Please explain to me how you found a Plainview with a Fox Valley and Durst types in the same cache? Those types are literally thousands of years apart.
he mentioned the difference between the original archaic and paleo mines and the later mines dug by settlers (settlers' mines are surrounded by rubble, tailings and overburden from looking for silver)
i wondered about this claim too, especially since he said they were archean age, and the penokean orogeny was a paleoproterozoic event. Also, could be wrong about that specific outcrop, but the other quartzites in wisconsin like that (Baraboo Interval) are not Ordovician age, but rather first deposited with the erosion of the Penokean Mountains (dates around 1730 Ma), later metamorphosed in the Mazatzal Orogeny (around 1630 Ma), and later altered in some areas by hydrothermal events associated with later igneous activity of the Mesoproterozic (likely the Granite-Rhyolite Province event). He said something like the Penokean Range was Archean age and then somehow that took 2 billion years to erode and be deposited in ordovician seas to form the hixton - nope. EDIT - actually, just researched this a little, it appears the Hixton is not associated with the Baraboo Interval and is actually Cambrian in age, otherwise known as the Wonewoc Formation, making it unmetamorphosed as such, I suppose this is why it is referred to as a silicified sandstone. But super interesting talk. Would like to know more about these proterozoic-aged quartzite deposits across the midwest.
