<p>Also keep in mind that <em>eluvium</em> and <em>eluvial</em> have a different meaning in soil science.  There, it means leaching of soil matter or chemical substances by water.  (Usually, after some downward transport, the substances precipitate in an <em>iluvial</em> horizon.)</p>

CC BY-SA 3.0
2015-04-23T23:40:04.913Z
and in spodosols one gets an _eluvial_ depleted horizon, often pure white quartz, and an _illuvial_ precipitated horizon below it, often dark red or even purple. Very striking in cross-section.
cphlewis
CC BY-SA 3.0
2015-04-20T14:39:04.823Z
2015-04-20T14:39:04.823Z
Florian Jenn
<p>It's also worth noting that Eluvial soil is moved by water, but not necessarily river water.  The geotech reporting on my hillside property which has no river on it, but experiences significant shift of soil when it rains due to the property's location in a trough (basically a topography-scale gutter on a hillside).  Basically, there's a lot of run-off down the mountainside through the property which shifts the soil on the property over time due to the impact of rain storms.  He referred to the displaced earth as el</p>

CC BY-SA 4.0
2018-09-08T00:02:34.147Z
2018-09-08T00:02:34.147Z
Dan B
<p>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.</p>
<p>Indeed, looking at the Wikipedia articles, the definitions sound identical to my (expertly untrained) ears:</p>
<blockquote>
<p><strong>Alluvium:</strong> 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.</p>
<p><strong>Eluvium:</strong> geological deposits and soils that are derived by in
situ weathering or weathering plus gravitational movement or
accumulation.</p>
</blockquote>
<p>So, both of these sound like soil and sediments, eroded and deposited. But obviously, they can't be the same thing.</p>
<p>What's the difference? How can I tell the difference if I see it &quot;in the wild&quot;?</p>

<geology><sedimentology><terminology>
What is the difference between eluvium and alluvium?
Richard
# What is the difference between eluvium and alluvium?

(Asked by: username_0 on 2014-11-25)

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"?

**Tags:** geology, sedimentology, terminology


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## 2 answers

### Answer by username_1 on 2015-04-20. Score: 7

Also keep in mind that *eluvium* and *eluvial* have a different meaning in soil science. There, it means leaching of soil matter or chemical substances by water. (Usually, after some downward transport, the substances precipitate in an *iluvial* horizon.)

> **Comments:**
> **username_2**: and in spodosols one gets an _eluvial_ depleted horizon, often pure white quartz, and an _illuvial_ precipitated horizon below it, often dark red or even purple. Very striking in cross-section.  

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### Answer by username_3 on 2018-09-08. Score: 0

It's also worth noting that Eluvial soil is moved by water, but not necessarily river water. The geotech reporting on my hillside property which has no river on it, but experiences significant shift of soil when it rains due to the property's location in a trough (basically a topography-scale gutter on a hillside). Basically, there's a lot of run-off down the mountainside through the property which shifts the soil on the property over time due to the impact of rain storms. He referred to the displaced earth as el


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