Lesson Plan 2
LESSON PLAN CODE: S-8-4-2
SUBJECT: Science
GRADE LEVEL/COURSE: Eighth grade
TITLE: The Rifting of Pangaea and the Gettysburg Battlefield
ALIGNMENTS:
Eligible Content: S8.C.2.1.1, S8.C.2.1.3, S8.D.1.1.2
Key Words: continental rifting, Gettysburg battlefield, Gettysburg rift basin, Gettysburg sill,
heat engine, lithosphere, mantle, Pangaea, rift basin, sill
VOCABULARY (TIER III):
 Heat engine: Transforms heat into mechanical motion.
 Lithosphere: The strong, rigid outermost shell of Earth composed of the crust and the
upper portion of the mantle.
 Mantle: The layer of rocky material between Earth’s crust and core.
 Rift basin: A large, low area in the Earth’s surface that forms when land masses are torn
apart.
 Extrude: When magma flows out on the Earth’s surface.
 Igneous: Refers to rocks that solidified from magma and lava.
OBJECTIVES:
In this lesson, students connect heat transformations within the Earth to rifting and formation of
igneous rock units. Students will:
 analyze and interpret an animated model of Earth’s rifting processes.
 connect Earth’s rifting processes with the Earth’s surface in the Gettysburg battlefield.
 extend geologic histories from Lesson 1 back in time to include the formation of the rift
basin and igneous sill in the Gettysburg area.
 apply the heat engine model of the Earth to the continental rifting that occurred in the
Gettysburg area millions of years ago.
ESSENTIAL QUESTIONS:
 What causes the great variation at Earth’s surface?

How do energy transformations explain that energy is neither created nor destroyed?
DURATION:
90 minutes/1–2 class periods
MATERIALS:
 computer with Internet access, projector, and screen
 group illustrated geologic histories from Lesson 1
 “Earth on a Slow Boil” article (see S-8-4-2_Earth on a Slow Boil Article in the Resources
folder)
 butcher paper per group and markers
SUGGESTED INSTRUCTIONAL STRATEGIES:
(Strategies: Active Engagement, Explicit Instruction)
W:
Students construct geologic histories for the formation of the rift basin and the igneous
sill in the Gettysburg area to enhance their geologic histories from Lesson 1. Students
interpret the Earth’s surface in the Gettysburg area in terms of a heat-engine model of
Earth.
H:
Students hypothesize connections between the rifting of Pangaea and the Earth’s surface
on the Gettysburg battlefield.
E:
Students analyze and interpret an animated model of continental rifting from a heatengine point of view.
R:
The class analyzes and connects heat energy transformations to ancient continental rifting
in the Gettysburg area.
E:
Students work in groups to construct geologic histories for the formation of the rift basin
and igneous sill in the Gettysburg area to enhance their geologic histories from Lesson 1.
T:
Use the following strategies and activities to meet the individual needs of your students
during the lesson and throughout the year. Post warm-up questions on the board that
focus on the content objective for the day. Students should speak and write in complete
sentences during class in order to develop scientific academic language and clarify their
reasoning. Give ample wait time for processing, provide sentence starters, give verbal
and visual cues, accept verbal responses, and reduce written responses.
Students construct geologic histories for the formation of the rift basin and the igneous
sill in the Gettysburg area to enhance their geologic histories from Lesson 1. Students
interpret the Earth’s surface in the Gettysburg area in terms of a heat-engine model of
Earth. To begin, students hypothesize connections between the rifting of Pangaea and the
Earth’s surface in the Gettysburg battlefield. Students proceed to analyze and interpret an
animated model of continental rifting from a heat-engine point of view. The class then
analyzes and connects heat energy transformations to ancient continental rifting in the
Gettysburg area. At the end of the lesson, students work in groups to construct geologic
histories for the formation of the rift basin and igneous sill in the Gettysburg area to
enhance their geologic histories from Lesson 1. Students submit their group geologic
histories for teacher review.
O:
INSTRUCTIONAL PROCEDURES:
“Today we’re going to extend your geologic histories of the Gettysburg battlefield back in
time to the breakup of Pangaea.”
