Skip to main content
eScholarship
Open Access Publications from the University of California

UCLA

UCLA Electronic Theses and Dissertations bannerUCLA

Experimental determination of fluorine and hydrogen partitioning between apatite and basaltic melt

  • Author(s): Huh, Michael Chahn
  • Advisor(s): Manning, Craig E;
  • Boyce, Jeremy W
  • et al.
Abstract

The mineral apatite incorporates OH, F, and Cl into its structure, so volatile concentrations in apatite could be used as a proxy for their abundances in magmas. I investigated this by conducting experiments on F-OH exchange between apatite and a simplified arc basalt at 10 kb and 1100 to 1250 °C for 48 hours. The experiments succeeded in growing, for the first time, apatites that were large enough (25-50 µm) for analysis by secondary ion mass spectrometry (SIMS), measurements were also conducted with the electron probe microanalyzer (EPMA). Results indicated that F is preferentially partitioned into apatite, whereas OH slightly favors the liquid. The exchange of F and OH between apatite and melt can be represented as Fliquid + OHapatite = OHliquid + Fapatite, for which the equilibrium constant is Keq=[Fap][OHliq]/[OHap][Fliq], assuming unit activity coefficients. Weighted least squares fitting to data yielded Keq = 59.

Main Content
For improved accessibility of PDF content, download the file to your device.
Current View