Post‐collisional ultrapotassic magmatism received special attention because it is an important indicator for mantle geodynamics in a collisional orogen. So far, no mantle‐derived magmatism has been identified within the Himalayan belt, hindering our understanding of the architecture and thermal state of the deep‐seated lithosphere in this area during the orogenesis. Here, we report the first discovery of mantle‐derived ultrapotassic rock in the Himalayan region. The middle Miocene (ca. 13 Ma) lamprophyre dike intruded the Tethyan Himalaya sedimentary cover of the Ramba dome on the shoulder of the Yadong‐Gulu rift. Geochemical analyses suggest that the ultrapotassic melt was derived from the subcontinental lithospheric mantle of the Indian plate, within a relatively shallow depth in the spinel stability field. The ultrapotassic magmatism indicates asthenospheric upwelling in the middle Miocene, a response to the mantle unrooting process beneath the Himalayan orogen.

中文翻译：

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喜马拉雅中新世中超钾盐岩浆作用：对造山带下地幔脱根过程的响应

碰撞后超钾质岩浆活动受到特别关注，因为它是碰撞造山带中地幔地球动力学的重要指标。到目前为止，在喜马拉雅带内尚未发现地幔起源的岩浆作用，这妨碍了我们对造山过程中该地区深层岩石圈的构造和热状态的了解。在这里，我们报告了在喜马拉雅地区首次发现地幔超钾盐岩。中新世（约13 Ma）的煌斑岩堤侵入亚东古鲁裂谷肩上的兰巴穹隆的特提斯喜马拉雅沉积覆盖层。地球化学分析表明，超钾盐熔岩来自印度板块的亚大陆岩石圈地幔，在尖晶石稳定区的一个相对较浅的深度内。