New paleomagnetic and geochronologic results from the eastern Tethyan Himalaya refine the size of Greater India in the Early Cretaceous

IF 2.7 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Asian Earth Sciences Pub Date : 2024-11-27 DOI:10.1016/j.jseaes.2024.106428

Jie Yuan, Wenxing Hao, Ruoyuan Qiu

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引用次数: 0

Abstract

Knowledge of the original size of Greater India in the Early Cretaceous is critical for Late Mesozoic East Gondwana reconstructions. However, estimates of Greater India extent have significant discrepancies in the Early Cretaceous. Here we report geochronologic and paleomagnetic studies on rocks of the Jiabula Formation in the northern subzone of the Tethyan Himalaya. The studied limestones are characterized by two-component magnetizations carried by detrital magnetite, which retains a primary remanence. Correspondingly, the high temperature magnetization components (350−525 °C) are isolated from 204 specimens using high-resolution thermal demagnetization. The new paleomagnetic data provide, after inclination shallowing estimation, an Early Cretaceous paleopole of 11.2°N/300.5°E, A₉₅ = 2.6°, which places the eastern part of the Tethyan Himalaya at a paleolatitude of 40.9° ± 2.6°S at ca. 126 Ma. Comparison of the new observed paleolatitude with the expected paleolatitude (49.7° ± 2.8°S) of India implies that Greater India had an extension of 968±418 km (8.8° ± 3.8°) at ca. 126 Ma. Integrating the new results with our previous Campanian results (ca. 75 Ma), we conclude that Greater India had a comparable extension of ∼900 km during ca. 126−75 Ma. The improved estimate of the dimensions of Greater India leads to an updated reconstruction of paleogeography in the Early Cretaceous.

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来源期刊

Journal of Asian Earth Sciences 地学-地球科学综合

CiteScore

5.90

自引率

10.00%

发文量

324

审稿时长

71 days

期刊介绍： Journal of Asian Earth Sciences has an open access mirror journal Journal of Asian Earth Sciences: X, sharing the same aims and scope, editorial team, submission system and rigorous peer review. The Journal of Asian Earth Sciences is an international interdisciplinary journal devoted to all aspects of research related to the solid Earth Sciences of Asia. The Journal publishes high quality, peer-reviewed scientific papers on the regional geology, tectonics, geochemistry and geophysics of Asia. It will be devoted primarily to research papers but short communications relating to new developments of broad interest, reviews and book reviews will also be included. Papers must have international appeal and should present work of more than local significance. The scope includes deep processes of the Asian continent and its adjacent oceans; seismology and earthquakes; orogeny, magmatism, metamorphism and volcanism; growth, deformation and destruction of the Asian crust; crust-mantle interaction; evolution of life (early life, biostratigraphy, biogeography and mass-extinction); fluids, fluxes and reservoirs of mineral and energy resources; surface processes (weathering, erosion, transport and deposition of sediments) and resulting geomorphology; and the response of the Earth to global climate change as viewed within the Asian continent and surrounding oceans.