Evidence for oxygen-conserving diamond formation in redox-buffered subducted oceanic crust sampled as eclogite
- Cratonic eclogite is the product of oceanic crust subduction into the subcontinental lithospheric mantle, and it also is a fertile diamond source rock. In contrast to matrix minerals in magma-borne xenoliths, inclusions in diamond are shielded from external fluids, retaining more pristine information on the state of the eclogite source at the time of encapsulation. Vanadium is a multi-valent element and a widely used elemental redox proxy. Here, we show that that xenolithic garnet has lower average V abundances than garnet inclusions. This partly reflects crystal-chemical controls, whereby higher average temperatures recorded by inclusions, accompanied by enhanced Na2O and TiO2 partitioning into garnet, facilitate V incorporation at the expense of clinopyroxene. Unexpectedly, although diamond formation is strongly linked to metasomatism and xenoliths remained open systems, V concentrations are similar for bulk eclogites reconstructed from inclusions and from xenoliths. This suggests an oxygen-conserving mechanism for eclogitic diamond formation, and implies that eclogite is an efficient system to buffer fO2 over aeons of lithospheric mantle modification by subduction-derived and other fluids.
Author: | Sonja AulbachORCiD, Thomas StachelORCiD |
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URN: | urn:nbn:de:hebis:30:3-695108 |
DOI: | https://doi.org/10.1038/s41467-022-29567-z |
ISSN: | 2041-1723 |
Parent Title (English): | Nature Communications |
Publisher: | Nature Publishing Group UK |
Place of publication: | [London] |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2022/04/08 |
Date of first Publication: | 2022/04/08 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2023/06/02 |
Tag: | Mineralogy; Petrology |
Volume: | 13 |
Issue: | art. 1924 |
Article Number: | 1924 |
Page Number: | 13 |
First Page: | 1 |
Last Page: | 13 |
Note: | Open Access funding enabled and organized by Projekt DEAL. |
Institutes: | Geowissenschaften / Geographie |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Sammlungen: | Universitätspublikationen |
Licence (German): | Creative Commons - CC BY - Namensnennung 4.0 International |