Constraining Silicate Weathering During the Middle Eocene Climatic Optimum (MECO) Using Radiolarian Ge/Si

Olivia R. Laub, Utah State University


Silicate weathering has long been considered a fundamental component of the earth system and has been cited as one of, if not the primary stabilizing feedback for climate. However, recent work has shown that the role of silicate weathering in the climate system is more complicated and dynamic than previously assumed. In this study I examine the role of weathering in the enigmatic warming event, the Middle Eocene Climatic Optimum (MECO) that occurred approximately 40 Ma. This event works as a good case study as there are multiple features of the MECO that differentiate it from other warming events that occur around the same time. Using a relatively neglected proxy, the ratio of germanium to silicon (Ge/Si) of siliceous microfossils, I show that silicate weathering does not always correlate with temperature. I suggest that weathering may have instead been the driver of the observed warming during the MECO. This study will increase our understanding of not only the Earth’s response to a singular warming event, but also provide context for how the Earth is and will continue to respond to rising temperatures due to current carbon emissions.