Paleomagnetic and Geochronological Results From the Zhela and Weimei Formations Lava Flows of the Eastern Tethyan Himalaya: New Insights Into the Breakup of Eastern Gondwana

Abstract

The breakup of eastern Gondwana is among the hottest topics in the Earth sciences because of its effect on global climate during the Jurassic-Cretaceous, its influence on the evolution of life, and its importance to paleogeographic reconstruction. To better constrain the Jurassic and Cretaceous paleogeographic position of the Tethyan Himalaya and the breakup of eastern Gondwana, a combined paleomagnetic and geochronological study was performed on the Zhela and Weimei Formations lava flows, dated at~138-135 Ma, in the Luozha area of the eastern Tethyan Himalaya. Both positive fold and reversal tests together with a maximum grouping at 100% unfolding indicate that the characteristic remanent magnetization directions are primary magnetizations acquired before folding. The tilt-corrected directions yielded a paleopole at 0.9°N, 293.4°E with A 95 = 7.0°and a corresponding paleolatitude of 53.5°S ± 7.0°S for the Luozha sampling area (28.9°N, 91.3°E), validating that the original erupted position of the Zhela and Weimei Formations lava flows was located in the center of the Kerguelen mantle plume. Our new results, together with the published paleomagnetic, geochronological, and geochemical results, demonstrate that the Comei-Bunbury large igneous province originated from the Kerguelen mantle plume. The temporal and spatial relationships between the Comei-Bunbury large igneous province and the Kerguelen mantle plume indicate that eastern Gondwana initially rifted at~147 Ma and that the Indian Plate fully separated from the Australian-Antarctic Plate before~124 Ma.

Paleomagnetism of the Late Cretaceous Red Beds From the Far Western Lhasa Terrane: Inclination Discrepancy and Tectonic Implications

“…Paleomagnetism is one of the major methods that can be used for quantifying plate paleolatitudes and is thus crucial for constraining the history of plate movement (Achache et al, 1984; Appel et al, 1998; Bian et al, 2019; Cao et al, 2019; Huang et al, 2015; Liebke et al, 2010; Lippert et al, 2014; Ma et al, 2016; Song et al, 2020; Sun et al, 2006; van Hinsbergen et al, 2012; Yang, Ma, Bian, et al, 2015; Yan et al, 2016). Because the Lhasa terrane (LT) was located at the southern margin of Asia prior to India‐Asia collision (Figure 1a), reliable Cretaceous paleomagnetic data from the LT are essential to constrain the locations and geometries of the precollisional margins of Asia.…”

Paleomagnetism of Middle Triassic Lavas From Northern Qiangtang (Tibet): Constraints on the Closure of the Paleo‐Tethys Ocean

“…The northern Qiangtang block in Central Tibet is one of these Cimmerian terranes and therefore is an important area to study the demise of the Paleo-Tethys Ocean. Paleomagnetism can provide quantitative estimates of latitude with time, from which minimum convergence rates can be calculated and which can provide unique kinematic information for reconstructing the tectonic evolution of the Tibetan Plateau (e.g., Bian et al, 2019;Cao et al, 2019;Huang et al, 2015;Huang et al, 2018;Li et al, 2018;Li et al, 2016;Lippert et al, 2014;Ma et al, 2019;Tong et al, 2017;Yan et al, 2016;Yan et al, 2018;Yang et al, 2015;Zhou et al, 2016). Paleomagnetic data from Paleozoic and Mesozoic rocks from the northern Qiangtang block are rare, but a recent paleomagnetic study of the Late Triassic basaltic lavas of the northern Qiangtang block suggests that the final suturing of the Paleo-Tethys Ocean was complete prior to Late Triassic time (204-213 Ma) (Song et al, 2015).…”

Precollisional Latitude of the Northern Tethyan Himalaya From the Paleocene Redbeds and Its Implication for Greater India and the India‐Asia collision

“…Three reliable Early Cretaceous paleomagnetic results have been acquired from volcanic rocks in the Tethyan Himalaya, and they not only satisfy the secular variation model but also fulfill all the seven quality criteria proposed by Van der Voo () to assess the reliability of paleomagnetic data. Noticeably, all suggest a minor paleolatitudinal difference between the Tethyan Himalaya and the Indian craton (Bian et al, ; Ma et al, ; Yang, Ma, Bian, et al, ), which implies a smaller Greater India during the Early Cretaceous.…”