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Seismic anisotrdpy in granuulte facies rocks of the Arunta Block, central Australia
Author(s) -
Greenhalgh S. A.,
Wright Cedric,
Goleby Bruce,
Soleman Sugiharto
Publication year - 1990
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl017i010p01513
Subject(s) - geology , granulite , facies , outcrop , metamorphism , crust , metamorphic facies , continental crust , petrology , seismology , geochemistry , geomorphology , structural basin
Using travel times from explosive sources recorded at distances less than 36 km, evidence for P‐wave anisotropy was obtained in an area of central Australia where granulite facies rocks from the lower crust are exposed at the surface; these rocks form the hanging wall of one of the most prominent ancient thrust structures seen anywhere in a continental interior. The azimuthal variation in seismic velocity for rocks at depths less than about 1 km is about 5%, and is comparable in magnitude to values reported for both continental and oceanic upper mantle. The maximum velocity (east‐west) is parallel to the predominant strike direction of gneissic foliation observed in outcrop in the survey region, which was produced during granulite facies metamorphism at about 1,800 Ma.