Inelastic yielding and forebulge shape across a modern foreland basin: North West Shelf of Australia, Timor Sea

摘要

The Timer Trough is a modern 'underfilled' foreland basin created by partial subduction of the outer north west continental shelf of Australia beneath Timer Island in the Outer Banda Arc of eastern Indonesia during the Cenozoic. A change of the effective elastic thickness (EET) of the continental foreland lithosphere from similar to 80 +/-20 km to similar to 25 km over a distance of similar to 300 km explains (1) the high curvature (similar to 10(-7) m(-1)) on the outer Trough wall, (2) the low shelf forebulge (-200 m) as measured along a reference base Pliocene unconformity, and (3) observed gravity. An inelastically yielding quartzite-quartz-diorite-dunite continental rheology can explain the EET gradient. New, shallow crustal (<8 km), seismic reflection images indicate that Jurassic basement normal faults are reactivated during bending of the foreland. [References: 29]