Coupling sulfur and oxygen isotope ratios in sediment melts across the Archean-Proterozoic transition

Abstract

The Archean-Proterozoic transition marks a time of fundamental geologic, biologic, and atmospheric changes to the Earth system, including oxygenation of the atmosphere (termed the Great Oxygenation Event; GOE), and the emergence of continents above sea level. The impacts of the GOE on Earth's surface environment are imprinted on the geologic record, including the disappearance of mass-independent fractionation of sulfur isotopes (S-MIF). Temporally overlapping geologic and geochemical observations (e.g. a change in oxygen isotope ratio of sediments and an increase in subaerial volcanism) imply the widespread subaerial emergence of continents was coeval with atmospheric oxygenation. Here we present triple sulfur isotope ratios in pyrite and oxygen isotope ratios in garnet and zircon in a global suite of Archean and Proterozoic granitoids derived from the partial melting of sedimentary protoliths. These crustal melts record an increase in average garnet and zircon d 18 O from 7.2‰ before 2.3 Ga to 10.0‰ post-2.3 Ga. Pre-2.3 Ga granitoids show small S-MIF signatures with D 33 S ranging from À0.29‰ to 0.13‰, whereas post-2.3 Ga granitoids record S-MDF (i.e. D 33 S = 0‰). The combination of sulfur and oxygen isotope signatures in the same sample with zircon U-Pb geochronology provides new insights on a potential causal link between the emergence of continents and Paleoproterozoic atmospheric oxygenation.

Significant Increase of Continental Freeboard During the Early Paleoproterozoic: Insights From Metasediment‐Derived Granites

“…Oxygen isotopes are sensitive to surficial geological processes and fractionate to higher δ 18 O values during low‐temperature alteration (Valley et al., 1994), and have been widely used to infer incorporation of supracrustal material into magmas (Payne et al., 2015; Spencer et al., 2017; Valley et al., 2005; Van Kranendonk et al., 2015; Wang et al., 2017). Several studies have carried out oxygen isotopes on zircon and other minerals from the metasediment‐derived granitoids with ages spanning from Neoarchean to Mesoproterozoic to detect the timing of geochemistry and isotopes shifts over the Archean and Proterozoic period (Bindeman, 2020; Liebmann et al., 2021), however, the lack of early Paleoproterozoic metasediment‐derived granitoids is a perennial problem in establishing the timing and rate of δ 18 O increase during the early Proterozoic.…”

“…of metasediment-derived granitoids spanning the Archean-Proterozoic boundary containing a large gap in dated metasediment-derived granitoids from ∼2.5 to ∼2.0 Ga (Bucholz & Spencer, 2019). This gap was subsequently filled by Liebmann et al (2021) who characterized coupled variation in sulfur and oxygen isotopes of Archean-Proterozoic metasediment-derived granitoids from the North China Craton including a single imprecisely dated sample at 2,374 ± 48 Ma (Liebmann et al, 2021). Nevertheless, additional data of early Paleoproterozoic metasediment-derived granitoids from other cratons are needed to constrain the aforementioned uncertainties.…”

Detrital Zircon Geochronology of the Volyn-Orsha Sedimentary Basin in Western Ukraine: Implications for the Meso-Neoproterozoic History of Baltica and Possible Link to Amazonia and the Grenvillian – Sveconorwegian – Sunsas Orogenic Belt

“…For instance, 1800-1740 Ma zircons are absent in the studied sample, whereas this age interval corresponds to the time of active intraplate magmatism in the Ukrainian Shield [55,56,57]. Zircons with ages of 2150-2050 Ma are also absent in the studied sample, whereas rocks of this age are widely distributed in the Ukrainian Shield [58,59,60,61]. The studied sample contains a small number of ca.…”

Large igneous provinces track fluctuations in subaerial exposure of continents across the Archean–Proterozoic transition

“…Furthermore, continental flood basalts that erupted in submarine environments are common in the Archean and Palaeoproterozoic, but are rare to absent in the Phanerozoic (Arndt, 1999; Kump & Barley, 2007). A spatially extensive emergence of continents above sea level in the early Palaeoproterozoic era has been inferred from multiple lines of evidence, including a change in the oxygen isotopic ratios of shales (2.43–2.31 Ga; Bindeman et al, 2018) and sediment‐derived melts (~ 2.4 Ga; Liebmann et al, 2021; Spencer et al, 2019), and a 2.5–2.2 Ga increase in 87 Sr/ 86 Sr ratios of marine carbonate implying increasing continental influence on ocean chemistry through crustal erosive run‐off (Chen et al, 2022; Flament et al, 2013; Shields & Veizer, 2002). Furthermore, the volcano‐sedimentary record of cratons that make up parts of the present‐day continents of Africa, India, Australia, North and South America, and Europe indicate a rapid increase in freeboard at ~2.4 Ga (Eriksson et al, 1999; Eriksson & Condie, 2014).…”

“…isotopic ratios of shales (2.43-2.31 Ga; Bindeman et al, 2018) and sediment-derived melts (~ 2.4 Ga; Liebmann et al, 2021;Spencer et al, 2019), and a 2.5-2.2 Ga increase in 87 Sr/ 86 Sr ratios of marine carbonate implying increasing continental influence on ocean chemistry through crustal erosive run-off (Chen et al, 2022;Flament et al, 2013;Shields & Veizer, 2002). Furthermore, the volcanosedimentary record of cratons that make up parts of the present-day continents of Africa, India, Australia, North and South America, and Europe indicate a rapid increase in freeboard at ~2.4 Ga (Eriksson et al, 1999;Eriksson & Condie, 2014).…”