<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=US-ASCII" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 9.00.8112.16443"></HEAD> <BODY style="FONT-FAMILY: Arial; COLOR: #000000; FONT-SIZE: 10pt" id=role_body bottomMargin=7 leftMargin=7 rightMargin=7 topMargin=7><FONT id=role_document color=#000000 size=2 face=Arial> <DIV>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:</DIV> <DIV> <BLOCKQUOTE style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><FONT style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Tahoma>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?<BR><BR>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.</FONT></BLOCKQUOTE>In reply, I submit this:</DIV> <DIV> </DIV> <DIV>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.)</DIV> <DIV> </DIV> <DIV>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):</DIV> <DIV> </DIV> <DIV>Hole number/location/sinter thickness in feet/underlying strata</DIV> <DIV> </DIV> <DIV>Carnegie 1 (Fenner, 1929)/Myriad Group/~7 (20 according to Allen and Day)/cemented and altered sand and gravel</DIV> <DIV>Y-1/ Black Sand (Whistle)/11.5/obsidian rich sediment, generally zeolitized and cemented</DIV> <DIV>Y-2/Firehole Lake/33.5 including travertine/altered sand, gravel and tuff</DIV> <DIV>Y-3/Ojo Caliente/none/altered silt, sand and gravel</DIV> <DIV>Y-4/Nez Perce quarry/none/rhyolite flow at surface</DIV> <DIV>Y-5/Rabbit Creek (old dump)/none/sand and gravel</DIV> <DIV>Y-7/Biscuit parking, north end/5.5/partly altered and cemented silt, sand and gravel</DIV> <DIV>Y-8/Biscuit near Rusty/~5/cemented sand and gravel</DIV> <DIV>Y-13/Porcupine Hills/7/glacial sand and gravel</DIV> <DIV> </DIV> <DIV>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.</DIV> <DIV> </DIV> <DIV>Scott Bryan</DIV> <DIV> </DIV> <DIV>P.S. And definitely, thanks for the video, Jake.</DIV></FONT></BODY></HTML>