T40 Creative Contributions in Volcanology and Petrology: In Honor of Katharine V. Cashman, Recipient of the 2023 Distinguished Geological Career Award from the Mineralogy, Geochemistry, Petrology and Volcanology Division (Posters)

Sunday, 15 October 2023
8:00 AM - 5:30 PM
Hall B

THE PARTITIONING OF LITHIUM BETWEEN MAFIC MINERALS AND TERRESTRIAL AND MARTIAN BASALTS

Paper number: T40-11
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

The abundance of lithium (Li), a light-lithophilic element, in Earth materials can provide evidence of planetary evolution. Although Li is thought to be moderately incompatible in mafic minerals, its behavior during crystallization and melting events is still unclear. New experimental measurements of Li compatibility in mafic systems are required to quantitatively use Li abundances as tracers of processes like magma differentiation or degassing. We quantified the partitioning of Li between basaltic minerals (clinopyroxene, orthopyroxene and plagioclase) and melt by running piston-cylinder experiments at varying temperatures (1025-1275˚C) and pressures (0.8-1.5GPa) using terrestrial and martian basaltic bulk compositions. All experiments were temperature cycled to enhance the growth of large mineral phases. Completed experiments were polished and analyzed using laser ablation ICP-MS to quantify the abundances of Li in all phases. Calculated mineral-melt partition coefficients indicate that Li is incompatible in all phases. In experiments where more than one mineral phase is present, Li is most compatible in clinopyroxene, followed by orthopyroxene then plagioclase. Our preliminary results show Li is more strongly partitioned into clinopyroxene at elevated temperatures and pressure in both terrestrial and martian compositions. This trend may provide an alternative explanation for the core-to-rim decrease in Li abundances observed in clinopyroxenes in martian meteorites (e.g., McSween et al. 2001).

McSween, H.Y. et al. (2001) Nature 409, 487-490.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-394767

© Copyright 2023 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.