Discovering Plate Tectonics Lab.docx (1)
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School
Colorado State University, Fort Collins *
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Course
121
Subject
Geology
Date
Dec 6, 2023
Type
Pages
8
Uploaded by GrandLightning12604
GEOL 121
Name
Lab Section
D
ISCOVERING
P
LATE
T
ECTONICS
Learning Objectives:
○
Summarize plate tectonics and demonstrate understanding of plate motions
○
Describe the features and processes found at different plate boundaries and
explain why they are found there
○
Developing geoscientific skills: analyzing/interpreting data; reading maps;
practicing quantitative skills; thinking in 3D
○
Understand that scientific inquiry is an ongoing/dynamic process; role of
evidence and technology in inquiry
Part 1: Expert analysis
(2pts.)
Geoscientists from different expertise areas will often collaborate to understand complex
problems. We are going to model this approach by having each of you become an expert on
one type of data. You will then share your understanding of that data with the rest of the group.
Instructions
:
Your TA will assign you one of the data sets listed below. Work with your expert group to
examine your dataset and answer the questions below.
Expert Groups (Circle Assigned Topic)
Seismology · Volcanology · Geochronology · Geography/Topography
1.
What is your data telling you? What do the symbols and colors mean?
When I look at the data i can see where all the earthqucksa have been record around the
world. The data also shows me the different levels of earth quacks. for example when i look
at the red i can see that it represents 0-33km of depth in the hypocenter. While other colors
like blue have a depth of 400-700 km of depth. This data shows the wide range of
magnitude on these earthquakes. The range is 7.0-7.5 all the way through 8.5-9.0.
2.
Compare your data to the Plate Boundary Map on the next page of this worksheet. Note any
differences or similarities.
-both of these pieces have is that earthquakes happen on the fault lines.
-earthquakes only occur around bodies of water.
3.
How does your data act on or near plate boundaries? (Examples: narrow/straight/curved,
symmetric/asymmetric, deep/shallow, active/inactive, ridge/valley, etc)
When looking at the data i can see that its all over these plate boundaries. They are mostly
occurring on there. You can see how it copies the line along with going through all of these
plate boundaries. Along the North American along with the Pacific Plate, you can see that
its separated by the mountain range which has a higher elevation and the ocean with a
negative elevation. The only plate that does not seem to be consistent throughout its
elevation is the Antarctic plate, making the elevation asymmetric.
Discovering Plate Tectonics
GEOL 121
Part 2: Examining Known Plate Boundaries
You will now examine sets of maps that show four different boundary types: divergent,
transform, convergent with subduction, and convergent without subduction. Answer the
following questions for each boundary type.
A) Divergent Boundaries (2pts.)
There are two pages showing divergent boundaries. One shows the Mid-Atlantic Ridge, in
the center of the Atlantic Ocean. The other shows a comparison of mid-ocean ridges that
are spreading (creating new ocean crust) at different rates, to give you an idea of how
different divergent boundaries can appear.
1) Describe how each of the datasets (Seismology, Volcanology, Geochronology,
Geography/Topography) behaves at this plate boundary.
Seismology: the earthquakes are following the correct behavior and aren’t doing
anything too random Earthquakes are deep and follow the plate boundary while
volcanos are minimal and spread out.
Volcanology: these volcanoes are a little bit out of place but they still have a pretty
normal behavior because they are near these boundary plates. Volcanos are minimal
due to the plate being divergent instead of transform or convergent.
Geochronology: the seafloor age is pretty normal and following all the norms. Divergent
plate boundaries causes sea floor spreading resulting in magma to appear, the large
line of red shows the younger layer of sea floor surrounded by older floor.
Topography: topography looks very normal and has no errors, it has all new seafloor as
well. The elevation is extremely low due to the being in the Mid-Atlantic ridge.
2) What are some distinguishing features at this type of plate boundary? What features
could you use to distinguish this boundary type from the others?
The divergent plate boundary is extremely low in elevation and it is noticeable to see
how few volcanos are in the area. A distinguishing feature of the divergent plate
boundary is how the majority of the sea floor is very young. The young sea floor is an
extreme difference that sets the divergent plates apart from transform or
convergent.Another distinguishing thing this plate boundary had was that it had almost
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Discovering Plate Tectonics
GEOL 121
no volcanoes around the plate boundary, usually there are a lot more than what you see
in this data sheet.
B) Transform Boundaries (2pts.)
There is one page showing a transform boundary along the western side of North America.
1) Describe how each of the datasets (Seismology, Volcanology, Geochronology,
Geography/Topography) behaves at this plate boundary.
Seismology: all of these earthquakes are normal and have no issues. The earthquakes
along the transform boundaries are red which represents how shallow they are, the
opposite of divergent boundaries.
Volcanology: all volcanoes are also doing their normal behavior without any issue. The
volcanos are close to the plate boundary and are not spread out, instead they tend to
either be in clusters along a thin tine with some scattered.
Geochronology: geochronology looks normal and has no issues. The seafloor is
extremely young and does not exceed over 60 million years, much younger than
divergent plates.
Topography: topography looks normal except the plate boundary isn’t easy to find its not
as outstanding as other plate boundaries. The deep sea floor turns into shallow sea
floor leading towards the mountain ranges with a drastic change in elevation. Although,
it is difficult to see a distinctive change in transformation boundaries
2) What are some distinguishing features at this type of plate boundary? What features
could you use to distinguish this boundary type from the others?
This image of transform boundaries provide a wide range of elevations between the
deep and shallow sea floor with mountain ranges and low valleys. The age of the sea
floor barely changes, which is unique to this area of plates. Something very distinctive
about these transforming boundaries is that the number of volcanos is significant due to
the plates being along the Ring of Fire.
