Lab 5 Assignment complete
docx
keyboard_arrow_up
School
Georgia State University *
*We aren’t endorsed by this school
Course
113
Subject
Geography
Date
Apr 3, 2024
Type
docx
Pages
7
Uploaded by johnchristiandavis
Lab 5: Weathering GEOG 1113L – Introduction to Landforms Lab
Name: ____Jack Davis_________
I.
What is Weathering?
1.
What does weathering create/provide and what would Earth’s surface be composed of if weathering did not happen? It provides nonorganic materials in the soil where the vegetation needs it in order to grow. If weathering did not occur then it would be solid bedrock. 2.
What is the difference between weathering and erosion?
Erosion is the rock actually moving while weathering just prepares the rock materials to be moved
3.
Describe the process of frost wedging (frost action).
The rock breaks due to stress from water freezing inside the pores of the rock which make it expand until its ready to break.
4.
Similar to frost wedging, ___salt crystal growth______ fractures rocks through crystal growth within the pores of the rock. These crystals originate from ____minerals that have dissolved through water___ inside the rock that later evaporates and leaves behind __mineral grains_____.
5.
The two previously mentioned types of weathering are both forms of what?
Granular disintegrationn
6.
Which type of weathering causes metal to rust?
oxidation
7.
Weathering that alters minerals in a rock via water, oxygen, carbon, and/or other organic acids is called what?
Chemical weathering
8.
Which type of weathering causes karst topography?
The carbonation weakening the limestone
9.
Name three features you might find in a karst landscape.
Sink holes caves and dry valley
10.
What is one fact (from the video) about caves that you find interesting?
I find it pretty cool that caves are their own entire ecosystsems where unique life grows out of.
11.
Tree roots, lichen, and humans all play a part in weathering as well. Which type of weathering is this called? Biological weathering
II.
Weathering Resistance
Use the two images below to answer questions about weathering resistance. Assume all rock layers in both images have been subjected to the same type/amount of weathering.
Image A:
1.
Which color/pattern represents a rock layer that is MOST resistant to weathering compared to the others? Dark grey layer
2.
Which color/pattern represents a rock layer that is LEAST resistant to weathering compared to the others? Black layer
3.
Which colors/patterns represent rock layers that share the same level of resistance to weathering compared to the others?
White with the black dashes layers
Image B:
4.
Within the red box, which layer appears to be most resistant to weathering (A, B, or C)?
A
5.
Within the red box, which layer appears to be the least resistant to weathering?
B
6.
What is one indication that a rock layer is more resistant to weathering?
Depending on how much of the surface is exposed to water, heat, wind
III. Physical Vs. Chemical Weathering For each location below, be sure to explore the photo by dragging your mouse around the 360
o
view around you and using the scroll feature on your mouse to zoom in and out on specific parts of the image.
Answer each question that accompanies the link.
1.
Visit Apikuni Falls
in Glacier National Park. Some of these rocks have a white color, but they have an orange color where they are exposed to water from the waterfall. Which type of weathering is producing the orange-colored rocks? a.
Carbonation
b.
Oxidation
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
c.
Exfoliation
d.
Frost wedging
2.
Visit Stone Foundation
in Wisconsin. There is evidence in this 360
O
photo for which type of weathering? a.
Salt crystal growth
b.
Oxidation
c.
Exfoliation
d.
Frost wedging
3.
Visit Starved Rock State
Park in Illinois. What type of weathering do you see in this 360
O
photo? a.
Carbonation
b.
Oxidation
c.
Exfoliation
d.
Frost wedging
4.
Support your claim about the weathering in Starved Rock State Park with evidence you observe in the 360
O
photo. What type of weathering is this (chemical or physical)?
Oxidation occurs in warm damp climates and in the photo there is water in-between the rock bed which is probably what is causing it to layer like that because when the water rises it breaks down the rocks and then when it dissipates it breaks down another layer.
5.
