Xie Shijie, Cao Zebin, Liu Lijun, Yang Dinghui, Liu Mengxue, Li Yanchong, Qi Rui
Department of Mathematical Sciences, Tsinghua University, Beijing, China.
State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2024 Aug 3;15(1):6571. doi: 10.1038/s41467-024-51055-9.
Paleolatitudes of volcanic rocks reveal that prominent changes in volcanic trend of the Hawaii-Emperor hotspot chain represent meridional migration of the magma source. However, models assuming latitudinal plume migration fail to explain the observed age distribution, rock composition, and erratic paleolatitude changes of the oldest Emperor seamounts. Here we use data-assimilation models to better reproduce the Hawaii-Emperor hotspot track by systematically considering plate reconstruction, plume-lithosphere interaction, and simplified melt generation and migration. Our results show that plate drag and plume-ridge interaction are both important in explaining the observed seamount ages. These shallow dynamic processes could account for 50% of the observed paleolatitude's secular reduction and erratic variations over time, where the necessary southward migration of the Hawaiian plume root is significantly less than previously thought. We conclude that plume-lithosphere interaction represents a common mechanism in affecting hotspot track, and has important implications in understanding mantle dynamics and plate reference frames.
火山岩的古纬度表明，夏威夷-帝王热点链火山趋势的显著变化代表了岩浆源的子午线迁移。然而，假设纬向地幔柱迁移的模型无法解释观测到的年龄分布、岩石成分以及最古老的帝王海山不稳定的古纬度变化。在此，我们使用数据同化模型，通过系统地考虑板块重建、地幔柱-岩石圈相互作用以及简化的熔体生成和迁移，来更好地重现夏威夷-帝王热点轨迹。我们的结果表明，板块拖曳和地幔柱-海岭相互作用在解释观测到的海山年龄方面都很重要。这些浅层动力学过程可以解释观测到的古纬度随时间长期降低和不稳定变化的50%，其中夏威夷地幔柱根部向南迁移的必要幅度明显小于先前的设想。我们得出结论，地幔柱-岩石圈相互作用是影响热点轨迹的一种常见机制，对理解地幔动力学和板块参考框架具有重要意义。
