An experimental study of trace-element partitioning between Ti-Al-clinopyroxene and melt: Equilibrium and kinetic effects including sector zoning
Abstract
Equilibrium and dynamic crystallization experiments were used to determine distribution coefficients (D-values) for the REE and the trace elements Sc, V, Rb, Sr, Y, Zr, Nb, Ba, Hf, Th, and U between Ti-Al-clinopyroxene and melt. Equilibrium values for D correlate well with previous studies where values have been determined. The D-values were also studied as a function of cooling rate. Increased cooling rates produce higher growth rates. At growth rates that exceed the diffusion rates in the crystals, the D-values increase to near unity and the HREE D-values exceed unity only at the most rapid crystal growth rates. The increase in D-values is the result of the inclusion of components into the growing pyroxene from the boundary layer that develops at the crystal-melt interface because of the disparity between the growth and diffusion rates. The origin of sector zoning is best explained as an interplay of primarily crystallographic control with kinetic effects.
Additional Information
© 2006 Mineralogical Society of America. Manuscript received September 28, 2005; Manuscript accepted April 5, 2006; Manuscript handled by C. Shearer. We thank A. Fahey and T. LaTourrette for analyses of ADE-106 and ADE-108, respectively. We thank A. Lanier for operation and maintenance of experimental equipment, L. Le for preparation of thick sections, and C. Schwandt for support with electron microprobe and SEM studies. We also thank the reviewers D. Draper and S. Simon for their contribution to the improvement of this paper. This project was supported by NASA RTOP 152-12-40-23 to GEL and NASA grants NAGW3040 and NAGW 3297 to G.J.W.Additional details
- Eprint ID
- 42565
- Resolver ID
- CaltechAUTHORS:20131119-104958848
- 152-12-40-23
- NASA RTOP
- NAGW 3040
- NASA
- NAGW 3297
- NASA
- Created
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2013-11-20Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field