Syn‐Drift Plate Tectonics

• Published in: Geophysical research letters 2024-01, Vol.51 (2), p.n/a
• Main Authors: Gün, Erkan, Pysklywec, Russell N., Topuz, Gültekin, Göğüş, Oğuz H., Heron, Philip J.
• Format: Article
• Language: English
• Subjects: Boundaries; Deformation; Drift; extensional deformation; Geophysics; intra ocean plate deformation; Lithosphere; Mathematical models; oceanic plateaux; Oceans; Plate boundaries; Plate tectonics; Plateaus; Plates; Plates (tectonics); slab pull; Subduction; Subduction (geology); Subduction zones; Tectonics
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL105452

The paradigm of plate tectonics holds that ocean plates are rigid during drift and only experience tectonic deformation at subduction zones, but new findings from the Pacific challenge this idea. Geological and geophysical evidence from the Ontong Java, Shatsky, Hess, and Manihiki oceanic plateaux indicates that extensional deformation during plate drift is a widespread phenomenon across the Pacific plate. These anomalously thick oceanic plateaux are weaker regions of the ocean lithosphere and more prone to tectonic deformation. Numerical geodynamic models demonstrate that a slab pull force from distant subduction plate boundaries can be effectively transmitted to oceanic plateaux through strong ocean lithosphere and cause substantial extension during plate drift. Our findings reveal that a wide expanse of the Pacific has experienced syn‐drift plate tectonics linked to pull from the western Pacific subduction factory. Plain Language Summary New findings from the Pacific Ocean challenge the conventional understanding of plate tectonics. It was previously believed that oceanic plates remained rigid during plate drift and only experienced deformation at subduction zones. However, geological and geophysical evidence from the Ontong Java, Shatsky, Hess, and Manihiki oceanic plateaux suggests that extensional deformation is a common occurrence during plate drift. These plateaux, which are weaker regions of the ocean lithosphere, are more susceptible to tectonic deformation. Through numerical geodynamic models, we have demonstrated that the slab pull force exerted by distant subduction plate boundaries can effectively cause substantial extension in these oceanic plateaux. This study reveals a significant presence of intra ocean plate deformation associated with the Western Pacific subduction factory. Key Points Seismic and petrologic data indicate that oceanic plateaux on the Pacific Plate are undergoing extensional deformation during plate drift Numerical modeling finds a slab pull force may be causing the extension as the force is transmitted far away from the subduction zone Oceanic plates can experience substantial tectonic deformation during their drift to subduction