Interactions between basaltic melt and orthopyroxenite (Opx) were investigated to gain a better understanding of the consequences of the residence and transport of ocean island basalts (OIBs) within the mantle. The experiments were conducted using a DS-3600 six-anvil apparatus at 3.0–4.5 GPa and 1300–1450 °C. The basaltic melt and Opx coexisted at local equilibrium at these pressures and temperatures; the initial melts dissolved Opx, which modified their chemical composition, and clinopyroxene (Cpx) precipitated with or without garnet (Grt). The trace-element contents of Grt, Cpx, and melt were measured and the mineral–melt distribution coefficients (D) of Cpx–melt and Grt–melt were calculated, which can be used to assess the distribution of trace elements between basalt and minerals in the mantle. Two types of reaction rim were found in the experimental products, Cpx, and Cpx + Grt; this result indicates that residual rocks within the mantle should be pyroxenite or garnet pyroxenite. Both rock types are found in mantle xenoliths from Hawaii, and the rare-earth-element (REE) pattern of Cpx in these mantle pyroxenites matches those of Cpx in the experimental reaction rims. Furthermore, residual melts in the experimental products plot in similar positions to Hawaiian high-SiO₂ OIBs on major-element Harker diagrams, and their trace-element patterns show the signature of residual Grt, particularly in runs at ≤1350 °C and 4.0–4.5 GPa. Trace-element concentrations of the experimental residual melts plot in similar positions to the Hawaiian OIBs on commonly used discrimination diagrams (Ti vs. Zr, Cr vs. Y, Cr vs. V, Zr/Y vs. Zr, and Ti/Y vs. Nb/Y). These results indicate that reaction between basaltic melt and pyroxenite might contribute to the generation of Hawaiian high-SiO₂ OIBs and account for their chemical variability.

研究了玄武质熔体与正辉石（Opx）之间的相互作用，以更好地了解地幔内海洋岛玄武岩（OIBs）的居住和运输后果。实验是使用DS-3600六砧装置在3.0–4.5 GPa和1300–1450°C下进行的。在这些压力和温度下，玄武质熔体和Opx在局部平衡下共存。最初的熔体溶解了Opx，从而改变了它们的化学成分，并在有或没有石榴石（Grt）的情况下沉淀出了Clinopyroxene（Cpx）。测量了Grt，Cpx和熔体中的痕量元素含量，并确定了矿物-熔体分布系数（D）计算了Cpx-熔体和Grt-熔体的含量，可用于评估地幔中玄武岩和矿物之间微量元素的分布。在实验产品中发现了两种类型的反应边缘，即Cpx和Cpx + Grt。该结果表明，地幔内的残留岩石应该是辉石或石榴石辉石。两种岩石类型都在夏威夷的地幔异岩中发现，并且这些地幔辉石岩中Cpx的稀土元素（REE）模式与实验反应边缘中Cpx的稀土元素模式匹配。此外，实验产品中的残留熔体位于与夏威夷高SiO ₂相似的位置主要元素Harker图上的OIB及其痕量元素模式显示出残留Grt的特征，尤其是在≤1350°C和4.0–4.5 GPa的运行中。在常用的判别图上（Ti与Zr，Cr与Y，Cr与V，Zr / Y与Zr，Ti / Y与Vs），实验残余熔体中痕量元素的浓度与夏威夷OIB的位置相似。 Nb / Y）。这些结果表明，玄武岩熔体与辉石的反应可能有助于产生夏威夷高SiO ₂ OIB，并解释了它们的化学变异性。