Mesozoic Microplates of East Asia: A New Reconstruction

Abstract

Abstract The complex tectonic evolution and regional remagnetization in East Asia since the Mesozoic have led to debates over plate reconstructions. By synthesizing high‐quality paleomagnetic poles and geological data, this study develops a new plate reconstruction model for East Asia between 270 and 110 Ma. In our model, the North China Plate and South China Plate collided in an east‐to‐west progression from 260 to 200 Ma, forming a unified East Asian continental margin. The majority of the Cimmerian microplates (e.g., South and North Qiangtang microplates) accreted to the southern margin of East Asia by 220 Ma, while the Lhasa Microplate accreted later around 110 Ma. A ∼7° southward movement of East Asia between 180 and 160 Ma is revealed by our model, consistent with the occurrence of a proposed True Polar Wander (TPW) event in this interval, rather than an anomalously rapid motion (“monster shift”) at 160–145 Ma as previously proposed. The subduction of Mongol–Okhotsk oceanic slabs in the northern polar region likely played an important role in driving the Jurassic TPW. The new model aligns closely with geological records and provides a new framework for advancing our understanding of Earth's system evolution.