Caprocks

 

Caprocks

 

Caprock is a geological term used to describe a harder or more weather resistant layer of rock overlying a softer or less weather resistant layer of rock.

Now let's look at some examples of caprocks.

 

Fin protected by hard caprock in Arches National Park

 

 

 

 

 

 

 

This fin or hoodoo in Arches National Park is being protected by a caprock.

 

 

 

 

 

 

 

 

 

 

 

Caprock creating Hoodoos in Cut Bank, Montana

 

 

 

Here you can see several hoodoos that have formed on the bank.

On these "hoodoos" it is easy to see the harder cap rock.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hoodoo & cap rock in Cut Bank, Montana

 

 

 

Only a small fragment of harder "cap rock" remains on the hoodoo on the left while the cap rock appears to be all but gone from the hoodoo on the right. Once the cap rock is gone the top of the hoodoo will become pointed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cap Rocks and hoodoos in Cut Bank, Montana

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hoodoos and cap rocks near Cut Bank, Montana.

 

Isn't it interesting how this hoodoo developed. In this picture it is fairly easy to see how the harder "cap rock" protects the softer material underneath from water born erosion.

 

 

A hard caprock is protecting this cliff

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I included this picture of a sandstone cliff to show the many different layers of sedimentary rock all being protected by a caprock.

 

 

Mexican Hat Rock example of a "caprock" protecting the softer layers below it

 

 

 

 

 

This is a better view of the eponyous Mexican Hat Rock. The "hat" is a fine example of a geological caprock.

 

Also look beyond the Mexican Hat Rock at the sedimentary rock in the bluff. Notice how the sedimentary layers are almost vertical on the left side of the picture. That is a fault line, probably a block fault where the right side faulted up and the left side faulted down.

 

The hat is also a fine example of a "caprock" as used in geological terms.

 

 

 

 

Wingate Sandstone beneath the caprock in Colorado National Monument

 

 

 

 

 

Sandstone weathers into unusual shapes. Here a ridge between two canyons is eroding into a series of domes. The key factor in shaping these adjacent monoliths is the upper layer of harder rock (Kayenta Formation). This caprock layer is breakable, but resistant to erosion. Where the cap layer remains, the softer rock (Wingate Sandstone) beneath is protected; where it has broken away, the underlying formation has rapidly eroded to a rounded form.

 

 

 

 

 

 

 

Kayenta formation caprock protecting Wingate Sandstone in Colorado National Monument

 

With the relatively resistant Kayenta Formation "caprock" intact, cliffs remain tall and fairly flat-topped. Only minor erosion occurs along vertical cracks.

 

 

 

 

 

 

 

 

 

 

 

 

How Kayenta caprock protects the Wingate Sandstone in Colorado National Monument

 

 

When the Kayenta formation camprock is eroded off, underlying Wingate Sandstone begins to erode from the top down, forming more rounded spires and dome shapes.

 

You can certainly see how the hard Kayenta "caprock" protects the Wingate Sandstone in these pictures.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Kayenta formation caprock protecting Wingate Sandstone Colorado National Monument

 

 

How many years will it take for these formations to take on the dome shapes of the formations above? But even a novice can see how the harder Kayenta formation caprock protects the softer Wingate Sandstone.

 

 

 

 

 

 

 

 

 

 

Kayenta formation caprock protecting Wingate Sandstone Colorado National Monument

 

 

 

Much harder caprock of the Kayenta formation protecting the softer Wingate under it.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Caprock protecting ash from an ancient volcano in Colorado National Monument

 

 

 

 

 

Here a hard caprock is protecting this deep layer of ash from an ancient volcano.

 

 

 

 

 

 

 

 

 

 

 

Layers of sedimentary rock exposing volcanic ash deposits

 

 

 

 

 

 

This layer of sedimentary rock is exposing how dustings of volcanic ash occurred many times over thousands of years with intervals in between when the ash would be covered with other sediments then covered with ash again only to have the process repeated time and again.

 

 

 

 

 

 

 

 

 

Volcanic ash and sandstone

 

 

 

 

Again, volcanic ash is evident in this sandstone formation. It is for the most part wind deposited sand in what is known as the slick rock formation that lies on top of the Kayenta Formation.

 

 

 

 

 

 

 

 

 

 

 

 

Hard caprock is protecting the softer material underneath

 

 

 

 

 

This sandstone hoodoo is being protected by a hard caprock.

 

 

 

 

 

 

 

 

 

 

 

Hoodoos carved in Entrada Sandstone

 

 

 

Hoodoos carved in Entrada Sandstone being protected and created by hard caprocks.

Joyce took this picture of caprocks and hoodoos in Arches National Park.

 

 

 

 

 

 

 

 

 

More Geology Pages

Some Miscellaneous Subjects ** Our Cute Signs

 

 

Mike & Joyce Hendrix

Mike & Joyce Hendrix who we are

We hope you liked this page. If you do you might be interested in some of our other Travel Adventures:

Mike & Joyce Hendrix's home page

Travel Adventures by Year ** Travel Adventures by State ** Plants ** Marine-Boats ** Geology ** Exciting Drives ** Cute Signs ** RV Subjects ** Miscellaneous Subjects

 

We would love to hear from you......just put "info" in the place of "FAKE" in this address: FAKE@travellogs.us

Until next time remember how good life is.