Paleomagnetic Study on the Permian Rocks of the Indochina Block and Its Implications for Paleogeographic Configuration and Northward Drifting of Cathaysialand in the Paleo‐Tethys

Abstract The drift of Gondwana‐derived blocks across the Tethys has remained unclear specifically because one of the largest components, Indochina, has remained unconstrained by paleomagnetism during the late Paleozoic, the interval comprising the first half of its journey towards the Eurasian landmass. Hence, we report a paleomagnetic study of Early‐Middle Permian limestones from central Thailand yielding a high‐quality data set for the Indochina Block with probable primary origin. The magnetization yields a paleomagnetic pole at 34.1°N, 331.7°E (K = 45.4, A95 = 5.7°) corresponding to a paleolatitude of 21.2 ± 5.7°S at the center of the study area (15°N, 101°E) and supporting a tropical restoration for late Paleozoic Indochina. A total of ~5,000 km northward transition from a proximity to Gondwana in the Early‐Middle Permian (ca. 280 Ma) to the southern margin of Eurasia by the Late Triassic (Norian, ca. 220 Ma) is identified and yields an average northward latitudinal drift rate of ~4.5 cm/year. A concurrent northward drifting history during the Permian is suggested for the Indochina, North Qiangtang, and South China blocks, and thus, the widely used model of Permian Cathaysialand is quantitively supported when combined with their paleobiogeographic affinities.