Tectonic Development of the Japanese Islands Controlled by Philippine Sea Plate Motion
Tectonic Development of the Japanese Islands Controlled by Philippine Sea Plate Motion
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菲律宾海板块运动控制日本列岛的构造发育
DOI：
10.5026/jgeography.115.116
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发表时间：
2006
影响因子：
3.1
通讯作者：
Masaki Takahashi
中科院分区：
文献类型：
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作者：
Masaki Takahashi
根据伊豆-小笠原弧与日本西南部（SW）的交汇点自15 Ma以来没有从南马格纳窝移动的地质约束，可以估计15 ~ 3 Ma期间菲律宾海板块（PHP）相对于稳定欧亚板块（EUP）的欧拉极位置在150°E，36°N附近。欧拉极迁移到现今位置（154°E，47°N）的时间应该发生在3 Ma，因为3 Ma时日本西南部的弧前盆地曾被黑泷不整合面中断。PHP向西北方向移动，并以4 cm/yr的收敛速度俯冲到日本西南部下方。伊豆-小笠原海沟（IT）也以与向西分量相同的速度移动（约100公里）。3厘米/年）PHP的运动。沟-沟-沟（TTT）三联点和日本海沟（JT）都应该向西迁移，因为厚，冷，坚固的太平洋板块（PAP）从未被TTT连接处的转换断层切割。日本东北部（NE）也将向西移动，因为沿着JT的构造侵蚀不足以使JT向西迁移。因此，目前的PHP运动导致向西迁移的IT，TTT交界处，JT，然后东北日本。日本东北部的这种向西运动与日本海坚固的海洋岩石圈的碰撞，导致日本东北部的东西向收缩，因为PHP的向北运动在3 Ma时变为NW。预计在PAP的厚而冷的岩石圈被TTT交界处的右旋转换断层撕裂之前，Izu-Ogasawara弧的薄而热的岩石圈的裂谷将达到破裂。当裂谷作用达到破裂时，PHP向西北方向的运动将被弧后扩张所补偿，这种运动不会传播到IT、JT和日本东北部。因此，当沿着伊豆-小笠原弧的弧后裂谷作用达到破裂时，日本目前的东西向收缩将在地质学上的不久的将来停止。McKenzie和Morgan（1969）讨论了TTT三联点是如何不稳定的，除了在一些不寻常的几何和运动学条件下。然而，PHP实际上在15 Ma时选择了这个特定的欧拉极点位置，而TTT三联点已经稳定了超过1000万年。虽然目前TTT结处于不稳定状态，但在不久的地质将来，通过PHP的弧后盆地扩张，它将再次变得稳定。因此，控制日本大地构造的日本中部近海TTT三联点在性质上将处于稳定状态。
The Euler pole position of the Philippine Sea Plate (PHP) relative to the stable Eurasian Plate (EUP) between 15 and 3 Ma can be estimated at around 150°E, 36°N, on the basis of the geological constraint that the intersection of the Izu-Ogasawara Arc with Southwest (SW) Japan has not moved from South Fossa Magna since 15 Ma. The timing of the migration of the Euler Pole to its present location (154°E, 47°N) should have occurred at 3 Ma because the fore-arc basin in SW Japan was once interrupted by the Kurotaki Unconformity at 3 Ma.PHP moves northwestward and subducts beneath SW Japan at a convergent rate of 4 cm/yr. The Izu-Ogasawara Trench (IT) also moves at the same rate as the westward component (ca. 3 cm/yr.) of the PHP motion. Both the trench-trench-trench (TTT) triple junction and the Japan Trench (JT) should migrate westward, because the thick, cold, and sturdy Pacific Plate (PAP) has never been cut by the transform fault at the TTT junction. Northeast (NE) Japan would also move westward because tectonic erosion along JT would not be sufficient for westward migration of the JT. Thus, the present PHP movement causes the westward migration of IT, TTT junction, JT and then NE Japan. This westward motion of NE Japan against the sturdy oceanic lithosphere of the Japan Sea has caused an E-W contraction of NE Japan since northward motion of PHP changed to NW at 3 Ma.It is expected that rifting of the thin, heated lithosphere of the Izu-Ogasawara Arc would reach break-up before the thick, cold lithosphere of the PAP would be torn by the right-lateral transform fault at the TTT junction. Once rifting reaches break-up, the northwestward movement of the PHP would be compensated by back-arc spreading, and this motion would not propagate to the IT, the JT nor NE Japan. Therefore, the present E-W contraction in Japan would cease in the geologically near future when back-arc rifting along the Izu-Ogasawara arc reaches break-up.McKenzie and Morgan (1969) discussed how the TTT triple junction was unstable except under a few uncommon geometrical and kinematic conditions. However, the PHP actually selected this particular Euler pole position at 15 Ma, and the TTT triple junction had been stable for more than 10 m.y. Although the present TTT junction is in an unstable condition, it would become stable again through back-arc basin spreading of the PHP in the geologically near future. Thus, the TTT triple junction offshore central Japan, which controls tectonics of Japan, would be in a stable state in nature.