The Paleo‐Asian Ocean, Tethys and Pacific Tectonic Domains: Phanerozoic Evolution in China and Adjacent Regions

ABSTRACT From a global geodynamic perspective, China and adjacent regions can be divided, during the Phanerozoic, into three major tectonic domains: the Paleo‐Asian Ocean, the Tethys and the Pacific. The Paleo‐Asian Ocean tectonic domain represents the eastern segment of the Iapetus–Paleo‐Asian Ocean tectonic domain and defines the Paleozoic tectonic framework of China and adjacent regions. The Tethys and Pacific domains are largely superimposed on the Paleo‐Asian domain: The former has shaped the Meso–Cenozoic tectonic architecture of western China, whereas the latter characterizes the Meso–Cenozoic tectonic features of eastern China. The Phanerozoic tectonic history of China and adjacent regions records the breakup of the Gondwana supercontinent, the accretion of the Siberian Craton and the evolution of the three aforementioned tectonic domains. However, this history was not simply characterized by the breakup of southern Gondwana, its subsequent northward drift and eventual accretion onto the margins of the Siberia‐centred Asian continent. In fact, the vast region from the Himalayas to Siberia was once part of the Gondwana supercontinent during the late Neoproterozoic. Starting from Sayan–Erguna, the breakup and accretionary processes involved episodic rifting of the Gondwana supercontinent and subsequent episodic amalgamation into the Siberia‐centred Asian continent. The dynamic systems controlling the Phanerozoic tectonic evolution of China and the adjacent regions are not simply three contemporaneously operative systems since the Neoproterozoic. Rather, they were three regimes that had emerged successively since the late Neoproterozoic: the Iapetus–Paleo‐Asian Ocean system, the Tethys–Paleo‐Pacific system and the Atlantic–Indian Ocean–Pacific system. The Paleo‐Asian Ocean dynamic system originated in the late Neoproterozoic and ended in the Middle Permian, governing the Paleozoic tectonic evolution of China and adjacent regions. The Tethys–Paleo‐Pacific dynamic system commenced in the Early Carboniferous and terminated in the Early Cretaceous, controlling the Mesozoic tectonic evolution of China and the adjacent regions. The Atlantic–Indian Ocean and the Pacific dynamic systems began in the mid‐Cretaceous and have dominated the Cenozoic tectonic evolution of China and adjacent regions. Interestingly, the transition from the Iapetus–Paleo‐Asian Ocean dynamic system to the Tethys–Paleo‐Pacific dynamic system during the Early Carboniferous–Middle Permian coincides with the 320–265 Ma Kiaman negative polarity superchron; the transition from the Tethys–Paleo‐Pacific dynamic system to the Atlantic–Indian Ocean–Pacific dynamic system in the mid‐Cretaceous coincides with the 126–83 Ma Cretaceous positive polarity superchron. These correspondences suggest that material motion in the core, which generates the geomagnetic field, may have played a very important role in the tectonic evolution of the Earth's crust.