Lagged and spatially attenuated negative coupling between crustal thickness and exhumation during lithospheric thinning

Continental lithospheric thinning can accelerate upper-crustal exhumation by reducing lithospheric strength and reorganizing topography, yet the magnitude, spatial attenuation, and time lag of this coupling are rarely quantified in a way that is directly comparable between regions. We integrate new apatite fission-track (AFT) and zircon (U–Th)/He (ZHe) data with regional thermochronology compilations and time-dependent crustal-thickness reconstructions for the eastern North China Craton, and apply the same standardized workflow to the Lhasa terrane (southern Tibet) and the western North American Cordillera—three regions that record rollback-related thinning by extension and/or gravitational removal of dense lower lithosphere (delamination or foundering). Using a multi-thermochronometer age-pair method, we calculate exhumation-rate time series and spatially resolved exhumation-rate maps, and we evaluate their correspondence to coeval crustal thickness variations through time. In North China, exhumation rates during the main thinning episode are highest near thinning centers and decrease toward the continental interior, defining a proximal-to-distal attenuation pattern. Across all studied regions, thinner crust systematically corresponds to higher mean exhumation rates, indicating a robust, negative association between crustal thickness and exhumation intensity during thinning. Cross-correlation between crustal thickness T(t) and exhumation rate E(t) is most negative (Pearson R = −0.8 to −0.9) when exhumation lags thinning by ~5–10 Myr, implying a multi-million-year delay between crustal thinning and the regional exhumation response. Together, these results provide quantitative constraints on the timescales and spatial footprint of deep–surface coupling during continental lithospheric thinning.