Sub- aerial processes/ Weathering - COASTS Flashcards
What are the three types of sub aerial processes
- Mechanical
- Chemical
- Biological
Mechanical
-Frost shattering- Water enters cracks and freeze and expands causing pressure on rocks and cracks happen repeatedly and and causes pierces of rocks to break
-Salt crystallisation- salt enters pores or cracks. When salt evaporate it leaves behind salt crystals which dry and expand and grow over time and extent stress on rock which abuse it to break.
-wetting and drying- frequent eating and drying, expand when wet and contract when dry. This can cause to the rocks to break
Chemical
-Carbonation - acid rain - rainwater absorbs CO2 which forms calcium carbonate and reacts with rock
-Oxidation - reaction of minerals with O2, rocks with iron leaving a rusty powder.
Biological
Breakdown of rocks by organic activity such as:
plants grow into cracks on a cliff face and widen and break up the rock.