Geology 101 Chapter 2 Flashcards

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Questions and Answers

What is a continental arc?

A type of volcanic arc along a continental margin (correct)

A type of oceanic structure

A linear zone of rock

A supercontinent

Who is credited with the hypothesis of Continental Drift?

Alfred Wegener

What is a continental rift?

A mountain range

A linear zone where continental lithosphere stretches (correct)

An ocean trench

A volcanic island

What is a continental shelf?

The gently sloping submerged portion of the continental margin Signup and view all the answers

What is convection?

The transfer of heat by mass movement Signup and view all the answers

What defines a convergent boundary?

A boundary where two tectonic plates move together Signup and view all the answers

What occurs at a divergent boundary?

Two plates move apart Signup and view all the answers

What is a fault?

A break in a rock mass Signup and view all the answers

What is a fracture zone?

A linear zone of irregular topography on the deep-ocean floor Signup and view all the answers

What is gabbro?

A dark-green to black intrusive igneous rock Signup and view all the answers

What characterizes granite?

Coarse-grained igneous rock Signup and view all the answers

Who is Harry Hess?

A geologist known for theories on sea floor spreading Signup and view all the answers

What is a hot spot?

A concentration of heat in the mantle Signup and view all the answers

What is an island arc?

A chain of volcanic islands Signup and view all the answers

What is the lithospheric mantle?

The uppermost portion of the mantle below Earth's crust Signup and view all the answers

What is magnetic reversal?

A change in Earth's magnetic field Signup and view all the answers

What is a mantle plume?

A mass of hotter-than-typical mantle material Signup and view all the answers

What is a marine magnetic anomaly?

Variation in strength of Earth's magnetic field Signup and view all the answers

What is a mid-ocean ridge?

A continuous mountainous ridge on the ocean floor Signup and view all the answers

What is an oceanic transform?

A transform fault Signup and view all the answers

What is paleoclimate?

A climate prevalent at a particular time in the geological past Signup and view all the answers

What is paleogeography?

The study of geographical features in geological past Signup and view all the answers

What is paleomagnetism?

The magnetism in rocks induced by Earth's magnetic field Signup and view all the answers

What is Pangaea?

The proposed supercontinent Signup and view all the answers

What is peridotite?

An igneous rock of ultramafic composition Signup and view all the answers

What is a plate boundary?

The lines where Earth's crust's moving plates meet Signup and view all the answers

What is plate tectonics?

A theory proposing that Earth's outer shell consists of moving plates Signup and view all the answers

What is sea-floor spreading?

A hypothesis suggesting new oceanic crust is produced at mid-ocean ridges Signup and view all the answers

What is subduction?

The process by which oceanic lithosphere plunges into the mantle Signup and view all the answers

What is a subduction zone?

Where one tectonic plate moves under another Signup and view all the answers

What is till?

Unsorted sediment deposited directly by a glacier Signup and view all the answers

What is a transform boundary?

A boundary where two plates slide past one another Signup and view all the answers

What is a trench?

A narrow, elongated depression of the seafloor Signup and view all the answers

What is a volcanic arc?

A chain of volcanoes formed above a subducting plate Signup and view all the answers

Who proposed the Continental Drift Theory?

Alfred Wegener Signup and view all the answers

Study Notes

Geology Concepts and Terms

Continental Arc: Volcanic arcs that form along continental margins where subduction occurs; displays arc-shaped topographic high regions.
Continental Drift: Hypothesis by Alfred Wegener asserting all continents were once connected as a supercontinent and began drifting apart around 200 million years ago.
Continental Rift: Linear zones indicating the stretching and pulling apart of continental lithosphere, potentially marking the start of a new ocean basin.
Continental Shelf: Submerged continental margin extending gently from coastlines to the continental slope.
Convection: Heat transfer through the circulation of substances, crucial in mantle dynamics.
Convergent Boundary: Area where two tectonic plates collide, leading to the subduction of oceanic lithosphere or the formation of mountain ranges from continental collisions.
Divergent Boundary: Plates move away from each other, allowing mantle material to rise and create new oceanic crust.
Fault: A fracture in rock where movement has occurred, affecting rock formations.
Fracture Zone: Irregular topographic regions on the ocean floor, associated with transform faults and their extensions.
Gabbro: Dark, intrusive igneous rock that forms a significant part of the oceanic crust.
Granite: A coarse-grained igneous rock, primarily composed of quartz and potassium feldspar, widely utilized in construction.

Influential Figures and Theories

Harry Hess: Geologist known for sea-floor spreading theories, analyzing relationships between geological features and mantle convection, pivotal for plate tectonic theory.
Hot Spot: Areas of concentrated heat in the mantle leading to magma production, exemplified by Hawaiian Islands' intraplate volcanism.
Island Arc: Chains of volcanic islands formed due to subduction of one oceanic plate beneath another, located near oceanic trenches.
Lithospheric Mantle: The upper layer of the mantle lying beneath the crust, differing in thickness under continental regions.

Geological Processes

Magnetic Reversal: Changes in Earth’s magnetic field from normal to reverse polarity, impacting geological formations.
Mantle Plume: An upward movement of hot mantle material, often leading to volcanic activity at the surface.
Marine Magnetic Anomaly: Variations in Earth’s magnetic field due to the magnetism of ocean floor rocks.
Mid-ocean Ridge: A continuous underwater mountain range at divergent plate boundaries, varying in width substantially across ocean basins.
Oceanic Transform Fault: A fracture in the Earth's crust resulting from horizontal motion of tectonic plates.

Paleogeography and Past Climates

Paleoclimate: Climate existing during a specific time in geological history, essential for understanding past environmental conditions.
Paleogeography: Exploration of ancient geographical features and how they have changed over time.
Paleomagnetism: Study of magnetic records in rocks that were formed under the influence of the Earth’s magnetic field at the time of their formation.
Pangaea: The hypothesized supercontinent that began to break apart approximately 200 million years ago into current continents.

Rock Types and Geological Features

Peridotite: Ultramafic igneous rock, theorized to be abundant in Earth's upper mantle.
Plate Boundary: Field divisions between moving plates in Earth’s crust where diverse geological processes occur.
Plate Tectonics: Theory detailing Earth's outer shell's composition and interactions, responsible for significant geological phenomena including earthquakes and volcanoes.
Sea-floor Spreading: Hypothesis proposing that new oceanic crust forms at mid-ocean ridges, indicative of divergent activity.
Subduction and Subduction Zones: Key geological processes and locations at convergent boundaries where one plate is forced under another into the mantle.

Other Geological Terms

Till: Unsorted sediment deposited by glaciers, providing insights into past climatic conditions.
Transform Boundary: Fault lines where two tectonic plates slide past each other without generating or recycling crust.
Trench: Deep, narrow depressions in the ocean floor, significant for subduction zones.
Volcanic Arc: Chains of volcanoes formed from subduction processes, characterized by distinct arc shapes.
Alfred Wegener: The scientist who introduced the Continental Drift Theory in the early 20th century, laying foundational concepts for modern geology.

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Description

Test your knowledge on key terms from Geology 101 Chapter 2. This quiz covers important concepts such as Continental Arc and Continental Drift, exploring their definitions and significance in geological processes. Perfect for students wanting to reinforce their understanding of plate tectonics and continental movements.