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Updated: Jul 11, 2026

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Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
Eclogites, pyroxene geotherm, and layered mantle convection
Summary
Temperatures of eclogite xenoliths suggest the Earth's mantle has layered convection. This geotherm indicates a convective boundary layer beneath the lithospheric plate, differing from whole mantle convection models.
Area of Science:
- Geochemistry
- Geophysics
- Petrology
Background:
- Eclogite xenoliths provide insights into the Earth's mantle conditions.
- Subcontinental geotherms are crucial for understanding lithospheric plate dynamics.
Purpose of the Study:
- To determine the equilibration temperatures of eclogite xenoliths from the Roberts Victor kimberlite pipe.
- To interpret the subcontinental geotherm and its implications for mantle convection.
Main Methods:
- Analysis of eclogite xenoliths' mineral compositions.
- Geotherm modeling based on xenolith equilibration temperatures.
Main Results:
- 81% of eclogite xenoliths equilibrated between 1000-1250°C.
- These temperatures align with the lower limb of an inflected subcontinental geotherm derived from garnet peridotite xenoliths.
- The geotherm's inflection gradient suggests a double thermal boundary layer.
Conclusions:
- The inflected geotherm likely represents the convective boundary layer beneath the lithospheric plate.
- The data supports a model of layered mantle convection rather than whole mantle convection.
- Archean eclogites provide evidence for ancient mantle processes.
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