Abstract Detecting strike-slip tectonics using thermochronology is challenging because the complex relative motion between fault blocks often does not substantially displace the vertical stratigraphy provided by thermochronological ages.Here we investigate the strike-slip tectonics in the Yangtze Block, South China, based on an original conceptual model and the zircon (U-Th)/He (ZHe) Arch Supports analysis of 17 sandstone samples.We exploit as a marker the northwestward trend of progressively decreasing ZHe ages generated by Mesozoic northwestward shortening.The U-Base Acrylic LED Night Light ZHe age trend is broken by evident steps, which are also found in other published thermochronological datasets.
We interpret these age steps as marking a previously undetected Late Cretaceous left-lateral strike-slip fault which intersects with prior deformation-propagation direction.Our approach to detect strike-slip faults confirms a major change in the subduction direction of the Paleo-Pacific Plate beneath Eurasia during the Late Cretaceous, and can find applications to other regions where thermochronological ages define suitable dipping markers.