Field Trip Project by Jack Smith

This geological field trip explores Colorado’s unique mixture of the 2.3 billion year old rocks atop Pikes Peak to the 300 foot orange sandstone rocks that makeup Garden of the Gods. Lastly we take a look at the coarse-grained sediments that make up Balanced Rock. The trip will last approximately eight to nine hours and is filled with rocks that reveal secrets of an ancient environment that make up part of earth’s history.

Field Trip Agenda and Map

(A)      Cog Railway Depot – Arrive no later than 8:50am for ticket purchase

515 Ruxton Ave • Manitou Springs, CO 80829

The train is scheduled to leave at 9:20am. Remember you will be traveling upwards to a 14,115 feet where weather can be unpredictable.

(B)      Garden of the Gods Visitor Center – Estimated Arrival 1:30pm

1805 North 30th Street • Colorado Springs, CO 80904

This destination is five miles from the Cog Railway Depot and will take approximately 15 minutes to commute. Here you will catch a broader view of the Garden of the Gods and Mountains behind it. Also a good place to pick up some additional literature. A café is located here in that you can pick up lunch if you had not packed one.

(C)      Perkins Central Garden Trail – Estimated Arrival 2:30pm

About one mile northwest of the visitor center. This paved path is an easy 1 ½ mile round trip with roughly a 30ft rise in elevation. This trail takes you to the base of the highest rock formations that make up part of the Garden of the Gods.

(D)      Balanced Rock – Estimated Arrival 4:30pm

About two miles along Garden Drive will take you past the South Spring Canyon Picnic Area to balanced rock. This area will not require extensive walking as the rock formation is right along Garden Drive with parking right next to the formation.

Pikes Peak – Pink Granite

First, before climbing to the top of Pikes Peak along the Cog Railway, it is imperative we know what makes up the majority of rocks you will see. It was first brought to my attention by the conductor that the rocks were primarily granite. Upon further research, pink granite to be more precise. The granite found along Pikes Peak is light gray or light pink, generally deeply weathered revealing a light brown color. Most of the rock were coarse-grained, containing primarily feldspar, quartz, pyrite and mica. As shown in the picture below, it was not uncommon to use the rocks from the local area to build with. Most buildings along the way contained the pink granite within the structure in some shape or form.

Source: Pikes Peak. (n.d.). The Geology of Pikes Peak. Pikes Peak – America’s Mountain. Retrieved October, 24, 2010 from http://www.pikespeak.us.com/Learn/geology.html.

Pikes Peak - Frost Wedging

Along your way to the top of Pikes Peak you will find rock formations such as the ones demonstrated above. Dating back only 3 million years ago the erosion we see in this photo above was caused by glaciers and the runoff during the Pleistocene Ice age. This erosion is expedited by what is known as “frost wedging.” It is the constant freezing, thawing and refreezing of the water that causes the wedges shown above. What is really interesting is that at the lower elevations you get water that was able to seep deeper into the rock causing the larger pieces of rock. As you reach higher elevations, where the weather is much colder, water is unable to seep as deep and tends to form smaller rock formations as shown below. Along the railway, it was primarily the rocks shown below that made up the last couple thousand feet climb to Pikes Peak.

Source: Pikes Peak. (n.d.). The Geology of Pikes Peak. Pikes Peak – America’s Mountain. Retrieved October, 24, 2010 from http://www.pikespeak.us.com/Learn/geology.html.

Pikes Peak – At 14,110 Feet

Pictured above my wife and I stand at 14,110 feet, or better noted as the summit of Pikes Peak. Behind us is a café and gift shop where you can escape the wind chilled temperature of 25 degrees on this particular day. Also noticed behind us are smaller chunks of the granite that are part of the frost wedging process as explained previously.

Pikes Peak – The Formation

Who would have guessed Pikes Peak came well before the Rocky Mountains. As you already know, the rocks forming Pikes Peak are well over 2.3 billion years old. The formation of the Rocky Mountains was only recently formed about 300 million years ago. Going back one billion years a dome of hot molten rock, called magma was pushed from the earth’s core to form a batholith. This formation never did make it to the surface remaining hidden for millions of years. During the first stages of the formation of the Rocky Mountains, the earth’s crust went through sea floor spreading at the mid-Atlantic Ridge. The stresses on the North American Plate eventually faulted along what is now known as the Rocky Mountains. It was during this time that the huge mass of Pikes Peak made its first appearance. After this a stage of intensive erosions took place. This is about the time places like Garden of the Gods was born. Another period when seawater and additional sediments layered the area another up-thrust of the earth’s crust formed the Rockies and along with it pushed the once sunken batholith of Pikes Peak. Since then, many of the mountains features have been carved out by glaciers and their runoff during the Pleistocene Ice Age.

