Xenoliths from the Wyoming craton

Since there are only rare locations in which mantle rock are exposed, xenoliths (rock fragments that were carried from large depths by erupted magma) can tell us on the composition, microstructure, and rheology of the deep mantle. Through a microstructual and chemical analysis the xenoliths from Wyoming can suggest on the evolution of the continental lithosphere below the North America plate.

3-D Electron Backscatter Diffraction of a peridotite mantle sample from Wyoming, USA (LabDCT technology at Xnovo Technology).The sample shows olivine grains with sharp boundaries. These tablet-shaped grains formed during static conditions and high temperatures ('annealing') and have different properties compared with the rest of the sample. Three pole figures of [100], [010], [001], olivine axes (from left to right) show the orientation modification of the tablet grains (secondary maximas in the pole figures).

During an EBSD scan at UC San Diego


Microstructure - orientation map using electron Backscatter Diffraction (EBSD). Colors show the crystals orientations.