Plate Tectonics and Continental Drift Vocabulary

Vocabulary flashcards covering key terms, historical figures, evidence, and mechanisms related to continental drift and plate tectonics based on the lecture transcript.

15 Major Lithospheric Plates

The major pieces into which Earth's lithosphere is divided, including the North American, Pacific, Australian, Philippine, and Indian plates.

Plate Movement Rate

The speed at which lithospheric plates typically move, which is between $2\text{ cm/year}$ and $12\text{ cm/year}$.

San Andreas Fault

A major fault zone created by the sliding past each other of the North American Plate and the Pacific Plate.

Alfred Wegener

A German meteorologist who postulated the continental drift hypothesis between 1910 and 1930 based on four main lines of evidence.

Continental Drift Hypothesis

The hypothesis that continents move across Earth's surface, colliding to form mountains and breaking apart and drifting away over time.

Pangaea

The ancient supercontinent model where all modern continents were once connected together as a single landmass.

Mesosaurus

A freshwater reptile whose fossils were found in both South America and the tip of Africa, serving as fossil evidence for continental drift.

Glacial Striations

Scratch marks left on rocks by the downhill movement of ancient glaciers carrying rock fragments on their undersides.

Coal

A sedimentary rock formed from ancient tropical vegetation and forest die-offs that were compressed and cemented together.

Mantle Convection

The thermal process where plastic material in the asthenosphere heats up, becomes less dense, rises, moves laterally, cools, and sinks back down, driving plate movement.

Asthenosphere

The plastic, malleable layer of the mantle that allows mantle convection and the movement of overlying lithospheric plates.

Paleomagnetism

The permanent record of Earth's magnetic field direction locked into iron-bearing minerals inside igneous rocks as they cool.

Zebra-like Magnetic Stripes

Symmetrical patterns of normal and reversed magnetic polarity preserved in the ocean floor on either side of mid-ocean ridges, proving seafloor spreading.

Mid-Ocean Ridges

Underwater mountain ranges where new ocean floor is continuously formed and where the youngest oceanic rocks are located.