Tittle: Switch of NE Asia from extension to contraction at the mid-Cretaceous: A tale of the Okhotsk oceanic plateau from initiation by the Perm Anomaly to extrusion in the Mongol–Okhotsk ocean
Abstract: Early Cretaceous NE Asia represents one of the largest crustal extensional provinces worldwide (> 3 × 106 km2), marked by various extensional tectonics including metamorphic core complexes, (half) graben basins, and ba- saltic, granitic and minor ultramafic intraplate magmatism. In addition, the Early Cretaceous Okhotsk oceanic plateau has also been identified in the western Pacific margin of NE Asia. Recently, a reversal to contractional deformation at the mid-Cretaceous has been widely documented in the regime. Clearly, elucidating the Early Cretaceous tectonic extension in NE Asia and its switch to contraction at the mid-Cretaceous is critical to un- derstanding the geodynamic/tectonic evolution of Eurasia.
Our literature survey reveals the extension-related Early Cretaceous basalts in NE Asia display distinct mantle plume signature. This, along with the vast areal expanse and temporal–spatial coupling of the intraplate mag- matism with the sedimentary basins and the metamorphic core complexes, indicates the extension regime and the Okhotsk oceanic plateau together could be product of the mantle plume upwelling event triggered by the Perm Anomaly on the core–mantle boundary during the Early Cretaceous. Waning of the influence of the mantle plumes at the plume tail stage could have initiated the switch to contractional deformation at the mid- Cretaceous. This correlates with the extrusion of the Okhotsk oceanic plateau to the western Pacific margin.
Citation: Zhang K., Yan L., Ji C., (2019). Switch of NE Asia from extension to contraction at the mid-Cretaceous: A tale of the Okhotsk oceanic plateau from initiation by the Perm Anomaly to extrusion in the Mongol–Okhotsk ocean. Earth-Science Reviews, 198, 102941.
