Plate Tectonics and Landforms

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Questions and Answers

What is the Plate Tectonics Theory?

It is the theory that explains the formation and movement of large sections (plates) of the Earth's lithosphere (crust and upper mantle).

What was Pangaea?

A supercontinent that existed during the late Paleozoic and early Mesozoic eras (approximately 335 to 175 million years ago) before breaking apart into the continents we see today.

Name Canada's 7 main landform regions.

Interior Plains, Canadian Shield, Hudson Bay - Arctic Lowlands, Great Lakes-St. Lawrence Lowlands, Appalachians, Innuitian Mountains, Western Cordillera.

What two main factors contributed to the formation and current landscape of the Appalachian Mountains?

<ol> <li>Underlying geology (tectonic forces creating mountain structures) and 2) The impact of glaciation (carving features like drainage patterns and depositing soil).</li> </ol> Signup and view all the answers

What is the rock cycle?

The continuous process by which rocks are created, changed from one form to another, destroyed, and then formed again. Signup and view all the answers

What are the three main types of rocks?

Sedimentary, Metamorphic, and Igneous. Signup and view all the answers

How is magma formed?

Magma is hot, molten rock that forms when existing rock melts, typically deep within the Earth's mantle or crust due to high temperatures and pressure, or the introduction of volatiles like water. Signup and view all the answers

How are sedimentary rocks formed?

Sedimentary rocks are formed from the accumulation and cementation of sediment (pieces of other rocks, minerals, or organic matter) that has been weathered, eroded, transported, and deposited. Signup and view all the answers

How are metamorphic rocks formed?

Metamorphic rocks are formed when existing rocks (igneous, sedimentary, or other metamorphic rocks) are transformed by intense heat, pressure, or chemical reactions, without melting completely. Signup and view all the answers

How are igneous rocks formed?

Igneous rocks are formed from the cooling and solidification of magma (molten rock below the Earth's surface) or lava (molten rock on the Earth's surface). Signup and view all the answers

What is Continental Drift?

The theory, first proposed in detail by Alfred Wegener, that Earth's continents have moved over geologic time relative to each other, thus appearing to have 'drifted' across the ocean bed. Signup and view all the answers

What evidence supported the theory of continental drift?

Key evidence included: 1) The complementary shapes of coastlines on opposite sides of oceans (like a jigsaw puzzle). 2) Similar rock formations and mountain ranges found on separated continents. 3) Identical fossils of plants and animals found on continents now far apart. 4) Evidence of past climates (like glacial deposits in current tropical areas) inconsistent with present locations. Signup and view all the answers

List the main compositional and mechanical layers of the Earth.

Compositional: Crust, Mantle, Core (Outer Core and Inner Core). Mechanical: Lithosphere (Crust and upper solid Mantle), Asthenosphere (part of upper mantle, semi-solid/plastic), Mesosphere (lower mantle, solid), Outer Core (liquid), Inner Core (solid). Signup and view all the answers

Describe the Earth's inner core.

The inner core is the Earth's innermost layer, consisting of a solid sphere composed mainly of iron and nickel. It is extremely hot but remains solid due to immense pressure. Signup and view all the answers

Describe the Earth's mantle.

The mantle is the thickest layer, situated between the outer core and the crust. It is composed mainly of silicate rocks and is mostly solid but behaves as a very viscous fluid on geological time scales (plasticity). Signup and view all the answers

What is the lithosphere?

The lithosphere is the rigid, outermost mechanical layer of the Earth, consisting of the crust and the solid uppermost part of the mantle. Signup and view all the answers

What are the four major geological eras, from oldest to most recent?

Precambrian, Paleozoic, Mesozoic, and Cenozoic. Signup and view all the answers

Approximately what percentage of Earth's history does each major geological era represent?

Precambrian: ~88%, Paleozoic: ~7%, Mesozoic: ~4%, Cenozoic: ~1%. Signup and view all the answers

Approximately how old is the Earth?

About 4.54 billion years old. Signup and view all the answers

What were key biological developments during the Precambrian era?

The origin of life, the evolution of the first single-celled organisms (prokaryotes and later eukaryotes), and the development of the first multicellular organisms, including early algae (plants). Signup and view all the answers

What were key biological developments during the Paleozoic era?

