Exogenic Processes and Degradation Overview

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Questions and Answers

What is the main role of exogenic processes in reshaping the Earth’s surface?

They transform rock into sediment. (correct)

They increase the Earth’s internal temperature.

They are responsible for the formation of magma.

They cause tectonic plate movement.

Which process is NOT classified as a degradation process?

Erosion

Deposition (correct)

Weathering

Transportation

What type of weathering involves breaking rocks without changing their chemical composition?

Hydrolysis

Chemical weathering

Biological weathering

Physical weathering (correct)

Which of the following best describes frost wedging?

Water freezing and expanding in rock cracks. Signup and view all the answers

What is a primary factor that influences mass wasting?

Vegetation cover Signup and view all the answers

Mass wasting is best defined as which of the following?

The rapid movement of rocks and soil due to gravity. Signup and view all the answers

Which weathering process involves the alteration of minerals when water reacts with them?

Hydrolysis Signup and view all the answers

How does the steepness of a slope affect mass wasting events?

Steeper slopes increase gravitational force on materials. Signup and view all the answers

What characterizes translational slides?

They involve movement along a well-defined surface. Signup and view all the answers

What is the primary difference between slurry flows and granular flows?

Slurry flows consist of mixtures with 20% to 40% water. Signup and view all the answers

Which agent of erosion is not mentioned in the provided content?

Volcanoes Signup and view all the answers

What process involves detaching soil particles by the impact of raindrops?

Splash erosion Signup and view all the answers

How is bank erosion primarily caused?

Continuous flow of water wearing out stones along the banks. Signup and view all the answers

What is the result of glacier plucking?

Incorporation of fractured bedrocks into ice. Signup and view all the answers

Which type of erosion involves water flowing in narrow channels to erode deep gullies?

Gully erosion Signup and view all the answers

What distinguishes rotational slides from translational slides?

They involve movement along a concave upward curvature. Signup and view all the answers

Study Notes

Exogenic Processes

Exogenic processes are external processes occurring near Earth's surface.
They are part of the rock cycle, transforming rock into sediment.
These processes involve degradation (weathering, mass wasting, erosion, and transportation) and aggradation (deposition).

Degradation Processes: Weathering, Mass Wasting, Erosion & Transportation

Weathering: Physical breakdown and/or chemical alteration of rocks near Earth's surface.
Types of Weathering: Mechanical and Chemical.
Mechanical Weathering: Large rocks break into smaller fragments without changing mineral composition.
Frost Wedging: Water in cracks expands when it freezes, causing rocks to break.
Insolation Weathering: Thermal stress from expansion and contraction of rocks due to temperature changes.
Unloading or Pressure Release: Overlying rock eroding, causing the outer layer to expand more than the layers underneath.
Chemical Weathering: Decomposes rocks through chemical changes.
Oxidation: Oxygen dissolved in water oxidizes some materials, creating reddish-brown rust.
Hydrolysis: Water is the most important chemical weathering agent, dissolving minerals into ions that react with water, forming clay minerals.
Carbonation and Solution: Carbon dioxide dissolves in water forming carbonic acid, reacting with carbonate rocks forming a soluble product (calcium bicarbonate).

Mass Wasting

Mass wasting is the movement of rocks, soil, and regolith.
It is a degradation process following weathering.
Gravity, steepness of slope, water content, and vegetation influence mass wasting.
Oversteepening is a factor affecting mass wasting.
Examples include rock fall, debris fall, slides (translational and rotational), and flows (slurry and granular).

Erosion

Erosion is a degradation process, transporting weathered sediments to different places.
Agents of erosion include water (splash, rill, gully, valley, bank, coastline), glaciers (plucking, abrasion), and wind.

Aggradation Processes (Deposition)

Deposition is the aggradation (accumulation) of weathered sediments.
Deposition leads to landform creation.
Depositional features include spits, deltas, alluvial fans, moraines, and sand dunes.

Transportation

Materials are transported in four distinct ways: solution, suspension, traction, and saltation.

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Description

This quiz explores exogenic processes that shape Earth’s surface through degradation and aggradation. You will learn about various types of weathering, including mechanical and chemical processes, and the role of erosion and sediment transportation. Test your knowledge on how these processes contribute to the rock cycle.