Triggers of widespread anoxia in the Western Interior Seaway during Oceanic Anoxic Event 2

Anthropogenic activity has affected the world’s oceans in various ways, causing warming, acidification and deoxygenation. Mechanisms driving and maintaining the latter can be understood by studying similar changes that occurred in the Earth’s past. This palynological study of Mid-Cretaceous (~94Ma) sediments from northern Canada sheds light on the drivers of anoxia and its development at higher latitudes. Changes in the palynological assemblages indicate that increased density stratification, through enhanced freshwater input and precipitation, were presumably the most important drivers. Changes in sea-level may have enhanced or counteracted the effects of stratification