Ding Jikai, Rogers Chris, Söderlund Ulf, Evans David A D, Gong Zheng, Ernst Richard E, Chamberlain Kevin, Kilian Taylor
Department of Earth & Planetary Sciences, Yale University, New Haven, CT, USA.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, China.
Nat Commun. 2024 Dec 30;15(1):10814. doi: 10.1038/s41467-024-55117-w.
Plate tectonics is a unique feature of Earth, but its proposed time of initiation is still controversial, with published estimates ranging from ca. 4.2 to 0.7 Ga. Paleomagnetic data can provide a robust argument for one essential aspect of plate tectonics: large-scale relative lateral motions of distinct, rigid crustal blocks. Previously, the oldest relative horizontal motion between two or more blocks was constrained to a broad age interval of ca. 2.7-2.17 Ga using paleomagnetic data. In this study, we obtain a robust ca. 2.48 Ga paleomagnetic pole from Wyoming craton. Combining this result with the ca. 2.7-2.17 Ga apparent polar wander paths from Wyoming and Superior cratons, we suggest that they assembled during ca. 2.7-2.5 Ga and remained directly juxtaposed until ca. 2.17 Ga. Tectonostratigraphic data and geological proxies also suggest Wyoming and Superior collided at ca. 2.6 Ga. The results provide strong evidence for relative horizontal motion between crustal blocks during the Neoarchean. Together with other tectonic proxies, the data suggest plate mobilism in operation prior to 2.5 Ga.
板块构造是地球的一个独特特征，但其推测的起始时间仍存在争议，已发表的估计范围从约42亿年到7亿年。古地磁数据可以为板块构造的一个基本方面提供有力证据：不同的刚性地壳块体的大规模相对横向运动。此前，利用古地磁数据，两个或多个块体之间最古老的相对水平运动被限制在约27亿年至21.7亿年的一个宽泛年龄区间内。在这项研究中，我们从怀俄明克拉通获得了一个可靠的约24.8亿年的古地磁极。将这一结果与来自怀俄明和苏必利尔克拉通的约27亿年至21.7亿年的视极移路径相结合，我们认为它们在约27亿年至25亿年期间聚合在一起，并一直直接并置到约21.7亿年。构造地层数据和地质指标也表明，怀俄明和苏必利尔在约26亿年发生碰撞。这些结果为新太古代期间地壳块体之间的相对水平运动提供了有力证据。与其他构造指标一起，这些数据表明在25亿年前板块就已经处于活动状态。
