Hydrodynamic controls on the evolution of bed forms and resulting cross-stratification
Sedimentary rocks are the archives of environmental conditions and ancient planetary surface processes that led to the formation of stratified rock. The geometry of sedimentary strata, thus, provide records of the sedimentary environments that once existed on Earth and Mars, for example. Self-organized landform patterns (e.g., ripples, dunes, bars, meanders) are common on Earth and other planets and arise from the fundamental coupling among bed topography, sediment transport, and flow dynamics – morphodynamics. The migration of these landforms leaves behind distinct geometrical features in the sedimentary rock record that provide natural records of ancient surface conditions. The geometry of sedimentary rock bodies is determined by movement of landforms, including any changes in their shape and/or direction of travel. The goal of our research is to understand how the shape of sedimentary rock bodies (and the surfaces that bound it) record the kinematics of landform evolution. Using physical experiments and field observations, we aim to: (1) derive general relations among morphology, dynamics of surface evolution, and the stratal geometry, and (2) to understand the environmental and hydrodynamic controls on the dynamics of self-organized landform patterns. Our work has implications for predicting sediment flux in modern and ancient environments from bed form kinematics and deposits, constraining source-to-sink sediment transfer in ancient sedimentary environments, and decoding the hydrological history of Earth and Mars.
Selected Articles on this Topic
- Mahon, R. C., V. Ganti, B. McElroy, and J. B. Shaw, Semi-empirical model for curvature of fluvial bed form cross set bounding surfaces, J. Geophys. Res. – Earth Surf., under review.
- Ganti, V., M. P. Lamb, and B. McElroy (2014), Quantitative bounds on morphodynamics and implications for reading the sedimentary record, Nature Comm., 5:3298, doi:10.1038/ncomms4298.
- Ganti, V., C. Paola, and E. Foufoula-Georgiou (2013), Kinematic controls on the geometry of the preserved cross-sets, J. Geophys. Res. – Earth Surf., 118, 1296–1307, doi:10.1002/jgrf.20094.