Ediacaran intracontinental channel flow

Abstract

Migmatitic lower-crustal rocks in the Ediacaran intracontinental Petermann orogen, central Australia, are bounded by regional-scale, low-angle shear fabrics that record opposing shear senses. New sensitive high-resolution ion microprobe (SHRIMP) titanite geochronology suggests that the contrasting shear systems developed synchronously. We argue that the macro scopic structural and metamorphic architecture satisfies the diagnostic criteria outlined by recently proposed channel flow models, and thus the remarkably well-preserved Petermann orogen is potentially an example of ancient intracontinental channel flow.