Major and trace element compositions of garnet, clinopyroxene, orthopyroxene, phlogopite, and ilmenite from garnet peridotite, ilmenite-bearing peridotite (dunites), and clinopyroxene–phlogopite xenoliths, as well as megacrysts of these minerals from the Grib kimberlite, Arkhangelsk diamond province, Russia, have been analyzed. These data are used to propose a model for mantle metasomatism of lithospheric mantle by kimberlite melts, including their generation and evolution, geochemical enrichment of depleted lithosphere mantle, and formation of megacrystic assemblage. The lithospheric mantle beneath the Arkhangelsk diamond province, from its base (depth ~180–210 km) to a depth of ~100–120 km (corresponding to a pressure of 3.5 GPa) experienced extensive metasomatism along the main kimberlite melt channel. Petrography of the peridotite xenoliths indicates a progressive refertilization of depleted harzburgite into garnet lherzolite, phlogopite–garnet wehrlite, and clinopyroxene–phlogopite rocks. Metasomatic refertilization occurred shortly before the capture of these xenoliths by the kimberlite melt. The model melt compositions calculated from garnet–clinopyroxene equilibria in different types of xenoliths and megacrysts show that alkaline–carbonate–ultramafic kimberlite melt acted as a metasomatic agent in the sheared peridotite at the base of the lithospheric mantle. High-Ti garnet and high-Cr clinopyroxene megacrysts in the middle part of the lithospheric mantle, as well as the main volume of garnet lherzolite xenoliths were formed in geochemical equilibrium with the kimberlite melts, which demonstrate an increase of silicate components and fractionation of Fe–Ti phases. The modification could be related to the interaction of ascending carbonate-rich protokimberlite melts with surrounding lithospheric mantle. The similarities in the compositions of garnet, clinopyroxene, phlogopite, and ilmenite megacrysts with minerals of peridotite xenoliths in the Grib kimberlite suggest that these megacrysts are disintegrated fragments of coarsest grained metasomatized garnet lherzolite, ilmenite-bearing peridotite, and clinopyroxene-phlogopite mantle rocks or formed under the same conditions as xenoliths or directly crystallized from metasomatic melts.

石榴石橄榄石，含钛铁矿的橄榄岩（榴辉岩），斜辉石-金云母的异岩以及石榴石，斜长石，斜长石，斜长石，斜长石和金刚砂的主要和微量元素组成，以及来自格里金伯利岩的这些矿物的大晶体，俄罗斯，已经进行了分析。这些数据被用来为金伯利岩熔岩对岩石圈地幔的地幔交代作用提出一个模型，包括其生成和演化，枯竭的岩石圈地幔的地球化学富集以及大晶组合的形成。从其底部（深度约180-210 km）到深度约100-120 km（对应于3.5 GPa的压力），阿尔汉格尔斯克钻石省以下的岩石圈地幔沿主要的金伯利岩熔体通道经历了广泛的交代作用。橄榄岩异岩的岩相学表明贫化的钙镁矿逐渐转化为石榴石绿铁矿，金云母-石榴石白云母和斜辉石-金云母岩。金伯利岩熔体捕获这些异种岩之前不久就发生了交代交联作用。根据石榴石-斜茂铁在不同类型的异岩和巨晶中的平衡计算出的模型熔体组成表明，碱性-碳酸盐-超拉金铁矿金伯利岩熔体在岩石圈地幔底部的剪切橄榄岩中起着交代作用。岩石圈地幔中部的高钛石榴石和高Cr斜辉石巨晶，以及与金伯利岩熔体形成地球化学平衡的石榴石绿铁矿异岩的主要体积，这表明硅酸盐成分的增加和Fe-Ti相的分馏。这种改变可能与上升的富含碳酸盐的原金伯利岩熔体与周围岩石圈地幔的相互作用有关。石榴石，斜辉石，金云母和钛铁矿巨型晶体与Grib金伯利岩中橄榄石异岩的矿物的相似性表明，这些巨型晶体是最粗粒化变质榴石榴辉岩，含钛铁锰矿和钙云母的红闪石，在与异石相同的条件下形成或直接从交代熔体中结晶出来的。