The Geologic Story of the Four Corners Independent Project:
The Geologic Story of the Four Corners: Sandstone and Sedimentology:
Introduction:
When we study rocks, we are able to see deep and ancient parts of our earth's history. We can see different events and patterns in rocks that will give us information about how our earth works. The data we collect from geological studies can help us make predictions about how our earth can change in the future. One of the subjects of rock we can look at is sandstone. Sandstone is a type of rock that is formed from sediment. What makes it sandstone is the type of minerals it is made from and the particular medium size particles it is made from. Sandstone and other sedimentary rocks are key to finding out about the earth's history. This particular study of looking at rock and their history is stratigraphy and sedimentology.
The Three Main Types of Sandstone:
Different types of sandstone that are found in different regions will consist of different minerals and sizes. The most common minerals that we can find in sandstone are quartz, feldspar, silt, clay, and other particles. When we take a look at the structure of sandstone, we label it by what minerals it contains. There are three main types: quatorze, arkose, and argillaceous sandstone. When the structure mainly consists of at least 85% quarts, it is quarantine. If we see around 25% feldspar, it is arkose sandstone. When there is more than the usual amount of clay, silt or other minerals, we call it argillaceous sandstone. Each of these types vary in color depending on how much of each mineral there is. For example, argillaceous sandstone typically appears more blue or gray because of its composition. Other factors like exposure to heat and light will affect the way the stone will appear.
Now, what makes sandstone different from other formations of rock, is the particle/mineral size and the history of the rock itself. Trying to define sand is a little tricky, as it can be viewed differently, though the size is key into classifying this grain. Sand is considered a medium grain and can range from having a diameter of 0.06 mm to 2 mm. Though, different geologists define the size constraints differently.
The Formation:
So, how does sandstone form? It begins with the small grains that make up the stone. Sand comes from different erosion and weathering processes. Over time, this sediment gathers and is pressed down by water or pressure. This is the basic steps to the formation of rock. Sandstone can be found pretty much everywhere in the world. The types of sandstone and way it is layered in certain areas can tell us about the region's history. What we typically look at is the minerals in the sandstone. Sandstone that consists of lots of feldspar can indicate sediment that is near mountains or carried down from mountainous regions. Also, depending on the roundness of the grains, we can predict how far the grains have traveled. Different patterns in the layering of the rock, like ripples, can show us if there was a strong current of wind or water. What I find most interesting is that observing layers of shale or conglomerate can show us a change in climate in the surrounding area. This is why we study sandstone and its formation, because it can show us not only the history, but how it responds to climate change.
Connection to the Four Corners:
Particularly, in the United States we see a lot of interesting features in stratigraphic studies and in sedimentology. In the four corners, we have diverse lands, but we can see a lot of similarities. Specifically, a type of rock called the Navajo Sandstone spreads over a large chunk of the United States and in the four corners; its area takes up approximately 1,500,000 square miles! To put that into perspective, our town of durango takes up about 17.2 miles squared! It can be found in Nevada, Arizona, Colorado and Utah as part of the Colorado Plateau. Because of the period it was formed in, it is not nearly all visible. There are many different places where we can observe it and certain cross bedding patterns. Some famous sites include Lake Powell, Antelope Canyon, and all around Zion National Park.
Navajo Sandstone on Lake Powell Navajo Sandstone in Antelope Canyon
Navajo Sandstone is very common, and comes in many different shapes and forms. Typically, we see a red, salmon type color. Though, it can appear more white or gold as well. The cross-bedding that occurs in this rock is said to be caused by the directional wind patterns before the rock had formed. This was over 180 million years ago, when it was still sand!
Cross Bedding In Navajo Sandstone Different Periods of Sandstone
Conclusions we Can Draw:
Because Navajo Sandstone takes up so much space, it may be very general, but differences in different regions can help us draw conclusions about Earth’s history. By looking at the cross-bedding and sedimentology of the Navajo Sandstone, we can make predictions about what our planet looked like long ago. We can see that large drafts created large sand dunes that took up a large portion of America 180 million years ago; especially the Four Corners Area. This ties into how we look at geology now. The next questions to ask when looking at these formations are, “what major climate changes caused drastic changes in sandstone sedimentology?”
Personal Connection Segment:
Why am I interested in the study of rocks, and particularly, Sandstone?
