Experimental calibration and implications of olivine-melt vanadium oxybarometry for hydrous basaltic arc magmas.

Shishkina, T. A., Portnyagin, Maxim , Botcharnikov, R. E., Almeev, R. R., Simonyan, A. V., Garbe-Schönberg, Dieter, Schuth, S., Oeser, M. and Holtz, F. (2018) Experimental calibration and implications of olivine-melt vanadium oxybarometry for hydrous basaltic arc magmas. Open Access American Mineralogist, 103 (3). pp. 369-383. DOI 10.2138/am-2018-6210.

[thumbnail of Preprint] Text (Preprint)
6210ShishkinaPreprintMar.pdf - Accepted Version

Download (2MB)
[thumbnail of Shishkina_2018.pdf] Text
Shishkina_2018.pdf - Published Version
Restricted to Registered users only

Download (2MB) | Contact

Supplementary data:

Abstract

The strong dependence of vanadium partitioning between olivine and silicate melt (DVOl-M) on redox conditions (fO2) can be used as sensitive oxybarometer in magmatic systems. Here we extend the experimental database on DVOl-M, obtained so far at high temperatures (mainly above 1250 °C), to lower temperatures that are typical for island-arc basalts. Crystallization experiments were performed using a composition from Mutnovsky volcano (Kamchatka), and the investigated temperature, pressure, and oxygen fugacity ranges were 1025–1150 °C, 0.1 and 0.3 GPa, and ΔQFM of –0.5 to +3.2, respectively. The water content in melts ranged from 0.6 to ∼6.5 wt% H2O. The data demonstrate a strong negative correlation between DVOl-M and oxygen fugacity, similar to the behavior observed previously at higher temperatures and in MgO-rich compositions. The correlation between DVOl-M and ΔQFM in the range from –0.5 to +3.2 is described for melts with MgO < 12 wt% and Na2O < 4 wt% at temperatures ≤1250 °C by the empirical equation: ΔQFM = −3.07−0.29+0.26 logDVOl-M – 3.34−0.49+0.40 with the standard error (SE) as a function of logDVOl-M: 2SE(ΔQFM) = –0.275logDVOl-M + 0.4.

We suggest that this equation can be used as an oxybarometer, which is particularly well applicable to the hydrous island-arc magmas at relatively low temperature. Application of the equation to the composition of melt inclusions and their host olivine phenocrysts from basalts of Mutnovsky volcano, containing vanadium concentrations in the range of 250–370 and 4–6 ppm, respectively, reveals an oxygen fugacity in the range ΔQFM +1.9 to +2.3. The estimates are in a good agreement with olivine-spinel oxybarometry for Mutnovsky basalts and may be typical for moderately evolved island-arc magmas.

Document Type: Article
Additional Information: 1Deposit item AM-18-36210, Supplemental Material. Deposit items are free to all readers and found on the MSA web site, via the specific issue’s Table of Contents (go to http://www.minsocam.org/MSA/AmMin/TOC/2018/Mar2018_data/ Mar2018_data.html).
Keywords: vanadium, oxybarometry, island arcs, melt inclusions, redox conditions
Research affiliation: Kiel University
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS
Refereed: Yes
Open Access Journal?: No
Publisher: Mineralogical Society of America
Date Deposited: 08 Jan 2018 11:43
Last Modified: 08 Feb 2021 07:27
URI: https://oceanrep.geomar.de/id/eprint/41261

Actions (login required)

View Item View Item