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"?