It staggers anyone’s sense of time and space. I am compelled to read about it over and over and over again after I get home from my May 2015 raft trip down the Colorado River. It takes quite a bit of “Wait. What?” before I can even begin to wrap my mind around its significance. It is the Grand Canyon Supergroup, gently tilted and isolated remnant wedges of the oldest limestones, sandstones, siltstones, mudstones, and basalts found in Grand Canyon. We are talking about sedimentary rocks that are more than a billion years old.
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| Finding the Grand Canyon Supergroup (click on any pic to enlargenate |
