<p>As far as I know the best estimate is &quot;upper mantle&quot; from <a href="https://earthandsolarsystem.wordpress.com/2012/11/24/mantle-xenoliths-a-window-into-the-interior-of-the-earth/" rel="nofollow noreferrer">mantle xenoliths</a> but that's not terribly specific. I am not sure if knowing more than that is possible right now.</p>

CC BY-SA 4.0
2023-10-04T05:06:10.640Z
2023-10-04T05:06:10.640Z
Ian
<p>Diamond is stable at high temperatures only under very high pressures. Mineral inclusions in a diamond, and the rocks in which a diamond are embedded, can offer further clues as to the depth from which the diamond came.</p>
<p>The <a href="https://en.wikipedia.org/wiki/Diamond#Geology" rel="noreferrer">Wikipedia article on diamond</a> claims &quot;A smaller fraction of diamonds (about 150 have been studied) come from depths of 330–660 km, a region that includes the transition zone. They formed in eclogite but are distinguished from diamonds of shallower origin by inclusions of majorite (a form of garnet with excess silicon). A similar proportion of diamonds comes from the <strong>lower mantle at depths between 660 and 800 km.</strong> [20]&quot; (my emphasis)</p>

CC BY-SA 4.0
2023-10-04T15:36:11.217Z
2023-10-04T15:41:46.240Z
2023-10-04T15:41:46.240Z
nigel222
<p>I wonder if this is even possible to know....</p>
<p>Do geophysicists and geologists have even a 'theoretical' idea about how deep Earth's churning of its layers goes?</p>

CC BY-SA 4.0
2023-10-04T15:11:06.380Z
The deepest we've dug is the https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole, which is 12.2km deep, or 0.42% of the way to the outer core. (Note that this doesn't actually answer any of your questions)
Mooing Duck
CC BY-SA 4.0
2023-10-04T15:16:40.073Z
I've found some [rock that originated in the outer core](https://en.wikipedia.org/wiki/Origin_of_the_Moon), possibly even the inner core
Valorum
<geology><geophysics><structural-geology><mantle><geologic-layers>
From how deep in the mantle has any rock ever been brought to the surface? Have scientists found anything they believe originated in the outer core?
Kurt Hikes
# From how deep in the mantle has any rock ever been brought to the surface? Have scientists found anything they believe originated in the outer core?

(Asked by: username_0 on 2023-10-04)

I wonder if this is even possible to know....

Do geophysicists and geologists have even a 'theoretical' idea about how deep Earth's churning of its layers goes?

**Tags:** geology, geophysics, structural-geology, mantle, geologic-layers

> **Comments:**
> **username_1**: The deepest we've dug is the https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole, which is 12.2km deep, or 0.42% of the way to the outer core. (Note that this doesn't actually answer any of your questions)  
> **username_2**: I've found some [rock that originated in the outer core](https://en.wikipedia.org/wiki/Origin_of_the_Moon), possibly even the inner core  

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## 2 answers

### Answer by username_4 on 2023-10-04. Score: 5

Diamond is stable at high temperatures only under very high pressures. Mineral inclusions in a diamond, and the rocks in which a diamond are embedded, can offer further clues as to the depth from which the diamond came.

The [Wikipedia article on diamond](https://en.wikipedia.org/wiki/Diamond#Geology) claims "A smaller fraction of diamonds (about 150 have been studied) come from depths of 330–660 km, a region that includes the transition zone. They formed in eclogite but are distinguished from diamonds of shallower origin by inclusions of majorite (a form of garnet with excess silicon). A similar proportion of diamonds comes from the **lower mantle at depths between 660 and 800 km.** [20]" (my emphasis)


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### Answer by username_3 on 2023-10-04. Score: 4

As far as I know the best estimate is "upper mantle" from [mantle xenoliths](https://earthandsolarsystem.wordpress.com/2012/11/24/mantle-xenoliths-a-window-into-the-interior-of-the-earth/) but that's not terribly specific. I am not sure if knowing more than that is possible right now.


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