I was originally born in Santa Fe, New Mexico. I spent much of my childhood exploring dried up arroyos and playing with rocks; a lot of the time, I was so fascinated with the way the sunset reflected off the gold faces of rock. By the age of six, I moved out to Durango where I was introduced into geology through my stepdad. Because he is a geology major, a five minute walk would turn into a 20 minute lecture on that trails history. During the weekends of my childhood, it became the norm to travel to Bluff, Utah - a rock lover paradise! I had already had a connection to rock that had formed through pressure and water in a desert area, but the vast cliffs of Utah had opened a new passion. As we traveled down the rivers, canyons, and trails of Utah, I learned about the different types of sandstone we were seeing and what made them special through the knowledge of my step dad. Since I was little, I have been captivated by the sun and the stone of the desert, and I have always been interested in expanding my knowledge surrounding it. Though looking at samples of layers of sandstone can tell us much about history and the furote of geology, I am more interested in the human connection to rocks and the climate.
Plethora of Sources:
https://www.thoughtco.com/what-is-sandstone-1441016
https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/45/3/651/113384/Stratigraphic-analysis-of-the-Navajo-Sandstone?redirectedFrom=full text
https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.850.9908&rep=rep1&type=pdf
https://en.wikipedia.org/wiki/Navajo_Sandstone
https://sed.utah.edu/Wingate.htm
https://mineralseducationcoalition.org/minerals-database/sandstone/
https://www.dec.ny.gov/docs/administration_pdf/lpsoilstudies.pdf
https://en.wikipedia.org/wiki/Sand#:~:text=The%20exact%20definition%20of%20sand%20varies.&text=An%20individual%20particle%20in%20this,mm%20down%20to%200.004%20mm).
https://gosfordquarries.com.au/news-media/2016/12/1/how-sandstone-is-formed#:~:text=Sandstone%20is%20a%20rock%20comprising,or%20on%20the%20ocean%20floor.&text=In%20time%2C%20the%20sandstone%20is,of%20these%20minerals%20coming%20together.
https://www.thoughtco.com/what-is-sandstone-1441016#:~:text=The%20sand%20grains%20in%20sandstone,countryside%20that%20produced%20the%20sand.
https://www.thoughtco.com/what-is-sandstone-1441016#:~:text=The%20sand%20grains%20in%20sandstone,countryside%20that%20produced%20the%20sand.
Introduction:
When we study rocks, we are able to see deep and ancient parts of our earth's history. We can see different events and patterns in rocks that will give us information about how our earth works. The data we collect from geological studies can help us make predictions about how our earth can change in the future. One of the subjects of rock we can look at is sandstone. Sandstone is a type of rock that is formed from sediment. What makes it sandstone is the type of minerals it is made from and the particular medium size particles it is made from. Sandstone and other sedimentary rocks are key to finding out about the earth's history. This particular study of looking at rock and their history is stratigraphy and sedimentology.
The Three Main Types of Sandstone:
Different types of sandstone that are found in different regions will consist of different minerals and sizes. The most common minerals that we can find in sandstone are quartz, feldspar, silt, clay, and other particles. When we take a look at the structure of sandstone, we label it by what minerals it contains. There are three main types: quatorze, arkose, and argillaceous sandstone. When the structure mainly consists of at least 85% quarts, it is quarantine. If we see around 25% feldspar, it is arkose sandstone. When there is more than the usual amount of clay, silt or other minerals, we call it argillaceous sandstone. Each of these types vary in color depending on how much of each mineral there is. For example, argillaceous sandstone typically appears more blue or gray because of its composition. Other factors like exposure to heat and light will affect the way the stone will appear.
Now, what makes sandstone different from other formations of rock, is the particle/mineral size and the history of the rock itself. Trying to define sand is a little tricky, as it can be viewed differently, though the size is key into classifying this grain. Sand is considered a medium grain and can range from having a diameter of 0.06 mm to 2 mm. Though, different geologists define the size constraints differently.
The Formation:
So, how does sandstone form? It begins with the small grains that make up the stone. Sand comes from different erosion and weathering processes. Over time, this sediment gathers and is pressed down by water or pressure. This is the basic steps to the formation of rock. Sandstone can be found pretty much everywhere in the world. The types of sandstone and way it is layered in certain areas can tell us about the region's history. What we typically look at is the minerals in the sandstone. Sandstone that consists of lots of feldspar can indicate sediment that is near mountains or carried down from mountainous regions. Also, depending on the roundness of the grains, we can predict how far the grains have traveled. Different patterns in the layering of the rock, like ripples, can show us if there was a strong current of wind or water. What I find most interesting is that observing layers of shale or conglomerate can show us a change in climate in the surrounding area. This is why we study sandstone and its formation, because it can show us not only the history, but how it responds to climate change.
