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Abstract
Sub-lithospheric diamonds from the Juina-5 and Collier-4 kimberlites and
the Machado River alluvial deposit in Brazil have carbon isotopic
compositions that co-vary with the oxygen isotopic compositions of their
inclusions, which implies that they formed by a mixing process. The
proposed model for this mixing process, based on interaction of
slab-derived carbonate melt with reduced (carbide- or metal-bearing)
ambient mantle, explains these isotopic observations. It is also
consistent with the observed trace element chemistries of diamond
inclusions from these localities and with the experimental phase
relations of carbonated subducted crust. The 18O-enriched
nature of the inclusions demonstrates that they incorporate material
from crustal protoliths that previously interacted with seawater, thus
confirming the subduction-related origin of superdeep diamonds. These
samples also provide direct evidence of an isotopically anomalous
reservoir in the deep (≥350 km) mantle.
Original language | English |
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Pages (from-to) | 374-380 |
Number of pages | 7 |
Journal | Earth and Planetary Science Letters |
Volume | 432 |
Early online date | 3 Dec 2015 |
DOIs | |
Publication status | Published - 15 Dec 2015 |
Bibliographical note
Date of Acceptance: 17/10/2015Keywords
- diamonds
- stable isotopes
- subduction
- majorite
- stishovite
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Dive into the research topics of 'Stable isotope evidence for crustal recycling as recorded by superdeep diamonds'. Together they form a unique fingerprint.Projects
- 1 Finished
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Deep Mantle Recycling Revealed in Diamonds and their Mineral Inclusions
Walter, M. J.
1/09/12 → 1/09/15
Project: Research