The Galápagos and Hawai'i archipelagos are formed by mantle plumes originating at the large low shear velocity province (LLSVP) boundary. We report new high‐precision Pb, Sr, Nd, and Hf isotopic analyses on 83 Galápagos samples and compare them with those of Hawai'i. The data confirm that like Hawai'i, Galápagos is a bilaterally asymmetric plume whose compositional boundary trends NW‐SE. On their northeast sides, the plumes share a common source, Pacific lower mantle, whose intermediate isotopic signature may be common to many plumes. The Hawaiian and Galápagos plumes' southwestern sides are anchored in the Pacific LLSVP and are compositionally distinct; in Hawai'i, Loa trend lavas reflect contributions from the EM1 mantle end‐member, whereas in Galápagos, HIMU is dominant, suggesting that the Pacific LLSVP is compositionally heterogeneous and includes different types of recycled material. Furthermore, the surficial expression of a bilaterally asymmetric plume is strongly influenced by its tectonic setting: (a) Thick Hawaiian lithosphere supports a volcano evolution process, including rejuvenated volcanism, whereas the thin Galápagos lithosphere inhibits Hawai'i‐style rejuvenated‐stage eruptive activity, instead causing extended, widespread volcanism; (b) the proximity of the Galápagos to a mid‐ocean ridge causes entrainment of the depleted upper mantle, overwhelming depleted material intrinsic to the plume and affecting volcanoes' magmatic architecture; and (c) the geometric relationship between the LLSVP boundary and plate motion influences geochemical patterns at the surface. Thus, despite striking differences in surficial expression of the Galápagos and Hawai'i plumes, they share a common generation mechanism, supplied by the Pacific LLSVP and the lower mantle.

中文翻译：

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深入了解地幔柱的起源和成分：加拉帕戈斯群岛和夏威夷州的比较

加拉帕戈斯群岛和夏威夷群岛由地幔柱形成，地幔柱起源于大的低剪切速度省（LLSVP）边界。我们对83个加拉帕戈斯群岛样品进行了新的高精度Pb，Sr，Nd和Hf同位素分析，并将其与夏威夷州的样品进行了比较。数据证实，与夏威夷一样，加拉帕戈斯群岛是双边不对称羽状流，其组成边界趋势为西北-东南。在它们的东北侧，这些羽共有一个共同的来源，太平洋下地幔，其中间同位素特征可能是许多羽所共有的。夏威夷和加拉帕戈斯群岛羽状体的西南侧锚定在太平洋低烟无卤油气中，并且成分独特。在夏威夷，Loa趋势熔岩反映了EM1地幔末段成员的贡献，而在加拉帕戈斯群岛，HIMU占主导地位，这表明Pacific LLSVP在成分上是异质的，并且包括不同类型的再生材料。此外，双侧不对称羽的表面表达受其构造环境的强烈影响：（a）夏威夷厚的岩石圈支持火山的演化过程，包括复兴的火山活动，而加拉帕戈斯群岛的薄岩石圈抑制了夏威夷式的复兴阶段的喷发活动。 ，而不是造成广泛而广泛的火山爆发；（b）加拉帕戈斯群岛靠近海洋中脊，导致夹带着枯竭的上地幔，压倒了羽流固有的枯竭物质，并影响了火山的岩浆构造；（c）LLSVP边界与板块运动之间的几何关系会影响地面的地球化学模式。从而，