Uppermost mantle anisotropy beneath the southern Laurentian margin: Evidence from Knippa peridotite xenoliths, Texas

作者：Satsukawa Takako^*; Michibayashi Katsuyoshi; Raye Urmidola; Anthony Elizabeth Y; Pulliam Jay; Stern Robert

来源：Geophysical Research Letters, 2010, 37: L20312.

DOI：10.1029/2010GL044538

Peridotite xenoliths from southern Texas consist of spinel lherzolite, harzburgite and minor dunite. Based on phase relations and temperature of equilibration, Knippa xenoliths come from the uppermost mantle, 40-70 km deep. Knippa xenoliths provide rare snapshots of upper mantle processes and compositions beneath south-central Laurentia. They preserve olivine a-axis fiber fabrics with a strong concentration of [100] and girdles of [010] and [001]. Assuming a lithospheric mantle having a horizontal flow direction parallel to fast directions, the mantle lithospheric fabric revealed by the xenoliths mostly explains the magnitude of observed shear-wave splitting observed along the southern margin of the Laurentian craton. Citation: Satsukawa, T., K. Michibayashi, U. Raye, E. Y. Anthony, J. Pulliam, and R. Stern (2010), Uppermost mantle anisotropy beneath the southern Laurentian margin: Evidence from Knippa peridotite xenoliths, Texas, Geophys. Res. Lett., 37, L20312, doi:10.1029/2010GL044538.

• 出版日期2010-10-27