One Process Physical And Chemical Weathering Flashcards
What does weathering processes do
Break down rock into smaller pieces - scree
There are 2 forms weathering..
Physical and chemical
What is physical mechanical weathering
The breakdown of rock into smaller pieces and no new substances formed
Two examples mechanicsl
Frost - freeze thaw action
Temp changes - exfoliation onion weathering
When does freeze thaw action occur
When temp goes above and below freezing point - on high mountains tops or lowlands in cold weather
How much does water expand in cracks when freezes
10%
Repeated freezing and thawing forms…
Rock to gather at foot of hillside as scree
Examples scree covered slopes
Wicklow mountains
What is chemical weathering
Breakdown of rock during a chemical reaction - rock dissolves and changes into new substance
Why is rain important in chemical weathering
Contains many dissolved substances that can chemically attack rock minerals
What minerals are resistant to chemical weathering
Quartz and mica
What is carbonation
The chemical weathering of limestone
What is limestone
An alkaline rock due to presence of calcium carbonate from sea shell fragments in the rock
Example carbonation
Burren co clare - vertical joints are weathered by carbonation into deep grooves = grikes flat surface of Clint’s dissolved by carbonation into tiny pits called karrens
