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Updated: Jun 28, 2026
06:04
Simulation of the Planetary Interior Differentiation Processes in the Laboratory
Published on: November 15, 2013
The Earth's missing lead may not be in the core.
M Lagos1, C Ballhaus, C Münker
1Steinmann-Institut, Universität Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany. lagos@uni-bonn.de
Nature
|November 7, 2008
Summary
Earth
Area of Science:
- Geochemistry
- Planetary Science
- Isotope Geology
Background:
- Earth is depleted in volatile elements compared to CI chondrites.
- Lead (Pb) is volatile, and its depletion on Earth is debated.
- Earth's mantle has unique lead isotope ratios suggesting post-accretionary Pb loss.
Purpose of the Study:
- Investigate the partitioning of lead in metal-sulphide-silicate systems.
- Determine the mechanism behind Earth's volatile element depletion, specifically lead.
- Reconcile Earth's lead deficit with planetary formation and evolution models.
Main Methods:
- Performed partitioning experiments in synthetic metal-sulphide-silicate systems.
- Analyzed lead partitioning coefficients under relevant planetary conditions.
- Utilized isotopic analysis to constrain lead loss models.
Main Results:
- Lead is not sufficiently siderophile or chalcophile to be sequestered in the core.
- Experimental data do not support sulfide melt segregation as the primary mechanism for Earth's lead deficit.
- Lead loss is unlikely to be solely explained by partitioning into the core.
Conclusions:
- Earth's lead deficit may result from accretion of volatile-depleted material.
- Lead loss via degassing after the Moon-forming impact is a plausible scenario.
- A deep mantle reservoir with complementary lead isotope signatures is possible, but core sequestration is unlikely.
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