Chemical imaging with NanoSIMS: A window into deep-Earth geochemistry - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Earth and Planetary Science Letters Année : 2007

Chemical imaging with NanoSIMS: A window into deep-Earth geochemistry

Résumé

We use a combination of nanometer-resolution secondary ion mass spectrometry (NanoSIMS) and analytical transmission electron microscopy (ATEM) for chemical imaging of material transformed in a laser-heated diamond anvil cell (LH-DAC), in the pressure and temperature range of Earth's lower mantle. MORB (mid-ocean ridge basalt), one of the components of subducted oceanic lithosphere, was transformed to an assemblage of Mg-perovskite, Ca-perovskite, stishovite and a calcium ferrite-structure phase at 55 GPa and 2100 °C in an LH-DAC. Elemental imaging spanning the entire range of concentrations, from major elements such as silicon (49.5 wt.% SiO2) to trace elements such as strontium (118 ppm), scandium, and yttrium (both at 40 ppm) was obtained with a Cameca NanoSIMS 50. We observe a preferential partitioning of scandium, yttrium and strontium in the calcium silicate perovskite phase, and we compare this to recently measured solid–liquid partition coefficients and fractionation at lower pressures. This type of measurement demonstrates that even the most complex mineral assemblages can be probed using this combination of techniques and opens new pathways towards the characterization and quantification of geochemical interactions and processes occurring in the deep Earth.

Domaines

Minéralogie

Dates et versions

hal-00195251 , version 1 (10-12-2007)

Identifiants

Citer

James Badro, Frederick J. Ryerson, Peter K. Weber, Angèle Ricolleau, Stewart J. Fallon, et al.. Chemical imaging with NanoSIMS: A window into deep-Earth geochemistry. Earth and Planetary Science Letters, 2007, 262, pp.543-551. ⟨10.1016/j.epsl.2007.08.007⟩. ⟨hal-00195251⟩
114 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More