How did South China connect with and separate from Gondwana? New paleomagnetic constraints from Middle Devonian red beds in South China

The paleogeographic relationship between the South China Block (SCB) and Gondwana is critical to understand the dispersion of Gondwana and accretion of Asia. But no consensus has been reached on the detailed connection and separation between the SCB and Gondwana mainly due to lack of robust Devonian paleomagnetic data. A new paleomagnetic investigation was performed on the red beds of Givetian Yuntaiguan Formation ( 385 Ma) in NW Hunan. The primary origin of this pole is supported by a positive fold test, a C-class reversal test and its distinction from all younger poles of the SCB. The new results, accompanied with previous high quality paleomagnetic data, placing the SCB at low-latitude region throughout the Paleozoic. Fitting of apparent polar wander paths (APWPs) of the SCB and Gondwana suggests that the SCB once connected with East Gondwana from Early Cambrian to 400 Ma, with its SW margin facing NW Australia and NE India. Thereafter, however, the 385 Ma and younger poles of the SCB diverge significantly from those coeval poles of Gondwana, indicating that the SCB commenced breaking up from Gondwana. By 360 Ma, the SCB had been separated from Gondwana by a broad ocean.