The lithosphere-asthenosphere transition and radial anisotropy beneath the Australian continent

Date

2015

Authors

Yoshizawa, K
Kennett, Brian

Journal Title

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Volume Title

Publisher

American Geophysical Union

Abstract

A new 3-D S wave speed model for the Australian region derived from multimode surface waves allows us to examine the nature of the lithosphere-asthenosphere transition (LAT) and its relation to radial anisotropy. In eastern Phanerozoic Australia the estimated depths of the LAT tie well with those from receiver functions. However, in the Archean and Proterozoic lithosphere in western and central Australia, the LAT derived from the surface wave model is generally much deeper than the discontinuities recognized from receiver functions and shows a smooth transition. There is significant radial anisotropy (SH > SV) in the upper lithosphere as well as in the LAT and the underlying asthenosphere. Strong anisotropy in the asthenosphere reflects the effects of present shear flow in the mantle beneath the continent. The lateral variation of lithospheric anisotropy correlates well with the suture zones between cratonic blocks, representing frozen anisotropy associated with the ancient tectonics of Australia.

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Citation

Source

Geophysical Research Letters

Type

Journal article

Book Title

Entity type

Access Statement

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DOI

10.1002/2015GL063845

Restricted until

2037-12-31