Plagioclase archives of depleted melts in the oceanic crust

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1130/G49840.1. This is version 2 of this Preprint.

Downloads

Download Preprint

Authors

David Axford Neave, Olivier Namur

Abstract

Mid-ocean ridge and ocean island basalts provide vital but incomplete insights into mantle chemistry. For example, high-anorthite plagioclase is generally too refractory and incompatible-element depleted to have crystallized from the melts that carry it to the surface. Moreover, erupted basalts rarely preserve the extreme isotopic and incompatible-element depletions found in some primitive melt inclusions and residual abyssal peridotites. By integrating experimental observations with analyses of natural crystals and glasses, we infer that high-anorthite plagioclase grows from high-degree melts of refractory but otherwise unexotic mantle sources with depleted incompatible element compositions. The widespread occurrence of high-anorthite plagioclase in oceanic basalts and the oceanic crust hence indicates that refractory melts pervade the uppermost mantle and lower crust. We thus suggest that refractory melts play much a greater role in crustal accretion than typically recognized, and that refractory and feasibly depleted peridotite is more prevalent in the upper mantle than previously thought.

DOI

https://doi.org/10.31223/X5NK86

Subjects

Geochemistry, Geology

Keywords

Dates

Published: 2021-11-15 11:46

Last Updated: 2022-02-17 11:49

Older Versions
License

CC BY Attribution 4.0 International

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.