Earth Detectives!!
Lorentyna Baldus (baldusl@grps.k12.mi.us)
Objective:
Using notes, readings and presentations from the unit, the student will, with the help of a group, identify a rock
and describe its characteristics. The student will then determine the geologic history of an area based on group
rock presentations.
Michigan State Standards
GLCE:
S.IP.M.1 – Inquiry involves generating questions, conducting investigations, and developing solutions to
problems through reasoning and observation
S.IA.M.1 – Inquiry includes an analysis and presentation of findings that lead to future questions, research and
investigations
S.RS.M.1 – Reflecting on knowledge is the application of scientific knowledge to new and different situations.
Reflecting on knowledge requires careful analysis of evidence that guided decision-making and the application
of science through out history and within society
E.SE.M.4 – Rock Formation – Rocks and rock formations bear evidence of the minerals, materials,
temperature/pressure conditions, and forces that created them
E.SE.M.5 – Plate Tectonics – The lithospheric plates of the Earth constantly move, resulting in major geologic
events, such as earthquakes, volcanic eruptions and mountain building
E.ST.M.4 – Geologic Time – Earth processes seen today (erosion, mountain building, and glacier movement)
make possible the measurement of geologic time through methods such as observing rock sequences and using
fossils to correlate the sequences at various locations
HSCE:
E1.1 Scientific Inquiry
E1.1D – Identify patterns in data and relate them to theoretical models
E1.1E – Describe a reason for a given conclusion using evidence from an investigation
E1.1g – Based on empirical evidence, explain and critique the reasoning used to draw a scientific
conclusion or explanation
E2.1 Earth Systems Overview
E2.1B – Analyze the interactions between the major systems (geosphere, atmosphere, hydrosphere,
biosphere) that made up the Earth
E3.p1 Landforms and Soils (prerequisite)
E3.p1A – Explain the origin of Michigan landforms. Describe and identify surface features using maps
and satellite images
E3.p1B – Explain how physical and chemical weathering leads to erosion and the formation of soils and
sediments
E3.p2 Rocks and Minerals (prerequisite)
E3.p2A – Identify common rock-forming minerals
E3.p2B – Identify common igneous, metamorphic, and sedimentary rocks and describe the processes
that change one kind of rock to another
E3.1 Advanced Rock Cycle
E3.1A – Discriminate between igneous, metamorphic, and sedimentary rocks and describe the processes
that change one kind of rock into another
E3.1B – Explain the relationship between the rock cycle and plate tectonics theory in regard to the
origins of igneous, sedimentary, and metamorphic rocks
E3.1c – Explain how the size and shape of grains in a sedimentary rock indicate the environment of
formation (including climate) and deposition
E3.1d – Explain how the crystal sizes of igneous rocks indicate the rate of cooling and whether the rock
is extrusive or intrusive
E4.p3 Glaciers (prerequisite)
E4.p3A – Describe how glaciers have affected the Michigan landscape and how the resulting landforms
impact our state economy
E5.3 Earth History and Geologic Time
E5.3C – Relate major events in the history of the Earth to the geologic time scale, including the
formation of the Earth, formation on an oxygen atmosphere, rise of life, Cretaceous-Tertiary (K-T) and
Permian extinctions, and Pleistocene ice age
Big Ideas of Earth Science:
Big Idea 1: Earth scientists use repeatable observations and testable ideas to understand and explain our planet.
- Students are synthesizing what they learned though out the unit to explain the geologic history of an
area.
Big Idea 2: Earth is 4.6 billion years old.
- The various rock samples illustrate how the geologic history of the earth has been recorded
Big Idea 3: Earth is a complex system of interacting rock, water, air and life.
- Students are using knowledge of the rock cycle and how other systems are interacting with rock (i.e.
the water cycle)
Big Idea 4: Earth is continuously changing.
- The rock cycle, plate tectonics, weathering and erosion all play a part in this activity.
Big Idea 5: Earth is the water planet.
- Specific samples used in this activity are formed with the help of water
Background:
This activity would come at the end of a rock unit. Both middle level and high school content expectations are
listed and could be adapted to both grade levels. The content knowledge needed for this activity would include
the basic rock types and common examples of each of the three types, how they are formed, sedimentary
structures and how they would form, and where different rock types would be found. This lesson is written to be
done in groups, but individual students could complete the activity in a station format.
Local geology would need to be understood before selecting rock samples for this activity. A National Park
would be a great example because the geology is more known for those areas and can be found on the website
listed below. However, find rocks outside of the park, not inside the park.
Claim – Evidence – Reasoning is a way of answering scientific questions. Students develop a claim based on
what they learned through out a chapter or unit. This claim would answer the question posed by the teacher
usually at the beginning of the chapter or unit. The students back up their claim with evidence. This evidence
could be data students collected while doing investigations, facts from readings or notes. Students then explain
how the evidence relates to their claim (reasoning).
For more information:
Peterson Field Guides – Rocks and Minerals
www.nps.gov
www.earthscienceliteracy.org
Vocabulary:
Rock Cycle – continuous process that changes rock types over time
Igneous – rocks that form from volcanic processes
Metamorphic – rocks that are changed by extreme heat and pressure
Sedimentary – rocks that form by sediments being cemented together
Ripple Marks – small ripples on sand from waves or wind; evidence of shallow water, ancient shoreline
Mud Cracks – cracks in the sediment due to drying
Graded Bedding –progressive decrease in grain size from the bottom of the bed to the top
Cross Bedding – produced by sediments being deposited at an angle (i.e. sand dune)
Materials:
Rock samples (of local geology) – this lesson was designed around Isle Royale National Park. Most of the rocks
can also be found in the Keweenaw, and therefore, can be collected legally. The samples would include:
basalt, conglomerate, sandstone, ripple marks, graded bedding, cross bedding, amygdaloid, and an
erratic, such as granite or gneiss.
