Ch. 14 - Weathering, Karst Landscapes, and Mass Movement Flashcards
What’s the difference between Erosion and Weathering?
The primary difference is that Weathering occurs in place whereas Erosion involves movement to a new location.
The process that involves rocks, soil and minerals being slowly broken down or broken apart by the Earth’s environment such as pressure, temperature, water and ice
Physical Weathering
What are the four types of Physical Weathering?
Frost Wedging
Salt Wedging
Hydration
Exfoliation
The erosion or disintegration of rocks, building materials, etc., caused by chemical reactions (chiefly with water and substances dissolved in it) rather than by mechanical processes.
Chemical Weathering
What are the three types of Chemical Weathering?
Oxidation
Hydrolysis
Carbonation
What is the term for the study of caves and cave-related features?
Speleology
What are the two main factors to consider relating to Mass Movement?
Gradient
Water/H2O (Can speed up or slow down the slope of a surface)
What is the “Angle of Repose”?
The steepness of a slope that results when loose particles come to rest; an angle of balance between driving and resisting forces, ranging between 33° and 37° from a horizontal plane.
What is a “Talus”?
The pile of rocks that accumulates at the base of a cliff, chute, or slope
Free-falling movement of debris from a cliff or steep slope, generally falling straight or bounding downslope.
Rockfall
What is a “Soil Creep”?
A persistent mass movement of surface soil where individual soil particles are lifted and disturbed by the expansion of soil moisture as it freezes or by grazing livestock or digging animals
Movement is generally 1cm/year
What is “Solifluction”?
The gradual movement of wet soil or other material down a slope, especially where frozen subsoil acts as a barrier to the percolation of water. Driven by freezing/thawing activity
Happens in high latitude areas.
Ice-saturated piece of ground is on bottom, with a water-saturated portion closer to the surface. A slab of ground can be partially frozen, partially water.
Diagram is important
What is a “Mudflow”?
Fluid downslope flows of material containing more water than earthflows
What is “Earthflow”?
A downslope viscous flow of fine-grained materials that have been saturated with water and moves under the pull of gravity.
It’s an intermediate type of mass-wasting that is between downhill creep and mudflow
What is a “Landslide”?
A sudden rapid downslope movement of a cohesive mass of regolith and/or bedrock in a variety of mass-movement forms under the influence of gravity; a form of mass movement
What is a “Stalactite”?
A tapering structure hanging like an icicle from the roof of a cave, formed of calcium salts deposited by dripping water
What is a “Stalagmite”?
An upward-growing mound of mineral deposits that have precipitated from water dripping onto the floor of a cave
What is an example of Oxidation?
Oxygen in the air causing Iron to rust, as seen on older architecture such as the parliament buildings. Brown iron turns green in color.
Oxygen + Iron = Iron Oxide
What is Hydrolysis?
The chemical breakdown of a compound due to reaction with water
- A sugar cube dissolving into a glass of water.
- Salt dissolving into water creates Saline Water
What is Carbonation?
The mixing of water with carbon dioxide to make carbonic acid. This type of weathering is important in the formation of caves
- Commonly reacts with calcium, magnesium, potassium, and sodium (especially limestone), transforming them into carbonates
- The mixture with CO2 with water vapour in the atmosphere creates Carbonic Acid/Acid Rain
What is a Karst Landform?
A geological feature created on the earth’s surface by the drainage of water into the ground. Typical karst forms include sinkholes, caves, natural bridges and sinking streams
What is Exfoliation?
The physical weathering process that occurs as mechanical forces enlarge joints in rock into layers of curved slabs or plates, which peel or slip off in sheets; also called sheeting
What is Hydration?
A chemical weathering process involving water that is added to a mineral, which initiates swelling and stress within the rock, mechanically forcing grains apart as the constituents expand
What is Frost Wedging?
A powerful mechanical force produced as water expands up to 9% of its volume as it freezes. Water freezing in a cavity in a rock can break the rock if it exceeds the rock’s tensional strength
What is Salt Wedging?
The process through which a distinctive saltwater layer creates a layer of freshwater because of density variation
