TY - JOUR

T1 - Sulfur partition coefficient between apatite and rhyolite

T2 - The role of bulk S content

AU - Parat, Fleurice

AU - Holtz, François

N1 - Funding Information: Acknowledgements We thank Jürgen Koepke for assistance to microprobe analyses, Marcus Freise for experiments with andesite, Fred Blaine for comments and Otto Diedrich for technical assistance during sample preparations. The manuscript was greatly improved with reviews by Bruno Scaillet and two anonymous reviewers. We thank Jochen Hoefs for editorial handling the manuscript. This research was supported by the European Community—Marie Curie Individual Fellowship (HPMF-CT-2001-01508). Copyright: Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2005/11/19

Y1 - 2005/11/19

N2 - Experimental studies have been performed to constrain sulfur behavior during apatite crystallization and to determine sulfur partition coefficient between apatite and melt (KdSapatite/melt) at oxidizing conditions. Crystallization experiments have been conducted with a hydrous rhyolitic melt and different bulk sulfur contents (0.15 to 2 wt.% S) at 900 and 1,000°C, 200 MPa and Δlog fO2 = NNO+3.6. The sulfur content in the glass increases with increasing amount of added S. Anhydrite crystallizes for S added = 0.75 wt.% (0.10 and 0.13 wt.% SO3 in glass at 900 and 1,000°C, respectively). The amount of anhydrite increases and the amount of apatite decreases with increasing amount of added sulfur. The sulfur exchange reaction in apatite is influenced by the bulk composition of the melt (e.g., P content). However, changing melt composition has only little effect on KdSapatite/melt for the investigated rhyolitic composition. The KdSapatite/melt does not depend directly on temperature, decreases from 14.2 to 2.7 with increasing S content in glass from SO3=0.03 to 0.19 wt.%, respectively, and can be predicted from the following equation: ln Kd = -0.0025×S in melt (in ppm)+2.9178. The combination of experimental data obtained for rhyolitic and andesitic melts reveals that the sulfur partition coefficient tends toward a value of 2 for high-sulfur content in the glass (>0.2 wt.% SO3). Using S in apatite as proxy for determining S content in melt is promising but additional experimental data are needed to clarify the individual effects of T, fS2, and P and Ca content in the melt on S partitioning.

AB - Experimental studies have been performed to constrain sulfur behavior during apatite crystallization and to determine sulfur partition coefficient between apatite and melt (KdSapatite/melt) at oxidizing conditions. Crystallization experiments have been conducted with a hydrous rhyolitic melt and different bulk sulfur contents (0.15 to 2 wt.% S) at 900 and 1,000°C, 200 MPa and Δlog fO2 = NNO+3.6. The sulfur content in the glass increases with increasing amount of added S. Anhydrite crystallizes for S added = 0.75 wt.% (0.10 and 0.13 wt.% SO3 in glass at 900 and 1,000°C, respectively). The amount of anhydrite increases and the amount of apatite decreases with increasing amount of added sulfur. The sulfur exchange reaction in apatite is influenced by the bulk composition of the melt (e.g., P content). However, changing melt composition has only little effect on KdSapatite/melt for the investigated rhyolitic composition. The KdSapatite/melt does not depend directly on temperature, decreases from 14.2 to 2.7 with increasing S content in glass from SO3=0.03 to 0.19 wt.%, respectively, and can be predicted from the following equation: ln Kd = -0.0025×S in melt (in ppm)+2.9178. The combination of experimental data obtained for rhyolitic and andesitic melts reveals that the sulfur partition coefficient tends toward a value of 2 for high-sulfur content in the glass (>0.2 wt.% SO3). Using S in apatite as proxy for determining S content in melt is promising but additional experimental data are needed to clarify the individual effects of T, fS2, and P and Ca content in the melt on S partitioning.

UR - http://www.scopus.com/inward/record.url?scp=28344450825&partnerID=8YFLogxK

U2 - 10.1007/s00410-005-0041-8

DO - 10.1007/s00410-005-0041-8

M3 - Article

AN - SCOPUS:28344450825

VL - 150

SP - 643

EP - 651

JO - Contributions to Mineralogy and Petrology

JF - Contributions to Mineralogy and Petrology

SN - 0010-7999

IS - 6

ER -