Differential weathering
means that some rocks breakdown more easily than others. For example,
in this picture
of a dolerite dike, you see a dark igneous rock forming a prominent low wall extending into the ocean. It sticks out above the beach sediment on either side of it (mostly sand) because the sand has formed from rocks that weathered away more easily. We consider the dolerite dike more resistant to weathering, because it resists weathering. Differential weathering in an outcropping of rock can produce dramatic landscapes. If a rock weathers easily, it will break down easily making gentle slopes. If a rock resists weathering, it will
make steep cliffs. Visit Monument Valley
in Arizona. Notice that the towers of rock are more resistant to weathering, while the gentle sided slopes at the bottom of the towers weather more
easily. Now visit LaSalle Canyon
at Starved Rock State Park in Illinois. The evidence of differential erosion is less obvious. Describe where in the LaSalle Canyon you see resistant or easily weathered layers. What evidence can you observe of differential weathering? Where the people with their dog are standing shows an area of rock that is more sloped which means it is less resistant to weathering and if you compare that to the rock way above them that is more of a dark color which I think is some sort of igneous rock, it shows that it is more resistant to weathering because the slope is way steeper, pretty much a direct dropoff.
6.
One type of physical weathering not covered yet is abrasion
. A scratch on your skin or eye is called an abrasion and an “abrasive” person is someone that grates on your nerves. So, this form of weathering is just like it sounds. When sand or silt is picked up by water or wind and bumps into other rocks, it can round off the edges, making things smooth.
River rocks are rounded because they roll around in rivers, bumping into one another and chipping off their rough edges. Sand carried by river water acts like sandpaper, smoothing the surface of the rocks. For example, see this photograph of rounded pebbles
. Abrasion also happens as a result of wind carrying sand. Visit Devil’s Garden
in Grand Staircase – Escalante National Monument in Utah. The towers of rock are called hoodoos. How are Devil’s garden hoodoos an example of differential weathering? Provide evidence from your observations of the 360
O
photo. The devils garden hoodoos are an example of differential weathering because they have been smoothed over from wind picking up nearby sand and slowly but surely working away at the rocks. Taking away the harsh corners and making them much more curvy and less pointy. 7.
What evidence is there in the 360
O
photo of Devil’s Garden that the hoodoos and other rock outcrops were weathered by abrasion? For starters you can see tons of sand lying around if you just turn the 360 photo and on top of that you can just look at the rocks and tell that over the years the sand being picked up has caused them to smooth over and lose a ton of their previous shell that was once probably jagged.
IV. Karst Topography
Choose one of the five locations provided and visit the Google Earth link: 1. Central Kentucky Karst, USA
, 2. Sof Omar Cave, Ethiopia
, 3. Postojna Cave, Slovenia
, 4. Tenglong Cave, China
, 5. Waitomo Cave, New Zealand
.
Once you have chosen your location, utilize the following links to learn more about karst topography and answer the questions below. https://home.wgnhs.wisc.edu/wisconsin-geology/karst-sinkholes/
https://www.nps.gov/subjects/caves/karst-landscapes.htm
https://education.nationalgeographic.org/resource/karst/
https://people.uwec.edu/jolhm/Cave2006/Karst.html
https://www.gsi.ie/en-ie/programmes-and-projects/groundwater/activities/understanding-irish-karst/
karst-landforms/Pages/default.aspx
1.
What is one indication that the location you chose has karst topography? Take a screenshot of this feature (must be visible in the picture) and attach it below along with the name of the
feature. From what I’ve read about karst topography through these links, it seems to be due to erosion within limestone and other rocks that eventually lead to sink holes, cracks running
along walls in caves, and streams. I. chose the Sof Omar Cave in Ethiopia and I looked at the first picture where it shows the massive body of water that was formed probably through cracks in the rock that are behind in the frame. There could potentially even be a sinkhole under the water or near it. Below is the picture and below that is the zoomed in area of what
im talking about.
2.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
3.
The most common bedrock that makes up karst topography is what?
limestone
4.
What are two negative impacts of karst topography?
Geomorphic hazards like sinkholes and degraded aquifers caused by floods
5.
What are three facts about karst topography from the provided links that you found interesting?
I found it interesting learning that sink holes are caused by karst topography, I never really knew how they came about and now I do which is pretty cool. It is sad though that people that live in in locations that are prone to topography have to be careful with where they build their homes.
In the first article I found it interesting that features of karst topography can be found in isolation and in clusters and can come in so many different
forms like being filled with vegetation and debris
In the second article I found the fact that 40% of groundwater in the united
states comes from karst aquafers and 20% of the us is underlain by the karst landscapes which have lots of contaminants and this can be hazardous for people drinking it.