Significant diversification of marine invertebrates (like trilobites), the emergence and diversification of fish, the colonization of land by plants and arthropods, the evolution of amphibians, and the appearance of the first reptiles. Signup and view all the answers

What are key biological developments during the Cenozoic era?

The diversification and rise to dominance of mammals (including primates and eventually humans), the continued diversification of birds and flowering plants, and cooling global climate trends leading to ice ages. Signup and view all the answers

What are the three basic types of tectonic plate boundaries based on relative movement?

<ol> <li>Divergent boundaries: plates move away from each other. 2. Convergent boundaries: plates move towards each other. 3. Transform (or Translation) boundaries: plates slide horizontally past each other.</li> </ol> Signup and view all the answers

What are three main geological processes responsible for building landforms (constructive forces)?

Folding, Faulting, and Volcanism. Signup and view all the answers

What is folding in geology?

Folding is the bending of rock layers, typically due to compressional stress, without breaking. This process often occurs during continental collisions and creates features like anticlines (upfolds) and synclines (downfolds), contributing to mountain formation. Signup and view all the answers

What is volcanism?

Volcanism is the geological process involving the eruption of magma (molten rock), volcanic gases, and ash onto the Earth's surface or into the atmosphere. Signup and view all the answers

How is the Earth's crust recycled?

The Earth's crust, particularly the denser oceanic crust (part of the lithosphere), is recycled back into the mantle through the process of subduction, which occurs at convergent plate boundaries. Signup and view all the answers

Why are certain minerals often found concentrated together in specific locations?

Minerals are often found together because they form under similar geological conditions (temperature, pressure, chemical environment) or are sorted and concentrated by physical processes (like flowing water or wind) based on shared properties such as density or chemical stability. Signup and view all the answers

What is a glacier?

A glacier is a large, long-lasting mass of ice formed on land from the compaction and recrystallization of snow, which moves slowly downslope or outward under the influence of gravity and its own weight. Signup and view all the answers

How do glaciers affect the land?

Glaciers act as powerful agents of erosion and deposition. They sculpt landscapes by carving valleys (U-shaped valleys), cirques, and arêtes through abrasion and plucking. They also transport and deposit vast amounts of sediment (till), creating features like moraines, drumlins, and eskers. Signup and view all the answers

How do glaciers form different landforms?

Glaciers form landforms through erosion (carving and scouring bedrock) and deposition (dropping sediment). Erosional features include U-shaped valleys, cirques, arêtes, and horns. Depositional features include moraines (ridges of till), drumlins (streamlined hills of till), eskers (ridges of sand/gravel from meltwater streams), and outwash plains. Signup and view all the answers

Why is the Innuitian Mountain region in Canada considered less eroded compared to ranges like the Appalachians?

The Innuitian Mountains are geologically much younger, having formed primarily during the Mesozoic Era. Consequently, they have been exposed to erosional forces for a shorter period compared to the ancient Appalachian Mountains, which formed during the Paleozoic Era. Signup and view all the answers

What is a fjord and how is it formed?

A fjord is a long, narrow, deep inlet of the sea bordered by steep cliffs or slopes. Fjords are formed when a valley, previously carved deep (often below sea level) by a glacier, is flooded by seawater after the glacier retreats. Signup and view all the answers

What are the three basic types of landform regions in Canada?

Shield, Highlands, and Lowlands. Signup and view all the answers

What is the theory of plate tectonics?

A theory explaining the formation and movement of large parts of the Earth's crust. It was proposed by Alfred Wegener in 1912, who initially called the concept continental drift. Signup and view all the answers

Name the seven major landform regions of Canada.

Interior Plains, Canadian Shield, Hudson Bay - Arctic Lowlands, Great Lakes-St. Lawrence Lowlands, Appalachians, Innuitian Mountains, Western Cordillera. Signup and view all the answers

What are two key factors in the formation of the Appalachian region's landscape?

<ol> <li>The underlying geology, including mountain structures formed by tectonic activity. 2) The impact of glaciers, which carved drainage patterns and deposited soil.</li> </ol> Signup and view all the answers

What is the theory of Continental Drift?

