What is the difference between eluvium and alluvium?
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"?