Yup, and people do not realize how lucky folks were the Teton Dam collapsed while being filled instead of 130' below the top. The next 100' was a Hell of a lot more water than the first.
There was also similar "bedrock" there that was the problem. And it was volcanic tuff as I recall with better properties than foliated basalt.
That's an interesting statement, since basalt can't be foliated - it's igneous. But never mind that - the bedrock at Teton wasn't tuff anyway, it was rhyolite, as is much of the bedrock in Idaho.
The fact is that the bedrock at Teton had fissures (typical of rhyolite) that weren't grouted sufficiently (if that is even possible), and the dam failed from low on one side. So the bedrock under Teton dam was not better than, or even similar to, what is under Oroville. And the dynamics of that dam failure were not in any way comparable to what is happening at Oroville (at this time).
