*This picture shows a great example of the difference in the Mountains located behind the Flatirons (the Rockies) and the Flatirons, as well as how the plains come to meet the Mountains so abruptly
As far as other rocks settled in Boulder, they are dated all the way back to the Precambrian period. These rocks consist of Granite and Metamorphic rock. Though the most prominent rocks in the area is Schist, Gneiss, and Quartzite.
The Flatirons Mountain Range is part of the Rocky Mountains formerly known as the Ancestral Rockies which were formed during the Pennsylvanian Period, about 300 million years ago. This unique mountain range was created when the subduction of tectonic plates created the Rockies and it pushed all the Precambrian Rock upwards. This movement eroded them and allowed the rocks to weather. The debris that came from the rocks later formed into a type of sandstone called Akrose. This is known as the Red stone that makes up the Boulder Flatirons, during a process called Fountain Formation.
*Example of the Sandstone, Akrose
I have grown up in Colorado my whole life but not really looked at the flat irons. I guess I take them for granted. What I learned from your blog was how many different types of rock are in the flat irons. (Gniess, Shist, etc.)
ReplyDeleteYour write well and very descriptive. What I'm curious about is..Did Red Rocks form the same way or in a different process?
Abby,
ReplyDeleteThis is a really cool outlook on something that is so close. Your descriptions of the formation involving the Precambrian Rocks was very detailed and gave a great picture. I also really liked how you describe the most prominent rocks in the area. I don't know if it is just my computer but only one of the images above showed up on my computer.