The low temporal completeness of fluvial strata could indicate that recorded events represent unusual and extreme conditions. However, field observations suggest that preserved strata predominantly record relatively common transport conditions—a paradox termed the strange ordinariness of fluvial strata. We theorize that the self-organization of fluvial systems into a morphodynamic hierarchy that spans bed to basin scales facilitates the preservation of ordinary events in fluvial strata. Using a new probabilistic model and existing field and experimental data sets across these scales, we show that fluvial morphodynamic hierarchy enhances the stratigraphic preservation of medial topography—ordinary events. We show that lower-order landforms have a higher likelihood of complete preservation when the kinematic rates of evolution of successive levels in the morphodynamic hierarchy are comparable. We highlight how relative changes in kinematic rates of evolution of successive levels in the morphodynamic hierarchy can manifest as major shifts in stratigraphic architecture through Earth history.
Bibliographical noteFunding Information:
We thank Woodward Fischer for useful discussions and Rob Duller and an anonymous reviewer for constructive reviews. This work was supported by a National Science Foundation grant to Ganti (EAR 1935669) and Hajek (EAR 1935513) and by the donors of the American Chemical Society Petroleum Research Fund to Ganti.
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- alluvial stratigraphy
- channel bars
- river kinematics