Prof. Gordon Moore for the models on water solubility, for the pleasant review and suggestions; Paolo Papale for the calculation of water solubility with his theoretical model; Hans Keppler and Yan Bottinga for their reviews. Italian Civil Protection, INGV and MIUR Cofin O2 for the financial support. [RR]
PY - 2004/12/15
Y1 - 2004/12/15
N2 - New data on water solubility in trachytic melts at pressures from 20 to 200 MPa and 850 °C are reported. Three trachytes, which differ mainly in Na/K ratio, were studied. The glasses obtained from water saturated experiments were analysed using both infrared spectroscopy (FTIR) and Karl Fischer Titration (KFT). The independent KFT data on total water contents were used to calculate linear molar absorptivity values for infrared bands at ∼4500 cm-1 (hydroxyl groups) and ∼5200 cm-1 (molecular water). Water contents in the three trachytic melts studied are higher than those observed in rhyolitic melts at similar pressures and approach 8 wt.% H2O at 200 MPa. Increasing Na2O content in the trachyte compositions investigated is found to correlate positively with melt water content, similar to the effect of Na2O in haplogranitic systems. The new solubility data, when compared with two theoretical models for water solubility [Papale, P., 1997. Thermodynamic modeling of the solubility of H2O and CO2 in silicate liquids. Contrib. Mineral. Petrol. 126, 237-251; Moore, G., Vennemann, T., Carmichael, I.S.E., 1998. An empirical model for the solubility of H2O in magmas to 3 kilobars. Am. Mineral. 83, 36-42], show that these models tend to systematically underestimate water solubilities in trachytic melts, probably because much of the available solubility data concern relatively alkali-poor, calc-alkaline melt compositions.
AB - New data on water solubility in trachytic melts at pressures from 20 to 200 MPa and 850 °C are reported. Three trachytes, which differ mainly in Na/K ratio, were studied. The glasses obtained from water saturated experiments were analysed using both infrared spectroscopy (FTIR) and Karl Fischer Titration (KFT). The independent KFT data on total water contents were used to calculate linear molar absorptivity values for infrared bands at ∼4500 cm-1 (hydroxyl groups) and ∼5200 cm-1 (molecular water). Water contents in the three trachytic melts studied are higher than those observed in rhyolitic melts at similar pressures and approach 8 wt.% H2O at 200 MPa. Increasing Na2O content in the trachyte compositions investigated is found to correlate positively with melt water content, similar to the effect of Na2O in haplogranitic systems. The new solubility data, when compared with two theoretical models for water solubility [Papale, P., 1997. Thermodynamic modeling of the solubility of H2O and CO2 in silicate liquids. Contrib. Mineral. Petrol. 126, 237-251; Moore, G., Vennemann, T., Carmichael, I.S.E., 1998. An empirical model for the solubility of H2O in magmas to 3 kilobars. Am. Mineral. 83, 36-42], show that these models tend to systematically underestimate water solubilities in trachytic melts, probably because much of the available solubility data concern relatively alkali-poor, calc-alkaline melt compositions.
KW - FTIR
KW - Molar absorptivity
KW - Solubility model
KW - Trachytic melts
KW - Water solubility
UR - http://www.scopus.com/inward/record.url?scp=10944226845&partnerID=8YFLogxK
U2 - 10.1016/j.chemgeo.2004.08.042
DO - 10.1016/j.chemgeo.2004.08.042
M3 - Article
AN - SCOPUS:10944226845
VL - 213
SP - 187
EP - 196
JO - Chemical geology
JF - Chemical geology
SN - 0009-2541
IS - 1-3
ER -