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.

Direct Paleomagnetic Constraint on the Closure of Paleo‐Tethys and Its Implications for Linking the Tibetan and Southeast Asian Blocks

“…The interpretation of geographic affinity is supported by the analyses of detrital zircons (Gehrels et al, 2011;Li et al, 2016) and paleomagnetic studies (Ali et al, 2013;Huang & Opdyke, 1991;Xu et al, 2014). Early Permian paleomagnetic data have been repeatedly reported from the Yan et al, 2018;2. Chi et al, 2016;3.…”

“…Abbreviation: SQT (South Qiangtang), NQT (North Qiangtang), TC (Tengchong), WB (West Burma), IBR (Indo-Burma Range), EKL-ANMQS (East Kunlun-A'nyemaqen Suture), JSJS (Jinshajiang Suture), LSS (Longmu Co-Shuanghu Suture), BNS (Bangong Co-Nujiang Suture), ITS (Indus-Tsangbu Suture), MFT (Main Frontal Thrust), XSH-XJ F. (Xiaoshuihe-Xiaojiang Fault), ALS-RR F. (Ailaoshan-Red River Fault), DBPF (Dien Bien Phu Fault), GLG F. (Gaoligong Fault), MJ (Mojiang), CN (Changning), ML (Menglian), CL (Chianglai), and CM (Chiangmai). References of paleomagnetic studies: A2013 (Ali et al, 2013), C2012 (Cheng et al, 2012), C2013 (Cheng et al, 2013), C2016 (Chi et al, 2016), HO1991 (Huang & Opdyke, 1991), H1992 (Huang et al, 1992), HO2016 (Huang & Opdyke, 2016), M2019 (Ma et al, 2019), S2012 (Song et al, 2012), S2015 (Song et al, 2015), S2017 (Song et al, 2017), X2014 (Xu et al, 2014), YB1993 (Yang & Besse, 1993), Y2017 (Yan et al, 2017), Y2018 (Yan et al, 2018), Z2015 , and Z2019 . (b) Geological map and sampling locations in the south Lancangjiang volcanic belt.…”

An ultra-low magnetic field thermal demagnetizer for high-precision paleomagnetism

“…The TD-PGL-100 built with those technologies allows the successful recovery of weak magnetizations blocked at high temperatures and has applications in recovering sedimentary magnetizations, records of geomagnetic polarity reversals, signals of the earliest geodynamo, as well as extraterrestrial magnetizations. One of this new thermal demagnetizer has been running normally for three years in the IGCCAS laboratory, and results demonstrate its excellent performance especially for these weakly magnetic natural specimens (Jiang et al, 2017, Yan et al, 2018. Magnetic eld measurement of conventional solenoid and new heating wire.…”

A palaeomagnetic study of the Middle Permian and Middle Triassic limestones from Shan State, Myanmar: Implications for collision of the Sibumasu Terrane and Indochina Terrane

“…Reliable palaeomagnetic results suggest that the Indochina Terrane was located at a palaeolatitude of 21.2 ± 5.7°S during the Early–Middle Permian (Yan, Huang, Zhang, Charusiri, & Veeravinantanakul, ), and it arrived at 15.6 ± 13.5°N (reference site: 23.9°N, 99.2°E) in the Late Triassic (K. Huang & Opdyke, ), whereas the Baoshan Block was located at ~42°S (Ali et al, ; K. Huang & Opdyke, ; Xu et al, ) in the Early Permian, it then drifted northward from Gondwana and reached a palaeolatitude of 15–18°N in the Late Triassic (Figure ; Zhao et al, ). The Component C from the Middle Triassic limestones indicates a palaeolatitude of ~18.3°N (Table , Figure ).…”