Sediment cores at sites J1002 and J1007 were collected from the Chilean Margin during D/V JOIDES Resolution Expedition 379T (JR100) in 2019. Sedimentary Green/Blue (G/B) ratio and sedimentary U/Th derived from natural gamma radiation data were collected during the expedition. We generated age models for sites J1002 and J1007 with radiocarbon dates and visual correlation of δ18O records of benthic foraminifera to the LR04 benthic stack. Measured biogenic opal contents and organic carbon contents were compared to the G/B to test the utility of G/B as a proxy for diatom productivity at Sites J1002 and J1007. Sedimentary U/Th was further used as a non-quantitative indicator of redox conditions of the sediments. Lastly, we calculated the opal mass accumulation rate (MAR) at Site J1007 over the last ~150,000 years. Laboratory measurements in this study were conducted in 2020 at Rutgers University.

Further funding: NETL Methane Hydrates Fellowship Program