The structural differences and evolution of the Yinshan-Hetao basin-mountain system at the northern margin of the North China Craton

The Yinshan-Hetao basin-mountain system along the northern margin of the North China Craton (NCC) is a key intracontinental deformation belt. Deciphering its structural contrasts and evolution is essential for understanding the mechanisms of intraplate orogeny. By integrating geological mapping, seismic tomography, joint gravity-magnetic-magnetotelluric inversion, apatite fission-track and (U-Th)/He low-temperature thermochronology, zircon U-Pb geochronology and geochemical tracers, we draw the following conclusions. 1) The region preserves a continuous tectonic record from 1.96 Ga to the present, which can be subdivided into five stages: Paleoproterozoic collisional basement formation, Neoproterozoic Rodinia break-up, Mesozoic Indosinian compressional orogeny, Yanshanian extensional destruction with initial basin-mountain differentiation, and Cenozoic differential reactivation. 2) The basin-mountain contrast is fundamentally caused by a sharp lateral change in lithospheric thickness during NCC destruction; a thermo-rheological boundary zone controls the present "compression in the west, extension in the east" pattern. 3) Superimposed far-field effects of multiple plates drive structural differentiation: India-Eurasia collision supplies N-S compression, Pacific slab rollback induces back-arc extension, and the remnant Paleo-Asian oceanic slab modifies deep thermal structure.These three processes synergistically control the spatio-temporal migration of magmatism, deformation and sedimentation. This study provides a new multi-scale observational template for intraplate basin-mountain coupling in a cratonic destruction setting.