Plate Tectonics Flashcards
(24 cards)
The hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
Continental Drift
A long undersea mountain chain that has a steep, narrow valley at its center, that forms as magma rises from the asthenosphere and that creates new oceanic lithosphere (sea floor) as tectonic plates move apart.
Mid-ocean ridge
The process by which new oceanic lithosphere (sea floor) forms as magma rises to Earth’s surface & solidifies as a mid ocean ridge
Sea floor spreading
The study of the alignment of magnetic minerals in rock, specifically as it relates to the reversal of Earth’s magnetic poles; also the magnetic properties that rock acquires during formation.
Paleomagnetism
the discontinuity between the crust and the mantle of the earth, occurring at depths that average about 22 miles beneath the continents and about 6 miles beneath the ocean floor.
Moho
Submerged volcanic mountains that are taller than 1 kllometer
Seamount
The solid outer layer of Earth that consists of the crust and the rigid upper part of the mantle.
Lithosphere
The boundary between 2 tectonic plates that are moving away from each other
Divergent boundary
The boundary between 2 tectonic plates that are sliding past each other horizontally
Transform boundary
The layer of rock between Earth’s crust and core
Mantle
A raised wedge at the base of the continental slope
Continental Rise
Deep V shaped valleys in the continental shelf and continental slope
Submarine canyon
The solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it.
Asthenosphere
The boundary between tectonic plates that are colliding
Convergent boundary
A narrow valley along the center of a mid ocean ridge.
Rift (valley)
The theory that explains how large pieces of the lithosphere, called plates, move.
Plate tectonics
The part of a continent covered by water
Continental shelf
A long narrow and steep depression that forms on the ocean floor as a result of subduction of a tectonic plate; runs along a chain of volcanic islands
Trench
A solid sphere in the middle of the fluid core such as the iron-nickel core of the Earth.
Inner core
A fluid layer about 2,300 km (1,400 mi) thick and composed of mostly iron and nickel that lies above Earth’s solid inner core and below its mantle.
Outer core
The thin and solid most outer layer of the Earth, above the mantle.
Crust
The super continent that formed 300 million years ago and started to break up 250 million years ago.
Pangaea
The slope between the outer edge of the continental shelf and the deep ocean floor
Continental slope
A large flat, almost level area of the deep ocean basin
Abysmal plain
