Megafan and fans sedimentology

Anne Mather, Laura Evenstar, Adrian Hartley

Landforms described as alluvial fans/megafans form across a spectrum of spatial (a few km2 to >1000km2 ) and temporal (century to millennial) scales. They are just one part of a system which comprises a catchment area and an associated depositional fan body. Within sedimentary basins it is typically the larger fan systems that are most likely to be preserved over the longest time-scales, and provide the longest, though not necessarily most complete sedimentary record. Often, particularly on large systems, the catchment area may have a very different climate to the associated fan depositional body. The fan depositional processes thus provide a valuable record of the catchment area characteristics such as mountain range climate, whilst the internal stratigraphy of the fan may reflect forcing factors such as significant catchment changes (e.g river capture; climate change) and piedmont tectonics. Alluvial fan systems are consequently powerful records of longer-term landscape change. We encourage papers on any aspect of fans and megafans embracing field, laboratory, theoretical, and numerical approaches intended to advance our knowledge of how to unlock the potential from alluvial fan archives. In particular we encourage contributions addressing sedimentary process and scaling relationships across fan systems and novel quantitative approaches to better understanding fan despositional systems.