Unit 4 · Earth's Restless Surface · Week 5 · Performance task
Seashells on the peak — and where is it safe to build?
Use everything from this unit to explain how marine fossils ended up on a mountaintop, then use the same model to tell a town where it is safest to build — and why.
Start here
How we work the performance task (our expectations)
- Use evidence from the whole unit
- A design is a claim — back it up
- Reasoning > being first or fastest
- Supports are for everyone — open any you want
30-second check-in self-management
This is the capstone for the unit, so it can feel big. Notice one feeling you have about it right now and name it to yourself. Take one slow breath. Remember: you already built every idea you need across Weeks 1–4 — today you just connect them. Any part can be read aloud with the Listen button.
This is the big task for the unit. Notice how you feel and take one slow breath. You already learned every idea you need in Weeks 1–4. Today you connect them. You can press Listen on any part.
Unit Do-Now Pull the whole unit back
No looking back. These four prompts each pull one week forward — you will use all of them in the task.
- W1 In one sentence: how can rock that formed at the bottom of an ocean end up at the top of a mountain?
- W2 What is the engine that moves the plates — and where does its energy come from?
- W3 When the ground shakes in an earthquake, where did that energy come from, and how was it stored?
- W4 A mountain wears down to sand over millions of years. Where did the mountain's matter go?
The task scenario
Your job has two parts. A town at the foot of this mountain has hired you as a young Earth scientist. First, they are curious: a hiker found a seashell fossil near the peak, and they want to know how that is even possible. Second — and this is what they are really paying for — they are about to build new homes and a school, and there is a fault line nearby. They need you to explain the risks and recommend where, and how, to build. Use your unit model: plates move (driven by the energy of mantle convection), boundaries build mountains and cause earthquakes and volcanoes, and rock is endlessly weathered, moved, and rebuilt while its matter is conserved. Explain the past, then protect the future.
You have two jobs. A town at the base of this mountain hires you. First: a hiker found a seashell fossil near the top. How? Second: the town wants to build homes and a school, but a fault line is close by. Where is it safe to build, and how? Use your unit model — plates move, boundaries make mountains and earthquakes, and rock is worn down and rebuilt while its matter stays the same. Explain the past, then protect the future.
Notice & Wonder. Before you plan, write one thing you notice in the cross-section and one thing you still wonder. Your wonder might become a question you investigate.
Synthesis Your four weeks are one model
Before you build your answer, see how the weeks connect. This is the model you will use for both parts of the task.
Earth's interior is hot, and that heat energy drives slow convection in the mantle (Week 2) — the same rising-hot, sinking-cool pattern you met in air and water. That convection drags the plates, so the surface is never still. Where plates meet (Week 3), rock bends and stores elastic energy until it slips — an earthquake — or magma rises and builds volcanoes and mountains. That is how seafloor rock, with its shells, was slowly lifted to a peak over deep time (Week 1). Meanwhile, at the surface, water and weather weather, erode, and deposit that rock (Week 4), carrying its matter downhill to become sediment and, eventually, new rock — none of it created or destroyed.
Earth's inside is hot. That heat moves the mantle in a slow convection loop (Week 2), and that loop drags the plates. Where plates meet (Week 3), rock stores energy and slips (earthquakes) or builds mountains and volcanoes. That lifted seafloor rock — and its shells — to a peak over a very long time (Week 1). At the surface, weather wears rock down and moves it (Week 4) to make new rock. The matter is never lost.
Worked example — how an expert chains the evidence
Question: Why is a marine fossil near the peak?
Claim: The rock formed underwater, then was uplifted.
Evidence → Reasoning chain: shells live in shallow seas → so the layer formed on a seafloor → matching tilted layers and folded rock show the crust was pushed and lifted → that pushing comes from plates colliding → plates move because mantle convection (heat energy) drives them → given millions of years, slow uplift raises seafloor into mountains. Each arrow is a "because." Your explanation should read as one unbroken chain like this.
Show the model as a picture Tier 2 · visual
Draw four linked boxes left to right: (1) Hot interior → convection (curved arrows) → (2) plates move & collide → (3) rock folds/lifts + stores then releases energy (mountain + earthquake) → (4) weather wears it down (arrows carrying matter downhill). Put the shell fossil on the rising layer in box 3, and write "matter conserved" under box 4.
Your task Explain the past, protect the future
Produce a short site report for the town. Choose how you present it — all modes earn full credit.
Part A — Explain the past. Using a claim–evidence–reasoning chain, explain how a seashell fossil ended up near the peak. Name the energy source that moves the plates.
Part B — Protect the future. Recommend where the homes and school should go relative to the fault, and at least two design or planning choices that reduce earthquake risk. Justify each with your model. Then name one thing you would investigate before finalizing (a fair question with data you'd collect).
Guided template — choose from options Tier 3 · re-teach
Part A — pick the true links and put them in order: [shells live in shallow seas] · [the layer formed on a seafloor] · [plates collided and lifted the crust] · [mantle convection, driven by Earth's heat, moves the plates] · [over millions of years the seafloor rose into a mountain]. Write them as a "because" chain.
Part B — Build (near / far) from the fault, on (loose sediment / solid bedrock), because ____. One design choice that reduces risk: ____. I would investigate ____ by collecting ____.
Say your two answers out loud before you write them.
I want sentence frames + a word bank Tier 2 · frames
Claim: The shell is near the peak because the rock ________.
Evidence: I know the plates move because ________, and the energy for that comes from ________.
Recommendation: Build ________ from the fault on ________, and use ________, because ________.
