The geochemistry of oceanic intraplate (primarily oceanic island and seamount) lavas can provide essential information on the composition and evolution of their mantle source and geodynamics. Due to very limited rock sampling of the many mid-Cretaceous Wake seamounts in NW Pacific, the mantle source lithology and petrogenesis of their lavas, and the geodynamic mechanism responsible for generating the lavas have not been fully delineated. In order to help resolve these issues, here we present whole-rock major-trace element and Sr-Nd-Pb-Hf isotopic data for twenty-one lava samples collected from Lamont, Dacheng, Xufu, Penglai, Niulang, Zhinyu, and Zhanlu seamounts in the Southern Wake seamount trail (WST). These lava samples are silica-undersaturated alkali basalt and basanites/nephelinite. They have high CaO, FeO^T and TiO₂ contents and CaO/Al₂O₃ ratios, consistent with their derivation from partial melting of a carbonated peridotite or reaction between carbonated MORB-eclogite-derived silicate melts and fertile peridotite. High Zr/Hf and negative Zr-Hf-Ti anomalies in the most mafic lavas further suggest a contribution from carbonated components in their mantle source. These lavas show FOZO (focal zone)-HIMU (high μ = ²³⁸U/²⁰⁴Pb)-like Sr-Nd-Pb-Hf isotopic compositions (e.g., (²⁰⁶Pb/²⁰⁴Pb)_i = 19.36–20.72), falling within the Arago (also known as “Young Rurutu” or “Atiu”) hotspot field. Combined with the sparse previous age and geochemical data, we propose that WST lavas were most likely derived from partial melting of secondary plume clusters emanating from the top of Arago mantle plume trapped at the mantle transition zone. Alternatively, WST lavas could have come from a number of secondary plumelets emanating from the top of the Pacific Large Low Shear Velocity Province (LLSVP). The simultaneously upwelling secondary plumes or plumelets generated chronologically overlapping, compositionally similar and closely-spaced Wake seamounts atop the moving Pacific plate.

大洋板内（主要是大洋岛和海山）熔岩的地球化学可以提供有关其地幔来源和地球动力学的组成和演化的重要信息。由于西北太平洋许多中白垩世尾迹海山的岩石采样非常有限，其熔岩的地幔源岩性和岩石成因以及产生熔岩的地球动力学机制尚未完全描绘。为了帮助解决这些问题，我们在此提供了从拉蒙特、大城、徐府、蓬莱、牛浪、织玉和占路采集的 21 个熔岩样品的全岩主要微量元素和 Sr-Nd-Pb-Hf 同位素数据南威克海山小径 (WST) 中的海山。这些熔岩样品是二氧化硅不饱和的碱性玄武岩和玄武岩/霞石。它们具有高 CaO、FeO ^T和 TiO ₂含量和 CaO/Al ₂ O ₃比率，与它们源自碳酸化橄榄岩的部分熔融或碳酸化 MORB 榴辉岩衍生的硅酸盐熔体与肥沃橄榄岩之间的反应。大多数基性熔岩中的高 Zr/Hf 和负 Zr-Hf-Ti 异常进一步表明其地幔源中的碳酸盐成分的贡献。这些熔岩显示 FOZO（焦点区）-HIMU（高 μ = ²³⁸ U/ ²⁰⁴ Pb）-类似 Sr-Nd-Pb-Hf 同位素组成（例如，（²⁰⁶ Pb/ ²⁰⁴ Pb）_i = 19.36–20.72)，落入 Arago（也称为“Young Rurutu”或“Atiu”）热点区域。结合稀疏的先前年龄和地球化学数据，我们提出 WST 熔岩最有可能来自被困在地幔过渡带的阿拉戈地幔柱顶部发出的次生柱状柱群的部分熔化。或者，WST 熔岩可能来自太平洋大低剪切速度省 (LLSVP) 顶部的许多次生羽流。同时上升的次生羽流或羽流在移动的太平洋板块顶部产生了按时间顺序重叠、成分相似且间隔很近的威克海山。