The theory, proposed initially by Alfred Wegener, suggesting that Earth's continents have moved over geologic time relative to each other, appearing to have "drifted" across the ocean bed. It posits that the crust is broken into pieces (plates) that float on the underlying mantle. Signup and view all the answers

List four pieces of evidence supporting the theory of continental drift.

<ol> <li>The apparent fit of continental coastlines (e.g., South America and Africa). 2) Matching geological formations and mountain ranges across oceans. 3) Identical fossils of ancient plants and animals found on continents now widely separated. 4) Evidence of past glaciation in regions that are currently in warm climates.</li> </ol> Signup and view all the answers

Match the layer of the Earth with its description.

Inner Core = Solid metal (primarily iron and nickel), hottest layer, under greatest pressure Outer Core = Liquid metal (primarily iron and nickel) layer surrounding the inner core Mantle = Thick layer of hot, semi-solid rock between the core and the crust Lithosphere = The rigid outer part of the Earth, consisting of the crust and upper mantle Asthenosphere = The highly viscous, mechanically weak part of the upper mantle just below the lithosphere; allows plate movement Signup and view all the answers

Name the four major geological eras in order from oldest to most recent.

Precambrian, Paleozoic, Mesozoic, Cenozoic. Signup and view all the answers

Match the geological era with its approximate duration as a percentage of Earth's total history.

Precambrian = ~88% Paleozoic = ~7% Mesozoic = ~4% Cenozoic = ~1% Signup and view all the answers

What were two key biological milestones of the Precambrian era?

The appearance of the first single-celled organisms (prokaryotes and later eukaryotes) and eventually the first simple multicellular organisms and potentially early plants (like algae). Signup and view all the answers

What were two key biological milestones of the Paleozoic era?

The appearance of the first fish and the first reptiles. (Also includes the Cambrian Explosion, colonization of land by plants and amphibians). Signup and view all the answers

Match the type of tectonic plate boundary movement with its description.

Divergent = Two plates move AWAY from each other (e.g., mid-ocean ridges) Convergent = Two plates move TOWARDS each other (can result in subduction or mountain building) Transform (Translation) = Two plates slide PAST each other horizontally (e.g., San Andreas Fault) Signup and view all the answers

What are three main tectonic forces or processes responsible for building large-scale landforms like mountains?

Folding (bending of rock layers), Faulting (fracturing and displacement of rock), and Volcanism (eruption of magma/lava). Signup and view all the answers

Describe folding in the context of landform creation.

Folding occurs when compressional forces, typically at convergent plate boundaries, cause layers of rock to buckle and bend without breaking, forming structures like anticlines (upfolds) and synclines (downfolds), which often manifest as mountain ranges. Signup and view all the answers

What is volcanism and how does it contribute to landform creation?

Volcanism is the eruption of molten rock (magma) onto the Earth's surface as lava, along with ash and gases. This process builds up volcanic cones and mountains layer by layer as the erupted material cools and solidifies. Signup and view all the answers

Why are certain types of minerals often found concentrated together?

Minerals often concentrate together because they form under specific, shared geological conditions (like temperature, pressure, and chemical environment) or because processes like magmatic crystallization, hydrothermal activity, weathering, erosion, and deposition selectively gather minerals with similar properties (e.g., density, chemical stability). Signup and view all the answers

How do glaciers primarily affect the land they move over?

Glaciers drastically reshape landscapes by eroding bedrock and surface materials through plucking (quarrying) and abrasion (scraping), and by transporting and depositing vast quantities of sediment (till) to create various landforms. Signup and view all the answers

Explain how the weight and movement of glaciers lead to the formation of different landforms.

The immense weight of a glacier exerts pressure, while its slow, grinding movement allows it to effectively erode the underlying surface through abrasion and plucking, carving features like U-shaped valleys and cirques. As the glacier melts or moves, it deposits the eroded material (till) it carries, forming features like moraines, drumlins, and eskers. Signup and view all the answers

Why is the Innuitian Mountain region of Canada considered geologically younger and less eroded compared to regions like the Appalachians?

The Innuitian Mountains were primarily formed during the Mesozoic era through compressional tectonics, making them significantly younger than the Appalachian Mountains, which originated in the Paleozoic era. Being younger, the Innuitians have undergone less time subject to erosional processes. Signup and view all the answers

What are the three broad physiographic categories that encompass Canada's diverse landforms?

