Suo Wang

The northern extent of Greater India is a critical, yet highly debated, parameter for reconstructing the India‐Asia collision. Previous paleomagnetic estimates, including the fill‐the‐gap and fixed great circle approaches, yield widely varying results, spanning from ∼200 to ∼3,000 km. These large discrepancies stem principally from two primary issues: the inherent uncertainties associated with both the Tethyan Himalaya (TH) and Indian apparent polar wander paths (APWP) based on paleomagnetic and geochronologic data, and India's complex kinematic history, particularly the large rotation in the Early Cretaceous followed by rapid northward translation in the Late Cretaceous. Because of limited data coverage from TH, discrete age‐matched comparisons between them compound these uncertainties. To address this, we introduce a refined APWP‐constrained approach that evaluates the TH paleomagnetic record as a temporal sequence. Assuming a coherent rigid attachment, this framework iteratively translates the TH northward, systematically quantifying the discrepancies between its restored paleomagnetic poles and the coeval poles expected from the updated Indian APWP while propagating uncertainties in both pole position and age using Monte Carlo simulations. Applying this to paleomagnetic data from the Jurassic–Paleocene units with age reassessment, we identify a statistically minimized discrepancy following a 7.9 ± 1.2° northward shift, which likely represents the pre‐shortening northern margin of Greater India. This optimal shift translates directly to a crustal shortening estimate of ∼880 km, consistent with geologic records of Greater India. This refined estimate provides a constraint for the India‐Asia collision and facilitates improved tectonic models of the Tibetan Plateau.

Supplemental Text S1: Further illustrations of quality criteria for paleomagnetic datasets used in this study. Figure S1: Photographs and lower hemisphere stereonet plot of bedding attitudes for defining the azimuth and dip of the regional tilt. Figure S2: Cathodoluminescence images of all zircon grains. Figure S3: Equal-area projections of the low-temperature or low-coercivity components. Table S1: Detailed bedding information. Tables S2 and S3: Summary and original zircon U-Pb data. Table S4: Characteristic remanent magnetization directions. Table S5: Summary of Late Cretaceous to Cenozoic paleomagnetic results from the Lhasa terrane, Xigaze forearc basin, Tethyan Himalaya, Kohistan–Ladakh arc, and Qiangtang terrane. Table S6: Poles used in APWP-online. Table S7: Predicted apparent polar wander paths. Table S8: The corresponding predicted paleolatitudinal differences.

Supplemental Text S1: Further illustrations of quality criteria for paleomagnetic datasets used in this study. Figure S1: Photographs and lower hemisphere stereonet plot of bedding attitudes for defining the azimuth and dip of the regional tilt. Figure S2: Cathodoluminescence images of all zircon grains. Figure S3: Equal-area projections of the low-temperature or low-coercivity components. Table S1: Detailed bedding information. Tables S2 and S3: Summary and original zircon U-Pb data. Table S4: Characteristic remanent magnetization directions. Table S5: Summary of Late Cretaceous to Cenozoic paleomagnetic results from the Lhasa terrane, Xigaze forearc basin, Tethyan Himalaya, Kohistan–Ladakh arc, and Qiangtang terrane. Table S6: Poles used in APWP-online. Table S7: Predicted apparent polar wander paths. Table S8: The corresponding predicted paleolatitudinal differences.

The closure of the Meso‐Tethys Ocean is crucial to understanding the global evolution of the Tibetan Plateau prior to the India‐Asia collision and its influence on the environment and climate. Nonetheless, large uncertainties exist regarding the process due to the scarcity of reliable Late Jurassic paleomagnetic results. Here we present a combined paleomagnetic and geochronologic study on the ca. 147 Ma Zenong Group volcanic rocks in the westernmost Lhasa terrane. We obtained a well‐dated high‐quality paleopole at 63.0°N, 304.9°E with N = 20 sites, K = 29.9, and A ₉₅ = 6.1°, yielding a paleolatitude of 11.9 ± 6.1°N for the sampling area. The primary origin of the magnetization is supported by positive fold and reversal tests, with the statistical distribution consistent with the expected geomagnetic paleosecular variation. This new paleomagnetic result permits reconstructing the northward trajectory of the Lhasa terrane from the Southern Hemispherical paleolatitude toward Eurasia. Direct comparison with the pre‐collisional paleolatitude of the Qiangtang terrane demonstrates that the western part of the Meso‐Tethys Ocean remained open at ca. 147 Ma. Furthermore, by integrating our results with other reliable Late Triassic to Early Cretaceous paleomagnetic data sets from the Lhasa and Qiangtang terranes, together with regional geological evidence, the comparative results reveal that the final closure of the Meso‐Tethys Ocean occurred during ca. 140–130 Ma in the western part.

