The concentrations of Te, As, Bi, Sb and Se (TABS+) in magmas from large igneous provinces (LIPs) are of interest because these elements are important in the formation of platinum-group minerals (PGM) found in magmatic NiCu platinum-group element (PGE) deposits. Furthermore, the TABS+ are volatile and hence they may be lost in degassing and have a role to play in the mass extinctions associated with LIPs events because these are mostly toxic elements. However, the concentrations of TABS+ in magmas from LIPs are not well documented due in part to the analytical difficulties and in part to the numerous processes that affect their distribution. We have determined the concentration of TABS+ and PGE in rocks from the Paraná Magmatic Province (PMP) in order to assess the effects of fractional crystallization, sulfide segregation and magma degassing. Decrease in the Rh, Ru and Ir concentrations with Mg and Cr indicate that these elements behaved as compatible elements during crystal fractionation. Based on changes in the Cu/Pd sulfide saturation occurred in some cases resulting into a decrease in Pd and Pt. Arsenic and Sb behave as incompatible elements, whereas Se, Te and Bi show variable behaviour. Most lavas from the PMP display negative As, Se and Te anomalies on mantle-normalized patters coupled with Te/Cu, Se/Cu and As/Th and Sb/Th ratios lower than mantle values, which we attribute to loss of the TABS+ during degassing.

中文翻译：

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巴拉那岩浆省铂族元素和 Te、As、Bi、Sb 和 Se (TABS+) 的分布：晶体分异、硫化物偏析和岩浆脱气的影响

来自大型火成岩省 (LIP) 的岩浆中 Te、As、Bi、Sb 和 Se (TABS+) 的浓度令人感兴趣，因为这些元素对于岩浆 NiCu 铂族中发现的铂族矿物 (PGM) 的形成非常重要元素（PGE）沉积物。此外，TABS+ 具有挥发性，因此它们可能会在脱气过程中丢失，并且在与 LIP 事件相关的大规模灭绝中发挥作用，因为它们大多是有毒元素。然而，LIP 岩浆中 TABS+ 的浓度没有得到很好的记录，部分原因是分析困难，部分原因是影响其分布的众多过程。我们测定了巴拉那岩浆省 (PMP) 岩石中 TABS+ 和 PGE 的浓度，以评估分步结晶、硫化物偏析和岩浆脱气的影响。Rh、Ru 和 Ir 浓度随 Mg 和 Cr 的降低表明这些元素在晶体分馏过程中表现为相容元素。基于 Cu/Pd 硫化物饱和度的变化，在某些情况下会导致 Pd 和 Pt 的减少。砷和锑表现为不相容元素，而硒、碲和铋则表现出不同的行为。大多数来自 PMP 的熔岩在地幔归一化图案上显示负 As、Se 和 Te 异常，加上 Te/Cu、Se/Cu 以及 As/Th 和 Sb/Th 比率低于地幔值，我们将其归因于 TABS+ 期间的损失脱气。