This is a partially developed activity description. It is included in the collection because it contains ideas useful for teaching even though it is incomplete.
Ideas for teaching about the early solid earth
These teaching ideas were submitted during the April 2007 workshop on Teaching About the Early Earth. They represent collaborative brainstorming rather than finished products, but they are a useful starting point when seeking ideas for your classroom.
What's up with continental crust? How did it form? When did it form? How fast or slow did it form?Submitted by Megan Jones, Darrell Henry, Mark Leckie, Lindy Elkins-Tanton, Joe Reese, Bosiljka Glumac, Bob Bauer
1. Intermediate majors course, maybe honors course - Literature-based discussion
Based on John Valley Scientific American Paper [Valley, 2005] . All students read article. One student presents. One week before presentation they must hand out 10 questions that students must answer and come to class with them answered so that they can be prepared for discussion.
Goals:All students: read primary literature, class discussion, assessment Individual student: give presentation, develop key questions from article, assessment.
ExampleHere is an example of a literature-based assignment using this topic, submitted by Dr. Lindy Elkins-Stanton, Massachusetts Institute of Technology. Scientific Paper Reading: Continental Growth (Microsoft Word 42kB Jul17 07) The file includes the reading list used in an introductory course for earth science majors.
2. Introductory Level - Jigsaw
Content:Different hypotheses for crustal growth- rapid vs. slow growth rates—can discuss before (intro, major) or after jigsaw group (non-major, intro)
Data:Three graphs or papers
- Rapid burst growth graph
First, expert groups for each graph or paper
Second, mixed group and explain their data to each other and form questions about their data discussion
Third, groups present their findings
- What conclusion did they get from their discussion?
- How did they weight the data to get to their conclusion?
- What would you do next?
Get paper references:
- Richard Armstrong—review paper: crustal growth curves
- John Valley—oxygen isotope
- Taylor, Scott McClellan—crustal growth curve paper
- Steven Parman—helium papers
Follow-up (major courses)—go back to specialty group and find out about methods.
Have students go find out about methods used in papers above.
Demonstrate relevance: look at curves, crustal growth, of present day and make predictions about future development of shallow water platforms necessary for evolution of atmosphere and life.
How do planets lose heat?Submitted by: John Zawiskie, James Kasting, Mark Skidmore, Joel Thompson, Alberto Patio, Joe Hill, Dianna Czeck
Comparative planetology activity between Earth, Venus, and Mars
Use global surface topography maps to determine tectonic and volcanic style differences.
How can we infer changes in heat flow over time for the Earth?
- Inference from radioactive decay curves activity
- Archean versus younger rock types as evidence: komatiites and basalts
Impact CratersSubmitted by: Alisa Hylton, Michelle Markley, Julie Baldwin, Susan Conrad, Huiming Bao
- How did the Earth first form?
- How did impacts affect the early Earth?
- Was there a magma ocean?
- What were the differences between the magma ocean on the Earth and Moon?
Goals and objectives
Clarification of gaps in knowledge such as atmosphere, ocean what surface was like.
Looking at the surface of moon can give analogy of early Earth surface.
Activities:Begin with pictures of volcanic craters and compare with impact craters.
Create model craters in flour by dropping marbles. Take measurements of height of drop, size and depth of crater, and ejecta.
View clip from "Deep Impact"
JigsawGroup #1 ages of rocks on moon and Earth
Group#2 composition of Earth and moon
Group#3 morphology of craters on moon and Earth
Group#4 morphology of craters on Earth
Reassemble to answer question: How did impacts affect early Earth?
How did the Earth form through accretion, and how is this process related to the age of the Earth?Submitted by: Becky Teed, Bruce Oldfield, Wally Borowski , Stan Awramik, Susan Childers, Dave Mogk
I. Problem: Age dating is a fundamental method of finding the age of earth materials.
- However, we can only sample the shallowest portion of the Earth rx (<200km?).
- How can we find the age of the Earth?
Background and Context:
- Explain nebular hypothesis
- Planets grow by accretion of "space stuff."
Exercise - Meteorite age data set
- Graph age frequency versus age.
- Can be done with "clean" data set by hand or Excel; or can introduce complexity with "dirty" data set.
Group Thinking activity
- Interpret the graph
- What is the connection between these meteorite dates and our estimate for the age of the Earth?
- Method of age-dating Earth
- Reason for age of Earth
II Problem: Given the heat production curve of the Earth, what are the components that contribute? A) kinetic energy from impact to heat, b) Radionuclides c) potential energy liberated due to sinking of dense (Fe) material to the core
Background and Context:
- Explain availability of heat available to do work in Early Earth system (melting, differentiation)
- Compare with Kelvin's early calculations of heat production and age of earth
- Contribution of "extinct" isotopes
- Review heat available to do work throughout Earth history - magma ocean, formation of continents, why no Precambrian blueschists?
- Project to the future - when will plate tectonics shut down?
- Back of envelope calculation of kinetic energy transferred to heat during impact; bolide of certain mass, moving at velocity, what energy is liberated; how much melt can be generated (latent heat of melting). Different sizes of planetismals -- what work will be done for different conditions.
- Practice in making graph--show contributions of various heat sources to construct heat curves.
- Comparative planetology - what are the heat production curves from Venus and Mars? Discuss and reach an understanding of how those curves were produced. Consider factors such as planetary size/mass, composition, and volatiles.
How did the Earth form?
Linda Sohl, Mike Phillips, Aaron Cavosie, Staci Loewy, Shoichi Kiyokawa, Paul Mueller, Mike Williams
Course: Historical Geology (undergrad), especially for large lecture classes
Discuss the history of hypotheses regarding the formation of the Earth; show how the discarding of old hypotheses does not mean that nothing is known, merely that new hypotheses need to be created from existing data (i.e., show how science progresses)
Exploring the significance of the Jack Hills zircons
- Use "Ripley's Believe It or Not" or other popular article as a launching point
- Show images of the Jack Hills location, other pics of Australia; relative sizes of zircons, pennies, etc. to make it "real" to students (zircon images)
- Give students Scientific American article on zircons [Valley, 2005] to read