TY - JOUR
T1 - Coupling sulfur and oxygen isotope ratios in sediment melts across the Archean-Proterozoic transition
AU - Liebmann, Janne
AU - Spencer, Christopher J.
AU - Kirkland, Christopher L.
AU - Bucholz, Claire E.
AU - Xia, Xiao Ping
AU - Martin, Laure
AU - Kitchen, Nami
AU - Shumlyanskyy, Leonid
PY - 2021/8/15
Y1 - 2021/8/15
N2 - 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 δ18O 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 Δ33S ranging from −0.29‰ to 0.13‰, whereas post-2.3 Ga granitoids record S-MDF (i.e. Δ33S = 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.
AB - 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 δ18O 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 Δ33S ranging from −0.29‰ to 0.13‰, whereas post-2.3 Ga granitoids record S-MDF (i.e. Δ33S = 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.
KW - Archean Proterozoic boundary
KW - Atmospheric oxygenation
KW - Continental emergence
KW - Great Oxygenation Event
KW - Multiple sulfur isotopes
KW - Oxygen Isotopes
KW - S-type granites
KW - Strongly peraluminous granites
UR - http://www.scopus.com/inward/record.url?scp=85109065951&partnerID=8YFLogxK
U2 - 10.1016/j.gca.2021.05.045
DO - 10.1016/j.gca.2021.05.045
M3 - Article
AN - SCOPUS:85109065951
SN - 0016-7037
VL - 307
SP - 242
EP - 257
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
ER -