Alexandre Corgne's Home Page

What do I do?

Experimental geochemists like me use a variety of presses and furnaces to recreate the conditions of pressure and temperature inside the terrestrial planets. These planets are the closest to the Sun and include the Earth, the Moon, Mars, Mercury and Venus. Combined to powerful analytical techniques, high-pressure and high-temperature experiments bring insights into the formation of terrestrial planets, as well as constraints on their internal structure and chemical composition.

As you may know, terrestrial planets are structurally divided into 4 layers: a central metallic core surrounded by a silicate mantle, a crust and a superficial exosphere. Until now, my research has mainly focused on determining the abundances of some minor and trace elements in the deep mantle and the core of the Earth. Please see my publications or the media releases for further information.

Earth's interior

Cutview of the Earth's interior. This figure shows the structure of our planet as evidenced by seismic and experimental observations. The central core is mainly composed of iron. Its inner part is solid whereas the outer part is liquid. The core (32.3% of the Earth's mass) is surrounded by two silicate layers with distinct compositions: the mantle (67.2%) and the crust (0.5%).

Earth's interior

The terrestrial planets. Their relative sizes and schematic views of their interior.

Experimental tools

I use the following devices to carry out experiments at high temperature and high pressure:

Gas-mixing furnace
(1 atm - 2000 K)

Piston-cylinder apparatus
(30 000 atm - 3000 K)

Multi-anvil press
(300 000 atm - 3000 K)

Diamond-anvil cell
(2 000 000 atm - 6000 K)

Analytical tools

I use the following probes to measure the major and trace element contents of the synthesized samples with a spatial resolution on the order of 1 to 10 microns (0.001-0.01 mm):

Electron probe micro-analyser

Laser ablation ICP-MS

Secondary ion mass spectrometer

Media releases

22/02/2009: Les actualités du CNRS. Les isotopes du fer, nouveaux traceurs de la genèse de la Terre.
17/09/2010: Communiqué CNRS. Quand le manteau de la Terre rencontre son noyau.
17/09/2010: ScienceDaily. Findings boost hypothesis of deep magma ocean
20/09/2010: USA Today. Earth's core, mantle melt together at their boundary.
23/09/2010: National Geographic. New magma layer found deep in Earth's mantle?

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Centre National de la Recherche Scientifique IRAP - UMR 5277 © 2009 Alexandre Corgne