Progressive development of ocean anoxia in the end-Permian pelagic Panthalassa

The end-Permian mass extinction (EPME) has been linked with the widespread development of oxygen-poor oceanic conditions. However, information on spatial extent anoxia in Panthalassa super-ocean limited. This study reports redox records from a deep-sea chert succession (the Waiheke 1 section, WHK 1, New Zealand) that was located southern mid-latitudes Panthalassa. High-resolution carbon isotope (δ13C) correlation between and Permian-Triassic boundary (PTB) type section indicates EPME is recorded thin black claystone interbedded siliceous mudstone beds at 1. Pyrite-dominated enrichment highly reactive iron, coupled elevated U/Al Mo/Al ratios, are prevalent through this bed overlying Permo-Triassic transition strata, suggesting euxinic water column Similar variations across horizon have reported other Panthalassic PTB sections. Comparison these sections conditions were low-latitude regions Panthalassan ocean, such developed earlier than mid-latitude settings, up to 100,000 years before EPME. suggests there gradual expansion ocean low middle-high latitude during transition. resulted decrease seawater inventory sensitive trace metals (e.g., Mo), which evident earliest Triassic strata studied coincides extreme climate warming associated effects changes circulation, marine eutrophication intensified by terrestrial weathering) likely critical triggers for deoxygenation.