Chapter 14: Karst Topography Flashcards
Karst Topography
- These are landforms that develop when the limestone bedrock starts to weather and empty spaces (like caves) form.
- The result of carbonation (chemical weathering).
Feature of Karst Topography
- Stalactite and stalagmite
- Sinkholes
- Caves
Caves
Natural underground areas large enough for humans to enter
Relate Karst topography to systems theory
The system of caves and passage ways that make up Karst topography is a dynamic system, it is always changing as it tried to reach equilibrium
- One possible result is the upward movement of caves
Sinkhole (dolline)
nearly circular depression created by the weathering of karst landscapes with subterranean drainage. may collapse through the roof of an undergorund cave
Factors affecting the formation of Karst topography
- bedrock that is at least 80% calcite minerals(Calcite is the main mineral in limestone which is reactive to weak acids)
- Bedrock that is fractured.(Fractures allow water and acid to get into the bedrock which promotes weathering)
- Organic material on and in the bedrock(This will make the water more acidic)
- An aerated zone
(this is a layer of bedrock at the surface that is not saturated with water. The downward movement of water in the aerated zone will help to sustain weathering)
Mass wasting/movement
“what happens when things fall downhill”.
Gravitationally driven movement of material downslope.
Process of mass movement
- As an object moves downhill it speeds up as gradient increases.
- Once it reaches the inflection point (where it has a maximum velocity),
- It begins to slow down as gradient decreases.
- friction can also prevent things from moving downhill
TYPES OF MASS MOVEMENT
- FALL
- SLIDE
- FLOW
- SOIL CREEP
Type of mass movement:
FALL
objects that move quickly downhill with little or no contact with underlying surface
Type of mass movement:
SLIDE
Objects moving downhill in constant contact with the underlying surface
Types of SLIDE mass movement
2 TYPES
- translational slide
- rotational slide
Translational slide
Objects move parallel to the surface.
Rotational Slide
Objects rotate as they move downhill.
Type of mass movement: FLOW
Water saturated material moves downhill in constant contact with the bottom.
- this material is able to flow further (friction is less) as it slows the pre-existing drainage of the land
Type of mass movement: SOIL CREEP
The slow step-like movement of material downhill due to frost action or wetting and drying.
- At A when sediment is frozen or wet it expands outwards away from the hillside.
- At B the sediment thaws or it dries. As a result it shrinks and collapses straight down.
- At C the result is a small net movement
- Repeated freeze/thaw or wet/dry cycles can result in significant downhill movement.
