Links between foreland rheology and the growth and evolution of a young mountain belt in New Guinea

摘要: We have studied the active and recent tectonics of New Guinea, using earthquake source modelling, analysis of gravity anomalies, seismic reflection profiles, and thermal and mechanical models. Our aim is to investigate the behaviour and evolution of a young continental deformation belt, and to explore the effects of lateral variations in foreland rheology on the deformation. We find that along-strike gradients in the lithosphere thickness of the southern foreland have resulted in correlated changes in seismogenic thickness, likely due to the effects on the temperature structure of the crust. The resulting variation in the strength of the foreland means that in the east, the foreland is broken through on thrust faults, whereas in the west it is relatively intact. The lack of correlation between the elevation of the mountain belt and the seismogenic thickness of the foreland is likely to be due to the time taken to thicken the …