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I collect and study xenoliths, rocks that come up from lower crust and upper mantle depths through volcanic eruptions.

My research aims to understand the rheological properties of the lower crust and upper mantle, particularly in actively deforming regions such as the Mojave in Southern California. I'm also actively working on understanding the factors that influence the development of olivine crystallographic aka lattice preferred orientation (CPO, LPO) more generally.

Bernard, R.E., Behr, W.M., Becker, T.W., and D.J. Young (in press) Relationships between olivine CPO and deformation parameters in naturally deformed rocks and implications for mantle seismic anisotropy. Accepted 4/2019 by Geochemistry, Geophysics, Geosystems. Preprint posted to ESSOAr here: https://doi.org/10.1002/essoar.10500834.1

Bernard, R.E. and W.M Behr (2017) Fabric heterogeneity in the Mojave lower crust and lithospheric mantle in Southern California. JGR Solid Earth. DOI: 10.1002/2017JB014280


One tool I use to investigate the rheological properties of these rocks — and measure LPO — is electron backscatter diffraction (EBSD). This tool allows for the identification of mineral phases based on their crystallographic structure, while also quantifying the orientations of those minerals. Below: (top) phase map of an awesome, highly deformed peridotite xenolith from Lunar Crater Volcanic Field in central Nevada; (bottom) the same mapped area, but with olivine colored based on orientation. This type of map allows us to investigate grain elongation, dynamic recrystallization, and crystallographic preferred orientation preserved in this spectacularly deformed rock.

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