Whole Earth Curriculum WEC

Lesson 11 — The Rock Cycle Recycles Earth's Materials

Learners meet the rock cycle: rock is made, broken down, and made again in a loop that never uses Earth's materials up. They learn the three rock types — igneous, sedimentary, and metamorphic — and the processes that turn one into another, and they trace one rock's long journey around the cycle.

D06 P3: Intellectual & Cognitive Awareness D06.S4 50 minutes Draft

Objectives

Essential question

How are rocks made, broken down, and made again in a cycle that never uses Earth's materials up?

rock cycleigneoussedimentarymetamorphicweatheringerosionmagmasediment

Materials

Standard materials

Low-tech / no-cost

Enriched / lab & device

Works in different contexts

A circular diagram of the rock cycle. At the top, a volcano releases magma labeled 'magma,' which cools into an igneous rock labeled 'igneous — made by cooling.' An arrow leads to 'weathering and erosion' which breaks rock into grains labeled 'sediment,' pressing into a layered rock labeled 'sedimentary — made by pressing layers.' Heat and pressure turn this into a folded rock labeled 'metamorphic — changed by heat and pressure,' which then melts back into magma, completing the loop. A caption reads: Earth's rock is recycled — broken down and made again, over and over. Labels, arrows, and shapes, not color alone, carry the meaning so it prints clearly in grayscale.
A circular diagram of the rock cycle. At the top, a volcano releases magma labeled 'magma,' which cools into an igneous rock labeled 'igneous — made by cooling.' An arrow leads to 'weathering and erosion' which breaks rock into grains labeled 'sediment,' pressing into a layered rock labeled 'sedimentary — made by pressing layers.' Heat and pressure turn this into a folded rock labeled 'metamorphic — changed by heat and pressure,' which then melts back into magma, completing the loop. A caption reads: Earth's rock is recycled — broken down and made again, over and over. Labels, arrows, and shapes, not color alone, carry the meaning so it prints clearly in grayscale.

Lesson 11 — The Rock Cycle Recycles Earth’s Materials

Summary

Learners meet the rock cycle: rock is made, broken down, and made again in a loop that never uses Earth’s materials up. They learn the three rock types — igneous (made by cooling), sedimentary (made by pressing layers), and metamorphic (changed by heat and pressure) — and the processes that turn one into another, then trace one rock’s long journey around the cycle.

Objectives

  • Explain how the rock cycle recycles Earth’s materials. (D06.S4.06.02)

Connection

The sand on a beach was once part of a mountain. The mountain, long before that, was once molten rock, and the grains of sand may one day be pressed into new stone and lifted again. Rock is not a thing that is used once and gone; it is recycled, broken down and rebuilt over times so long we cannot watch them. Today you learn the cycle that makes every mountain, beach, and pebble part of one slow, endless story.

Materials

  • Rock-cycle diagram
  • Rock-type cards
  • Cycle page

Preparation

  • Print or draw the rock-cycle diagram, cards, and cycle page.
  • Recall Grade 5: weathering, erosion, and the slow changes to Earth’s surface.
  • Have clay, sand, and stones ready if using the hand model.

Facilitator note

Written to the learner (“you”). The one idea to land: rock is recycled — made, broken down, and made again, in a loop that has run for billions of years. Three rock types, each tied to a process: igneous (cooled from magma or lava), sedimentary (pressed from layers of sediment), metamorphic (changed by heat and pressure). The cycle is driven by Earth’s internal heat (melting) and surface processes (weathering, erosion, deposition). Model the worked example with the clay/sand model and trace one rock around the diagram aloud. The deep-time scale is evidence-based (radiometric dating of rocks); the sense of wonder — that the ground under us is ancient and recycled — can seed an environmental reflection about caring for what is never truly “used up,” but name it as a value. Keep the “how do we know” line: we cannot watch a cycle that takes millions of years, so we infer it from the rocks we can see and measure. See docs/facilitation.md.

Procedure

  1. Gather (5 min). Hold a pebble or a grain of sand. How old is it, and where has it been? Write a guess: could it have once been part of a mountain?
  2. Meet the cycle (10 min). Look at the diagram. The rock cycle is a loop. Magma (melted rock) cools into igneous rock. Weathering and erosion break rock into sediment, which presses into sedimentary rock. Heat and pressure change rock into metamorphic rock, which can melt back into magma — and the loop begins again. Point to each step and say what happens.
  3. Arrange the cycle (10 min). With your cards, lay out the three rock types and the processes between them in a circle: cooling, weathering/erosion, pressing, heat/pressure, melting. Check each arrow with a partner: does this process turn that rock into the next one?
  4. Trace one rock (15 min). On your cycle page, draw the loop and trace one rock’s journey: born from cooling magma, weathered into sand, pressed into sandstone, folded by pressure, and melted to begin again. Label each rock type as you go.
  5. Close (5 min). Nothing about rock is used up and thrown away. It is broken down and rebuilt, over and over — the oldest recycling system on Earth.

Differentiation

  • Support: Sort rock samples or cards into the three types first; trace the cycle with a moving token and say each change aloud.
  • Extension: Explain how one rock could become all three types over deep time, naming the process that drives each change (cooling, pressing, heat/pressure).

Assessment

  • Formative (observation): Can the learner name the three rock types, the process that makes each, and state that the cycle recycles Earth’s materials?
  • Self-check: The learner asks, “Can I start anywhere in the cycle and trace a rock all the way around, naming each rock type and change?”

Home connection

Find a rock near home and decide which type it might be and how it likely formed. Tell someone the cycle that rock has been part of — and will rejoin.

Resources