<p>I hiked the Lanikai Pillbox trail (<a href="https://www.google.com/maps/place/Lanikai+Pillbox/@21.3893391,-157.716528,16.75z/data=!4m13!1m7!3m6!1s0x7c0014f892682f7f:0xec50e2c96a16e2b1!2sLanikai+Beach!3b1!8m2!3d21.3925378!4d-157.7151208!3m4!1s0x7c0014f7ab4d2761:0xc586727ccfefbd4a!8m2!3d21.3855953!4d-157.7166534" rel="nofollow noreferrer">Oahu, HI</a>). I noticed eroded concentric rings in the igneous rock with a hard center. I'm unable to find the geologic cause of these rings. Are they Liesegang rings? There were several instances (~20) I observed on the hike.</p>
<p><a href="https://i.sstatic.net/OvPtt.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/OvPtt.jpg" alt="Concentric rings in igneous rock in Oahu, HI hike." /></a></p>

CC BY-SA 4.0
2021-04-13T20:06:33.433Z
Maybe try to crash it with a hammer and see what is inside the hard center? By the way, it looks like the model of a cell : )
User123
CC BY-SA 4.0
2021-04-14T08:59:10.593Z
It's unlikely to [Liesegang rings](https://en.wikipedia.org/wiki/Liesegang_rings_(geology)), they are colored rings which *usually* occur in sedimentary rocks. They can occur in permeable igneous rocks that have been chemically weathered, where they appear as rings of iron oxide. I don't see any significant color differences in your picture.
Fred
CC BY-SA 4.0
2021-04-14T09:02:45.277Z
Query: Is the circular rock, at the center of the ringed structure, flat or domed?
Fred
CC BY-SA 4.0
2021-04-14T11:47:49.923Z
@Fred circular rock is slightly domed.
user3424230
<geology><petrology><igneous><weathering>
Are these igneous Liesegang rings on a popular Oahu, Hawaii hike?
user3424230
# Are these igneous Liesegang rings on a popular Oahu, Hawaii hike?

(Asked by: username_0 on 2021-04-13)

I hiked the Lanikai Pillbox trail ([Oahu, HI](https://www.google.com/maps/place/Lanikai+Pillbox/@21.3893391,-157.716528,16.75z/data=!4m13!1m7!3m6!1s0x7c0014f892682f7f:0xec50e2c96a16e2b1!2sLanikai+Beach!3b1!8m2!3d21.3925378!4d-157.7151208!3m4!1s0x7c0014f7ab4d2761:0xc586727ccfefbd4a!8m2!3d21.3855953!4d-157.7166534)). I noticed eroded concentric rings in the igneous rock with a hard center. I'm unable to find the geologic cause of these rings. Are they Liesegang rings? There were several instances (~20) I observed on the hike.

[![Concentric rings in igneous rock in Oahu, HI hike.](https://i.sstatic.net/OvPtt.jpg)](https://i.sstatic.net/OvPtt.jpg)

**Tags:** geology, petrology, igneous, weathering

> **Comments:**
> **username_1**: Maybe try to crash it with a hammer and see what is inside the hard center? By the way, it looks like the model of a cell : )  
> **username_2**: It's unlikely to [Liesegang rings](https://en.wikipedia.org/wiki/Liesegang_rings_(geology)), they are colored rings which *usually* occur in sedimentary rocks. They can occur in permeable igneous rocks that have been chemically weathered, where they appear as rings of iron oxide. I don't see any significant color differences in your picture.  
> **username_2**: Query: Is the circular rock, at the center of the ringed structure, flat or domed?  
> **username_0**: @username_2 circular rock is slightly domed.  

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## 0 answers

