May 30, 2010

Dinosaur National Monument, CO/UT

After leaving Steamboat Springs, we cruised across the sage-scrub prairies of Northwastern Colorado on the way to Dinosaur National Monument.

Along the way, we encountered millions of bugs crossing the road. As the density got thicker and thicker, we decided to stop and figure out what they were. It turns out they were Mormon Crickets. A weird looking insect to say the least.

Mormon Cricket

Dinosaur National Monument consists of two primary units. The first we visited still within Colorado is the deep canyon where the Green and Yampa Rivers meet. This region had been designated a national monument in the early 1900's due to the plentiful amounts of dinosaur bones found in the formations.

But, in the 1950's there was a movement to build a dam on the Green River and flood the two conjoining canyons to form the Echo Park Dam and Reservoir. This created a major outcry across the country in one of the first major moves of the modern environmental movement. The Sierra Club sponsored a rafting trip down the rivers in the canyons and filmed the adventure and then distrubuted the film to all members of congress and the public. Soon thereafter, the canyons were protected forever against empoundment.

Here you can see the tilted layers of sediment with horizontal layers on top.

The view east along the escarpment

From the cliffs and canyon area, we continued west into Northeastern Utah to the town of Vernal and to the Quarry Area, where the dinosaur bones have been found in the highest concentrations. The rocks here are sandstones and siltstones of the Morrison Formation that formed in a lowland area of slow-flowing rivers and marshes. The thick accumulation of dinosaur bones occurs as they died and sank into the muddy sediments.

Ever present thunderstorms of the Rockies here at the Visitor Center

The visitor center has a wall of rock inside that was excavated to reach the bones, but left in-situ to see the actually bones in their original positions.

Bones of Allosaurs and numerous other species have been found here

A thigh bone of a dinosaur embedded in the original rock

The Morrison Formation is highly tilted and deformed by the uplift of the nearby Uinta Mountains

Here Linda stands next to a leg of large herbivorous dinosaur

No comments: