Abstract Non-volcanic tremor (NVT) and episodic slow slip events (SSEs) have been observed below the seismogenic zone of relatively warm subduction zones for the past 20 years. Geophysical and geologic observations show that this portion of the subduction interface is fluid-rich, and many models for these slip behaviors necessitate high pore fluid pressures. However, whether these fluids are sourced from local dehydration reactions in particular lithologies, or require up-dip transport from greater depths is not known. We present thermodynamic models of the petrologic evolution of four lithologies typical of the plate interface (average MORB, seafloor altered MORB, hydrated depleted MORB mantle, and metapelite) along predicted plate boundary pressure–temperature (P-T) paths at several warm subduction segments where NVT and SSEs are observed at depths between 25-65 km. The models suggest that 1-2 wt% H2O is released at the depths of NVT/SSEs in Jalisco-Colima, Guerrero, Cascadia, and Shikoku due to punctuated dehydration reactions within MORB, primarily through chlorite and/or lawsonite breakdown. These reactions produce sufficient in-situ fluid across a narrow P-T range to cause high pore fluid pressures at NVT/SSE depths. Dehydration of hydrated peridotite is minimal at these depths for most margins, and metapelite releases H2O (

中文翻译：

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幕式滑移和震颤深处暖俯冲带的板块脱水

摘要 过去 20 年来，在相对温暖的俯冲带的发震带下方观察到了非火山性震颤 (NVT) 和间歇性慢滑移事件 (SSE)。地球物理和地质观测表明，俯冲界面的这一部分富含流体，并且这些滑动行为的许多模型需要高孔隙流体压力。然而，这些流体是否来自特定岩性中的局部脱水反应，还是需要从更深的深度向上倾输运尚不清楚。我们提出了板块界面的四种典型岩性（平均 MORB、海底蚀变 MORB、水合耗竭 MORB 地幔、和变泥岩）沿着几个暖俯冲段预测的板块边界压力-温度（PT）路径，其中在 25-65 公里的深度观察到 NVT 和 SSE。模型表明，由于 MORB 内的间断脱水反应，主要通过绿泥石和/或硬柱石分解，在哈利斯科科利马州、格雷罗州、卡斯卡迪亚和四国的 NVT/SSE 深处释放了 1-2 wt% 的 H2O。这些反应在狭窄的 PT 范围内产生足够的原位流体，从而在 NVT/SSE 深度产生高孔隙流体压力。对于大多数边缘，在这些深度处水合橄榄岩的脱水最小，并且变泥质岩释放 H2O（主要通过绿泥石和/或硬镁石分解。这些反应在狭窄的 PT 范围内产生足够的原位流体，从而在 NVT/SSE 深度产生高孔隙流体压力。对于大多数边缘，在这些深度处水合橄榄岩的脱水最小，并且变泥质岩释放 H2O（主要通过绿泥石和/或硬镁石分解。这些反应在狭窄的 PT 范围内产生足够的原位流体，从而在 NVT/SSE 深度产生高孔隙流体压力。对于大多数边缘，在这些深度处水合橄榄岩的脱水最小，并且变泥质岩释放 H2O（