Plate Tectonics. Drifting Continents Chapter 17.1. Vocabulary . Continental Drift – the continents were joined as a single landmass that broke apart 200 mya Still drifting Pangaea – ancient landmass made up of all the continents
Magnetic reversal – when Earth’s magnetic field changes polarity between normal and reversed
Magnetic field demo
Magnetometer – used to map the ocean floor by detecting small changes in magnetic fields
Isochron – imaginary line on a map that shows points of the same age; formed at the same time
Mid-Atlantic Range – chain of underwater mountains that run throughout the ocean basins
Rift valley – long, narrow depression that forms when continental crust begins to separate at divergent boundaries
So how are convergent and divergent movement related to mantle convection?