Details
| Originalsprache | Englisch |
|---|---|
| Seiten (von - bis) | 456-467 |
| Seitenumfang | 12 |
| Fachzeitschrift | Journal of Earth Science |
| Jahrgang | 31 |
| Ausgabenummer | 3 |
| Frühes Online-Datum | 15 Juni 2020 |
| Publikationsstatus | Veröffentlicht - Juni 2020 |
Abstract
The effects of melt composition, temperature and pressure on the solubility of fluorite (CaF2), i.e., fluorine concentration in silicate melts in equilibrium with fluorite, are summarized in this paper. The authors present a statistic study based on experimental data in literature and propose a predictive model to estimate F concentration in melt at the saturation of fluorite (CF in meltFl-sat). The modeling indicates that the compositional effect of melt cations on the variation in CF in meltFl-sat can be expressed quantitatively as one parameter FSI (fluorite saturation index): FSI=(3AlNM+Fe2++6Mg+Ca+1.5Na-K)/(Si+Ti+AlNF+Fe3+), in which all cations are in mole, and AlNF and AlNM are Al as network-forming and network-modifying cations, respectively. The dependence of CF in meltFl-sat on FSI is regressed as: CF in meltFl-sat=1.130−2.014·exp (1 000/T)+2.747·exp (P/T)+0.111·CmeltH2O +17.641·FSI, in which T is temperature in Kelvin, P is pressure in MPa, CmeltH2O is melt H2O content in wt.%, and CF in meltFl-sat is in wt.% (normalized to anhydrous basis). The reference dataset used to establish the expression for conditions within 540–1 010 °C, 50–500 MPa, 0–7 wt.% melt H2O content, 0.4 to 1.7 for A/CNK, 0.3 wt.%–7.0 wt.% for CF in meltFl-sat. The discrepancy of CF in meltFl-sat between calculated and measured values is less than ±0.62 wt.% with a confidence interval of 95%. The expression of FSI and its effect on CF in meltFl-sat indicate that fluorine incorporation in silicate melts is largely controlled by bonding with network-modifying cations, favorably with Mg, AlNM, Na, Ca and Fe2+ in a decreasing order. The proposed model for predicting CF in meltFl-sat is also supported by our new experiments saturated with magmatic fluorite performed at 100–200 MPa and 800–900 °C. The modeling of magma fractional crystallization emphasizes that the saturation of fluorite is dependent on both the compositions of primary magmas and their initial F contents.
ASJC Scopus Sachgebiete
- Erdkunde und Planetologie (insg.)
- Allgemeine Erdkunde und Planetologie
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in: Journal of Earth Science, Jahrgang 31, Nr. 3, 06.2020, S. 456-467.
Publikation: Beitrag in Fachzeitschrift › Artikel › Forschung › Peer-Review
}
TY - JOUR
T1 - Experiments on the Saturation of Fluorite in Magmatic Systems
T2 - Implications for Maximum F Concentration and Fluorine-Cation Bonding in Silicate Melt
AU - Li, Xiaoyan
AU - Zhang, Chao
AU - Wang, Lianxun
AU - Behrens, Harald
AU - Holtz, Francois
N1 - Funding Information: This study was supported by the National Natural Science Foundation of China (No. 41902052) and the German Research Foundation (DFG) (No. BE 1720/40). We thank two anonymous reviewers for their helpful comments that have substantially improved this paper. The final publication is available at Springer via 10.1007/s12583-020-1305-y.
