Abstract
How geometry and anisotropy affect residual strain in host-inclusion systems: Coupling experimental and numerical approaches
Highlights
Elastic geobarometry for host-inclusion systems is based on measurements of the residual strains produced during exhumation as a consequence of the contrast in elastic properties between the host and the inclusion
Our experimental results coupled with selected numerical simulations demonstrate that the magnitude and the rate of the strain release depend on the contrast in elastic properties between the host and the inclusion and on the inclusion crystallographic orientation with respect to the external surface
Models for elastic geobarometry only apply to the simple case of elastically isotropic host-inclusion pairs with a simple ideal geometry where a small spherical inclusion is trapped in an infinite host (Angel et al 2015)
Summary
Elastic geobarometry for host-inclusion systems is based on measurements of the residual strains produced during exhumation as a consequence of the contrast in elastic properties between the host and the inclusion. We propose an alternative way to test the effect of the geometry of the host-inclusion system on the Raman signal and on the calculated residual pressure upon polishing: to collect spectra from selected inclusions with different shape, size, and crystallographic orientation, while performing several steps of polishing of the rock thick-section to bring the inclusion closer to the external surface of the host In this manuscript we report the Raman spectra of rounded and elongated zircon inclusions and a rounded coesite inclusion in pyrope from the ultrahigh-pressure (UHP) Alpine Dora Maira Massif measured before and after several subsequent steps of polishing. For the application of elastic geobarometry, we selected garnet-core and rim domains unaltered and free of fractures In these domains, the coesite and zircon inclusions are surrounded by birefringent haloes (Fig. 1), indicating that the structure of the garnet host around the inclusions is anisotropically strained
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
