Interaction between basement inherited strike-slip structures and thrust wedge propagation in the northern Tianshan foreland basin: Insight from analogue modelling experiments

Abstract

Basement inherited structures represent a significant factor affecting thrust propagation dynamics during the growth of fold-and-thrust belts. In this study inspirited from seismic data analysis of Gaoquan anticline in the Northern Tianshan foreland basin, we devised an experimental approach to investigate the structural and kinematical evolution of deformation from preexisting basement restraining bend to subsequent contractional deformation. Tested parameters included reactivation of the basement restraining bend and erosion. Results indicated that when preexisting basement restraining bend was reactivated and folded an overlying décollement, subsequent thrust nucleated preferentially at the top of the folded décollement. Erosion helped localize deformation, thereby reducing the width of the deformation zone and promoting “out-of-sequence” thrusting during compression. Finally, as we employed silicone polymer to simulate overpressured mudstone layer in the major décollement, our experiments also provide insights into a better understanding of the relationship between shallow salt-detached thrusting and deep inherited basement structures, such as in the Jura Mountains structures.