Plate Tectonics Flashcards

Grade 6 · Science · Flashcards

Review vocabulary and key concepts about tectonic plates and Earth's dynamic crust.

Flashcards

Tectonic plates: Giant slabs of Earth's lithosphere that slowly move on the asthenosphere.
Lithosphere: Earth's rigid outer layer, consisting of the crust and upper mantle; broken into tectonic plates.
Asthenosphere: The hot, partially molten layer of the mantle that tectonic plates move on.
Divergent boundary: Where two plates move apart; magma rises to form new crust and mid-ocean ridges.
Convergent boundary: Where two plates collide; forms mountains, volcanoes, or ocean trenches depending on plate types.
Transform boundary: Where plates slide horizontally past each other; causes earthquakes.
Subduction: When a denser oceanic plate sinks beneath a less dense plate into the mantle.
Seafloor spreading: The process of new oceanic crust forming at divergent boundaries as magma rises and cools.
Continental drift: Alfred Wegener's hypothesis that today's continents were once joined as a supercontinent called Pangaea.
Pangaea: The ancient supercontinent that existed about 300 million years ago before the continents split.
Mid-ocean ridge: A long underwater mountain chain formed at a divergent boundary.
Subduction zone: The area where an oceanic plate dives beneath another plate, forming deep trenches.
San Andreas Fault: A famous transform fault in California where the Pacific and North American plates slide past each other.
Himalayas: Earth's tallest mountain range, formed by the collision of the Indian and Eurasian tectonic plates.