Continental Drift, Plates, and the Evidence
Look at a world map and you might notice that South America and Africa seem to fit together like puzzle pieces. That observation launched one of the biggest ideas in earth science: the continents move. Understanding continental drift and the evidence for it explains why Earth’s surface looks the way it does.
This lesson covers continental drift, the plates that carry the continents, and the evidence behind the theory.
Continental drift is the idea that Earth’s continents were once joined in a single landmass and have slowly moved apart. Alfred Wegener proposed it, supported by matching coastlines, matching fossils, and matching rock formations across oceans. The continents ride on large sections of Earth’s crust called tectonic plates.
What is continental drift?
In 1912, scientist Alfred Wegener proposed that all the continents were once joined in a single supercontinent he called Pangaea. Over hundreds of millions of years, he argued, this landmass broke apart and the pieces drifted to their present positions. The idea seemed strange at first because no one could explain how continents could move, but the evidence kept piling up.
What evidence supports it?
Wegener gathered several independent clues. The coastlines of continents like South America and Africa fit together. Matching fossils of the same ancient plants and animals appear on continents now separated by wide oceans, which makes sense only if the land was once connected. And matching rock formations and mountain ranges line up across oceans when the continents are fitted back together. Later, evidence of seafloor spreading finally explained the mechanism.
| Evidence | What it shows |
|---|---|
| Matching coastlines | Continents once fit together |
| Matching fossils | Land was connected in the past |
| Matching rock and mountains | Formations line up across oceans |
What are tectonic plates?
The continents do not plow through the ocean floor; they ride on it. Earth’s rigid outer shell is broken into large pieces called tectonic plates that float on the hot, slowly flowing mantle beneath. These plates move a few centimeters a year, about as fast as your fingernails grow, carrying the continents with them. The modern theory of plate tectonics combined Wegener’s drift idea with the discovery that the plates themselves move.
Watch: A Short Video Lesson
edexcel geography made simple walks through this skill clearly in a few minutes. It is a helpful companion to the reading above:
A routine for continental drift questions
- Recall the supercontinent Pangaea broke apart over time.
- List the evidence: coastlines, fossils, rock formations.
- Remember matching fossils across oceans show past connection.
- Know the continents ride on tectonic plates.
- Plates float and move on the mantle.
Practice questions
- What was the single supercontinent called?
- Who proposed continental drift?
- Name two pieces of evidence for continental drift.
- What do the continents ride on?
- About how fast do tectonic plates move?
- True or false: matching fossils across oceans support continental drift.
Answers:
- Pangaea.
- Alfred Wegener.
- Any two of: matching coastlines, matching fossils, matching rock formations.
- Tectonic plates.
- A few centimeters per year.
- True.
Where this fits
Continental drift is the foundation of plate tectonics, and the moving plates meet at the plate boundaries you study next. The fossils used as evidence connect to extinction and fossils. Find all topics on the ASVAB General Science Learning Hub.
Recommended Prep Books
These study guides and practice books help you keep building momentum as you prepare:
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