Paleoproductivity drivers in the Banggai Waters, Sulawesi, Indonesia: Insights from elemental analysis of marine surface sediment

Abstract

Marine productivity, a pivotal factor in marine ecosystems and global carbon cycling, is influenced by various factors including upwelling and terrigenous nutrient influx. We investigated past marine productivity in Banggai Waters, Indonesia, using sediment samples (BUDEE22-29BC and BUDEE22-57BC) and Micro X-Ray Fluorescence (micro-XRF) analyses. Geochemical proxies (K/Ti, Ba/Al, and Zr/Al) help to assess terrigenous influx, upwelling events, and paleoproductivity. Our methodology categorizes productivity into upwelling-driven (UPW), terrigenous influx-driven (TER), and TUP (combined). The incorporation of geochemical proxy data has enabled a comprehensive understanding of historical marine productivity patterns. In BUDEE22-29BC, the K/Ti ratio initially rises and then falls below its threshold, whereas Ba/Al shows spikes and declines before rising again. Zr/Al ratios vary across depths, indicating different paleoproductivity drivers such as terrigenous influence and upwelling. BUDEE22-57BC displayed similar trends in K/Ti, Ba/Al, and Zr/Al ratios, with fluctuations indicating changes in paleoproductivity drivers, including mixing and upwelling effects. The unique positioning of Banggai Waters allows interactions between upwelling, terrigenous influx, and productivity. This study lays the groundwork for further research on past productivity changes and their drivers, thereby enhancing our understanding of marine dynamics.