Poster board/large paper (rolls of butcher paper work well)
Markers/crayons/colored pencils (watch for sales in the summer)
Students’ notes from unit
Textbook
Before Lesson:
Make sure to have enough different rock samples for student groups of 3-4 students. Copy student handouts to
have enough for each student and have C-E-R instructions and rubric ready to hand out after presentations.
Claim-Evidence-Reasoning (C-E-R) needs to be understood by students in order to complete the assessment
portion. If this has not been taught, do so before this lesson and have examples. If this is the first C-E-R the
students will be completing, walk through it with them and adjust the scoring accordingly, if needed.
Teachers should plan for at three class periods to complete this activity. The first day will be explaining the
activity, grouping students and groups beginning their posters. The second day, groups will finish their posters
and presentations will start. The third day, presentations will finish (if this was not done on day two) and
students will complete the C-E-R assessment.
Procedure:
1. Pass out the “Earth Detectives” student handout to each student.
2. Read the directions and the steps. Answer any questions the class has.
3. Put students into groups of 3-4 students in each group. Use the method of grouping students that works
best for your classroom.
4. Give each group a rock sample
5. Groups will complete the questions on the handout regarding their rock sample
6. Groups will create a poster with the information about their rock included
7. Each group will present their posters
8. Students will take notes as groups are presenting
9. Pass out “Evaluation: Claim-Evidence-Reasoning” and explain directions
10. Students complete C-E-R individually
Hands-on Connections:
Using rock samples from an area the students are familiar with will be more meaningful and will spark their
curiosity to learn more. Also, students should recognize physical features of an area they are familiar with. For
example, students in Grand Rapids, MI are very familiar with the Grand River running through downtown and
some are aware of the gypsum mine located in the city. Having a slide show of the geologic history of the area
at the conclusion of the activity (after the evaluation) would give students a visual of what occurred in their own
backyard, so to speak.
An example of rock samples - these were from Isle Royale and some
where found in the N. King Huber collection.
Assessment Rubric:
See student handout for scoring rubric
Earth Detectives!!
I was out collecting rocks one day and wondered where they came from. I need your help; they
must have a story! Each group will be given a rock. It is your job, as Earth Detectives, to
determine what it is. You may use your notes and textbook to help develop a presentation that
answers the following questions:
1. Which of the three rock types is your rock? __________________________
2. What is the name of the rock? ____________________ How do you know? ___________
_______________________________________________________________________
3. How would this rock have formed? ___________________________________________
_______________________________________________________________________
_______________________________________________________________________
4. What significant features does it have, if any? __________________________________
_______________________________________________________________________
5. Where could this rock have been found? ______________________________________
Create a poster with all the information above included. Make sure you add a picture of your
rock! As always, neatness and creativity earn extra credit!! 
Presentations of each groups’ findings (hint: take good notes!!)
Group 1 _____________________
Notes:
Group 2 _____________________
Notes:
Group 3 _____________________
Notes:
Group 4 _____________________
Notes:
Group 5 _____________________
Notes:
Group 6 _____________________
Notes:
Group 7 ____________________
Notes:
Group 8 ____________________
Notes:
Evaluation: Claim-Evidence-Reasoning
Surprise! All of these rocks were found in the same place. How can that be? They are all
so different. Based on what we have discussed this unit, make a claim as to where this place is
and its geologic history. Don’t forget to back up your claim with evidence and reasoning. You may
use only the notes you took during the presentations. Read the rubric carefully so you know
what it takes to get full credit!
Grading Rubric
Claim
Evidence
Reasoning
Mechanics
5 points
Claim is
given that
answers the
question in a
complete
sentence
with detail
5 pieces of
evidence are
used
correctly
5 pieces of
evidence are
correctly
liked back to
your claim
Paragraphs
indented,
full
sentences,
correct
grammar and
punctuation
4 points
Claim is
given that
answers the
question in a
complete
sentence
3 points
Claim is
given that
answers the
question
4 pieces of
evidence are
used
correctly
4 pieces of
evidence are
correctly
linked back
to your claim
Full
sentences,
correct
grammar and
punctuation
3 pieces of
evidence are
used
correctly
3 pieces of
evidence are
correctly
linked back
to your claim
Full
sentences,
correct
grammar
2 points
Claim is
given in a
complete
sentence but
does not
answer the
question
2 pieces of
evidence are
used
correctly
2 pieces of
evidence are
correctly
linked back
to your claim
Bullet points
used instead
of
paragraphs
and full
sentences,
correct
grammar
1 point
Claim is
given in a
bullet point
0 points
No claim
given
1 piece of
evidence is
used
correctly
1 piece of
evidence is
correctly
linked back
to your claim
Bullet points
used instead
of
paragraphs
and full
sentences
No evidence
used or all
evidence was
incorrect
No evidence
is linked
back to your
claim
What was
written does
not relate to
assignment
CER Grade ______/15
Poster Grading
Title
Rock Type
Name of Rock
How do you know
_____/5
_____/5
_____/5
_____/10
How formed
Significant features
Where found
Extra credit
Total
_____/10
_____/5
_____/10
+_____
_____/50