Thrusts control the thermal maturity of accreted sediments

Thermal maturity assessments of hydrocarbon-generation potential and thermal history rarely consider how structures developing during subduction influence the trajectories of accreted sediments. Our thermomechanical models of subduction support that thrusts evolving under variable sedimentation rates and decollement strengths fundamentally influence the trajectory, temperature, and thermal maturity of accreting sediments. This is particularly true for the frontal thrust, which pervasively partitions sediments along a low and a high maturity path. Notably, our findings imply that interpretations of the distribution of thermal maturity cannot be detached from accounts of the length and frequency of thrusts and their controlling factors. Taking these factors into consideration, our approach reduces former inconsistencies between predicted and factual thermal maturity distributions in accretionary wedges and provides a first-order predictive indicator for thermal maturity distribution based on known fault architectures.