---
title: "Rock layers and Earth's history"
description: "Interpret cross-section diagrams of the Earth's interior, geological strata, and rock cycle; read and label layers (crust, mantle, outer core, inner core); understand that deeper layers in sedimentary"
canonical: https://lightmysky.com/learn/science/rock-layers-and-earths-history-mt_0_K-GrKQpd
source: https://lightmysky.com/learn/science/rock-layers-and-earths-history-mt_0_K-GrKQpd.md
retrieved: 2026-10-19
---

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# Rock layers and Earth's history

Interpret cross-section diagrams of the Earth's interior, geological strata, and rock cycle; read and label layers (crust, mantle, outer core, inner core); understand that deeper layers in sedimentary sequences are older

Subject: Science · Area: Earth's Systems · Ages 10 to 11
Page: https://lightmysky.com/learn/science/rock-layers-and-earths-history-mt_0_K-GrKQpd

## Ready when they can

- Label the four layers of the Earth on a cross-section diagram using the correct terms
- Interpret a diagram of sedimentary rock layers and identify which layer was deposited first
- Read a rock cycle diagram and trace the pathway of a rock from igneous to sedimentary to metamorphic

## Lesson: Rock layers and Earth's history

Earth is built like a hard-boiled egg. The thin shell is the crust, the ground under your feet. Under that is the mantle, a thick layer of hot rock that flows very slowly, like thick honey. Deeper still is the outer core, made of melted metal. At the very center sits the inner core, a solid ball of metal, the hottest part of the whole planet.

*(drawing: Start at the crust and go inward: crust, mantle, outer core, then inner core at the very middle.)*

**Example.** A scientist cuts open a cliff and sees flat bands of rock stacked like a sandwich. The bottom band formed first, long before the top band. Each new layer of sand or mud settles on top of the layer before it, so in an undisturbed stack, the deepest layer is always the oldest.

**Tip.** In a stack that has never been disturbed, reading rock layers is like reading a diary from the bottom up. The oldest entry sits at the bottom, and every new page gets added on top.

Rocks change from one kind to another in a cycle. Melted rock cools and hardens into igneous rock. Wind and water break igneous rock into tiny pieces that pile up and press together into sedimentary rock. Heat and pressure deep underground squeeze sedimentary rock into metamorphic rock, which can melt again and start the cycle over.

**Recap.** Earth has four layers, crust to inner core, and in an undisturbed stack of rock layers the bottom layer is always the oldest.

## Practice

24 questions on this page, each with its working shown.

## Needs first

- [Types of rocks](https://lightmysky.com/learn/science/types-of-rocks-mt_bqL8DD1SbV)
- [3-D shapes (age 9+)](https://lightmysky.com/learn/mathematics/3-d-shapes-age-9-mt_wUSbRt3-qw)

## Opens up

- [Finding patterns in data](https://lightmysky.com/learn/science/finding-patterns-in-data-mt_-G6erQvLig)