[GRASSLIST:3115] Re: A few questions for making geology in Grass.

[Roger Miller]

On Sunday 10 February 2002 19:01, Antonio wrote:

> I was wondering if a few tasks could be achieved in grass mainly inherint
> to geological problems.
>
> a) Is there some site on the internet where I can find some icons a docs on
> how to implement geological symbols for maps in grass, for example, icons
> for structural inclinations and dips?

I don't know of any internet sources.  You can construct your own icons using 
ps.icon and place them on a map using ps.map, but you would not be able to 
rotate those icons to match the measured orientations.  Perhaps you could 
construct a different icon for each 5-degreee increment (for instance) of 
orientation and use those, but it would be work-intensive.

> b) Is it possible to overlay a
> litological raster map over a DTM in d.3d or nviz? 

Yes, using nviz.   It should give a great-looking illustration.

c) Is it possible to
> gain geological sections of a region in some manner in grass?

It is possible to cut vertical sections through 3-d objects built with g3d.  
G3d is hard to work with and it would be difficult to get something that 
looks like a geologic section.  I used G3d with model-generated data on 
ground water contaminant plumes and got some very illustrative views.  With 
enough data g3d would probably work very well to illustrate complex objects 
like ore bodies or maybe oil reservoirs.


Roger Miller