Lithospheric Rheology Controls the Spatial Distribution of Cenozoic Volcanoes in Northeast China

Abstract The mechanism controlling the temporal and spatial distribution of intraplate volcanic activity in Northeast China is still under debate. To explore the potential interplay between the spatial distribution of intraplate volcanic activity and the underlying lithospheric architecture, here we employ a multi‐observation probability density inversion method to constrain the thermal, lithological and rheological structure of the lithosphere in Northeast China. Our results reveal that the lithosphere is thinner in the eastern region (∼60 km) and thicker in the western region (∼140 km). The lower crust beneath the Orogenic Belt is primarily composed of felsic granulite, while the Songliao Block is dominated by mafic granulite. Furthermore, our results reveal that the lithosphere beneath volcanic regions is relatively thin (<100 km) with low strength (<2 × 10 3 MPa), while the lithosphere in the eastern Songliao Block, though similarly thin (<100 km), exhibits greater strength (>2 × 10 3 MPa). We argue that small scale mantle convection caused by the lithospheric delamination of the Songliao Block and the mantle upwelling caused by the retreat of the Pacific Plate, which generates melts that preferentially penetrate the weaker rifts and orogenic belts surrounding the Songliao Block, rather than the stronger lithosphere of the Songliao Block, which can explain the lack of volcanoes within the Songliao Block. Our results demonstrate that the spatial distribution of Cenozoic volcanoes in Northeast China is characterized by their occurrence exclusively in regions with thin lithosphere (<100 km) and weak lithospheric strength (<2 × 10 3 MPa).