Discovering Plate Tectonics Lab
docx
keyboard_arrow_up
School
Colorado State University, Fort Collins *
*We aren’t endorsed by this school
Course
121
Subject
Geology
Date
Dec 6, 2023
Type
docx
Pages
8
Uploaded by CoachHedgehogPerson992
GEOL 121
Tim Trostel
Lab Section L18
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
1.
What is your data telling you? What do the symbols and colors mean?
The data is telling us the location of each earthquake, along with their depths and magnitudes.
2.
Compare your data to the Plate Boundary Map on the next page of this worksheet. Note any
differences or similarities.
The locations of the earthquakes line up perfectly with the plate boundary lines.
3.
How does your data act on or near plate boundaries? (Examples: narrow/straight/curved, symmetric/asymmetric, deep/shallow, active/inactive, ridge/valley, etc)
Almost all of our seismic activity occurs directly on top of the plate boundary lines. Though the depths of the earthquakes are not consistent.
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: There are shallow earthquakes among the entire Mid-Atlantic Ridge. There is also a large cluster of shallow earthquakes to the plant boundary going between Europe and
Africa. Volcanology: There are just a few volcanoes scattered along the plate boundary.
Geochronology: There is new crust along the boundary and the crust gets older the closer to land it gets. Topography:
The topography shows elevated sea floor levels directly on top of the plate boundary. This is due to the new crust forming there.
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?
Some distinguishing features of this plate boundary are the shallow earthquakes and the elevated sea floor. This tells us that there is new crust being formed into mountains so it must be divergent. 2
Discovering Plate Tectonics
GEOL 121
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: There is very high earthquake activity, which almost all are shallow. It follows right along the boundary line.
Volcanology: There are quite a few volcanoes formed to the east of the boundary line.
Geochronology:
There is new crust being formed right along the land from all the volcanic activity. Topography: There is high elevation on the continental plate and fairly shallow ocean levels.
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?
Some distinguishing features about this type of boundary are the sheer amount of shallow earthquakes located right on the boundary line. This tells us that this is a transform plate boundary. 3
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
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: There are many deep earthquakes on top of and slightly to the side of the boundary line.
Volcanology: There are many volcanoes formed on the land off center of the boundary line.
Geochronology:
Right off of the land there is a lot of new crust being formed.
Topography: There is a deep ocean trench
and high elevation on the land.
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?
Some distinguishing features of this boundary are the deep ocean trench, the deep earthquakes, and the large amount of volcanoes formed on the land. All of those are unique to convergent boundaries with subduction. 4
Discovering Plate Tectonics
GEOL 121
D) Convergent Boundary without Subduction (2pts.)
There is one page 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. Seismology: There are many shallow earthquakes with deep earthquakes at the corners of the plate.
Volcanology: There are very few volcanoes formed on the land near the boundaries.
Geochronology: There is no new crust being formed
Topography: Right of the boundary there is a massive mountain collection.
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?
Distinguishing features of this boundary are the lack of new crust being formed, the massive mountain collection right on top of the boundary line. This is unique to convergent boundaries without subduction.
Check in with your TA before proceeding to Part 3.
5
Discovering Plate Tectonics
GEOL 121
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?
There is a convergent without subduction boundary on this map.
2) How do you know? What is your evidence?
There are mountains being formed right along the boundary line with very shallow earthquakes meaning it must be without subduction.
B) Unknown Boundary 2 (2pts.)
1) What type of boundary is there in this map?
There is a convergent with subduction boundary on this map.
2) How do you know? What is your evidence?
There are many deep earthquakes and trenches found along the edge of the boundary line. There are also many volcanoes found on the plate that did not subduct, therefore this must be a convergent boundary with subduction.
6
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
Discovering Plate Tectonics
GEOL 121
C) Unknown Boundary 3 (2pts.)
1) What type of boundary is there in this map?
This is a transform boundary. 2) How do you know? What is your evidence?
There is a lot of new crust formed right on top of the boundary line. There are also shallow earthquakes that line the boundary. The elevation is unchanged so this must be a transform boundary.
D) Unknown Boundary 4 (2pts.)
1) What types of boundaries is there in this map (there is more than one type)?
There are two types of boundaries on this map. There is a convergent boundary with subduction and there is a divergent boundary.
2) How do you know? What is your evidence?
The convergent boundary is just below Mexico. There are deep earthquakes and volcanoes on the plate that did not subduct. The divergent boundary is located along the west coast of Mexico. There is high elevation along the boundary line and new crust is being formed. There are also very few volcanoes.
7
Discovering Plate Tectonics
GEOL 121
Part 4: Reflection (2pts.)
1) What are three things that you learned from this lab?
I learned how to tell the difference between convergent boundaries with and without subduction. I learned that divergent boundaries form higher elevation and new crust. I learned that the Himalayas are formed from a convergent boundary without subduction. 2) What questions do you still have about identifying plate boundaries?
I can not think of any other questions at this time. 8