Crustal Flow‐Driven Plateau Growth and Expansion Front in NE Tibet: Insights From High‐Resolution Attenuation Tomography With High‐Density ChinArray Lg Data

Abstract The Northeastern (NE) Tibet, as the front of plateau growth, widely absorbs northeastward extrusion, leading to significant uplift and forming a basin‐mountain tectonic framework. However, it remains unclear how the crust of NE Tibet deformed in response to the far‐field effects of the India‐Eurasia collision. Here, we construct a high‐resolution broadband crustal Q Lg model in NE Tibet using seismic attenuation tomography based on high‐density ChinArray Lg data. Strong Lg attenuation was observed beneath the Songpan‐Ganzi, suggesting crustal ductile material flow. The Qilian orogeny, characterized by relatively weak low‐ Q Lg anomalies, may have experienced an early stage of plateau formation. The lateral variation in crustal rheology, as revealed by the Lg attenuation gradient, exhibits a distinct strength contrast between the plateau interior and the forelands, indicating a crustal‐scale boundary of plateau expansion. Cenozoic tectonic extrusion and subsequent ductile material flow jointly govern the crustal deformation of NE Tibet.