Saturday, June 5, 2010

Mega road trip - Day 4

Today's trip was from Goodland, Kansas over the Rockies to Grand Junction, CO.  Western Kansas and eastern Colorado are indistinguishable but it is neat to finally see snowcapped mountains off in the distance after hours of driving across the high plains as we approached Denver.

One stop made today was Dinosaur Ridge just west of Denver.  It's a 2 mile round-trip walk on a paved road closed to vehicular traffic (other than the visitor center shuttle which we avoided), which goes up and around a hogback of Dakota Sandstone well marked with interpretive signs.  Exposed along the road are multiple dinosaur trackways, ripple marks, worm burrows, and dinosaur bones. 

Trackways of Iguanodon and Ornithomimus type dinosaurs
Tracks are accentuated by charcoal on a steeply-dipping slab

Below is a picture my wife took of me at the site (my pictures are still on my camera down in the car as I type this in a hotel room so it's the only one I have at the moment).

I wore my Viva La Evolucion t-shirt in honor of passing through Kansas today (a hotbed of anti-evolution pseudoscience).  The dinosaurs that left their tracks here were basically walking on the beaches and mud flats of the Western Interior Seaway (see my prior Day 3 post).

While the east side of the ridge was primarily Cretaceous age Dakota Sandstone, the western side had exposures of the earlier Late Jurassic Morrison Formation.  One of the neat things on the west side was an outcrop showing casts of apatosaurus tracks.  Here's a cross-section of the larger area from the website linked below:

The Dakota Sandstone forms the hogback on which Dinosaur Ridge is located.  How did these rocks get tilted?  The Idaho Springs mass of metamorphic rocks was pushed up during the formation of the Rocky Mountains and shoved those younger sedimentary rocks aside.

You can read more about Dinosaur Ridge geology here...

The rest of the ride through the Rocky Mountains on I-70 is one of the most spectacular drives in America.  I especially enjoyed Glenwood Canyon which follows the Colorado River through a narrow canyon with walls up to 1,000 feet high.

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