Plate Tectonics and Continental Formation

Questions and Answers

What supercontinent existed about 1.1 billion years ago before Pangaea?

Gondwanaland

Rodinia (correct)

Panthalassa

Laurasia

Which sea surrounded Pangaea during the time it existed?

Mediterranean Sea

Tethys Sea

Coral Sea

Panthalassa (correct)

What are the primary materials that compose oceanic plates?

Limestone and Clay

Basalt and Pyroxene (correct)

Sandstone and Shale

Granite and Quartz

Which of the following was NOT a part of Wegener's theory of continental drift?

Formation of oceanic ridges Signup and view all the answers

Which layer of the Earth's crust is generally thicker and less dense?

Continental plate Signup and view all the answers

Which of these plates is considered both a primary and secondary plate?

Nazca Plate Signup and view all the answers

What is the primary component of granite?

Feldspar Signup and view all the answers

What type of plate is characterized as thin and dense, primarily composed of basalt?

Oceanic Plate Signup and view all the answers

What theory suggests that the gravitational forces pull down the lithosphere during subduction?

Slab Pull Theory Signup and view all the answers

Which layer of the Earth is the thinnest, making up only 1% of the Earth's volume?

Crust Signup and view all the answers

Which layer of the Earth is responsible for generating its magnetic field?

Outer Core Signup and view all the answers

What is the Mohorovicic Discontinuity known for?

Boundary between crust and mantle Signup and view all the answers

Which of the following landforms is specifically created by the action of wind?

Dunes Signup and view all the answers

What is the primary composition of the Earth's mantle?

Molten rock Signup and view all the answers

How thick is the inner core of the Earth?

1,250 km Signup and view all the answers

What is Loess and how is it characterized?

A silty sediment that varies in thickness Signup and view all the answers

What does the Raisin Theory suggest about the formation of Earth's continents?

The Earth contracted due to a cooling process. Signup and view all the answers

What is the main premise of the Theory of Isostasy?

The Earth's crust is floating on the mantle, similar to a boat on water. Signup and view all the answers

Which scientist is known for proposing that continents may have once been a single land mass?

Abraham Ortelius Signup and view all the answers

How did Abraham Ortelius support his theory of continental drift?

By examining the shape of continent coastlines. Signup and view all the answers

What concept did Georges-Louis Leclerc contribute regarding continental fit?

Earthquakes caused the separation of continents. Signup and view all the answers

What was Francois Paget's belief about the Atlantic Ocean's origin?

It existed before the continents divided. Signup and view all the answers

What term describes the process affecting the structure of the Earth's crust over time?

Tectonics Signup and view all the answers

The word 'Tecton' originally means what in Greek?

Builder Signup and view all the answers

What evidence supports the idea that continents were once connected?

Similarity of land reptiles' fossils across different continents Signup and view all the answers

Which scientist proposed that magma creates new crust through seafloor spreading?

Harry Hess Signup and view all the answers

What describes the process of subduction?

When one tectonic plate moves beneath another Signup and view all the answers

Which type of convergent boundary involves oceanic plates subducting under continental plates?

Oceanic-Continental Signup and view all the answers

What is a major characteristic of transform boundaries?

Plates sliding past each other without creating new land Signup and view all the answers

What is the Wadati-Benioff zone known for?

Regions of frequent earthquakes during subduction Signup and view all the answers

Which of the following theories did Eduard Suess support?

Fossil distribution supports the idea of past continental connections Signup and view all the answers

Which scientist believed that heat and volcanic activity were responsible for the movement of continents?

Roberto Mantovani Signup and view all the answers

What is the primary characteristic of mesas?

They have a flat top and steep sides. Signup and view all the answers

How are buttes different from mesas?

Buttes cover a smaller area than mesas. Signup and view all the answers

What geological process mainly forms canyons and gorges?

Water erosion Signup and view all the answers

What are the two main types of glaciers?

Alpine and Continental Signup and view all the answers

What defines a V-shaped valley?

Created primarily by water erosion Signup and view all the answers

Which statement about deltas is true?

Deltas are triangular areas where a river meets a larger body of water. Signup and view all the answers

What is a characteristic of hills compared to mountains?

Hills are smaller and have sloped sides. Signup and view all the answers

What type of landform is characterized by steep sides and a narrow shape, and is usually formed from river or glacial erosion?

