Magma differentiation fractionates Mo isotope ratios: Evidence from the Kos Plateau Tuff (Aegean Arc)

Vögelin, Andrea; Pettke, Thomas; Greber, Nicolas; von Niederhäusern, Brigitte; Nägler, Thomas (2014). Magma differentiation fractionates Mo isotope ratios: Evidence from the Kos Plateau Tuff (Aegean Arc). Lithos, 190-191, pp. 440-448. Elsevier 10.1016/j.lithos.2013.12.016

[img] Text
voegelin_pettke.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (693kB) | Request a copy

We investigated high temperature Mo isotope fractionation in a hydrous supra-subduction volcano-plutonic system (Kos, Aegean Arc, Greece) in order to address the debate on the δ98/95Mo variability of the continental crust. In this igneous system, where differentiation is interpreted to be dominated by fractional crystallization, bulk rock data from olivine basalt to dacite show δ98/95Mo ratios increasing from +0.3 to +0.6‰ along with Mo concentrations increasing from 0.8 to 4.1 μg g−1. Data for hornblende and biotite mineral separates reveal the extraction of light Mo into crystallizing silicates, with minimum partition coefficients between hornblende- silicate melt and biotite-silicate melt of 0.6 and 0.4 δ98/95Mo, respectively. Our data document significant Mo isotope fractionation at magmatic temperatures, hence, the igneous contribution to continental runoff is variable, besides probable source-related variability. Based on these results and published data an average continental δ98/95Mo of +0.3 to +0.4‰ can be derived. This signature corresponds more closely to the average of published data of dissolved Mo loads of large rivers than previous estimates and is consistent with an upper limit of δ98/95Mo = 0.4‰ of the Earth's upper crust as derived from the analysis of molybdenites.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Isotope Geology

UniBE Contributor:

Vögelin, Andrea; Pettke, Thomas; Greber, Nicolas; von Niederhäusern, Brigitte and Nägler, Thomas

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0024-4937

Publisher:

Elsevier

Funders:

[4] Swiss National Science Foundation

Language:

English

Submitter:

Nicolas Greber

Date Deposited:

26 Mar 2014 14:19

Last Modified:

26 Jun 2016 01:48

Publisher DOI:

10.1016/j.lithos.2013.12.016

BORIS DOI:

10.7892/boris.45313

URI:

https://boris.unibe.ch/id/eprint/45313

Actions (login required)

Edit item Edit item
Provide Feedback