EXPERIMENTAL DESIGN TO CULTURE ORGANISMS FOR SUBSEQUENT TRACE ELEMENT ANALYSES

Constraining the marine chemical evolution of certain elements throughout Earth history is widely applied through various techniques. However, many micronutrients that are redox‑sensitive have been constrained for punctuated events indirectly as they are inferred from black shale enrichments. Paleoclimate studies have utilized foraminiferal elemental concentrations that were incorporated during original precipitation. Additionally, it has been documented that foraminiferal trace metal concentrations increase due to anthropogenic release of toxic elements that have detrimental effects. Here, we are testing the utility of foraminifera to track the global seawater trace metal inventory using a controlled culture experiment. We will present new results from culturing Ammonia tepida under different marine trace metal concentrations of molybdenum at 10, 50, 100 and 200 percent of the modern inventory for approximately four weeks under well‑controlled growing conditions. This will be the first study to assess the viability of using well‑preserved foraminifera as a proxy to reconstruct the marine trace metal concentration of redox‑sensitive elements. Future work will require additional growth experiments for various durations, different redox‑sensitive elements, and additional foraminiferal species.