Earth System Science Chapter 8 Study Summary Table PDF

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Chapter 8 summary...

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Chapter 8: The Development of the Landscape Key Concept 1: Nature of the Lithosphere and Morphology of its Structures

Key Concept 2: Structures Affecting Continental Surfaces

Key Concept 3: Weathering and Sediment Production

Key Concept 4: Slope Processes

Chapter 8: The Development of the Landscape -Made up of rocks + sediments. IGNEOUS ROCKS: -Form from the cooling + consolidation of liquid magma, either at the Earth’s surface or deep within it. -There are two types: Extrusive + Intrusive. -Basalt (Extrusive) is black in the beginning due to its high iron content + alters to pale grey before becoming reddish during weathering because of the amount of iron released. -Granite is a type of intrusive rock + is made up of quartz, orthoclase, plagioclase, biotite + muscovite. SEDIMENTARY ROCKS: -Form because of weathered materials or sediments being laid down by water, wind or glaciers + becoming lithified. -Include sandstone + limestone. METAMORPHIC ROCKS: -Are Igneous or sedimentary rocks that have been subjected to extreme heart or pressure + have thus become less permeable + more resistant. E.g. Marble.

FAULTING: -A fault line is a fracture in the Earth’s crust resulting from tension or shear forces associated with plate movement. -Because of the enormous force involved, rocks along the fault are shattered into angular fragments called breccia + sometimes ground into fine rock flour. -When a normal fault occurs, the blocks forced downwards are called graben + the blocks forced up are called horst. -Faults produced by stresses or horizontal displacement can result in offset channels or interruptions in groundwater movements. -Fault movement is generally accompanied by earthquakes. FOLDING: -When compressional forces are applied to rocks formed via lithogenesis (formed out of sediments), the individual layers are folder + crumpled. -Folds are called anticlines when sedimentary or metamorphic rocks are forced upwards in folds where central rocks are most compressed + external rocks are subjected to tension or stretching forces. JOINT PATTERNS AND BEDDING PLANES: -Scale lines of weakness within rocks. -In Igneous rocks, they form from fracture patterns associated with cooling + contraction of the molten body. -They may appear in metamorphic rocks that have been subject to high pressure + temp. MICROFISSURES: -Fractures in rocks that are microscopic.

-Sediments are produced because of weathering of rocks at + near the earth’s surface. PHYSICAL WEATHERING: -Rocks are broken down with little or no chemical alteration. -Sheeting fractures occur in fresh, massive rocks + are stress-related. -Insolation weathering occurs because of heating + cooling. -Weathering by fire is when the outer layer heats + expands before fracturing + flaking after the fire. -Abrasion occurs due to movement of wind, ice or water. -Frost shattering occurs when water freezes inside rocks + the expansion causes rocks to shatter. -Salt weathering refers to the action of salts crystallising in rocks. CHEMICAL WEATHERING: -In hot weather, it occurs more rapidly + at greater depths. -Hydration is the addition of water to crystal lattice, leading to expansion of mineral. -Hydrolysis is when water combines with mineral + results in formation of clays. -Solution involves liquid water dissolving minerals within a rock. BIOLOGICAL WEATHERING: -Physical fracturing from growth of roots.

ROCK FALLS: -A form of mass movement that usually occurs on cliffs or vertical rock faces. SOIL CREEP: -Very slow downslope movement of materials under the force of gravity. -Sheetwash (movement of water down a slope) + slopewash (rock or solid material that has moved down a slope sue to gravity or water flow) are often involved. LANDSLIDES AND MASS MOVEMENT: -Occur when sediments become saturated + are usually rapid....