Word bank: seafloor · uplift · plate boundary · mantle convection · Earth's interior heat · elastic energy · bedrock · sediment · weathering · conserved
Push my thinking Extension
Trade-off challenge: bedrock far from the fault is safest but it is uphill, expensive to reach, and erodes the slope when cleared (Week 4). Weigh safety against cost and erosion, and defend a recommendation that is not simply "build as far as possible." Then propose how the rock cycle might change your site over the next 500 years.
Check yourself Is your model airtight?
- explains the fossil with an unbroken claim–evidence–reasoning chain and names the energy source for plate motion;
- recommends a site and risk-reducing choices, each justified by the unit model;
- keeps energy and matter accounted for — nothing appears from nowhere or vanishes.
Which recommendation best uses the unit's model?
Re-teach: energy and matter are always accounted for Tier 3
Two rules hold across this whole year. Energy is never created from nothing: the plates move because of heat already inside Earth, and earthquakes release energy that was stored as rock bent — not invented at the moment of the quake. Matter is never destroyed: a mountain worn to sand still exists as sediment that becomes new rock. A good report never has energy or matter appear or vanish — re-read option B and notice it traces both.
The 3-dimensional rubric (what "excellent" looks like)
You will score yourself on this in a moment — so read it before you finish.
| Dimension | Developing | Proficient | Excellent |
|---|---|---|---|
| SEP Explaining & designing | Gives an answer with little evidence. | Explains the fossil and recommends a site with some evidence. | Unbroken evidence→reasoning chain; design choices each justified; names a fair investigation. |
| DCI Plates, hazards, rock cycle | Names plates or hazards loosely. | Uses plate motion and hazard ideas correctly. | Integrates uplift, boundary energy, hazards, and the rock cycle into one coherent model. |
| CCC Stability/Change · Energy & Matter | Mentions change or energy once. | Tracks change over time or energy direction. | Accounts for both energy and matter end to end — nothing created or destroyed. |
Score yourself, then reflect
Reflection metacognition + SEL
Which part felt strongest — explaining the past or protecting the future — and which support (if any) helped most? Noticing this is how scientists improve their own process.
Exit — rubric self-assessment. Rate yourself honestly; this calibrates your judgment before it is scored.
- SEP Circle your level (Developing / Proficient / Excellent) for your evidence→reasoning chain, and give one reason.
- DCI Circle your level for using plates, hazards, and the rock cycle together, and give one reason.
- CCC Circle your level for accounting for energy and matter, and give one reason.
- Revise Name one change that would move you up a level, and why.
- Transfer A town near a coastline worries about a different hazard — flooding as sea level rises (Unit 6 preview). Name one piece of data you'd collect before advising them, and why.
Educator panel — facilitation, accommodations, rubric guidance
At a glance
Standards: NGSS MS-ESS3-2 (analyze and assess natural-hazard data to forecast and mitigate), integrating MS-ESS2-1 (rock cycle), MS-ESS2-2 (surface change over time/scale), MS-ESS2-3 (plate-motion evidence). 3D: SEP Constructing Explanations & Designing Solutions · DCI ESS2.A/B & ESS3.B · CCC Stability & Change + Energy & Matter. Throughline: closes Unit 4's "where did the energy/matter go?" — plate motion is interior heat; hazards are stored energy released; the rock cycle conserves matter.
Materials (fully digital-capable): the embedded cross-section; student notebook or device. Optional: a block-and-sandpaper "stick-slip" demo for the brain-break idea. No lab required.
Facilitation arc (Rosenshine)
- Unit Do-Now interleaving W1–W4 while you take attendance (5 min).
- Synthesis — walk the four-box connected model; check the worked example chain (8 min).
- Performance task — circulate; name which tier students reach for; push for "because" chains (22 min).
- Self-check + re-teach branch for any A/C responders (4 min).
- Brain break (2 min).
- Rubric self-assessment + reflection — collect as the formative signal for grouping (9 min).
IEP / 504 accommodation cards
Common accommodations mapped to this task
| Accommodation | How it's already built in / what to do |
|---|---|
| Text read aloud | Every passage has a Listen button (TTS); the simplified toggle shortens it. |
| Reduced reading load | "Reading: Simplified" swaps in shorter plain-language text site-wide. |
| Chunking / extended time | The task is in two named parts with a guided template; progress saves — students can stop and resume. |
| Sentence frames / word bank | Tier-2 panel under the task provides both. |
| Reduced-choice scaffold | Tier-3 "choose from options" template lets students assemble the chain without open recall. |
| Alternative response mode | Students may draw a labeled cross-section, speak/record a council presentation, or write — all accepted. |
| Behavior / focus (504, ADHD) | Named expectations (PBIS), the 30-sec check-in, and a built-in brain break. |
| Multilingual / EL | Simplified text, the labeled visual, word bank, and home-language drafting is allowed. |
Rubric guidance & look-fors
Part A exemplar chain: shells → shallow-sea layer → folded/tilted layers show uplift → plate collision → mantle convection (interior heat) drives plates → millions of years → seafloor becomes peak. Part B proficient: set back from the fault, on bedrock not loose sediment, flexible well-anchored structures; investigates soil type or historical quake records. Common misconception to route (#reteach-conservation): energy invented at the moment of a quake, or rock treated as permanent so matter "stays put forever." Re-anchor on stored-then-released energy (W3) and conserved-but-moving matter (W4).
Why it's designed this way
A summative NGSS task asks students to use all three dimensions on a new problem, not recall facts (NRC 2012). The two-part structure (explain, then design) spans SEP explanation and SEP design within one authentic context. The synthesis box and worked chain manage cognitive load before release (Sweller; Rosenshine); tiered templates keep the goal constant while varying support (UDL 3.0 / MTSS); the rubric-as-exit makes assessment a calibration of student judgment (Black & Wiliam). The coastal-flooding transfer item previews Unit 6's human-impact and Unit 3's climate connections.