“What was Pangaea anyway?” A supercontinent that existed from 200–300 million years ago.
“Where did Pangaea start to break apart?” In the area of what is now Gettysburg along old
convergent plate boundaries of what are now Africa and Pennsylvania (North America). “How
do you think this breakup of Pangaea might have affected the present day Gettysburg
area?” Facilitate a class discussion.
“Let’s take a look at this animation to see what started to happen in the Gettysburg area
about 200 million years ago.” Go to
http://esminfo.prenhall.com/science/geoanimations/animations/35_VolcanicAct.html and click
on the Continental Rift Volcanism. Focus attention on the animation to the left (formation of
plateau basalts did not occur in this area) and facilitate a class discussion analyzing and
summarizing the Earth processes depicted. The brown and tan layers represent the crust and
upper mantle of the lithosphere. Call attention to the arrows in the tan layer that represent forces
pulling in opposite directions on the Earth’s lithosphere. Move the toggle slowly through the
animation. The hot material (shown in red and orange) wells up from the mantle, pushing up on
the lithosphere, and producing the rifting forces that stretch the lithosphere until it breaks. The
lithosphere cracks (faults) and big blocks of the lithosphere shift downward, creating rift basins
(in this case the Gettysburg rift basin). Magma develops below the rift basins and moves towards
the Earth’s surface, intruding into the lithosphere and extruding on the Earth’s surface. Although
not pictured, some magma forces its way in between rock layers in the lithosphere, forming sills
like the Gettysburg sill.
“So, what started all of this rifting anyway?” Upwelling of hot mantle material. “What
causes this movement of hot mantle material?” Refer to the “Earth on a Slow Boil” article
(see S-8-4-2_Earth on a Slow Boil Article in the Resources folder) to discuss the Earth as a heatengine model. Then go to
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0805/es0805page01
.cfm?chapter_no=visualization to discuss convection currents in the mantle.
“So, let’s summarize our analysis of what happens …” Facilitate a class discussion. Heat
from inside the Earth causes material within the Earth to heat up and become more buoyant (less
dense). The more buoyant material rises up past more dense material. As this heated material
moves up towards the Earth’s surface, it spreads apart, cools, and sinks back down. The
movement of the heated material tugs in opposite directions on the lithosphere overlying the
spreading center, causing it to break (rift) and great basins shift downward. Portions of the
heated material melt, forming magma that intrudes into the lithosphere and flows out on the
Earth’s surface as lava.
“You’re going to work today again in the same groups from Lesson 1. I’m going to return
your geologic histories to you so you can create and add a rifting ‘prequel.’ Be sure to
include labeled diagrams to illustrate your new chapter.”
Extension:


For students requiring further practice with the standards, they can complete a compare
and contrast the mechanisms of a combustion engine (automobile) with the convection
currents present in the Earth’s interior. Students would present their information in essay
form or a poster.
Students hypothesize a scenario where Earth’s internal core has stopped producing heat.
Students will create a timeline, highlighting significant events that would happen once
heat production stopped. Timeline events would highlight the following:
 Climate
 Tectonic forces
 Civilization
 Living organisms
FORMATIVE ASSESSMENT:
 Observe students during class and group discussions, providing feedback in order to
facilitate fair and appropriate partner work.
 Provide feedback and guide student understanding during the analysis of the animated
model of continental rifting in order to help students associate common features of an
engine with the more complex inner workings of Earth’s interior.
 Geologic histories and the group discussions surrounding the creation of them are
relevant to the lecture in order to keep students on task.
RELATED RESOURCES:
 Continental rift volcanism:
http://esminfo.prenhall.com/science/geoanimations/animations/35_VolcanicAct.html
 The Restless Earth: A Geologic Primer:
http://www.washington.edu/burkemuseum/geo_history_wa/The%20Restless%20Earth%20v.
2.0.htm
 Animation of Convection in the Mantle:
http://www.classzone.com/books/earth_science/terc/content/visualizations/es0805/es0805pag
e01.cfm?chapter_no=visualization
 “Earth on a Slow Boil” article:
http://www.washington.edu/burkemuseum/geo_history_wa/The%20Restless%20Earth%20v.
2.0.htm