The in situ stress field of the Perth Basin, Australia

Abstract

A total of 17 wells in the Perth Basin were interpreted to have 114 breakouts covering a combined length of 3.2 km and a mean σHmax orientation of 108°N. The inferred mean orientation of σHmax in the Perth Basin is broadly consistent with that in the adjacent basement, Yilgarn Block. The new data confirm that σHmax orientation in the region is consistent with other stress indicators, different depths and different geological provinces. The new data also confirm that the orientation of σHmax does not parallel the NNE direction of absolute plate velocity. Anomalous north-south σHmax orientations identified in a number of wells in the Perth Basin can be attributed to local structural effects. Copyright 2000 by the American Geophysical Union.