The Mineoka Ophiolite Mélange is located at the intersection of the Pacific, Philippine Sea, Eurasian, and North American plates. The Mineoka ophiolite origin is disputed, and it has been ascribed to a fully subducted plate or part of the Pacific and Philippine Sea plates. In this paper, we present a kinematic reconstruction of the Mineoka Ophiolite Mélange and its relation with the Pacific Plate, based on new paleomagnetic data and bulk‐rock ⁴⁰Ar/³⁹Ar ages of basaltic rocks. In addition to standard analyses for paleolatitudes, we performed a Net tectonic rotation analysis on sheeted dolerite dikes to infer the paleospreading direction that formed the ophiolite. The analysis shows that 85–80 Ma MOR pillow basalts erupted at a paleolatitude of N ∼16°, whereas ∼50 Ma basalts formed at N ∼34°. Net Tectonic Rotation analysis suggests that the spreading direction was NE 60°. Ar–Ar ages yielded 53–49 Ma for MORBs and 41–35 Ma for island‐arc basalts. The formation of this ophiolite occurred in the back‐arc spreading of the Nemuro–Olyutorsky arcs of the NW Pacific. It infers that the final consumption of Izanagi below Japan instigated a subduction jump and flipped its polarity. Subduction initiated parallel to the ridge, and a piece of the original back‐arc crust got trapped near the Japan trench during the northwards motion of the Philippine Sea Plate. The contrasting motion between the Pacific and the Philippine Sea plates generated a highly unstable setting followed by a subduction zone that left a small‐sized and short‐lived plate (“Mineoka”), surrounded by subduction zones.

中文翻译：

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白垩纪至中新世西北太平洋板块运动学约束：Mineoka OphioliteMélange的古磁性和Ar–Ar年代学（日本）

Mineoka Ophiolite混杂岩位于太平洋，菲律宾海，欧亚大陆和北美板块的交汇处。Mineoka蛇绿岩的起源是有争议的，并且已被归因于完全俯冲的板块或太平洋和菲律宾海板块的一部分。在本文中，我们基于新的古磁数据和块岩⁴⁰ Ar / ³⁹，提出了Mineoka Ophiolite混杂岩的运动学重建及其与太平洋板块的关系。Ar时代的玄武岩。除了古纬度的标准分析之外，我们还对片状白云石堤进行了净构造旋转分析，以推断形成蛇绿岩的古扩展方向。分析表明，85〜80 Ma MOR枕形玄武岩在古纬度为N〜16°喷发，而约50 Ma玄武岩在N〜34°形成。净构造旋转分析表明，传播方向为NE 60°。钼铁的Ar–Ar年龄为53–49 Ma，岛屿弧形玄武岩的Ar–Ar年龄为41–35 Ma。蛇绿岩的形成发生在西北太平洋Nemuro-Olyutorsky弧的弧后扩散中。它推断出，Izanagi在日本之后的最终消费量引发了俯冲跃升并颠倒了其极性。俯冲平行于山脊开始，菲律宾海床向北运动时，一块原始的后弧地壳被困在日本海沟附近。太平洋和菲律宾海板块之间形成鲜明对比的运动产生了高度不稳定的环境，其后是一个俯冲带，留下了一个小型且寿命短的板块（“ Mineoka”），周围是俯冲带。