<p>Molten rock must be a liquid, mobile rock is any rock capable of moving, sand and mud can be mobile. </p>

CC BY-SA 4.0
2020-01-20T14:09:50.157Z
So, sand or mud (mobile rocks) can form intrusions also, right?
Diksha
CC BY-SA 4.0
2020-01-20T14:35:49.517Z
yes, you may want to look up mud volcanoes and sand volcanoes.
John
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2020-01-20T13:16:38.823Z
2020-01-20T13:16:38.823Z
John
<p>I believe the author's was referring to phenomena like salt diapirs (where mobile salt deposits intrude into heavier overlying sediments).  These produce low hills in the gulf coast region of the United States.  The salt that is moving is not liquid, it is merely mobile.</p>

<p>I do not believe the author of the book you reference was referring to sand and mud diapirs as these deposits are not considered "rocks".</p>

CC BY-SA 4.0
2020-01-26T04:12:20.177Z
2020-01-26T04:51:37.120Z
2020-01-26T04:51:37.120Z
verisimilidude
<p>In the book <a href="https://rads.stackoverflow.com/amzn/click/com/0415567750" rel="nofollow noreferrer" rel="nofollow noreferrer">Fundamentals of Geomorphology (Routledge Fundamentals of Physical Geography)</a> by  Richard John Huggett there is a  sentence " Intruded rocks, which must be mobile but not necessarily molten, may have a direct effect on landforms by causing doming of the surface." What is the difference between molten &amp; mobile rock?</p>

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2020-01-20T16:40:51.127Z
You were far too quick to accept the one answer you received, an answer that completely misses the mark.
David Hammen
CC BY-SA 4.0
2020-01-21T03:47:19.827Z
Okay. I didn't about an important point being missed. Apologies. How would you improve this?
Diksha
<geology><volcanology><petrology><igneous>
What is the difference between mobile & molten rock?
Diksha
# What is the difference between mobile & molten rock?

(Asked by: username_0 on 2020-01-20)

In the book [Fundamentals of Geomorphology (Routledge Fundamentals of Physical Geography)](https://rads.stackoverflow.com/amzn/click/com/0415567750) by Richard username_2 Huggett there is a sentence " Intruded rocks, which must be mobile but not necessarily molten, may have a direct effect on landforms by causing doming of the surface." What is the difference between molten & mobile rock?

**Tags:** geology, volcanology, petrology, igneous

> **Comments:**
> **username_1**: You were far too quick to accept the one answer you received, an answer that completely misses the mark.  
> **username_0**: Okay. I didn't about an important point being missed. Apologies. How would you improve this?  

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## 2 answers

### Answer by username_2 on 2020-01-20. Score: 2

Molten rock must be a liquid, mobile rock is any rock capable of moving, sand and mud can be mobile.

> **Comments:**
> **username_0**: So, sand or mud (mobile rocks) can form intrusions also, right?  
> **username_2**: yes, you may want to look up mud volcanoes and sand volcanoes.  

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### Answer by username_3 on 2020-01-26. Score: 1

I believe the author's was referring to phenomena like salt diapirs (where mobile salt deposits intrude into heavier overlying sediments). These produce low hills in the gulf coast region of the United States. The salt that is moving is not liquid, it is merely mobile.

I do not believe the author of the book you reference was referring to sand and mud diapirs as these deposits are not considered "rocks".


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