Open AccessIntensified Ocean Deoxygenation During the end Devonian Mass Extinction
Author(s) -
Liu Jiangsi,
Luo Genming,
Lu Zunli,
Lu Wanyi,
Qie Wenkun,
Zhang Feifei,
Wang Xiangdong,
Xie Shucheng
Publication year - 2019
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2019gc008614
Subject(s) - extinction event , geology , conodont , carbonate , devonian , extinction (optical mineralogy) , late devonian extinction , paleontology , carbonate platform , isotopes of oxygen , permian–triassic extinction event , water mass , isotopes of carbon , carboniferous , oceanography , ecology , total organic carbon , geochemistry , chemistry , facies , biostratigraphy , biology , biological dispersal , population , demography , organic chemistry , structural basin , sociology
The end‐Devonian mass extinction (~359 Ma) substantially impacted marine ecosystems and shaped the roots of modern vertebrate biodiversity. Although multiple hypotheses have been proposed, no consensus has been reached about the mechanism inducing this extinction event. In this study, I/Ca ratio of carbonate was used to unravel the changes in local oxygen content of the upper water column during this critical interval. The Devonian‐Carboniferous boundary was recorded in two shallow water carbonate sections in south China. I/Ca values at both locations show a clear decline in the Middle and Upper Siphonodella praesulcata conodont zones, which coincides with a positive shift in carbonate carbon isotope composition and a negative shift in nitrogen isotope composition. These results suggest that deoxygenation was intensified during this critical interval, which likely influenced shallow water habitats, lending support to the notion that oxygen deficiency likely was a direct mechanism impacting the end‐Devonian mass extinction.