Canadian Shield, Highlands, and Lowlands. Signup and view all the answers

What two main factors contributed to the formation and shaping of the Appalachian Mountains?

<ol> <li>The underlying geology, such as mountain structures formed by tectonic plate collisions. 2) The impact of glaciers, which carved drainage patterns and deposited soil.</li> </ol> Signup and view all the answers

Name the layers of the Earth described in the flashcards, starting from the inside.

Inner core, Outer core, Mantle (containing the Asthenosphere), Lithosphere (containing the Crust). Signup and view all the answers

What are the characteristics of the Earth's inner core?

It is believed to be made of solid iron and nickel alloy. It is the hottest layer and under the greatest pressure. Signup and view all the answers

What is the Earth's mantle?

The thick layer of hot, mostly solid but slowly flowing rock located between the Earth's core and crust. Signup and view all the answers

How old is the Earth estimated to be?

Approximately 4.54 billion years old. Signup and view all the answers

What were some key biological characteristics of the Precambrian era?

The appearance of the first single-celled organisms (bacteria, archaea) and later, the first simple multicellular organisms like algae. Signup and view all the answers

What were some key biological developments during the Mesozoic era?

The rise and dominance of reptiles (including dinosaurs), the appearance of the first mammals and birds, and the evolution of flowering plants. Signup and view all the answers

What are some key biological characteristics of the Cenozoic era?

The diversification and dominance of mammals following the extinction of the dinosaurs, the rise of birds, and the evolution of primates, including humans. Signup and view all the answers

What are the three basic types of tectonic plate movements?

Divergent (plates move away from each other), Convergent (plates move towards each other), and Transform/Translation (plates slide horizontally past each other). Signup and view all the answers

What are three main geological forces or processes responsible for building landforms?

Folding, Faulting, and Volcanism. Signup and view all the answers

What is faulting?

Faulting is the fracturing and displacement of Earth's crust along a fault line due to tectonic stresses (compression, tension, or shear). Movement along faults causes earthquakes. Signup and view all the answers

How does the Earth's crust recycle itself?

Through the process of subduction at convergent plate boundaries, where denser oceanic crust sinks beneath less dense continental or oceanic crust, returning to the mantle where it melts and becomes incorporated back into the mantle. Signup and view all the answers

Why are different minerals often found together in specific locations?

Minerals form under specific conditions of temperature, pressure, and chemical environment. Different minerals that form under similar conditions often occur together in the same geological setting or rock type. Also, physical processes like erosion and deposition can concentrate minerals with similar properties (like density) together. Signup and view all the answers

How do glaciers affect the land they move over?

They erode the land through processes like plucking (lifting pieces of bedrock) and abrasion (grinding the bedrock with embedded debris), and they deposit vast amounts of sediment (till) when they melt, creating distinctive glacial landforms. Signup and view all the answers

How does the combination of a glacier's weight and movement lead to the formation of different landforms?

A glacier's immense weight provides the pressure needed for erosion, while its slow, powerful movement grinds and scrapes the underlying bedrock (abrasion) and tears away rock fragments (plucking). This carves out valleys and basins. As the glacier melts, it deposits the eroded material, forming features like moraines, eskers, and drumlins. Signup and view all the answers

Why is the Innuitian Mountain region considered geologically younger and less eroded than some other Canadian mountain regions?

The Innuitian Mountains were primarily formed during the Mesozoic era, making them younger than ranges like the Paleozoic-era Appalachians. They have therefore undergone less time subject to erosional forces. Their high-latitude location also influences weathering and erosion processes. Signup and view all the answers

What are the three basic topographic types of landforms that categorize Canada's regions?

Canadian Shield, Highlands, and Lowlands. Signup and view all the answers

Flashcards

What is Plate Tectonics Theory?

Explains the formation and movement of large parts of Earth's crust.

What is Pangaea?

A supercontinent that existed during the Paleozoic and Mesozoic eras, which broke apart into today's continents.

Name 7 Landform Regions of Canada

Interior Plains, Canadian Shield, Hudson Bay - Arctic Lowlands, Great Lakes-St. Lawrence Lowlands, Appalachians, Innuitian Mountains, Western Cordillera