South Dakota Science MS-ESS2-3

ScienceGrades 6–8Earth and Space Science

The Standard

Analyze and interpret data on the age of the Earth, distribution of fossils and rocks, continental shapes, and seafloor structures to provide evidence of the past plate motions. (SEP: 4; DCI: ESS2.B, ESS1.C; CCC: Patterns)

South Dakota Science Standards (2024) · Earth’s Systems

Teacher's field guide

What This Standard Means

What Students Need to Do: Students compare continent shapes, fossils, rock layers, and seafloor ages on maps. They use the patterns to explain where plates were in the past and how they moved. They compare the age of ocean crust with Earth's much older age.
What Mastery Looks Like: A student can match fossil and rock patterns across continents, not just fit coastlines together. They can use young rock at a mid-ocean ridge and older rock farther away to show that the seafloor spread. They know ocean crust is much younger than Earth.
Common Misconceptions: Students may treat matching coastlines as proof on their own or think the same animals crossed an ocean. Some think the oldest seafloor is at the ridge or that Earth is only as old as today's ocean crust.
How to Assess It: Give students a map with matching fossils on South America and Africa and Atlantic seafloor ages marked from the ridge outward. Ask: Where were the continents in the past, and which two patterns support your answer?

Lesson moves

Ways to Teach It

Give pairs paper cutouts of South America and Africa with labeled fossil and rock sites; have them align the evidence and sketch earlier positions.
Ask students to write: Why is a coastline match weaker evidence than matching fossils and rock layers across an ocean?
Have students place 0, 50, and 100-million-year-old rock cards on both sides of a paper mid-ocean ridge.
Show a transatlantic cable route on a seafloor-age map; have students locate the spreading ridge beneath the cable.

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