Cedar Canyon Geology
By Bradley Brooks
10/19/2014
The location that I have chosen for my site visit is Cedar Canyon. Cedar Canyon is full of
geologic features . Just driving along the road you are able to see many of these features from
your car. Over sixty million years ago the area of Cedar Canyon and the surrounding areas were
covered with a giant lake about the size of Lake Erie. It is easy to see that massive forces were
needed in order to reveal the geology in the canyon and the Cedar Breaks area. Some of the
rocks you will encounter while up Cedar Canyon are: Siltstone, Sandstone, Mudstone, Navajo
Sandstone, Igneous rock, and quaternary basalt. At the mouth of the canyon you can see rock
that was upended and that predates the Hurricane fault. As you work your way up to the top
you will start to see the red hoodoos of Cedar Breaks. Farther up past Cedar Breaks you get to
massive lava fields that are around 7000 years old, and in the distance you can see a cylindrical
cone of the ancient volcano.
At the bottom of the canyon the road is frequtley closed due to landslides. In this area
of the canyon the rocks are a dark brown and purple siltstone, and sandstone of the Moenkopi
Formation. When driving you need to look quickly for the Kayenta Formation which is very thin
in cedar canyon as compared to other locations. A little further up the canyon you will start to
see more stripped sandstone, siltstone, gypsum, and limestone.
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Once you get up to Cedar Breaks you start to see the white and orange hoodoos, and it
looks just like a smaller version of Bryce Canyon. The hoodoos are created with help from the
steep slopes which give the environment required where faults and compressional joint forces
guide the erosion process. The process in which the hoodoos are made involve a lot of cold and
then a thaw, which means that during the colder months there is a freezing and thawing
loosens the rock and it gets carried away and works on softer rocks and then creates the
canyons and gullies. Then harder rock is then left behind and eroded along the vertical cracks
and then goes through the freeze and thaw again which is how the hoodoos are carved.
View from the top of Cedar Breaks looking down to the hoodoos below.
Once you are past cedar breaks you get to an area which almost looks like it shouldn’t
belong up where you are. Massive lava fields take over the landscape and stretch for quite a
ways. The lava fields are considered geological new and are thought to only be about 2000
years old. Much of this lava did not come from a single volcano. It came from underground
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fissures in the earth’s surface, although you can see a cylinder volcano just north of Navajo lake.
The lava beds even have some cool features like lava tubes.
Lava beds in the distance created by lava coming up from underground.
Up cedar canyon there are so many different types of geologic features to see, just
going on this short drive I was able to see all of these things from the orange hoodoos to
massive lava beds.
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Sources
Utah’s Roadside Geology second edition by Felicie Williams, Lucy Chronic, and Halka Chronic
Pages 170-174
The Field guide to Geology by David Lambert and The Diagram Group
Pages 102-103
http://thelarsonlodge.com/activities/lavafields
http://www.zionnational-park.com/cbgeology.htm
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