<p>At least in Germany, another approach is very common („Verwitterungsprofil“): the width of layers shows their competence (resistance to weathering/erosion). So competent rocks (which don’t weather easily) “stand out” opposed to soft rocks.  This is a very idealised representation of what a “real”, weatherd outcrop could look like.</p>

<p>Edited to add: my experience with “German columns” is that grain-size profiles are indicated by a labeled axis at the top or bottom (as in <a href="https://earthscience.stackexchange.com/a/3158/22">kwinkunks</a>’s answer). If there is no indication, it usually is a competence profile.</p>

CC BY-SA 3.0
2015-04-20T19:15:39.300Z
This is also true for a lot of older literature. Especially (?) Quaternary logs. It can be confusing sometimes.
user2821
CC BY-SA 3.0
2015-04-20T19:30:31.893Z
Very interesting, and very pertitent to one of my more specific interests: Alpine geology (I live on the westernmost edge of the Apennines and the Alps of the Sestri-Voltaggio area are in front of my house)!
Self-teaching worker
CC BY-SA 3.0
2015-04-21T08:30:49.810Z
In some cases, when a real outcrop is presented (instead of a idealised stratigraphic or “normal” profile), the width and shape of the layers in the colum may show the actual appearance of the profile, i.e. layers standing out, eroded parts (e.g. at the bottom by a river), etc.
Florian Jenn
CC BY-SA 3.0
2015-04-20T14:33:01.790Z
2015-04-21T08:39:51.227Z
2017-04-13T12:50:30.540Z
Florian Jenn
<p>The width of a unit in a stratigraphic column, or 'log', sometimes represents the average  grainsize of the rock. I can imagine it being keyed to some other property, but grainsize is common. You'll find lots of examples with a quick <a href="https://www.google.ca/search?q=sedimentary+log&amp;es_sm=91&amp;source=lnms&amp;tbm=isch" rel="nofollow noreferrer">search for 'sedimentary log'</a>.</p>

<p>The height of a unit typically represents thickness if the vertical axis is length, height or depth. Alternatively, if the vertical axis is time, then the height of a unit corresponds to time duration.</p>

<p>I've tried to illustrate some of the typical layouts here:</p>

<p><img src="https://i.sstatic.net/aY5kE.png" alt="Some types of stratigraphic log"></p>

<p>On a <a href="http://en.wikipedia.org/wiki/Well_logging" rel="nofollow noreferrer">wireline log</a>, the horizontal axis is some physical property such as natural gamma-ray emission rate or bulk density. Check the legend.</p>

<p>There's no reason not to represent other parameters with the horizontal axis (or the vertical one, or the colour), but then you'd need to be careful about labelling things clearly.</p>

<p>Footnote: often colour is keyed to lithology. This may or may not closely follow the grainsize. Symbols may be added to represent other relevant characteristics of the rock, such as sedimentary structures and fossils.</p>

CC BY-SA 3.0
2014-12-29T21:17:50.220Z
2014-12-29T21:17:50.220Z
Matt Hall
<p>I am trying to understand whether there is one "standard" meaning of the width of represented strata in stratigraphic columns, but I can find nothing online or in my geology books.</p>

<p>I notice that, sometimes, under stratigraphic columns there can be legenda explaining how the width of the represented strata relates to the measure of the clasts of a conglomerate, but I have also found stratigraphic columns with no stratum of conglomerate or breccia where not all the strata are equally large.</p>

<p>Is the width of strata usually an increasing function of the area occupied by the respective stratum? Can width represent other characteristics of the described stratum?</p>

CC BY-SA 3.0
2014-12-29T21:04:42.423Z
Can you clarify what you mean by 'largeness'? I think you mean width (horizontal size on the page), but it's not clear. I'll have a go at answering anyway.
Matt Hall
CC BY-SA 3.0
2014-12-29T21:45:51.110Z
Indeed. What is "largeness"?
Gimelist
CC BY-SA 3.0
2014-12-31T09:47:03.550Z
Excuse me: I didn't remember the correct English word. Edited
Self-teaching worker
<geology><measurements><stratigraphy>
Width of strata in stratigraphic column
Self-teaching worker
# Width of strata in stratigraphic column

(Asked by: username_0 on 2014-12-29)

I am trying to understand whether there is one "standard" meaning of the width of represented strata in stratigraphic columns, but I can find nothing online or in my geology books.

I notice that, sometimes, under stratigraphic columns there can be legenda explaining how the width of the represented strata relates to the measure of the clasts of a conglomerate, but I have also found stratigraphic columns with no stratum of conglomerate or breccia where not all the strata are equally large.

Is the width of strata usually an increasing function of the area occupied by the respective stratum? Can width represent other characteristics of the described stratum?

**Tags:** geology, measurements, stratigraphy

> **Comments:**
> **username_1**: Can you clarify what you mean by 'largeness'? I think you mean width (horizontal size on the page), but it's not clear. I'll have a go at answering anyway.  
> **username_2**: Indeed. What is "largeness"?  
> **username_0**: Excuse me: I didn't remember the correct English word. Edited  

---

## 2 answers

### Answer by username_1 on 2014-12-29. Score: 14 | Accepted answer

The width of a unit in a stratigraphic column, or 'log', sometimes represents the average grainsize of the rock. I can imagine it being keyed to some other property, but grainsize is common. You'll find lots of examples with a quick [search for 'sedimentary log'](https://www.google.ca/search?q=sedimentary+log&es_sm=91&source=lnms&tbm=isch).

The height of a unit typically represents thickness if the vertical axis is length, height or depth. Alternatively, if the vertical axis is time, then the height of a unit corresponds to time duration.

I've tried to illustrate some of the typical layouts here:

![Some types of stratigraphic log](https://i.sstatic.net/aY5kE.png)

On a [wireline log](http://en.wikipedia.org/wiki/Well_logging), the horizontal axis is some physical property such as natural gamma-ray emission rate or bulk density. Check the legend.

There's no reason not to represent other parameters with the horizontal axis (or the vertical one, or the colour), but then you'd need to be careful about labelling things clearly.

Footnote: often colour is keyed to lithology. This may or may not closely follow the grainsize. Symbols may be added to represent other relevant characteristics of the rock, such as sedimentary structures and fossils.


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### Answer by username_3 on 2015-04-20. Score: 5

At least in Germany, another approach is very common („Verwitterungsprofil“): the width of layers shows their competence (resistance to weathering/erosion). So competent rocks (which don’t weather easily) “stand out” opposed to soft rocks. This is a very idealised representation of what a “real”, weatherd outcrop could look like.

Edited to add: my experience with “German columns” is that grain-size profiles are indicated by a labeled axis at the top or bottom (as in [kwinkunks](https://earthscience.stackexchange.com/a/3158/22)’s answer). If there is no indication, it usually is a competence profile.

> **Comments:**
> **username_4**: This is also true for a lot of older literature. Especially (?) Quaternary logs. It can be confusing sometimes.  
> **username_0**: Very interesting, and very pertitent to one of my more specific interests: Alpine geology (I live on the westernmost edge of the Apennines and the Alps of the Sestri-Voltaggio area are in front of my house)!  
> **username_3**: In some cases, when a real outcrop is presented (instead of a idealised stratigraphic or “normal” profile), the width and shape of the layers in the colum may show the actual appearance of the profile, i.e. layers standing out, eroded parts (e.g. at the bottom by a river), etc.  

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