Subduction initiation often takes advantage of previously weakened lithosphere and may preferentially nucleate along pre‐existing plate boundaries. To evaluate how past tectonic regimes and inherited lithospheric structure might lead to self‐sustaining subduction, we present an analysis of the Puysegur Trench, a young subduction zone with a rapidly evolving tectonic history. The Puysegur margin, south of New Zealand, has experienced a transformation from rifting to seafloor spreading to strike‐slip, and most recently to incipient subduction, all in the last ∼45 million years. Here we present deep‐penetrating multichannel reflection and ocean‐bottom seismometer tomographic images to document crustal structures along the margin. Our images reveal that the overriding Pacific Plate beneath the Solander Basin contains stretched continental crust with magmatic intrusions, which formed from Eocene‐Oligocene rifting between the Campbell and Challenger plateaus. Rifting was more advanced to the south, yet never proceeded to breakup and seafloor spreading in the Solander Basin as previously thought. Subsequent strike‐slip deformation translated continental crust northward causing an oblique collisional zone, with trailing ∼10 Myr old oceanic lithosphere. Incipient subduction transpired as oceanic lithosphere from the south forcibly underthrust the continent‐collision zone. We suggest that subduction initiation at the Puysegur Trench was assisted by inherited buoyancy contrasts and structural weaknesses that were imprinted into the lithosphere during earlier phases of continental rifting and strike‐slip along the plate boundary. The Puysegur margin demonstrates that forced nucleation along a strike‐slip boundary is a viable subduction initiation scenario and should be considered throughout Earth's history.

中文翻译：

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滑移使失败的裂谷下的俯冲作用成为可能：来自新西兰Pysegur gin陷的新地震约束

俯冲引发通常利用先前弱化的岩石圈的优势，并可能优先沿先前存在的板块边界成核。为了评估过去的构造状态和继承的岩石圈结构如何导致自我维持的俯冲，我们对Puysegur海沟进行了分析，这是一个构造历史迅速发展的年轻俯冲带。在过去的大约4500万年中，新西兰南部的Puysegur边缘经历了从裂谷到海底扩散再到走滑，再到初期俯冲的转变。在这里，我们展示了深穿透的多通道反射和海底地震仪层析图像，以记录沿边缘的地壳结构。我们的图像显示，索兰德盆地下方的上覆太平洋板块含有伸展的大陆壳，具有岩浆侵入，这是由坎贝尔高原和挑战者高原之间的始新世-渐新世裂谷形成的。裂谷向南发展，但从未像以前所想的那样在索兰德盆地破裂和海底扩散。随后的走滑变形使大陆壳向北平移，形成了一个倾斜的碰撞带，并伴有大约10 Myr的大洋岩石圈。最初的俯冲作用从南​​面以大洋岩石圈的形式强行推入了大陆碰撞带。我们认为，在Puysegur海沟俯冲作用的开始是通过在大陆裂谷和沿板块边界的走滑早期阶段印在岩石圈中的继承的浮力对比和结构弱点来进行的。Puysegur边缘表明，沿走滑边界强迫成核是可行的俯冲起始场景，应在整个地球历史中予以考虑。