3.2 Weathering Flashcards
What is thermal fracture?
Physical weathering. Large diurnal ranges of temperature in deserts cause rocks and minerals to expand during the day and contract during the night, resulting in disintegration.
What is granular disintegration?
When weathering causes rocks to disintegrate into mineral grains. Responsible for producing sand in deserts. Ergs.
What is block disintegration?
Produces rock fragments not mineral grains and results in the features of stony deserts known as reg.
What is salt crystal growth?
Physical weathering process where salt solutions within the pores or joints of a rock crystallise. The crystals expand and force the rock apart.
What is dilatation?
Also known as pressure release or unloading. This process occurs where weight is removed from a previously deeply buried rock. Once the weight and pressure is released from a rock, it is weakened as it develops ‘pseudo’ lateral bedding planes.
What is hydrolysis?
Involves the breakdown of minerals within a rock due to a reaction with water.
What is hydration and dehydration?
Wetting and drying can cause the addition or removal of water from the molecules of some minerals, causing expansion or contraction which assists to disintegration.
What is carbonation?
Process of chemical weathering where carbonate minerals in rocks are attacked by carbonic acid in rainfall. Responsible for Karst limestone scenery.
What is oxidation?
The reaction that occurs when minerals in rocks are exposed to air. Causes rocks to crumble.
What is regolith?
The surface cover of loose, unconsolidated material including alluvium, glacial deposits, and peat.
What is scree/talus?
Angular rock fragments
What are blockfields?
Surfaces covered by boulders/angular rocks.
What is a reg?
A stony area in a desert.
What is an erg?
A sandy area in a desert.
What is a karst landscape?
Terrain usually characterized by barren, rocky ground, caves, sinkholes, underground rivers, and the absence of surface streams and lakes.
