🔬 6th Grade Science · Unit 3
Earth's History
15 short narrated lessons in 3 chapters, each with pictures, a quiz with a hint and a second try, and an explanation for every answer.
Standards: MS-ESS1-4 MS-ESS2-3
What your child will learn
Rock layers tell a story
- Sedimentary LayersDescribe how layers of sediment build up and harden into rock over time.
- Oldest on the BottomApply the law of superposition to put rock layers in order from oldest to youngest.
- Clues That Cut AcrossExplain how faults and intrusions that cut through layers are younger than those layers.
- Rock Layers Tell a Story: Review ReviewReview how scientists read rock layers to learn the order of past events.
Fossils and geologic time
- How Fossils FormDescribe several ways that the remains or traces of living things become fossils.
- Index FossilsExplain how index fossils help match rock layers in different places.
- Radioactive DatingExplain how steady radioactive decay works like a clock to date some rocks.
- The Geologic Time ScaleDescribe how Earth's 4.6-billion-year history is divided into eons, eras and periods.
- Fossils and Geologic Time Review ReviewReview how fossils and rock ages are used to build the geologic time scale.
Moving continents
- Continents That Fit TogetherDescribe how the shapes of continents suggest they were once joined.
- Fossil and Rock EvidenceAnalyze matching fossils and rocks on different continents as evidence of past motion.
- Mapping the Sea FloorExplain how ocean-floor maps revealed mid-ocean ridges and deep trenches.
- Sea-Floor SpreadingExplain how new ocean floor forms at ridges and moves away over time.
- Moving Continents Review ReviewReview the fossil, rock and sea-floor evidence that continents have moved.
- Unit 3 Test: Earth's HistoryShow what you learned in the whole unit (Rock layers tell a story, Fossils and geologic time, Moving continents) by answering mixed questions.
Try a question from this unit
From the lesson “Sedimentary Layers”
A fast stream carrying sand flows into a still pond. What happens to most of the sand?
Show the answer
It sinks and settles on the pond bottom.. When the water slows, it can no longer hold up the sand, so the grains sink and settle. Becoming rock takes a very long time, after many layers pile up on top.
Hint kids see after a wrong try: “Think about what happens to moving water when it reaches the still pond.”
Key words
- sediment
- strata
- superposition
- fault
- intrusion
- fossil
- trace fossil
- index fossil
- radioactive decay
- half-life
- geologic time scale
- era
- continental drift
- Pangaea
- evidence
- mid-ocean ridge
- trench
- sea-floor spreading
- magnetic stripes
Try these lessons in Kids Shelf
Narrated lessons, pictures and quizzes for every grade from K to 8. Works offline.
