Liang Jiacheng, Bian Weiwei, Jiao Xianwei, Peng Wenxiao, Ma Jiahui, Wang Suo, Ma Yiming, Zhang Shihong, Wu Huaichun, Li Haiyan, Shi Yuruo, Yang Tianshui
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China.
School of Earth Sciences and Resources, China University of Geosciences, Beijing, 100083, China.
Sci Rep. 2023 Nov 16;13(1):20035. doi: 10.1038/s41598-023-47268-5.
The relationship between the Kerguelen mantle plume and the breakup of eastern Gondwana is still debated. The new Zircon SHRIMP U-Pb dating of 139.9 ± 4.6 Ma, as well as previous ages from the Zhela Formation volcanic rocks in the Tethyan Himalaya, show that the studied Zhela Formation volcanic rocks formed during the Late Jurassic-Early Cretaceous, rather than the Middle Jurassic. The calculated volume of the Comei-Bunbury igneous rocks is ~ 114,250 km, which is compatible with the large igneous provinces and, consequently, the typical mantle plume models. The new date results, along with existing dates, show that the volcanism attributed to the Kerguelen mantle plume in the Tethyan Himalaya ranges from ca.147 Ma to ca.124 Ma, with two peaks at approximately 141 Ma and 133 Ma. This new finding, together with geochemical and palaeomagnetic data obtained from the Comei-Bunbury igneous rocks, indicate that the Kerguelen mantle plume contributed significantly to the breakup of eastern Gondwana and that eastern Gondwana first disintegrated and dispersed at ca.147 Ma, the Indian plate separated completely from the eastern Gondwana before ca.125 Ma.
凯尔盖朗地幔柱与东冈瓦纳大陆解体之间的关系仍存在争议。新的锆石SHRIMP U-Pb测年结果为139.9±4.6百万年，以及此前特提斯喜马拉雅地区遮拉组火山岩的测年结果表明，所研究的遮拉组火山岩形成于晚侏罗世-早白垩世，而非中侏罗世。计算得出的科梅-邦伯里火成岩体积约为114,250立方千米，这与大火成岩省相符，因此也符合典型的地幔柱模型。新的测年结果与现有结果表明，特提斯喜马拉雅地区归因于凯尔盖朗地幔柱的火山活动时间范围约为147百万年至124百万年，在大约141百万年和133百万年出现两个峰值。这一新发现，连同从科梅-邦伯里火成岩获得的地球化学和古地磁数据，表明凯尔盖朗地幔柱对东冈瓦纳大陆的解体有重大贡献，东冈瓦纳大陆在约147百万年首次解体和离散，印度板块在约125百万年之前完全与东冈瓦纳大陆分离。
