Kimberlite magmatism occurs as a result of volatile fluxed melting of the convecting upper mantle underlying cratonic lithospheric mantle regions. During passage to the Earth's surface, proto-kimberlite magma can interact with, and assimilate, variably enriched cratonic mantle producing hybrid melts consisting of asthenospheric and cratonic mantle components including contributions from metasomatic domains. The halogen elements (F, Cl, Br, I) and chlorine isotope ratios (³⁷Cl/³⁵Cl) are increasingly used as tracers of recycled crustal materials within the Earth's mantle yet are only rarely reported in analyses of kimberlites. As a result, the origin and distribution of halogens in kimberlite magmas is poorly constrained. Here, we present novel, combined elemental (F, Cl, Br) and isotopic (δ³⁷Cl) halogen data for 14 fresh kimberlite samples from the North Atlantic Craton (NAC) of West and South-West Greenland.

The F composition of kimberlites from the NAC appears to be controlled by melting in the convecting upper mantle with minimal effect from interaction with metasomatized lithospheric mantle or volatile loss during or after emplacement. By contrast, Cl and Br in the studied samples have undergone significant devolatilization during kimberlite dyke emplacement and post-emplacement processes, whereby up to 99% of the original halogen budget was removed.

Whilst all the studied kimberlites broadly follow the same geochemical pattern, there exists some regional variability in their halogen systematics. The northern NAC kimberlite samples from Majuagaa have mantle-like δ³⁷Cl values of −0.2 to −0.5‰ [versus SMOC (standard mean ocean chloride)]. In contrast, kimberlite dykes from Nigerdlikasik and Pyramidefjeld near the southern craton margin display positive δ³⁷Cl values of +0.4‰ to +1.3‰, in addition to a relative Cl and Br enrichment, which is consistent with the assimilation of recycled crust-derived halogens by the kimberlite magmas. The data support a scenario in which recycled halogens were sampled either from within an OIB-type reservoir in the convecting mantle or through interaction with subduction-modified lithospheric mantle reservoir during eruption. We prefer a scenario in which the ascending kimberlite magmas assimilated Cl-rich, metasomatized regions within cratonic mantle lithosphere.

金伯利岩岩浆作用是由于克拉通岩石圈地幔区域下面对流上地幔的挥发性助熔剂熔化而产生的。在金伯利岩岩浆进入地球表面的过程中，它会与变质富集的克拉通地幔相互作用并吸收，产生混合流熔体，其中包括软流圈和克拉通地幔组分，包括交代作用域的贡献。卤素元素（F，Cl，Br，I）和氯同位素比（³⁷ Cl / ³⁵Cl）被越来越多地用作地幔中可回收地壳物质的示踪剂，但在金伯利岩的分析中很少报道。结果，金伯利岩岩浆中卤素的来源和分布受到限制。在这里，我们本发明的新颖，结合元素（氟，氯，溴）和同位素（δ ³⁷ Cl）的用于从西北大西洋克拉通（NAC）和西南格陵兰14个新鲜金伯利岩样品卤素数据。

来自NAC的金伯利岩的F组成似乎是通过在对流的上地幔中熔融而受到控制的，而与交代岩石圈地幔的相互作用或就位过程中或之后的挥发性损失最小。相比之下，被研究样品中的Cl和Br在金伯利岩堤和安置后过程中经历了严重的脱挥发分，从而去除了高达99％的原始卤素预算。

虽然所有研究的金伯利岩大体上遵循相同的地球化学模式，但它们的卤素系统存在一定的区域差异。从Majuagaa北部NAC金伯利岩样品具有地幔状δ ³⁷的-0.2〜-0.5‰CI值[对SMOC（标准平均海洋氯化物）]。与此相反，从Nigerdlikasik和Pyramidefjeld金伯利岩堤坝南部克拉通余量显示正靠近δ ³⁷Cl和Br相对富集，Cl值为+ 0.4‰至+ 1.3‰，这与金伯利岩岩浆对循环壳衍生卤素的吸收作用一致。数据支持这样一种场景：从对流地幔中的OIB型储层中或在喷发过程中与俯冲修饰的岩石圈地幔储层相互作用，对回收的卤素进行采样。我们更喜欢这样一种场景，即金伯利岩岩浆上升沿同化克拉通地幔岩石圈内富含Cl的交代区域。