Project Info

Calcite and pyrite weathering profiles in variably metamorphosed shales, East River CO

Alexis Sitchler | asitchle@mines.edu

The project objectives are to quantify depth of weathering of calcite and pyrite in the Mancos Shale formation that underlies the East River Valley, CO. In this watershed, rock weathering contributes dissolved carbon, metals, and nutrients to pore and surface waters, contributing nutrients and energy sources for microbial life. Ultimately, we want to be able to model the hydrology and geochemistry of the water shed in a way that accurately captures export of nutrients and dissolved solutes and use the model to predict how nutrient and solute export changes with perturbation in climate, land-use, or vegetation changes. By quantifying the depth of weathering we can calculate rates of mineral weathering, thus constraining rates of solute production and flux into the water. To achieve these goals, we will analyze the chemistry and mineralogy as a function of depth in four cores retrieved during well installation in the East River watershed. The cores are taken from different areas of the watershed where the Mancos Shale is variably contact metamorphosed by igneous intrusions to constrain weathering processes as a function of metamorphic gradient within the watershed.

More Information

http://watershed.lbl.gov/

https://onlinelibrary.wiley.com/doi/abs/10.1002/eco.1779

https://www.sciencedirect.com/science/article/pii/S0048969716306957?via%3Dihub

Grand Engineering Challenge: Manage the nitrogen cycle