Abstract In magmatic nickel-copper-platinum-group element (PGE) deposits, the PGEs are found both in solid solution in base metal sulfides and as platinum group minerals (PGMs). Apart from S, the most common elements that the PGEs combine with to form PGMs are Te, As, Bi, Sb, and Sn (TABS). Whether the TABS play a role in collecting the PGEs or simply partition into the sulfide liquid along with the PGEs and later combine with PGEs when the sulfide phase becomes saturated with PGMs is not currently clear. This is in part because the concentrations of TABS in the magmas (picrites and basalts from large igneous province and komatiites) that form these types of deposits are not well established, and hence it is not evident whether the magmas contain sufficient TABS to control PGEs. In order to establish the concentrations of Te, As, Bi, Sb, and Se (TABS+) in these rock types and to document the processes affecting these concentrations, we have determined TABS+ concentrations in komatiites, in mid-ocean ridge basalt, and in picrites and basalts from large igneous provinces. Using TABS+ mantle-normalized diagrams, the affects of different mantle sources, crystal fractionation, crustal assimilation, degassing, and alteration are considered. We estimate the concentrations of TABS+ in komatiites to be approximately twice primitive mantle values. In picrites the concentrations vary: approximately 10 times primitive mantle values for As and Sb and decreasing through Bi to Te from 7 to 2 times primitive mantle. Assimilation of S-bearing sedimentary rocks is thought to be important in triggering sulfide saturation leading to the formation of Ni-Cu-PGE deposits. Assimilation of such sediments would enrich the magma in Th over Nb and in As, Sb, and Bi. Evidence of assimilation in the form of TABS and Th enrichment is clear in the PGE reef deposits of the Bushveld and Stillwater Complexes, but the deposits do not contain sufficient TABS to control the PGEs. This is also true in the Norilsk-Talnakh Ni-Cu-PGE deposits. However, at Norilsk degassing of the magma has resulted in the loss of TABS, which results in negative As, Bi, Se, and Te anomalies on primitive mantle-normalized plots.

中文翻译：

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Te、As、Bi、Sb 和 Se 在大洋中脊玄武岩和科马提岩以及大火成岩省苦铁矿和玄武岩中的分布：对岩浆镍铜铂族元素矿床形成的启示

摘要 在岩浆镍铜铂族元素（PGE）矿床中，铂族元素既存在于贱金属硫化物的固溶体中，也存在于铂族矿物（PGMs）中。除了 S，与 PGE 结合形成 PGM 的最常见元素是 Te、As、Bi、Sb 和 Sn (TABS)。TABS 是否在收集 PGEs 中发挥作用，或者只是与 PGEs 一起分配到硫化物液体中，然后当硫化物相被 PGMs 饱和时与 PGEs 结合，目前尚不清楚。这部分是因为形成这些类型矿床的岩浆（来自大型火成岩省的苦铁矿和玄武岩和科马提岩）中的 TABS 浓度尚未确定，因此尚不清楚岩浆是否含有足够的 TABS 来控制 PGE。为了确定 Te、As、Bi 的浓度，这些岩石类型中的 Sb 和 Se (TABS+) 并记录影响这些浓度的过程，我们已经确定了科马提岩、大洋中脊玄武岩以及来自大型火成岩省的苦灰岩和玄武岩中的 TABS+ 浓度。使用 TABS+ 地幔归一化图，考虑了不同地幔来源、晶体分馏、地壳同化、脱气和蚀变的影响。我们估计科马提岩中 TABS+ 的浓度约为原始地幔值的两倍。在苦味石中，浓度各不相同：As 和 Sb 的浓度约为原始地幔值的 10 倍，而从 Bi 到 Te 的浓度从原始地幔的 7 倍减少到 2 倍。含硫沉积岩的同化被认为是引发硫化物饱和从而形成 Ni-Cu-PGE 矿床的重要因素。此类沉积物的同化将使 Th 中的岩浆比 Nb 以及 As、Sb 和 Bi 中的岩浆富集。在 Bushveld 和 Stillwater 复合体的 PGE 礁沉积物中，TABS 和 Th 富集形式的同化证据很明显，但沉积物中没有足够的 TABS 来控制 PGE。Norilsk-Talnakh Ni-Cu-PGE 矿床也是如此。然而，在诺里尔斯克，岩浆的脱气导致 TABS 的损失，这导致原始地幔归一化图上的 As、Bi、Se 和 Te 负异常。Norilsk-Talnakh Ni-Cu-PGE 矿床也是如此。然而，在诺里尔斯克，岩浆的脱气导致 TABS 的损失，这导致原始地幔归一化图上的 As、Bi、Se 和 Te 负异常。Norilsk-Talnakh Ni-Cu-PGE 矿床也是如此。然而，在诺里尔斯克，岩浆的脱气导致 TABS 的损失，这导致原始地幔归一化图上的 As、Bi、Se 和 Te 负异常。