Weathering

What is weathering?

The breakdown of material by elements without removing it from its environment

What is mechanical weathering?

It breaks off rock fragments of varying sizes which fall to the foot of the cliff where they protect the cliff from erosion

What is freeze thaw?

The repeated freezing and thawing of water which causes a type of crystal growth that is most effective on high latitude coasts with significant precipitation

What is salt crystallisation?

Where salty or sea water enters rock cracks (cliffs) and evaporates - as the crystals grow it exerts pressure on the rock

What is pressure release?

Where deeply buried rocks and fracture as the immense pressure from overlying rock or ice is removed

What is wetting and drying?

When rocks and soil repeatedly expand when wet and contract when dry, which causes them to crack and crumble

What does wetting and drying do to the coast?

It weakens coastal cliffs d contributes to slow soil movement on gentle slopes

What is the process of wetting and drying most effective on?

The expansion and contradiction is most effective on clay and micro-tidal environments

What is solution?

A process of erosion and transportation where soluble rocks are dissolved by water which typically contains weak carbonic acid

What soluble rocks are subject to erosion and transportation during the solution process?

Limestone and chalk

What is hydration?

Where water molecules chemically bond with minerals and alters them

What does hydration do to crystals and rocks?

It weakens them and makes them more susceptible to other weathering processes

What is hydrolysis?

The breaking down of rocks into softer minerals and weaker rock due to water reacting to minerals in the rock

During hydrolysis what type of water can help break down minerals in rocks?

Slightly acidic rainwater

What type of minerals in rock is susceptible to breakdown during hydrolysis?

Feldspar in granite

What softer minerals can rocks be broken down into during hydrolysis?

Clay

What does hydrolysis contribute to?

Landforms such as tors, nutrient cycling and soil transformation - this is a fundamental process in shaping the earths surface

What is oxidisation/reduction?

The transferring of electrons (adding or removing oxygen) icy primarily effects iron and manganese minerals in rocks and soil

What does oxidisation/reduction play a significant role in?

Breaking down materials and influencing landscape features

What is chelation?

Where organic compounds (acids) produced by living organisms bind and dissolves metallic ions in rocks

What does chelation do after dissolving?

Releases nutrients and breaks down minerals

What are plant roots?

Roots from plants which grow into rock cracks and physically forces them wider as the roots expand and breaks the rock apart

How can animals cause biological weathering?

They can break rocks apart or break them down by burrowing, scraping and secreting acids, which loosens soil and opens cracks