Wednesday, October 22, 2014

On the Road: Geo-challenge 1

Where are we?

Plants & Rocks is on vacation.  First destination was an east-west mountain range often described as an anomaly because contemporaneous ranges mostly trend southeast-northwest.  Actually there are several others like it, though not as large.  This one may have been influenced on the north by the Cheyenne Belt -- an east-west suture zone where crust was accreted to ancient North America roughly 1.5 billion years ago.
Red sedimentary beds on left are Precambrian.  They fooled all three early geological explorers.
The Precambrian core of the range is sedimentary – conglomerate, sandstone, siltstone and shale.  Sediments were deposited in a rift valley when the continent was coming apart, close to where it had been sutured.  It didn’t tear all the way, but was deep enough to accumulate 20,000+ feet of material.
Something like seven hundred million years later, the east-west mountains rose during a great regional mountain-building event (below).
Sedimentary strata on the flanks of the uplift were steeply folded, making for great scenery.  Some roads follow strike valleys between spectacular hogbacks.
The sedimentary rocks are just as wonderful on the south side of the mountains – like the ones below.
Josie Bassett ranched here at the mouth of the box canyon until she was 89.  “Independent in both action and thought, she lived life on her own terms.”


  1. Looks like Dinosaur National Monument and Flaming Gorge country to me!

    1. You got it, Garry. BTW I've been thinking about you -- wondering how you manage to post so much on road trips ... seems like quite a challenge

    2. THANKS! All the memories of my time in that very country go back to when I was ten. I still remember getting the bejeezus scared out of me at that gas station where the full-size T-Rex stature stands near the pumps. I walked over to check it out when my Dad went to pay, and the attendant triggered the deafening ROAR speaker in the belly! Never ran faster in my entire life.

    3. Great story, Richard! chuckle chuckle :-)

  2. Mostly I'm delusional and crazy. Really though, I don't post a lot when I am on a trip, mostly over the days and weeks afterward. I'm still posting on the Canada trip I finished in late July! If I get a few moments during a trip, I'll post pictures and not so much text.

  3. gorgeous geology and countryside.. thanks for posting this!

  4. Do you always look for geological locations where wild women lived - amongst famous outlaws?

  5. Amazing photos, Hollis. I hope you're having a great time on holiday. I came across a site that you might find interesting - 100 of the UKs greatest Geosites (for if you ever come across)