Testing the role of palaeolatitude in biotic recovery after the Permian–Triassic mass extinction: A palaeomagnetic comparison between South China and Oman

To evaluate whether palaeolatitude influenced spatial variations in biotic recovery following the end-Permian mass extinction, we conducted a palaeomagnetic comparison between two representative regions, South China and Oman, where contrasting recovery patterns have been documented. Detailed palaeomagnetic investigations were carried out in the Lower Triassic Yelang and Maocaopu formations in the Zunyi area of the South China Block. Characteristic remanent magnetizations (ChRMs) were isolated from 31 specimens across five sites (Ds = 224.4°, Is = -10.5°, α95 = 6.7°). Rock magnetic measurements and scanning electron microscopy (SEM) observations indicate that the principal magnetic carriers are detrital magnetite and hematite. Together with the positive fold test, the ChRMs are interpreted as primary remanent magnetization acquired during deposition. This interpretation is further supported by the consistency of our results with other Early Triassic palaeomagnetic data from South China. The primary remanent magnetization directions yield a palaeolatitude of approximately 5°N for the Zunyi region in South China during the Early Triassic, placing it within the low-latitude Tethyan realm and comparable to coeval palaeolatitudes of Oman. These similar low-latitude settings suggest that latitudinal position alone is unlikely to have controlled the differences in biotic recovery between the two regions. Instead, other palaeogeographic factors, including the position relative to Pangaea and the consequent variations in ocean circulation, oxygenation state, and nutrient supply, may have played a more significant role in the spatial heterogeneity of Early Triassic ecosystem recovery.