The drift history of the Tethyan Himalaya provides key constraints on the India‐Asia collision, Himalayan‐Tibetan orogenesis, and associated global climate change. Here we present rock magnetic, petrographic, geochronologic, and paleomagnetic results of the Bolinxiala Formation limestones in the western Tethyan Himalaya. In situ calcite U‐Pb dating and biostratigraphy indicate that the Bolinxiala Formation limestones were formed during the Early Cretaceous (∼125–100 Ma), not Middle Jurassic as previously thought. The site‐mean direction for the 23 sites is D _g = 23.3°, I _g = +10.0°, k _g = 40.1 and α ₉₅ = 4.8° in situ and D _s = 20.8°, I _s = +19.0°, k _s = 67.2 and α ₉₅ = 3.7° after tilt‐correction, yielding a paleomagnetic pole position at 61.6°N, 212.9°E with A ₉₅ = 2.7°, corresponding to a paleolatitude of 10.3° ± 2.7°N. A positive fold test indicates a prefolding origin. When compared with reliable Cretaceous–Eocene paleopoles from the western Tethyan Himalaya, we suggest that the Bolinxiala Formation limestones likely underwent remagnetization during ∼54–49 Ma. Petrologic evidence, including the presence of framboidal oxides derived from sulfides (primarily pyrite) and calcite veins, supports chemical remanent magnetization as the primary mechanism responsible for the remagnetization. Our new results, combined with reliable Cretaceous paleomagnetic data from the western Lhasa terrane, indicate that the western part of the India‐Asia collision occurred no later than ∼54–49 Ma.

The temporal‐spatial relationships of widely distributed latest Jurassic–Early Cretaceous igneous rocks in the Tethyan Himalaya (TH) are crucial for understanding the breakup of eastern Gondwana and the paleogeography of the Neo‐Tethys Ocean. However, no paleomagnetic data are available from the Early Cretaceous volcanic rocks in the central‐western TH. Here, we report the first paleomagnetic and geochronological results from Early Cretaceous volcanic rocks, dated at ∼144‒142 Ma, in the western TH. The tilt‐corrected site‐mean direction for 31 sites is Ds = 303.9°, Is = −58.7° with α₉₅ = 4.3°, yielding a mean pole at 1.9°N, 303.2°E (A₉₅ = 5.0°) and a paleolatitude of 40.8 ± 5.0°S for the Zhongba area. Positive fold and reversal tests support pre‐fold primary magnetizations. Our paleomagnetic and geochronological results, combined with those from the eastern TH, northeastern India, and southwestern Australia, reveal that the latest Jurassic–Early Cretaceous volcanic rocks were emplaced across a paleolatitudinal range from approximately 40.8°S to 55.5°S, with a central paleolatitude of about 48.2°S, which is consistent with the present‐day latitude of the Kerguelen Mantle Plume (KMP). This, along with the affinity of these rocks to the KMP‐related magmatic rocks supports that the latest Jurassic–Early Cretaceous TH igneous rocks originated from the KMP, and that the KMP contributed to the breakup of eastern Gondwana. Comparison of Early Cretaceous paleolatitudes observed from the western TH and Lhasa terrane shows that the latitudinal width of the Neo‐Tethys Ocean was ∼6,600 km at ∼144–142 Ma.

To refine the postcollisional extrusion and convergence history of the southeastern Tibetan Plateau, we report a quality paleomagnetic data set from Upper Cretaceous redbeds of the eastern Qiangtang Terrane (QT), where is situated at the front edge of eastern Himalayan Syntaxis. The 32 site‐mean directions provide a mean pole at 75.4°N, 176.8°E (A₉₅ = 2.4°) and a paleolatitude of 31.8 ± 2.4°N for the Mangkang area. Comparison with reliable Late Cretaceous paleomagnetic data from the eastern QT and East Asia indicates that the eastern QT experienced a southward extrusion of 940 ± 310 km after the Late Cretaceous. Comparing Late Cretaceous paleolatitudes estimated from the eastern QT and Lhasa terrane (LT) reveals a paleolatitude difference of 2,390 ± 620 km. Such a great latitudinal convergence can be attributed to the fact that some continental terranes originally located between the eastern LT and QT were laterally extruded after the Late Cretaceous.

