This year, for the first time ever, I took students to map at Block Mountain, a classic field camp mapping site near Dillon, Montana.
Here’s a quick look (enlarge it by a gazillion-fold by clicking through) of some columnar jointing in the Eocene Block Mountain basalt flow, a paleo-drainage turned mountain through the miracle of topographic inversion…
This is where it outcrops along the Burma Road… not bad at all.
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