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Discovering Plate Tectonics
GEOL 121
C) Convergent Boundary with Subduction (2pts.)
There are two pages showing convergent boundaries with subduction: one near Fiji in the
southwestern Pacific Ocean, and one along the west coast of South America.
1) Describe how each of the datasets (Seismology, Volcanology, Geochronology,
Geography/Topography) behaves at this plate boundary.
Seismology: the behavior of these earthquakes looks normal, all of these earthquakes
are happening closely to the plate boundary.The earthquakes in the convergent
boundaries with subduction range in all depths and happen frequently. All of the
earthquakes are clustered together when they do occur, but Fiji's convergent plate has
significantly more deep earthquakes that occur underwater.
Volcanology: the behavior of these volcanoes looks normal and has no issues, they are
all passing through the plate boundary or are very close to it. The volcanos are on the
opposite side of the subduction plate but still follow the plate boundary line.
Geochronology: the sea floor is behaving correctly but their is one fascinating thing
about it, it has a piece of land that is new and that is very odd because its in the middle
of the land. The seafloor does not have much data rather than the small pocket of
young sea floor with a further boarding older floor.
Geography: the geography on this is acting normally and doesn’t look odd, it also has a
much older surface. The topography in the images is rather shallow ocean along one
side of the convergent plate with deeper ocean on the other side.
2) What are some distinguishing features at this type of plate boundary? What features could
you use to distinguish this boundary type from the others?
A distinguishing feature of the plate boundary is the separation in topography on each side of
the plate; the image of the change in topography along Fiji's plate boundary is easier to see than
Chile. Another significant difference is the number of earthquakes and the variety of depths that
they have, unlike divergent plates.
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Discovering Plate Tectonics
GEOL 121
D) Convergent Boundary without Subduction (2pts.)
There is one pages showing a convergent boundary where subduction is not taking place in
the Himalayan Mountains where India is colliding with Eurasia.
1) Describe how each of the datasets (Seismology, Volcanology, Geochronology,
Geography/Topography) behaves at this plate boundary.
The topography shown provides high elevation of mountain ranges and shallower
ocean.
Seismology: earthquakes aren’t behaving the way that they should be because they are
all scattered around instead of following the plate boundary . Volcanology: volcanoes
aren’t behaving correctly, they are not following the fault line and are just scattered
instead. There are very few volcanos, and the volcanos that do exist do not follow along
the plate boundaries because they cannot form without subduction.
Geochronology: seafloor age is behaving pretty good and is following the right pattern of
behaviors. There is very minimal sea floor in the image shown, but the sea floor that is
provided is not young, instead it is leaning towards the oldest floor in the images.
Geography: geography is behaving normally and their aren’t any issues or concerns
with the way that it looks and behaves. The earthquakes on the convergent boundary
without subduction are all shallow, they do not exceed over 70km. Some earthquakes
are scattered but the majority are in clumps.
2) What are some distinguishing features at this type of plate boundary? What features
could you use to distinguish this boundary type from the others?
A distinguishing feature of this plate boundary is the lack of volcano formation due to no
subduction. Another identifiable feature is the minimal knowledge of sea floor, and the
sea floor that is provided is the only image with only older sea floor. the boundary plate
doesn’t go alone the coast. Instead it goes through a chunk of land.
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Discovering Plate Tectonics
GEOL 121
Check in with your TA before proceeding to Part 3.
Part 3: Unknown Boundaries
Now that you have developed a mental model of what each of the datasets does at different
plate boundary types, your challenge is to use the data to identify some unknown boundaries.
A) Unknown Boundary 1 (2pts.)
1) What type of boundary is there in this map?
Divergent
2) How do you know? What is your evidence?
I believe this due to the fact that the younger sea floor is in between the plates, along with
the fact that only small shallow earthquakes and evidence of a mid ocean ridge
B) Unknown Boundary 2 (2pts.)
1) What type of boundary is there in this map?
Convergent boundary with subduction
2) How do you know? What is your evidence?
When I look at this picture I can see that there is a lot of deep earthquakes. Another thing is
how there are alot of ocean trenches where the plate is definitely subducting and volcanoes
are on the overiddimng plate
6
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Discovering Plate Tectonics
GEOL 121
C) Unknown Boundary 3 (2pts.)
1) What type of boundary is there in this map?
Divergent
2) How do you know? What is your evidence?
I think this due to the fact that it has a small string of earthquakes, it also has young
seafloors and an island where the plates would be separating
D) Unknown Boundary 4 (2pts.)
1) What types of boundaries is there in this map (there is more than one type)?
Convergent with subduction
2) How do you know? What is your evidence?
When looking at the imagine i think this because there is a trench off the coast of the
continent. There is also a big mountain range thats formed along the plate boundary.
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Discovering Plate Tectonics
GEOL 121
Part 4: Reflection
(2pts.)
1) What are three things that you learned from this lab?
One thing that I learned from this lab is the ability to identify the different details within different
plate boundaries. I can now look at an assortment of details such as topography, earthquake
depth, and number of volcanos to be able to piece together what kind of plate boundary I am
looking at. Before this lab, I did not know how to describe seismic waves or geochronology, but I
am now able to understand what I am looking at in those images. A finally thing I learned from
this lab was how the plates move in each form of boundary. I can identity the movement of
convergent, transform, and divergent plates
2) What questions do you still have about identifying plate boundaries?
I do not have any questions about identifying plate boundaries, but would like to practice more
on identifying them through geochronology and topography.
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