PY - 2020/6
Y1 - 2020/6
N2 - The effects of melt composition, temperature and pressure on the solubility of fluorite (CaF2), i.e., fluorine concentration in silicate melts in equilibrium with fluorite, are summarized in this paper. The authors present a statistic study based on experimental data in literature and propose a predictive model to estimate F concentration in melt at the saturation of fluorite (CF in meltFl-sat). The modeling indicates that the compositional effect of melt cations on the variation in CF in meltFl-sat can be expressed quantitatively as one parameter FSI (fluorite saturation index): FSI=(3AlNM+Fe2++6Mg+Ca+1.5Na-K)/(Si+Ti+AlNF+Fe3+), in which all cations are in mole, and AlNF and AlNM are Al as network-forming and network-modifying cations, respectively. The dependence of CF in meltFl-sat on FSI is regressed as: CF in meltFl-sat=1.130−2.014·exp (1 000/T)+2.747·exp (P/T)+0.111·CmeltH2O +17.641·FSI, in which T is temperature in Kelvin, P is pressure in MPa, CmeltH2O is melt H2O content in wt.%, and CF in meltFl-sat is in wt.% (normalized to anhydrous basis). The reference dataset used to establish the expression for conditions within 540–1 010 °C, 50–500 MPa, 0–7 wt.% melt H2O content, 0.4 to 1.7 for A/CNK, 0.3 wt.%–7.0 wt.% for CF in meltFl-sat. The discrepancy of CF in meltFl-sat between calculated and measured values is less than ±0.62 wt.% with a confidence interval of 95%. The expression of FSI and its effect on CF in meltFl-sat indicate that fluorine incorporation in silicate melts is largely controlled by bonding with network-modifying cations, favorably with Mg, AlNM, Na, Ca and Fe2+ in a decreasing order. The proposed model for predicting CF in meltFl-sat is also supported by our new experiments saturated with magmatic fluorite performed at 100–200 MPa and 800–900 °C. The modeling of magma fractional crystallization emphasizes that the saturation of fluorite is dependent on both the compositions of primary magmas and their initial F contents.
AB - The effects of melt composition, temperature and pressure on the solubility of fluorite (CaF2), i.e., fluorine concentration in silicate melts in equilibrium with fluorite, are summarized in this paper. The authors present a statistic study based on experimental data in literature and propose a predictive model to estimate F concentration in melt at the saturation of fluorite (CF in meltFl-sat). The modeling indicates that the compositional effect of melt cations on the variation in CF in meltFl-sat can be expressed quantitatively as one parameter FSI (fluorite saturation index): FSI=(3AlNM+Fe2++6Mg+Ca+1.5Na-K)/(Si+Ti+AlNF+Fe3+), in which all cations are in mole, and AlNF and AlNM are Al as network-forming and network-modifying cations, respectively. The dependence of CF in meltFl-sat on FSI is regressed as: CF in meltFl-sat=1.130−2.014·exp (1 000/T)+2.747·exp (P/T)+0.111·CmeltH2O +17.641·FSI, in which T is temperature in Kelvin, P is pressure in MPa, CmeltH2O is melt H2O content in wt.%, and CF in meltFl-sat is in wt.% (normalized to anhydrous basis). The reference dataset used to establish the expression for conditions within 540–1 010 °C, 50–500 MPa, 0–7 wt.% melt H2O content, 0.4 to 1.7 for A/CNK, 0.3 wt.%–7.0 wt.% for CF in meltFl-sat. The discrepancy of CF in meltFl-sat between calculated and measured values is less than ±0.62 wt.% with a confidence interval of 95%. The expression of FSI and its effect on CF in meltFl-sat indicate that fluorine incorporation in silicate melts is largely controlled by bonding with network-modifying cations, favorably with Mg, AlNM, Na, Ca and Fe2+ in a decreasing order. The proposed model for predicting CF in meltFl-sat is also supported by our new experiments saturated with magmatic fluorite performed at 100–200 MPa and 800–900 °C. The modeling of magma fractional crystallization emphasizes that the saturation of fluorite is dependent on both the compositions of primary magmas and their initial F contents.
KW - experimental petrology
KW - fluorine
KW - fluorite solubility
KW - silicate melt
UR - http://www.scopus.com/inward/record.url?scp=85086505912&partnerID=8YFLogxK
U2 - 10.1007/s12583-020-1305-y
DO - 10.1007/s12583-020-1305-y
M3 - Article
AN - SCOPUS:85086505912
VL - 31
SP - 456
EP - 467
JO - Journal of Earth Science
JF - Journal of Earth Science
SN - 1674-487X
IS - 3
ER -