U2S3 Continental Drift - Vocabulary Flashcards

Vocabulary flashcards covering key terms from the Continental Drift notes.

Continental drift

The theory that the continents were once joined as a single landmass (Pangaea) and have drifted apart over time.

Alfred Wegener

German scientist who proposed the theory of continental drift, suggesting continents were once connected.

Pangaea

The supercontinent that existed about 300 million years ago and later broke apart to form today’s continents.

Continent

One of Earth's large landmasses; there are seven: North America, South America, Africa, Europe, Asia, Australia, Antarctica.

Fossil

A trace of an ancient organism preserved in rocks.

Lystrosaurus

A fossil organism used as evidence that continents were once connected across different regions.

Evidence from land features

Observations such as matching coastlines, mountain ranges, and coal fields across continents that indicate past connections.

Evidence from fossils

Distributions of plants and animals across continents that could not have swum across oceans, supporting past connections.

Evidence from climate change

Past climate clues, such as tropical fossils in polar regions and signs of past glaciers, indicating different continental positions.

Coastlines

Coastlines of continents that appear to fit together, suggesting they were once joined.

Mountain ranges that line up

Similar mountain chains on different continents that align when reassembled, supporting drift.

Coal fields

Coal deposits that match across continents, indicating they were once connected.

Plate tectonics

The theory that Earth's outer shell is divided into moving plates that carry the continents.

Plates

Giant masses of rock on which continents sit; they move slowly and interact at boundaries.

Plate movement

The three motions of plates: moving apart to form valleys and new ocean floor, colliding to form mountains or volcanic features, and sliding past to create narrow breaks in crust.

Rate

The distance moved by a plate per unit time; rate = distance ÷ time.

Distance

The length between two points in a movement calculation.

Time

The measured duration between the start and end of an action or process.

cm/year

Centimeters per year; a unit of rate for plate motion.

m/year

Meters per year; a unit of rate for plate motion.

km/year

Kilometers per year; a unit of rate for plate motion.