METEOGENIC TRAVERTINE DEPOSITION THROUGH VARIED FLOW VELOCITIES: A MODEL OF THE FOSSIL CREEK TRAVERTINE SYSTEM IN VERDE, ARIZONA

Carbon dioxide outgassing from groundwater supersaturated with calcium carbonate is a critical driver for deposition of meteogenic travertine. Increasing the flow velocity creates turbulence, which can lead to higher rates of CO₂ outgassing. The recent decommissioning of a hydroelectric dam along the Fossil Creek (Arizona) restored previously higher baseflow conditions, creating travertine deposition along the system once more. We present a simplified numerical model of this system to predict the regrowth of the travertine deposit with the restored baseflow conditions. The model runs with critical conditions for calcite precipitation, including water temperature, atmospheric and water pressure, and water chemistry. The results of this model geometrically match the morphology of a step-pool travertine system. The calculated rates of deposition are close to values observed in the Fossil Creek and other travertine systems. Our results suggest the nature of meteogenic travertine deposition makes them sensitive to climate changes reflecting changing flow regime, thus studying ancient deposits can provide insight into high-frequency fluctuations in regional paleoclimate.