Measuring Ancient Landscape Dynamics from Sedimentary Deposits
Internal, or autogenic, dynamics in sedimentary systems impart significant variability in sedimentation through space and time across Earth’s surface. These processes can produce depositional patterns that mimic stratigraphy generated by climate, tectonic, or eustatic forcing. Differentiating deposits that resulted primarily from internal dynamics from deposits that reflect changes in climate or tectonics is a key challenge for sedimentary geologists aiming to interpret the history of surface conditions on Earth and other planets. New methods allow us identify sedimentary deposits of stochastic sediment-transport dynamics and constrain the scales of sedimentary packages that primarily reflect changes in the balance of sediment supply and accommodation creation caused by climate, tectonic, and sea-level changes. This perspective helps us understand the scales over which climate or tectonic changes might significantly influence landscapes and leave a signature in the sedimentary record, and also allows us to reconstruct the range of autogenic dynamics that occurred on ancient landscapes. This work is useful for constraining uncertainties on paleoenvironmental reconstructions and for comparing how past landscapes responded to different types of climatic, tectonic, and land-cover changes.