Free / Grades 5-6, with reading support
Rock Evidence Lab
What can rocks tell us about the order of events, and what remains unknown?
4 flexible sessions / about 155 minutes including practice / Earth processes, measurements and evidence-based explanations
Suggested rhythm: two sessions a week for two weeks. First explore processes; then build and revise a history. Speak, dictate or work on paper, and take longer when useful.
Reading, watching and paper activities are free. Parents and instructors can save a collection; scheduling it for a student requires Plus or Lifetime. No upload is required.
Before you begin
Read a short evidence card, subtract whole-number measurements and explain a before-and-after relationship. No rock identification or collecting experience is needed.
Paper evidence, not a collecting trip. No collecting, climbing, digging, hammering, heating, freezing, acids or dust experiments. Use only the invented records and drawings. Do not taste or lick rocks or handle unknown samples. No outdoor visit, rock purchase, upload or public presentation is needed.
Materials
- 4 sheets per learner: Project journal
Print four pages or copy their headings into a notebook.
- 2 sheets per learner: First explanation and revised history
Use clean scrap paper and retain both versions.
- 1 per learner: Pencil
Speak, dictate, point or use an accessible writing tool.
- 1 shared: Browser or printed teaching pages
Read the transcript and supplied evidence together; separate worksheet printing is optional.
Choose the support that fits
- More support: read one event aloud and sort it as breaking down, moving or settling. Use letter labels and pointing rather than copying whole sentences.
- More challenge: draw a different valid pathway or event order, then specify which extra evidence would distinguish it. Keep unknown years unknown.
- Access options: all drawings have written equivalents. A private spoken or dictated explanation can replace handwriting; collecting and uploading are never required.
What good evidence looks like
- Distinguish breakdown, transport and deposition using the stated event.
- Name a formation process, not just a rock color.
- Use the stated upright, undisturbed-layer condition when ordering deposition.
- Separate thickness and event order from an age in years.
- Retain an original explanation and justify a revision with new evidence.
These are discussion criteria, not a new automatic score. Existing lesson and worksheet records keep their own subjects. Checking off a planned task does not demonstrate mastery or add a second grade.
Session 1 / about 35 minutes
Break, move and settle
Goal: Identify weathering, erosion and deposition from an event description, and avoid guessing a missing process.
Preparation / about 8 minutes of adult support: Prepare journal 1 and a first-explanation sheet. Read the supplied cards; no real rock or water experiment is required.
Weathering breaks down or changes rock where it is. Erosion removes and transports material; deposition happens when transported material settles or is left behind. In a worked story, ice widens a crack, a stream carries the loosened pieces, and pieces settle on a bar. Those are three different processes, even if they belong to one journey. A crack by itself does not prove that anything traveled. A sand pile by itself does not tell us the transport route. Rocks do not come with tiny delivery receipts, so we must read the evidence we actually have.
Which words show motion? What evidence would you need before claiming that a fragment traveled from a particular hill?
- Separate Weathering, Erosion, and Deposition / about 10 minutes
- Sort the process evidence / about 15 minutes
- Keep my first rock-history explanation / about 10 minutes
Fun fact: Mechanical weathering can break a rock into smaller fragments without changing the chemical makeup of its individual minerals. Source
S3U / Rock Evidence Lab / Journal 1 of 4
A process needs evidence
Invented cards: A, a root widens a crack and the pieces stay beside it. B, wind carries loose grains across a dry surface. C, those grains stop moving and collect behind an obstacle. D says only: loose grains were found. Name the supported process for A-C; explain what D cannot establish.
| Record | Supported process and evidence |
|---|---|
| A: crack widens; pieces remain | |
| B: grains move with wind | |
| C: transported grains collect | |
| D: loose grains, no journey recorded |
Explain why breaking a piece and moving it are not the same event. Could both happen during a longer story?
On a separate sheet, answer the opening question: What could rock layers tell us, and could a drawing alone tell their age in years? Keep this first explanation for session 4.
Session 2 / about 40 minutes
Choose a pathway, not a race track
Goal: Connect three rock groups to formation processes and explain why a rock need not follow one fixed cycle.
Preparation / about 8 minutes of adult support: Prepare journal 2. The familiar video is introductory support; the new cards require a reason about formation rather than a visual rock guess.
Igneous rock forms as molten rock cools and solidifies. Many sedimentary rocks form when deposited fragments become compacted and cemented; other sedimentary rocks form in other ways, including minerals forming from solution. Metamorphic rock changes from an existing rock while remaining essentially solid, under conditions such as heat and pressure. Melting followed by solidifying belongs to an igneous pathway, not simply metamorphism. These processes offer several routes. An igneous rock might be weathered into sediment or changed by metamorphism. It does not need to collect three rock-group stamps in a fixed order.
Which word separates cooling molten material from changing an existing solid rock? Can a group name alone give a rock an age in years?