Connection to the Four Corners:
Particularly, in the United States we see a lot of interesting features in stratigraphic studies and in sedimentology. In the four corners, we have diverse lands, but we can see a lot of similarities. Specifically, a type of rock called the Navajo Sandstone spreads over a large chunk of the United States and in the four corners; its area takes up approximately 1,500,000 square miles! To put that into perspective, our town of durango takes up about 17.2 miles squared! It can be found in Nevada, Arizona, Colorado and Utah as part of the Colorado Plateau. Because of the period it was formed in, it is not nearly all visible. There are many different places where we can observe it and certain cross bedding patterns. Some famous sites include Lake Powell, Antelope Canyon, and all around Zion National Park.
Navajo Sandstone on Lake Powell Navajo Sandstone in Antelope Canyon
Navajo Sandstone is very common, and comes in many different shapes and forms. Typically, we see a red, salmon type color. Though, it can appear more white or gold as well. The cross-bedding that occurs in this rock is said to be caused by the directional wind patterns before the rock had formed. This was over 180 million years ago, when it was still sand!
Cross Bedding In Navajo Sandstone Different Periods of Sandstone
Conclusions we Can Draw:
Because Navajo Sandstone takes up so much space, it may be very general, but differences in different regions can help us draw conclusions about Earth’s history. By looking at the cross-bedding and sedimentology of the Navajo Sandstone, we can make predictions about what our planet looked like long ago. We can see that large drafts created large sand dunes that took up a large portion of America 180 million years ago; especially the Four Corners Area. This ties into how we look at geology now. The next questions to ask when looking at these formations are, “what major climate changes caused drastic changes in sandstone sedimentology?”
Personal Connection Segment:
Why am I interested in the study of rocks, and particularly, Sandstone?
I was originally born in Santa Fe, New Mexico. I spent much of my childhood exploring dried up arroyos and playing with rocks; a lot of the time, I was so fascinated with the way the sunset reflected off the gold faces of rock. By the age of six, I moved out to Durango where I was introduced into geology through my stepdad. Because he is a geology major, a five minute walk would turn into a 20 minute lecture on that trails history. During the weekends of my childhood, it became the norm to travel to Bluff, Utah - a rock lover paradise! I had already had a connection to rock that had formed through pressure and water in a desert area, but the vast cliffs of Utah had opened a new passion. As we traveled down the rivers, canyons, and trails of Utah, I learned about the different types of sandstone we were seeing and what made them special through the knowledge of my step dad. Since I was little, I have been captivated by the sun and the stone of the desert, and I have always been interested in expanding my knowledge surrounding it. Though looking at samples of layers of sandstone can tell us much about history and the furote of geology, I am more interested in the human connection to rocks and the climate.
Plethora of Sources:
https://www.thoughtco.com/what-is-sandstone-1441016
https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/45/3/651/113384/Stratigraphic-analysis-of-the-Navajo-Sandstone?redirectedFrom=full text
https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.850.9908&rep=rep1&type=pdf
https://en.wikipedia.org/wiki/Navajo_Sandstone
https://sed.utah.edu/Wingate.htm
https://mineralseducationcoalition.org/minerals-database/sandstone/
https://www.dec.ny.gov/docs/administration_pdf/lpsoilstudies.pdf
https://en.wikipedia.org/wiki/Sand#:~:text=The%20exact%20definition%20of%20sand%20varies.&text=An%20individual%20particle%20in%20this,mm%20down%20to%200.004%20mm).
https://gosfordquarries.com.au/news-media/2016/12/1/how-sandstone-is-formed#:~:text=Sandstone%20is%20a%20rock%20comprising,or%20on%20the%20ocean%20floor.&text=In%20time%2C%20the%20sandstone%20is,of%20these%20minerals%20coming%20together.
https://www.thoughtco.com/what-is-sandstone-1441016#:~:text=The%20sand%20grains%20in%20sandstone,countryside%20that%20produced%20the%20sand.
https://www.thoughtco.com/what-is-sandstone-1441016#:~:text=The%20sand%20grains%20in%20sandstone,countryside%20that%20produced%20the%20sand.