But there is also another definition of diluvium. Wikipedia again:The present consensus is that "alluvium" refers to loose sediments of all types deposited by running water in floodplains or in alluvial fans or related landforms.[...]. 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 and coasts and young rock of both marine and fluvial origin. Alluvium and diluvium were grouped together as colluvium in the late 19th century. However, "colluvium" is now generally understood to mean sediments produced by gravity-driven transport on steep slopes, while 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".
a term in geology for superficial deposits formed by flood-like operations of water, and so contrasted with alluvium or alluvial deposits formed by slow and steady aqueous agencies. The term was formerly given to the boulder clay deposits, which some early geologists supposed had been caused by the Noachian deluge, a concept known as flood geology or diluvialism.
In the late 20th century Russian geologist Alexei Rudoy proposed the term "diluvium" for description of deposits created as a result of catastrophic outbursts of Pleistocene giant glacier-dammed lakes in intermontane basins of the Altai.[...] The term "diluvium" in the meaning of A. N. Rudoy has become accepted, and the process of diluvial morpholithogenesis can be found in modern textbooks.
Then it gets more confusing with another -luvial word - Eluvium: In geology, eluvium or eluvial deposits are those geological deposits and soils that are derived by in situ weathering or weathering plus gravitational movement or accumulation. See also Illuvium.
The process of removal of materials from geological or soil horizons is called eluviation or leaching. There is a difference in the usage of this term in geology and soil science. In soil science, eluviation is the transport of soil material from upper layers of soil to lower levels by downward percolation of water across soil horizons, and accumulation of this material (illuvial deposit) in lower levels is called illuviation. In geology, the removed material is irrelevant, and the deposit (eluvial deposit) is the remaining material. Eluviation occurs when precipitation exceeds evaporation. A soil horizon formed due to eluviation is an eluvial zone or eluvial horizon. In a typical soil profile, the eluvial horizon refers to a light-colored zone located (depending on context and literature) either at the lower part of the A horizon (symbol: Ae) or within a distinct horizon (E horizon) below the A, where the process is most intense and rapid. Yet some sources consider the eluvial zone to be the A horizon plus the (distinct) E horizon, as eluviation technically occurs in both. The strict eluvial horizon (E horizon) is typically light gray, clay-depleted, contains little organic matter and has a high concentration of silt and sand particles composed of quartz and other resistant minerals.
