Abstract
Birch's law implies a unique relationship between elastic wave velocity υ and density ρ for materials of common mean atomic weight M¯ irrespective of whether density changes are due to crystallographic structure, pressure, or temperature. Velocity data are presented for materials undergoing the olivine-spinel, olivine-beta phase, quartz-rutile, pyroxene-garnet, pyroxene-ilmenite, and ilmenite-perovskite phase transformations. These data indicate that υ-ρ relationships across such polymorphic transformations are not always equivalent to υ-ρ changes caused by varying pressure, temperature, or composition at constant mean atomic weight. For the earth these data imply that previous discussions of the composition (specifically the iron content) of the upper and lower mantles based on υ-ρ systematics may have to be reevaluated.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.