Understanding the compositional heterogeneity of the deep mantle requires identifying the nature of recycled crustal materials in the sources of mantle-plume-related magmas. However, it is still unclear whether or not the deep mantle contains recycled carbonates from the Earth’s surface. In this study, we present comprehensive data on whole-rock high-precision zinc isotopes, as well as major- and trace-element geochemistry, and Sr–Nd–Pb isotopes of basalts on Hainan Island to examine the influence of recycled materials (particularly carbonates) on the mantle source heterogeneity of the Hainan mantle plume. The basalts have highly variable δ⁶⁶Zn values ranging from 0.21‰ to 0.42‰. These variable Zn isotopic compositions cannot be accounted for by processes such as post-magmatic alteration and crustal contamination, or by fractional crystallization and partial melting; instead, they reflect mantle heterogeneity. Comparisons of the major- and trace-element compositions (e.g., CaO and TiO₂ contents and Zn/Fe and Fe/Mn ratios), FC3MS and FCKANTMS peridotite and pyroxenite melting parameters, as well as pseudo-ternary projections of the primary Hainan basaltic magmas with experimental data suggest that the primary magmas were partial melts of silica-deficient pyroxenitic lithologies with peridotite residue. The heterogeneous geochemical and lithological compositions of the Hainan basalts indicate that recycled sedimentary carbonates and siliceous rocks were important constituents in their mantle source. Quantitative modeling reveals that the addition of 1–10% subducted sediments into the source of the Hainan basalts closely reproduces their Zn–Sr–Nd–Pb isotopic values. The source component with the heaviest Zn isotopic composition measured for the Hainan basalt samples could have contained more than 9% recycled carbonate. Our findings provide insights into the role of subducted materials to mantle heterogeneity and highlight the contribution of subducted sedimentary carbonates in the deep recycling of oceanic slabs, including—in the case of the Hainan mantle plume—recycled deep mantle (i.e., the mantle transition zone and lower mantle).

了解深部地幔的成分异质性需要确定与地幔柱相关的岩浆来源中回收的地壳物质的性质。然而，目前尚不清楚深部地幔是否含有来自地球表面的回收碳酸盐。在本研究中，我们提供了海南岛玄武岩全岩高精度锌同位素、主量元素和微量元素地球化学以及 Sr-Nd-Pb 同位素的综合数据，以研究再生材料（特别是再生材料）的影响。碳酸盐岩)对海南地幔柱地幔源非均质性的影响. 玄武岩的 δ ⁶⁶ Zn 值变化很大，范围为 0.21‰ 至 0.42‰。这些可变的锌同位素组成不能用岩浆后蚀变和地壳污染等过程或分步结晶和部分熔融等过程来解释；相反，它们反映了地幔的异质性。海南原生玄武岩的主量和微量元素组成（例如CaO和TiO ₂含量以及Zn/Fe和Fe/Mn比）、FC3MS和FCKANTMS橄榄岩和辉石岩熔融参数以及拟三元预测的比较岩浆的实验数据表明，原生岩浆是含有橄榄岩残留物的贫硅辉石岩岩性的部分熔体。海南玄武岩的非均质地球化学和岩性组成表明，再循环的沉积碳酸盐和硅质岩是其地幔来源的重要组成部分。定量模型表明，在海南玄武岩源中添加 1-10% 的俯冲沉积物可以准确再现其 Zn-Sr-Nd-Pb 同位素值。海南玄武岩样品中测得的锌同位素组成最重的源组分可能含有超过 9% 的回收碳酸盐。我们的研究结果提供了关于俯冲物质对地幔非均质性的作用的见解，并强调了俯冲沉积碳酸盐在大洋板块深层再循环中的贡献，包括海南地幔柱的再循环深部地幔（即地幔过渡带）和下地幔）。