[Geysers] Rainbow Springs question

[s at weststartv.com]

Hi Jeff,

There is an intermittent spring just in the Roaring 
Mountain area.  There is one in the far northwest corner 
of 100 Springs Plain and the third that I know of from 
observation was active in the area known as "The Gap" in 
1996-1998.  During the large expansion of the area in 1998 
it was "eaten" by another spring and lost the oily 
surface.
There were also several of the "iron oxide" type of 
springs for a short time in "The Gap".  I was also shown 
the "twig trick" by a geologist from the USGS when I was 
showing him this area.  That is how I found out that these 
three springs had "oily" deposits on them and not oxide.

Take Care,

Smokey

On Wed, 21 Mar 2007 18:08:10 -0600
  jacross <jacross at lamar.colostate.edu> wrote:
> Where are the oil springs at Norris?
> 
> While the issue is up, it is worth noting that iron 
>oxide minerals will also 
> give water an oily sheen.  You can tell whether the 
>sheen is really oil by 
> dragging a twig across the surface of the water.  If the 
>sheen breaks up into 
> cakes, it is iron-based, but if it swirls around the 
>twig without breaking up, 
> it is oil.
> 
> Jeff Cross
> jacross at lamar.colostate.edu