Affiliation:
1. Far East Geological Institute, Far Eastern Branch of the Russian Academy of Sciences
Abstract
In this paper we provide primary data on multi-isotope sulfur composition of the Neoarchean BIF sulfides of the Kostomuksha greenstone belt in Karelia (the Karelian Craton on Fennoscandian Shield). These sulfides formed at 2760–2740 Ma. Pyrite associated with fine-grained magnetite showed negative δ34S values (up to –7.8‰) and positive Δ33S values (up to +0.7‰). At the same time, pyrrhotite of vein-disseminated ores associated with shale demonstrated both negative δ34S (up to –6‰), and Δ33S values (up to –0.46‰). Based on the obtained data we assume that sulfur for the BIF sulfides was transported from three reservoirs: - atmospheric (photolytic), hydrospheric (seawater sulfate), and magmatogenic. Sulfur isotope ratios in sulfides preserved the evidence of interaction between abiological (atmospheric, hydrothermal) and biological processes (dissimilatory microbial reduction) that occurred during the formation of iron ore deposits of the Kostomuksha greenstone belt in Karelia.
Publisher
The Russian Academy of Sciences