Geology Definitions Flashcards

Questions and Answers

What is a rift valley?

A linear-shaped lowland created by geologic rift or fault (correct)

A type of mountain range

A highland area

An oceanic trench

What is the Earth's inner core primarily made of?

Iron-nickel alloy and some light elements

What lies between the Earth's core and crust?

Mantle

What is the outermost solid shell of a rocky planet called?

Crust Signup and view all the answers

What defines the lithosphere?

Rigid outermost shell of a terrestrial-type planet Signup and view all the answers

What is the asthenosphere?

A zone of Earth's mantle beneath the lithosphere Signup and view all the answers

Convergent means two things going in different directions.

False Signup and view all the answers

Divergent means going towards each other.

False Signup and view all the answers

What does it mean to transform?

To undergo a dramatic change Signup and view all the answers

What is subduction?

Sideways and downward movement of a tectonic plate into the mantle Signup and view all the answers

What is a tectonic plate?

A massive slab of solid rock made of both continental and oceanic lithosphere Signup and view all the answers

What was continental drift?

A theory explaining how continents shift position on Earth's surface Signup and view all the answers

What is Pangaea?

A supercontinent that existed during the late Paleozoic and early Mesozoic eras Signup and view all the answers

Study Notes

Rift Valley

Linear lowland between highlands or mountain ranges.
Created by geological rifting or fault action at divergent plate boundaries.
Formed through crustal extension leading to the drop of a center block, resulting in steep walls.
Evolves into wider valleys and basins filled with sediment over time.
Example: East African Rift.

Inner Core

Earth's innermost part, primarily a solid ball.
Approximately 1,220 km (760 miles) in radius.
Composed mainly of an iron-nickel alloy with some lighter elements.

Mantle

Layer between the core and crust in terrestrial planets.
Formed through planetary differentiation by density.
Composed of silicate rock in Earth, Venus, Mars, and Mercury, as well as some of Jupiter's moons.
Other celestial bodies like Titan and Triton may have a mantle of ice or solid volatiles.

Crust

Outermost solid shell of rocky bodies, distinct from the mantle.
Formed primarily through igneous processes.
Rich in incompatible elements compared to underlying mantles.

Lithosphere

Rigid outer shell of a terrestrial planet, including crust and elastic upper mantle.
Defined by mechanical properties rather than chemical composition.

Asthenosphere

Layer of Earth’s mantle beneath the lithosphere.
Much hotter and more fluid, extending from 100 km (60 miles) to about 700 km (450 miles) below the surface.

Convergent

Describes two entities moving towards one another.

Divergent

Describes entities moving in different directions.

Transform

Refers to undergoing a dramatic change or transformation.

Subduction

Horizontal and downward movement of an edge of a tectonic plate into the mantle beneath another plate.

Tectonic Plate

Large, irregularly shaped slabs of solid rock, including both continental and oceanic lithosphere.
Sizes vary significantly; large examples include the Pacific and Antarctic Plates.

Continental Drift

Theory postulated by Alfred Wegener in 1912 explaining the movement of continents.
Accounts for similarities in fossils and rock formations across different continents.

Pangea

A supercontinent that existed 300 million years ago during the late Paleozoic and early Mesozoic eras.
Formed from earlier continental units and began breaking apart about 175 million years ago.

Description

Explore key geological terms with this flashcard quiz. Each card provides a definition of important concepts, starting with 'rift valley'. Perfect for students looking to strengthen their understanding of geology.