A numerical and experimental investigation on seismic anisotropy of Finero peridotite, Ivrea-Verbano Zone, Northern Italy

摘要

The Ivrea-Verbano Zone offers a unique opportunity to study lower crust/upper mantle rocks unaffected by serpentinization. Peridotites from Finero (North-East Ivrea-Verbano Zone) have been collected to investigate the influence of individual mineral phases on seismic anisotropy. The methods involve experimental ultrasonic P-wave velocity measurements using a hydrostatic pressure vessel, and electron backscatter diffraction (EBSD) analysis to investigate the crystallographic preferred orientation (CPO). CPO was analyzed by large area EBSD scans for major minerals including olivine, orthopyroxene, but also for metasomatic hornblende. The CPO of olivine is confirmed to be the major source of detected seismic anisotropy. Minor influence can arise from hornblende if it is sufficiently abundant.