[Geysers] North Goggles Major and Goggles Spring -- 4/22/2012 @ 1950

[TSBryan at aol.com]

A portion of what Jeff Cross wrote regarding the depth of UGB/Geyser Hill  
sinter, the location of possible reservoirs, and etc., is as follows:
 
I've  always wondered what the boundary between the deepest sinter and the 
bedrock  of Geyser Hill looks like. This was the surface across which the 
first hot  spring waters flowed when Geyser Hill began to form. Today, that 
surface is  doubtless buried deep beneath the surface. But how deep?

It's also  occurred to me that the sinter-bedrock plane could be a good 
place to form a  large, open cavity that could serve as a geyser reservoir, and 
that the  ejection of rocks from this level would be a process that would 
form such a  cavity.
In reply, I submit this:
 
I sincerely doubt that there are reservoirs of any size located at or  near 
the "boundary" between surface sinter and any underlying sediments. Reason: 
 that interface is simply not "buried deep beneath the surface." In all 
known  cases, the thickness of sinter is only a few feet (when there is any at 
all).  (As for the case in point around North Goggles Geyser, I'd bet the 
thickness is  a handful of feet at most and there most definitely is no 
reservoir  there.)
 
I submit the data (only for holes actually drilled within thermal areas in  
the Firehole Basins), taken from White, et al. ("Physical Results of 
Research  Drilling...", USGS Professional Paper 892):
 
Hole number/location/sinter thickness in feet/underlying strata
 
Carnegie 1 (Fenner, 1929)/Myriad Group/~7 (20 according to Allen and  
Day)/cemented and altered sand and gravel
Y-1/ Black Sand (Whistle)/11.5/obsidian rich sediment, generally zeolitized 
 and cemented
Y-2/Firehole Lake/33.5 including travertine/altered sand, gravel and  tuff
Y-3/Ojo Caliente/none/altered silt, sand and gravel
Y-4/Nez Perce quarry/none/rhyolite flow at surface
Y-5/Rabbit Creek (old dump)/none/sand and gravel
Y-7/Biscuit parking, north end/5.5/partly altered and cemented silt, sand  
and gravel
Y-8/Biscuit near Rusty/~5/cemented sand and gravel
Y-13/Porcupine Hills/7/glacial sand and gravel
 
The balance of evidence is that there are NO large, open reservoirs  
anywhere in a geyser's system. Certainly, there are some more-or-less open  
channels, but apparently most of a geyser's (indeed, a thermal area's)  
"reservoir" is permeable rock that can be hundreds, perhaps thousands, of feet  below 
the surface.
 
Scott Bryan
 
P.S. And definitely, thanks for the video, Jake.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: </geyser-list/attachments/20120425/7e40af57/attachment.html>