Editing Alluvium (section)

==Definitions==
The present [[Scientific consensus|consensus]] is that "alluvium" refers to loose [[sediments]] of all types deposited by running water in [[floodplains]] or in [[alluvial fans]] or related [[landforms]].<ref name=dictalluvium/>{{sfn|Allaby|2013|loc="alluvial"}}<ref name=Miller2020>{{cite journal |last1=Miller |first1=Bradley A. |last2=Juilleret |first2=Jérôme |title=The colluvium and alluvium problem: Historical review and current state of definitions |journal=Earth-Science Reviews |date=October 2020 |volume=209 |pages=103316 |doi=10.1016/j.earscirev.2020.103316|bibcode=2020ESRv..20903316M |doi-access=free }}</ref> However, the meaning of the term has varied considerably since it was first defined in the French dictionary of [[Antoine Furetière]], posthumously published in 1690. Drawing upon concepts from [[Roman law]], Furetière defined ''[[alluvion]]'' (the French term for alluvium) as new land formed by deposition of sediments along rivers and seas.<ref name=Miller2020/>

By the 19th century, the term had come to mean recent sediments deposited by rivers on top of older ''[[diluvium]]'', which was similar in character but interpreted as sediments deposited by [[Noah's flood]]. With the rejection by geologists of the concept of a primordial universal flood, the term "diluvium" fell into disfavor and was replaced with "older alluvium". At the same time, the term "alluvium" came to mean all sediment deposits due to running water on plains. The definition gradually expanded to include deposits in estuaries, coasts, and young rock of marine and [[fluvial]] origin.<ref name=Miller2020/>

Alluvium and diluvium were grouped as ''[[colluvium]]'' in the late 19th century. "Colluvium" is now generally understood as sediments produced by gravity-driven transport on steep slopes. At the same time, the definition of "alluvium" has switched back to an emphasis on sediments deposited by river action. There continues to be disagreement over what other sediment deposits should be included under the term "alluvium".<ref name=Miller2020/>