Canyon Signup and view all the answers

Study Notes

Theory of Plate Tectonics and Formation of Continents

Raisin Theory: Earth cooled after the Big Bang, causing it to contract like a grape turning into a raisin, leading to mountain formation and ocean basins.
Theory of Isostasy: Earth's crust floats on the mantle, achieving equilibrium between buoyancy and gravity.
Tectonic Processes: Result in the structure and properties of the Earth's crust; referred to as tectonic plates, which are massive slabs of rock.
Abraham Ortelius (Theatrum Orbis Terrarum): Proposed that continents were once a single landmass, evidenced by fitting coastlines.
Georges-Louis Leclerc (Count Buffon): Supported the idea that continents like Africa and South America were once connected.
Francois Paget: Suggested an undivided continent existed before the Atlantic Ocean was formed due to sinking during Noah’s Flood.

Wegener’s Theory of Continental Drift

Alfred Wegener (1915): Proposed that Pangaea existed during the Permian period, with earlier supercontinent Rodinia existing about 1.1 billion years ago.
Continental Movements: Laurasia drifted southward, colliding with Gondwanaland around 514-425 million years ago, leading to the formation of Panthalassa.
Pangaea Splitting: During the late Triassic period, Pangaea divided into Laurasia and Gondwanaland, moving to northern and southern poles, respectively.

Evidence of Plate Movement

Fossil Similarities: Land reptiles' fossils, such as Lystrosaurus and Cynognathus, show striking resemblances across continents.
Snider Pellegrini: Theorized a connected continent in the Pennsylvanian Period, disrupted by the "Great Flood."
Eduard Suess: Argued that the fern Glossopteris's seed distribution supported the theory of continental drift.

Plate Boundaries

Seafloor Spreading Theory (Harry Hess): Describes magma from volcanic activity creating new crust, resulting in ridges on the seafloor.
Divergent Boundaries: Plates move apart, resulting in new seafloor formation as mantle material rises.
Convergent Boundaries: Plates collide, leading to subduction where one plate moves beneath another, creating subduction zones and Wadati-Benioff zones.
- Types of Convergent Boundaries:
  - Oceanic-Continental: Oceanic subducts under continental.
  - Oceanic-Oceanic: One oceanic plate subducts under another.
  - Continental-Continental: Plates collide to form mountains.
Transform Boundaries: Plates slide past each other horizontally, e.g., San Andreas Fault.
Rift Valleys: Formed at divergent boundaries through crustal extension.

Mantle Convection Theory

Arthur Holmes (1929): Proposed that mantle movement pulls the lithosphere in a conveyor belt manner, driven by convection.
Slab Pull Theory: Suggests that gravitational forces pull down older, denser slabs into the mantle.

Internal Structure of the Earth

Crust: Outermost layer, about 1% of Earth, sits on the asthenosphere; Mohorovicic Discontinuity marks the boundary with the mantle.
Mantle: Largest layer, made of molten rock, extends 2,900 km deep; divided into upper (660 km) and lower mantle.
Outer Core: Liquid layer made of iron and nickel; responsible for Earth's magnetic field; temperature around 5,000°C.
Inner Core: Solid, deepest layer at about 5,000°C to 6,000°C, thickness around 1,250 km.

Landforms

Formation: Created by water, wind, ice, and tectonic forces; vary from rapid formation to millions of years.
Types of Landforms: Mountain ranges, hills, plains, plateaus.

Aeolian Landforms

Created by wind: Includes dunes, loess, and mushroom rocks.
- Dunes: Sand mounds; shapes include crescent or parabolic.
- Loess: Mineral-rich dust deposits.
- Mushroom Rock: Eroded rock formations.

Erosional Landforms

Created from erosion: Includes mesas, buttes, canyons, and gorges.
- Mesas: Flat-topped mountains, surrounded by resistant rock.
- Buttes: Smaller than mesas, formed by erosion.
- Canyons/Gorges: Deep ravines carved by water or glaciers.

Mountainous and Glacial Landforms

Volcanoes: Created through volcanic activity.
Hills: Smaller than mountains, formed by faulting, typically under 300m tall.
Valley/Dale: Low-lying areas formed by river or glacier actions.
Glacial Landforms: Created by glaciers, include V-shaped (water) and U-shaped (glaciers) valleys.

Fluvial and Coastal Landforms

Deltas: Formed where rivers meet oceans or estuaries; rich in alluvium, dating back around 7,000 years.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the fundamental theories of plate tectonics and the formation of continents in this quiz. Delve into Clarence Edward Dutton's theories and understand concepts like the Raisin Theory, which likens Earth's cooling process to a grape shriveling into a raisin. Test your knowledge on how these theories explain the geological features of our planet.