What is the difference between eluvium and alluvium?

Question

I was reading about kimberlite on Wikipedia and it mentioned eluvium. I've heard of alluvium, alluvial fans, alluvial deposits, etc. However, when I looked up eluvium, it sounded exactly like alluvium.Indeed, looking at the Wikipedia articles, the definitions sound identical to my (expertly untrained) ears:> **Alluvium:** loose, unconsolidated (not cemented together into> a solid rock) soil or sediments, which has been eroded, reshaped> by water in some form, and redeposited in a non-marine setting.> **Eluvium:** geological deposits and soils that are derived by in> situ weathering or weathering plus gravitational movement or> accumulation.So, both of these sound like soil and sediments, eroded and deposited. But obviously, they can't be the same thing.What's the difference? How can I tell the difference if I see it "in the wild"?

Answer 1

The alluvium is water-deposited sediments typically by rivers. Conversely, eluvium is near source deposited sediments, meaning it didn't get picked up by something and transported to a new area.