Physical Geography Test Grade 9 Flashcards
Definition of “Geology”
Geology is the study of the Earth, its structure, composition, and the processes that shape it over time. It includes understanding rocks, minerals, landforms, and the forces that drive natural phenomena like earthquakes, volcanoes, and glaciation.
The Layers of the Earth
Made up of three layers, Crust, mantle and core
Crust
The outermost layer. It’s solid and consists of two types:
Continental crust: Thicker, less dense, and made mostly of granite. (land)
Oceanic crust: Thinner, denser, and made mostly of basalt. (water)
Mantle
The layer beneath the crust, made of semi-solid rock that can flow slowly over time.
Core
Divided into:
Outer core: Liquid iron and nickel.
Inner core: Solid iron and nickel.
Continental Drift Theory / Pangea
The theory of continental drift suggests that continents were once joined together in a supercontinent called Pangea and have since drifted apart. This theory was proposed by Alfred Wegener in the early 20th century.
Alfred Wegener and the 4 Pieces of Evidence
Wegener proposed the theory of continental drift and supported it with 4 key pieces of evidence:
Fit of the continents: Continents like South America and Africa seem to fit together like puzzle pieces.
Fossil evidence: Identical fossils found on different continents (e.g., Mesosaurus found in both South America and Africa).
Rock formations: Similar rock layers and mountain chains are found on continents that were once connected.
Climate evidence: Evidence of past climates (e.g., glacial deposits) on continents that are now in warmer climates.
Tectonic Plates
The Earth’s lithosphere (outer layer) is divided into large slabs called tectonic plates. These plates float on the semi-fluid asthenosphere beneath them, and their movements shape Earth’s surface.
(these guys also cause earthquakes when they move against each other)
Who was John Tuzo Wilson?
John Tuzo Wilson was a Canadian geophysicist who contributed to the theory of plate tectonics. He proposed the idea of hotspots (areas where magma rises from deep in the mantle, forming volcanic islands) and helped refine the understanding of plate movements.
Plate Boundaries (3 types)
Convergent (plates collide): Can cause mountains, volcanoes, and earthquakes.
Divergent (plates move apart): Can cause mid-ocean ridges and volcanic activity.
Transform (plates slide past each other): Can cause earthquakes.
Earthquakes
Earthquakes occur when stress along faults (fractures in Earth’s crust) causes a sudden release of energy. This energy travels as seismic waves, shaking the ground.
Volcanoes
Volcanoes are openings in the Earth’s surface where magma, gas, and ash can escape. They form at convergent and divergent boundaries or over hotspots.
Landform Regions of Canada (seven main)
Canadian Shield
Western Cordillera
Interior Plains
Hudson Bay Lowlands
Appalachian Mountains
Great Lakes-St. Lawrence Lowlands
Arctic Lowlands
Canadian Shield
What/Where: The Canadian Shield is the largest landform region, covering much of eastern and northern Canada. It’s a vast, rocky region.
Description of Land: It has old, exposed rock (mostly granite), and it’s often referred to as the “backbone” of Canada.
Resources: Rich in mineral resources (e.g., gold, copper, nickel) and freshwater lakes.
Population: The population is sparse, as it’s largely inhospitable for large human settlements, though there are mining towns and some Indigenous communities.
The Rock Cycle
Describes how rocks change from one type to another through processes like melting, cooling, erosion, and pressure… there are three main ones like Igneous, sedimentary and metamorphic
Igneous
Formed from cooled magma (e.g., basalt, granite).
Sedimentary
Formed from compressed sediments (e.g., sandstone, limestone).
Metamorphic
Formed from heat and pressure on existing rocks (e.g., marble, slate).
what are the like 5 main ways rocks change?
Cooling: Magma or lava cools and solidifies into igneous rock.
Erosion: Rocks are broken down into smaller pieces by wind, water, or ice.
Compaction: Sediments are pressed together under pressure to form sedimentary rocks.
Metamorphism: Rocks change due to heat and pressure, becoming metamorphic.
Melting: Rocks melt into magma, starting the cycle over.
Glaciers
What are glaciers?
Glaciers are large masses of moving ice formed by the accumulation and compaction of snow.
Types of glaciers:
Alpine glaciers: Found in mountain ranges.
Continental glaciers: Cover vast areas, like in polar regions.
How are they formed? Snow accumulates in cold areas, compressing into ice over time.
Glaciation
Glaciation refers to the process by which glaciers shape the landscape. This includes the movement of glaciers that carve out valleys, shape mountains, and deposit materials like moraines and eskers.
