Basic Rock Types Around Moab, Utah

     The Moab region of eastern Utah contains access to numerous state and national parks, each of which boasts its own beautifully unique rock formations. Two specific areas around the city of Moab contain gorgeous examples of two of the three basic rock types: sedimentary and igneous rock. These areas include Arches National Park and The La Sal Mountain Range.

This photo features a handful of the 2,000 arches located within Arches National Park. The park contains numerous other geological formations in addition to its beautiful arches. 

(Photo courtesy of: Jim Karczewski - National Park Service (http://blog.usa.gov/post/20179890214/from-americas-great-outdoors-arches-national))

Taken from within Arches National Park, this photo reveals the not-so-distant La Sal Mountain Range. This range contains examples of igneous rocks.
(Photo by: Jessica Logar)

     According to the Discover Moab website, Arches National Park contains "the world's largest concentration of natural sandstone arches." Sandstone, as we have learned, is a typical clastic sedimentary rock. Sedimentary rocks are those that are formed when sediment accumulates in layers, called strata. The term "clastic" refers to a classification category of sediment that is comprised of fragmented pieces of pre-existing minerals or rocks. The type of sediment that makes up sandstone is none other than, yes, sand! The size of the clast that makes up sandstone ranges anywhere from 1/16 mm to 2 mm. 

This diagram helps to visualize the processes that must occur in order for sedimentary rock to be formed. From this, we can understand how sand was pressured and cemented in order to form the red sandstone rock arches within Arches National Park.
(Photo courtesy of: http://image.slidesharecdn.com/5-2sedimentaryrocks-130115232148-phpapp01/95/52-sedimentary-rocks-1-638.jpg?cb=1358314228)  

     Arches aren't the only sandstone formations to be featured within the park. Sandstone fins can also be found here. Regardless of the shape of the formation, both are comprised of sedimentary rock.

This photo features massive sandstone fins, located in Arches National Park. These fins, like the sandstone arches found in the park, are formed through the same processes.
(Photo courtesy of: http://www.discovermoab.com/images/arches/a03.jpg)

     The La Sal Mountain Range, located southeast of Moab, is partly comprised of another one of the three basic rock types: igneous rock, This relatively small range of mountains contains some sedimentary rock as well. In its formation process, molten rock repeatedly attempted to swell upwards until a dense layer of sedimentary rock blocked its path from erupting as a volcano. Since the magma was never able to explode onto the surface, it eventually cooled down during the solidification process. Later during the Ice Age, glaciers wore away at the peaks of the mountain range, revealing the igneous core. These types of rocks are formed due to the cooling and crystallization of molten rock. 

The La Sal Mountains are featured in the background of this photo. Igneous rocks played a key role in their formation and can even be found at the peaks of the range.
(Photo courtesy of: https://c1.staticflickr.com/5/4090/5005922833_81766ec4d1_z.jpg)

     Sources: 

http://www.discovermoab.com/archesnationalpark.htm

http://www.moabhappenings.com/Archives/ScenicRoads0908LaSalLoopRoad.htm

Arches National Park photo courtesy of: http://33.media.tumblr.com/tumblr_m1nn2tEqK21r81c8do1_1280.png

http://blog.usa.gov/post/20179890214/from-americas-great-outdoors-arches-national

http://www.discovermoab.com/images/arches/a03.jpg

https://c1.staticflickr.com/5/4090/5005922833_81766ec4d1_z.jpg