Atmospheric sulfur is recycled to the crystalline continental crust during supercontinent formation

• Published in: Nature communications Vol. 9; no. 1; pp. 4380 - 9
• Main Authors: LaFlamme, Crystal, Fiorentini, Marco L., Lindsay, Mark D., Bui, Thi Hao
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.10.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 140/58; 704/2151/209; 704/2151/210; Continental crust; Cratons; Fractionation; Humanities and Social Sciences; Isotope fractionation; Isotopes; Lithosphere; Magma; Mantle; multidisciplinary; Oxidation; Reservoirs; Science; Science (multidisciplinary); Sediments; Spatial discrimination; Sulfur; Sulfur cycle; Sulfur isotopes; Tracks (paths)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-06691-3

The sulfur cycle across the lithosphere and the role of this volatile element in the metasomatism of the mantle at ancient cratonic boundaries are poorly constrained. We address these knowledge gaps by tracking the journey of sulfur in the assembly of a Proterozoic supercontinent using mass independent isotope fractionation (MIF-S) as an indelible tracer. MIF-S is a signature that was imparted to supracrustal sulfur reservoirs before the ~2.4 Ga Great Oxidation Event. The spatial representation of multiple sulfur isotope data indicates that successive Proterozoic granitoid suites preserve Δ 33 S up to +0.8‰ in areas adjacent to Archean cratons. These results indicate that suturing of cratons began with devolatilisation of slab-derived sediments deep in the lithosphere. This process transferred atmospheric sulfur to a mantle source reservoir, which was tapped intermittently for over 300 million years of magmatism. Our work tracks pathways and storage of sulfur in the lithosphere at craton margins. The long-term evolution of the sulfur budget in the lithosphere is poorly constrained. Here, using mass independent isotope fractionation as an indelible tracer, the authors track the pathway of sulfur from the Earth’s surface to punctuated episodes of granitoid magmatism during collisional orogenesis.