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Difficulty: HardWeathering and Mass Wasting Processes

In physical geography, weathering and mass wasting operate through distinct chemical reactions and mechanical failure modes governed by specific climatic and geological conditions. Which option correctly pairs each weathering or mass wasting process on the left with its corresponding environmental mechanism and landform result on the right?

  • Carbonation-SolutionDissolution of limestone along joint planes by weak carbonic acid (H2CO3H_2CO_3), generating karst subterranean features like sinkholes and caverns.
  • HydrolysisReplacement of rock cations by hydrogen ions in acidic groundwater, altering orthoclase feldspar into kaolinite clay minerals.
  • SolifluctionSlow flowage of waterlogged regolith over an impermeable permafrost bedrock base during summer thaw in tundra landscapes.
  • Slumping (Rotational Slide)Downslope displacement of saturated soil mantle along a curved concave shear plane, producing backward-tilted step terraces.

Answer

Carbonation-Solution pairs with the dissolution of limestone by carbonic acid forming karst landforms; Hydrolysis pairs with hydrogen ion substitution altering feldspar into kaolinite clay; Solifluction pairs with slow flowage of thawed saturated soil over permafrost; Slumping pairs with downslope displacement along a curved concave shear plane forming backward-tilted terraces.
Carbonation dissolves limestone via carbonic acid to produce karst landforms; Hydrolysis alters silicate minerals like feldspar to clay through hydrogen ion substitution; Solifluction is the slow downslope flow of saturated soil over permafrost; Slumping is rotational displacement along a concave surface forming step-like terraces.

Step-by-Step Solution

1
Analyze the chemical mechanism of Carbonation-Solution.
Carbonation requires carbon dioxide dissolved in water (H2CO3H_2CO_3) dissolving calcium carbonate in limestone to form underground karst topography.
Calcium carbonate is insoluble in pure water but dissolves readily in carbonated groundwater.
2
Examine the process of Hydrolysis.
Hydrolysis involves reactive H+H^+ ions replacing cations in silicate minerals such as feldspar, converting them into kaolinite clay.
Hydrolysis changes the fundamental chemical composition of rock minerals to produce soft hydrous clays.
3
Differentiate between Solifluction and Slumping mass wasting movements.
Solifluction requires permafrost acting as an impermeable layer for saturated soil flow in tundra regions, whereas Slumping involves rotational slip along a concave failure plane creating backward-tilted step terraces.
Solifluction is thermal-climatic and flow-based, while slumping is structural shear failure along a curved surface.

Key Concept

Chemical weathering mechanisms and mass wasting failure modes
Estimated Time:2m 0s
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Topics

Weathering and Mass Wasting Processes

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