My name is Shelby Gunnells and I am a senior geology student at North Dakota State University. This past summer I worked with Dr. Colleen Hoffman in the Bundy lab on characterizing the metals and organics found within a chimney sample from the Lost City Hydrothermal Field.
Most hydrothermal systems are found on mid-ocean ridge spreading centers and are driven by magmatic processes. Lost City is a unique hydrothermal field in that it has formed 15 km off axis from the Mid-Atlantic Ridge and is dominated by a process called serpentinization. From previous studies, we know this process results in hydrated minerals that are low in metal concentrations.
Our objective was to quantify the labile (or easily extractable) trace metals within the chimney, identify metal-binding organic compounds, and to determine the ligand concentrations in the vent fluids. This would allow for a complete picture of the hydrothermal system from its composition on the seafloor to the seawater it produces. Each of these sets of data utilized separate methods, which allowed for great experience in using various techniques, equipment, and software.
After performing these methods, we reaffirmed the claim that Lost City is low in metal concentrations. However, we were surprised to find that the chimney sample was high in metal-binding organic compounds, a test that has never been run in this hydrothermal location before. What does this mean? Organic compounds bind to trace metals and keep them in the dissolved phase when they would otherwise likely precipitate. As such, this binding serves as a transportation mechanism for dissolved metals to circulate throughout the ocean, a very important feature considering some trace metals are critical micronutrients in an organism’s diet.
Through my research this summer, I gained incredible research experience while studying an extremely interesting seafloor environment that wouldn’t be possible in the Midwest. After not having an extensive research background, I was able to immerse myself into a typical science experiment, albeit fast-paced, and see what the process is like. Through this all, I had great support and encouragement from every member of the Bundy lab and from all the fellow interns.