Despite it’s critical role in the global carbon cycle, data documenting organic carbon oxidation and silicate weathering rates within rivers and their floodplains are rare, and the mechanisms controlling total silicate weathering and oxidative losses from sediment source to sink are poorly understood. We are currently performing a combination of laboratory flume experiments and targeted field measurements designed to disentangle weathering occurring in active river transport versus during temporary deposition in floodplains. Because organic carbon loading of sediments tends to increase with decreasing grain size, we are measuring the grain size distribution of our samples in the Sediment Laboratory to correct for any grain-size dependencies that exist. The results will elucidate the major mechanistic controls on silicate weathering and organic carbon oxidation in fluvial transit from source to sink, and allow for building process-based models linking sediment transport, organic carbon oxidation, and silicate weathering capable of predicting the influence of changing tectonic and climatic regimes on the global carbon cycle.
Principal Investigators
- Joel Scheingross
- Niels Hovius
- Dirk Sachse
Associates
- Marisa Repasch & Jens Turowski
- Hella Wittmann-Oelze (Earth Surface Geochemistry)
- Andrea Vieth-Hillebrand (Organic Geochemistry)
- Anja Schleicher (Inorganic and Isotope Geochemistry)
- Ricardo Szupiany (National University of the Littoral and National Council of Scientific and Technical Research, Santa Fe, Argentina)
- Oscar Orfeo (Center of Applied Ecology of the Littoral, National Council of Scientific 14and Technical Research, Corrientes, Argentina)
- Tim Eglinton & Maarten Lupker (Biogeoscience Group, Geological Institute, ETH Zürich, Switzerland)
- Robert Hilton, Mathieu Dellinger & Darren Gröcke (Department of Geography, University of Durham)
- Margret Fuchs (Helmholtz-Zentrum Dresden-Rossendorf)
