Metal isotopes are versatile pollutant source trackers, but biogeochemical processes can overprint or alter the original source isotopic fingerprint and thus hinder contamination tracing. Here, we explore Fe isotope systematics for the complete range of natural and metallurgical processes related to Ni lateritic ores from Barro Alto, Brazil, to assess its potential as a tracer in polluted lateritic soil contexts developed in an ultramafic system.

The homogeneous δ⁵⁷Fe values from protolith to soil confirmed that no significant Fe isotopic variation occurred during the formation of the deep lateritic profile. In addition, no Fe isotopic fractionation was found during the smelting process. Although the δ⁵⁷Fe values resulting from mining activities fall within the range of terrestrial sample signatures, the conservation of the δ⁵⁷Fe values from the ores to the by-products is an advantage for tracing anthropogenic sources when (i) the pyrometallurgical plant uses feeding material with Fe ores imported from other geological formations exhibiting different δ⁵⁷Fe values and/or (ii) the by-products are transported or dispersed to other locations with different δ⁵⁷Fe signatures in the topsoil.

金属同位素是通用的污染物源跟踪器，但是生物地球化学过程会叠印或更改原始源同位素指纹，从而阻碍了污染物的追踪。在这里，我们探索了与巴西Barro Alto的镍红土矿石有关的自然和冶金过程的全部范围的铁同位素系统，以评估其在超镁铁矿系统中开发的受污染的红土土壤环境中作为示踪剂的潜力。

均质δ ⁵⁷从原岩土壤铁值证实，深红土剖面的形成过程中没有发生显著铁同位素变化。此外，在熔炼过程中未发现铁同位素分馏。虽然δ ⁵⁷从开采活动造成的Fe值落在地面样品签名的范围内，则δ的养护⁵⁷的Fe的值从矿石到副产物是有利的用于跟踪人为来源当（i）的火法冶金厂的用途与来自其他地质构造中导入铁矿石呈现不同δ给料^57倍的Fe的值和/或（ii）所述的副产物被输送或分散于具有不同δ其它位置⁵⁷铁在表土中的签名。