Inherited lithospheric weakness enabled rapid stress transmission across Tibet

The rate and efficiency of stress transmission across continental interiors during collision remain poorly constrained. The >1600-km-long Altyn Tagh Fault, bounding the northern Tibetan Plateau, offers a key test of stress propagation models. Here, we integrate multiscale structural analysis with K–Ar dating of synkinematic illite to date its faulting history. The data document episodic faulting spanning >110 million years, including an ~115 Ma event marking a lithospheric weakness zone predating Cenozoic collision, and an Early Eocene faulting age (~56 Ma), which is nearly synchronous with India–Asia collision onset, implying rapid far-field stress transmission across distances exceeding 1500 km within 10 million years of collision initiation. Reactivation at ~26 Ma, ~2.7 Ma and ~0.6 Ma reflects localization during plateau growth. These results show that inherited lithospheric structures enable efficient, long-distance stress transmission and remain persistent deformation loci, indicating that continental interiors respond to plate-boundary forcing faster than slow, progressive propagation models predict. K–Ar dating reveals >110 Myr of episodic Altyn Tagh Fault activity, beginning at ~115 Ma along a Cretaceous lithospheric weakness. Reactivation at ~56 Ma records rapid India–Asia collisional stress transmission >1500 km into the continental interior.