Welcome to the Colorado River Refuge. The Refuge is connected to 95 acres of hike and bike trails along the Colorado River. The trail system at the CRR is about 2 - 6 miles in and out, depending on how you hike. There are the two main trails Cottonwood Kings and Two Bridges Trail. There are other trails and I recommend you see the sign near parking to see the trail map. The trails are well maintained and hiking next to the river is amazing.
The CRR is in care of the Pines and Prairies Land Trust.
If you have been in the Bastrop State Park or Buescher State Park you have seen this type of rock. It has been used since the 1900s for building projects, especially by the CCC in the parks listed above. You may recognize it by it's reddish hue, caused by Iron in the rock.
At the earthcache, you will see an interesting formation. They call it a cliff, but it's actually part of a caprock. The stone above is the caprock that is usually tilted and used to protect the mudrock that is below it. Over centuries there has been erosion of the rock below. That is due to the rocks above being a much more resistant, harder rock. The mudrock is much less resistant, being weaker. This is a sign of erosion. Some of the most common, and most beautiful, types of the formations are called “hoodoo”. If you look up hoodoos you can see what erosion can do to softer rocks underneath harder rocks.
The red sandstone located here is also called carrizo sandstone. The sandstone is a clastic sedimentary rock. It is comprised of sand sized grains of minerals or other rocks. Most sandstone is comprised of quartz and/or feldspar, with lithic fragments. One of the most common materials found in sandstone is quartz. This is a much harder rock and one of the most common sedimentary rocks around. Also, there may not be sand in sandstone. It is called that due to the sand sized particles. Interesting facts include it is often used as a building material and works as a very effective water filter.
Mudstone, also know as mudrock, is a fine grained sedimentary rock. It is mostly made up of clay, mud, silt and can have slate and shale in it. These grains are too small to be seen without a microscope. This rock is much weaker in hardness than the sandstone. It is too soft to use for building materials, but has been known to be used to create jewelry.
Interesting notes:
Sandstone forms the metamorphic rock quartzite.
Mudstone forms the metamorphic rock slate.
Answer these questions below. Do NOT put these answers in your log. Your log will be deleted immediately if you do. This also applies to taking pictures that will give away answers.
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What are the various colors you see on the caprock?
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What pattern do you see on the mud rock? What possibly caused this?
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You will also see something here that could have been dangerous, depending on where you were standing when it happened. What is the danger and what do you think caused the danger?
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Based on other nearby factors, what contributed to this geological structure?
If you enjoyed this earthcache, feel free to give it a favorite point so others may be more inclined to visit this location!