The drift history of the Lhasa terrane plays an essential role in understanding the tectonic evolution of the Bangong-Nujiang Tethyan Ocean and the Neo-Tethyan Ocean, as well as the evolutionary history of the Tibetan Plateau. Here, a combined rock magnetic, petrographic, and palaeomagnetic study is performed on the Upper Permian–Lower Triassic limestones (∼259–251 Ma) in the western Lhasa terrane. The site-mean direction for the 28 sites is D_g = 32.1°, I_g = 50.3°, k_g = 47.9, and α₉₅ = 4.0° in situ and D_s = 342.9°, I_s = 32.7°, k_s = 43.2, and α₉₅ = 4.2° after tilt-correction, yielding a palaeopole at 68.9° N, 314.4° E with A₉₅ = 4.3°, corresponding to a palaeolatitude of 18.0° ± 4.3° N. The fold tests are not significant because the sampling section shows monoclinic features with minor variations in their bedding attitudes. The palaeopoles for the directions before and after tilt-correction are compared with reliable Late Permian–Palaeogene palaeopoles obtained from the Lhasa terrane. Based on these comparisons, the studied limestones were remagnetized prior to tilting and this remagnetization most likely occurred during the Early Cretaceous. The depositional environment of the limestones may have changed from anoxic to suboxic and oxic during the Early Cretaceous, leading to the oxidation of iron sulphide to authigenic magnetite. Meanwhile, the Late Jurassic–Early Cretaceous convergence between the western Lhasa and Qiangtang terranes may have resulted in tectonic fluid migration and the formation of calcite veins and stylolites in the limestones. This is supported by the presence of small calcite veins and stylolites in some samples, as well as the fact that the framboidal oxides were formerly sulphides (mostly pyrite), implying that the majority of the iron oxides observed in the limestones were authigenic. These processes indicate that chemical remanent magnetization caused by the growth of magnetic minerals related to tectonic fluid migration was most likely the mechanism for the limestone remagnetization.

The paleogeography of the Tethyan Himalaya (TH) during the Mesozoic is vital to constrain the evolutionary history of the Neo‐Tethys Ocean, but reliable paleomagnetic data from Jurassic rocks in this area are scarce. Here, we report the first high‐quality paleomagnetic results from the Middle Jurassic (∼175–173 Ma) Lanongla Formation limestones in the Nyalam area of the TH. For most specimens, stepwise thermal or hybrid demagnetization reveals two well‐defined magnetization components. A low‐temperature component, which is isolated between natural remanent magnetization and 200–300°C, is consistent with the present geomagnetic field direction. A high‐temperature component, which is isolated between 300–350°C/10–25 mT and 500–580°C/60–120 mT, passes fold tests at the 95% and 99% confidence level, indicating a prefolding primary magnetization. The tilt‐corrected site‐mean direction for 28 paleomagnetic sites is Ds = 331.0° and Is = −49.9° with α₉₅ = 2.7°, which provides a Fisherian site‐mean paleopole at 23.7°N, 292.9°E with A₉₅ = 2.8° and a paleolatitude of 31.7 ± 2.8°S for the Nyalam study area (28.6°N, 86.1°E). A comparison between the reliable Middle Jurassic‐Early Cretaceous poles obtained from the TH and those observed from the Lhasa terrane reveals that the Neo‐Tethys Ocean for the reference point (29.1°N, 86.1°E) had a latitudinal width of 3,500 ± 1,000 km at ∼174 Ma, reached its greatest width of 7,000 ± 1,000 km at ∼137 Ma, and had an average latitudinal spreading rate of ∼10.4 cm/year during ∼174–137 Ma.

The drift history of the Lhasa terrane is crucial for understanding the tectonic evolution of Tethyan Oceans and Jurassic true polar wander. However, high‐quality Middle Jurassic paleomagnetic data from the Lhasa terrane are limited in number. Here we report a combined paleomagnetic and geochronologic study on the Yeba Formation volcanic rocks, dated at ∼170 Ma, from the Lhasa terrane. Robust field and reversal tests indicate that the characteristic remanent magnetizations are primary. Our results provide a reliable Middle Jurassic (∼170 Ma) paleopole at 29.8°N, 180.7°E with A ₉₅ = 5.7° and a paleolatitude of 14.4 ± 5.7°N for the Lhasa area. Compared with previous paleomagnetic and geologic evidence, we propose that the Meso‐Tethys Ocean probably began to close in the eastern part at ∼168 Ma and that the Lhasa terrane underwent a ∼2,900 km southward “monster shift” during the Late Jurassic.