Monday, June 20, 2011

The Rippling Brook By: Bailey, Hailee, and Makayla

The Uinta Mountains were formed, 60 to 30 million years ago, when the ground lifted up and formed an arch known as the Uinta Mountain Arch. These mountains formed as part of the Rocky Mountains. Later the Uintas eroded away and were covered by younger layers. It was on the younger layers that the Green River established its course. About 10 million years ago uplift caused the Green River to cut down into the rocks exposing the layers we see today, this is called rejuvenation. When we put in the Green River the first day we were in the center of the Uinta Mountain Arch. All we saw was the Uinta Mountain Group Layer which is the oldest layer of rock. On the second day we reached the end of the Arch and the Lodore Formation and Madison Limestone layers became visible. When we stopped for lunch we were able to go on a hike to a beautiful waterfall, called the Rippling Brook.

During the hike we were fortunate enough to view the Lodore Formation and Madison Limestone layers more closely. The Lodore Formation is a very distinct layer of rock which was formed during the Cambrian Period. It resembles pink pancakes stacked upon each other. The Madison Limestone alternated between gray and sandy red colors within the layer. (Both of these differed from the darker colored lower layer of the Uinta Mountain Group.) Large chunks of the Madison Limestone surrounded the trail and we saw sections of it where the chert hadn’t eroded as fast as the limestone. The hike was a lot of fun and when we reached the top we enjoyed a vigorous shower due to the waterfall. We all enjoyed it and the opportunity to learn more about the layers close up.


phlexicon said...

what were the actual dates you were on the river?

Franklin said...

we were on the river june 10th through the 12th

phlexicon said...

tnx franklin
was just curious at what flow ur running. was 6600 on th 10th and 11th while u were im lodore canyon. went up to 8600 on th 12th when u were running split Mtn