- Rock detectives / about 10 minutes
- Follow More Than One Rock-Cycle Path / about 10 minutes
- Explain the formation cards / about 20 minutes
Fun fact: The rock cycle has no required starting point and includes many possible pathways, rather than one compulsory lap. Source
S3U / Rock Evidence Lab / Journal 2 of 4
Formation, not a color guess
Invented records: J formed as molten material cooled and solidified. K formed when buried sand was compacted and cemented. L changed under heat and pressure while remaining solid. M is described only as dark. Use the formation evidence; a color alone is not a formation record.
| Record | Group supported, or missing evidence |
|---|---|
| J: cooled from molten material | |
| K: sand compacted and cemented | |
| L: existing solid rock changed | |
| M: described only as dark |
Draw or describe two possible next pathways for the rock in J. Name the processes; do not require it to pass through every group.
Repair this claim: Heating a rock always makes it igneous. Explain the difference between changing while solid and melting followed by solidifying.
Session 3 / about 35 minutes
Read order without inventing years
Goal: Order deposition in a stated upright, undisturbed sedimentary column and distinguish thickness from elapsed time.
Preparation / about 8 minutes of adult support: Prepare journal 3. Read the condition before the labels: these are upright layers with no overturning or faulting, not every real rock exposure.
For the upright, undisturbed sedimentary layers in our model, lower layers were deposited before the layers above them. In the worked column, U is below V and V is below W, so their deposition order is U, V, W. This is a relative order, not an age in years. A layer that is twice as thick did not necessarily take twice as long to form: deposition rates can differ and time may be missing between deposits. Real layers can later tilt, fold or overturn. Read the stated conditions instead of giving every rock drawing the same answer.
What does older than establish? What information is missing when someone says that each drawn layer represents exactly one thousand years?
- Order the layer records / about 15 minutes
- Compare thickness without inventing time / about 10 minutes
- Write an evidence-limited conclusion / about 10 minutes
Fun fact: Geologists can establish an event order from relationships between rocks even when that evidence alone supplies no numeric ages. Source
S3U / Rock Evidence Lab / Journal 3 of 4
Order is not a birthday
An invented upright, undisturbed sedimentary column has R at the bottom, 8 m thick; S in the middle, 2 m thick; T at the top, 5 m thick. No deposition rates or numeric ages are given. Another drawing shows folded rocks but gives no evidence that the sequence stayed upright.
| Question | Conclusion and its limit |
|---|---|
| R, S and T: deposition order | |
| How much thicker is R than S? | |
| Does thickness give the years taken? | |
| Can the folded drawing use the same shortcut? |
Respond to: S is thinnest, so it must be youngest. Cite the position evidence and the stated condition.
Write one statement supported by the column and one question it cannot answer. Keep meters, before/after and years separate.
Session 4 / about 45 minutes
Revise a history with new evidence
Goal: Combine a cross-cutting intrusion and an erosion surface with layer order, then explain a supported revision and a remaining uncertainty.
Preparation / about 10 minutes of adult support: Bring all journals and the first explanation. Prepare a final-history sheet. A private spoken account can replace a written report or presentation.
An intrusion forms when molten material enters older rock and solidifies there. A feature that cuts a rock is younger than the rock it cuts. Our drawing has intrusion Z cutting layers A and B. An erosion surface truncates, or cuts off, B and the top of Z. Later sediment C lies on that surface. The evidence orders A, B, Z, erosion, C. Merely failing to draw Z inside C would not prove that order; the surface cutting off Z supplies the relationship. Combine observations, explain each step, and revise when new evidence changes your account. An old rock can still bring new evidence to the meeting.
Which exact relationship puts erosion after the intrusion? Why is an unknown numeric age not a reason to discard a supported event order?
- Build the revised event history / about 20 minutes
- Explain what changed in my account / about 15 minutes
- Present my evidence privately / about 10 minutes
Fun fact: A solidified intrusion can be younger than the layers it cuts, even when most of it appears lower in a drawing. Position alone is not its age rule. Source
S3U / Rock Evidence Lab / Journal 4 of 4
My history and its evidence
New invented evidence: sedimentary L was deposited, then M above it; both stayed upright. Solidified igneous intrusion I cuts L and M. Erosion surface E truncates M and the top of I. Sediment N was later deposited on E. No numeric ages or event durations are supplied.
| Evidence question | My revised account |
|---|---|
| Five events from earliest to latest | |
| Why I follows both L and M | |
| Why E precedes deposition of N | |
| One date or duration still unknown |
On a separate sheet, present the five-event account with a reason for each relationship. Explain why I being low in the drawing does not make it older than the layers it cuts.
Compare your first explanation with the final account. Name one revision and its evidence, then one question still unanswered. If your first explanation remains sound, explain how the new evidence supports it.
What changed in your explanation?
Show your evidence, explain one revision, and choose a question to investigate next. You can keep everything on paper.
Optional: record actual offline learning in Learning Records. Keep reported minutes separate from website time. For an assigned pack, use your existing daily tasks; this page does not award additional completion credit.