Source: Pikes Peak. (n.d.). The Geology of Pikes Peak. Pikes Peak – America’s Mountain. Retrieved October, 24, 2010 from http://www.pikespeak.us.com/Learn/geology.html.

Garden of the Gods – Visitor Center

A quick stop at the Garden of the Gods Visitor Center revealed the necessary information to complete this trip. Here you can pick-up lunch, maps and general information pertaining to your visit to the park. Turns out, Garden of the Gods has been home to many different development periods, part of what make it what it is today. Garden of the Gods was once home to a tropical haven, inland sea, sand dunes and swampy floodplains. As we have already learned, Pikes Peak was created out of the molten rock cooled to create the granite about 310-270 million years ago. The 300 foot sandstone pictured behind me in the photo below were once sand dunes. It was 65 million years ago that the rock formations were formed. This period formation is attributed to the slamming of the Pacific and North American Plate.

Source: Friends of Garden of the Gods. (n.d.). Geology. Retrieved October 24, 2010 from http://www.friendsofgardenofthegods.org/GeologyandEcology.aspx.

Garden of the Gods – Morrison Formation

Morrison Formation is just one of the many different types of sediment found around the Garden of the Gods. It is white in appearance and made up of clays, siltstones and carbonates. As you will notice below, you can see the various sediment layers when taking a closer look at the rocks.

Source: Samantha T. (n.d.). Garden of the Gods. University of Colorado. Retrieved October 24, 2010 from http://www.uccs.edu/~geomorph/sites/garden_of_the_gods.html.

Garden of the Gods – Vertical Sediment

Part of what makes Garden of the Gods so amazing are the vertical sediment layers pictured here. As the front range mountains were rising, overlying sedimentary rocks were bent in a upward position. Over time the softer rocks eroded creating valleys where harder rocks stand to makeup the vertical sediment. It is this distinct element that makes the park popular to millions of people every year.

Source: Friends of Garden of the Gods. (n.d.). Geology. Retrieved October 24, 2010 from http://www.friendsofgardenofthegods.org/GeologyandEcology.aspx.

Garden of the Gods – Layers

As you analyze the rocks, one feature to notice is the layers found within the various sediments. Layers are found all over the park. Below is a listing of the various types of rocks found within the park:

Fountain Arkose - course-grained sediment generally found in places such as balanced rock

Lyons Sandstone - made of fine-grained quartz sandstone

Lykins Formation - made of a red, thin-bedded, sand siltstones where shells are often found

Morrison Formation - made of clays, siltstones and shale

Purgatoire Formation – bleached sandstone, shale, siltstone

Dakota Sandstone – marine sandstone

Benton Group – shale and limestone found all over the Garden of the Gods

Niobara Formation – mostly limestone and marine fossils

Pierre Shale – the youngest rock where clams, ammonites and bones of fossil fish can be found

Source: Samantha T. (n.d.). Garden of the Gods. University of Colorado. Retrieved October 24, 2010 from http://www.uccs.edu/~geomorph/sites/garden_of_the_gods.html.

Garden of the Gods – Balanced Rock

Balanced Rock was made possible today by my exceptional strength and balance. However if that is not a good enough explanation then please continue reading to reveal the true reason this rock maintains its stationary position today. Balanced Rock was exposed 60 million years ago when the Rocky Mountains were rising. The shape was defined by the soft bottom layer of shale that eroded much faster than the harder sandstone and conglomerate found atop the 700-ton bolder. Around balanced rock, as pictured below, you will see additional formations formed by the erosion of the softer shale layers.

Source: Park Informational Sign, found on site at Balanced Rock on October 16, 2010

This is the End

This geological field trip exposed you to a variety of geologic finds. Not only is the trip enjoyable in terms of the amazing sites but one to be learned from. By now you should understand a little more about Pikes Peak, and what frost wedging is all about. You can now impress your friends while visiting the Garden of the Gods by explaining the phenomenon that caused the vertical sediment layers. You will also have a good idea how erosion presented places like Balanced Rock. Overall it is a trip well worth the time necessary to take it. As the photos only begin to uncover the beauty this area has to offer, I implore you to take the time to adventure to the top of Pikes Peak and on into the Garden of the Gods.