Spatio-temporal constraints on thrusting across fold-and-thrust belts worldwide

Fold-and-thrust belts (FTBs) are fundamental geological structures whose spatio-temporal evolution can be reconstructed using s-t graphs that integrate thrust positions and timing to trace sequences of activation and reactivation. However, accurately constraining the timing of thrusting events remains difficult due to methodological uncertainties and inconsistencies among different dating techniques. To address these challenges and offer a refined view of FTB evolution, we compile and integrate time constraints from stratigraphic, thermochronological, and radiometric data across ten FTBs that span diverse geodynamic contexts, including the Rocky Mountains, Idaho-Montana Belt, Sevier Belt, Mexican Fold Belt, and Central Andes in the Cordilleran orogen, and Apennines, Southern Pyrenees, Jura Mountains, Southern Alps, and Himalayas in the Alpine-Himalayan orogen. We assess the strengths and limitations of each method: stratigraphy provides broad but often imprecise age constraints; radiometric dating yields precise yet spatially and temporally sparse data; thermochronology offers insights into vertical displacements linked to thrusting. By constructing and comparing s-t graphs, we identify consistent thrusting patterns across regions. FTBs display a piggy-back propagation style characterized by long-lasting, partially overlapping activity of multiple thrusts. These observations support a revised piggy-back model that incorporates prolonged, synchronous thrust activity within a generally forward-propagating system.