Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 515-522 |
| Seitenumfang | 8 |
| Fachzeitschrift | Earth and Planetary Science Letters |
| Jahrgang | 184 |
| Ausgabenummer | 2 |
| Frühes Online-Datum | 10 Jan. 2001 |
| Publikationsstatus | Veröffentlicht - 15 Jan. 2001 |
Abstract
Molecular water and hydroxyl groups are stable species in hydrous rhyolitic melts. To quantify the species concentrations we have used in situ IR spectroscopic measurements at 773-1073 K and 100-300 MPa in combination with an internally consistent calibration. The derived reaction enthalpy and entropy values for the homogeneous species reaction (H2Omelt +Omelt = 2 OHmelt) are 35.0 ± 1.2 kJ mol-1 and 27.7 ± 1.3 J mol-1 K-1, respectively and are independent of water content in the range 1.27-5.15 wt% water. Both values are significantly higher than extrapolated data based on species measurements of hydrous glasses at room temperature. The reaction entropy and enthalpy of hydroxyl formation are fundamental quantities for understanding and modeling hydrous magma properties.
ASJC Scopus Sachgebiete
- Erdkunde und Planetologie (insg.)
- Geophysik
- Erdkunde und Planetologie (insg.)
- Geochemie und Petrologie
- Erdkunde und Planetologie (insg.)
- Erdkunde und Planetologie (sonstige)
- Erdkunde und Planetologie (insg.)
- Astronomie und Planetologie
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in: Earth and Planetary Science Letters, Jahrgang 184, Nr. 2, 15.01.2001, S. 515-522.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Water in rhyolitic magmas
T2 - Getting a grip on a slippery problem
AU - Nowak, Marcus
AU - Behrens, Harald
N1 - Funding Information: We thank F. Holtz, H. Keppler, and Y. Zhang for helpful discussions. The critical reviews of F. Spera and C. Mandeville were beneficial to this work. We particularly thank F. Spera for providing the MD simulation data. Supported by the Deutsche Forschungsgemeinschaft (SFB 173). [EB]
PY - 2001/1/15
Y1 - 2001/1/15
N2 - Molecular water and hydroxyl groups are stable species in hydrous rhyolitic melts. To quantify the species concentrations we have used in situ IR spectroscopic measurements at 773-1073 K and 100-300 MPa in combination with an internally consistent calibration. The derived reaction enthalpy and entropy values for the homogeneous species reaction (H2Omelt +Omelt = 2 OHmelt) are 35.0 ± 1.2 kJ mol-1 and 27.7 ± 1.3 J mol-1 K-1, respectively and are independent of water content in the range 1.27-5.15 wt% water. Both values are significantly higher than extrapolated data based on species measurements of hydrous glasses at room temperature. The reaction entropy and enthalpy of hydroxyl formation are fundamental quantities for understanding and modeling hydrous magma properties.
AB - Molecular water and hydroxyl groups are stable species in hydrous rhyolitic melts. To quantify the species concentrations we have used in situ IR spectroscopic measurements at 773-1073 K and 100-300 MPa in combination with an internally consistent calibration. The derived reaction enthalpy and entropy values for the homogeneous species reaction (H2Omelt +Omelt = 2 OHmelt) are 35.0 ± 1.2 kJ mol-1 and 27.7 ± 1.3 J mol-1 K-1, respectively and are independent of water content in the range 1.27-5.15 wt% water. Both values are significantly higher than extrapolated data based on species measurements of hydrous glasses at room temperature. The reaction entropy and enthalpy of hydroxyl formation are fundamental quantities for understanding and modeling hydrous magma properties.
KW - Chemical fractionation
KW - Infrared spectroscopy
KW - Melts
KW - Rhyolites
KW - Water
UR - http://www.scopus.com/inward/record.url?scp=0035116268&partnerID=8YFLogxK
U2 - 10.1016/S0012-821X(00)00343-5
DO - 10.1016/S0012-821X(00)00343-5
M3 - Article
AN - SCOPUS:0035116268
VL - 184
SP - 515
EP - 522
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
IS - 2
ER -