Multiple sulfur isotopes from the Neoarchaean Serra Sul black shale, Carajás mineral province, northern Brazil

In-situ laser ablation and multicollector–inductively coupled plasma–mass spectrometry were combined to analyse for sulfur isotopes in sulfide minerals that occur in the 2.7-billion-year-old black shale of Serra Sul, Carajás mineral province, Brazil. The black shale is part of a banded-iron-formation unit – the Carajás Formation – that hosts world-class iron-ore deposits. An obvious signal of mass-independent fractionation of sulfur isotopes...