Thursday, June 26, 2014

Geo 730: June 26, Day 542: Quarry Curiosity

The curiosity here is "What is actually in the quarry?" For a reason I'll show tomorrow, we didn't investigate more closely than this. (Hint: Woody Guthrie's line, "That side was made for you and me.") While I hadn't actually visited this spot since the mid to late 80's, this visit didn't help refresh my memory. What I seem to recall is that the rock that was being quarried is basalt, and that recessed area on the left in back is an interval of pillows, which had been tilted up to vertical. That would imply that the overlying, nearly horizontal beds of Lookingglass Formation in Bushnell Rock were deposited on an angular unconformity after this basalt was beveled off. However, to be clear, I'm not positive we're in the right spot here. That is, I'm sure I've seen such an outcrop and quarry, but because we didn't look any closer than this, I'm not sure this is where it is. In fact, I'm quite suspicious that the spot I'm recalling was a bit farther south, near the Wildlife Safari Fault. We didn't get there on this trip.

Photo unmodified. March 9, 2012. FlashEarth location.

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