Fossils & Rock Layers in Grand Canyon
by Jency G. Brock
‘And this shall be your northern border: From the Great Sea you shall mark out your border line to Mount Hor'
Grand Canyon National Park is one of the natural wonders of the world… and for a good reason. With its majestic cliffs, to it’s tiny million year old fossils, it is no surprise five million visitors come to see it every year. Also in this lofty haven are the main things that make it up: rock layers. There are many different types of them and they sometimes even affect the plant life, thus affecting the types of fossils found in those layers. As well as the layers geologists also study the fossils found in Grand Canyon and we can learn many things about what plants and animals roamed the Earth many years ago. Index fossils are also a great learning device for geologists when studying many rock layers and other fossils in Grand Canyon and other places as well. Grand Canyon has many different fossils and rock layers that tell us about its epic journey to how it became what it is today.
Types of Fossils & Rocks They Are Found In:
Within Grand Canyon there are many different types of fossils, such as trilobites, brachiopods, sponges, bryozoans which are small animals, as well as some precambrian fossils. Fossils are most common in sedimentary rock. Some other common types of rock fossils are found in are limestone, sandstone and shale. “Types of rock that normally lack fossils are metamorphic rocks… and igneous rocks… The scarcity of fossils in these rocks are due to the harsh manner in which they form, which usually destroys or severely deforms any remains of living things.” (Where Fossils Are Found) Fossils tell us many things about Grand Canyon.
Fossils we saw in Grand Canyon
Learning Things About the Past from Fossils & Rock Layers:
Fossils help to tell us a small piece of information about something that happened in the past, such as types of animals or plants. Curiously, there have not been dinosaur fossils found in Grand Canyon. Even though there are no dinosaurs, there have been fossils found that are much older than them, like a set of footprints probably from some sort of lizard or small mammal. The farther someone hikes down the canyon, the older the fossils get, which shows why the footprint fossils we found on our trip to Arizona were fairly far down. From all of the fossils in Grand Canyon scientist have learned so much; from the youngest fossil being around 250 to 255 million years old, to the oldest one being 505 to 525 million years old.
Foot prints we found in Grand Canyon that are talked about in the above section.
Index Fossils in Grand Canyon:
Index fossils are used for finding the more correct dates on how old rock layers and other fossils are. The exact definition for index fossil is “A fossil that is useful for dating and correlating the strata in which it is found.” In the canyons there are correlations, explained in the following quote: “The word correlation means a mutual similarity between two things. In this case, it is three things. The three canyons all share one or two rock layers. The Grand Canyon's two top rock layers, Kaibab and Moenkopi, are also Zion's two bottom layers. The Zion Canyon's two top layers, Navajo and Carmel, are the Bryce Canyon's two bottom layers.” This shows how there are same layers in different canyons, so if a scientist found an index fossil in a layer in, say, Bryce Canyon that had the same kind of layer as in Grand Canyon, they could know how old the layer is in Grand Canyon from the one in Bryce. Index fossils are very useful for finding out many different ages of things all over Grand Canyon.
In conclusion, there are many things in Grand Canyon that teach us all about the rock layers and how they affect the fossils. The fossils there also teach us about the types of plants and animals that were here on Earth millions of years ago. Finally, there are index fossils which teach us many things about the ages of rock layers, other fossils and so many things in Grand Canyon. Without index fossils the age of lots of things would be unknown. All in all Grand Canyon has many amazing fossils and rock layers that teach us about how it got the way that it is today.
"In What Types of Rocks Do Fossils Form?" K-5 GeoSource Content Science Content Fossils. Web. 06 June 2016.
“Layers in Time: Geology of Grand Canyon”
"Seven Natural Wonders (CNN)." Wikipedia. Wikimedia Foundation. Web. 06 June 2016.
Walters, Ken. Personal interview. 9th May, 2016