What is Weathering Weathering The breaking down of
What is Weathering?
Weathering • The breaking down of rock into smaller pieces that remain next to each other. • Weathering forms sediments. • There are two types of weathering. • Mechanical (Physical) • Chemical
Mechanical Weathering • Mechanical weathering is the ____________________________. • Sometimes called “_____” weathering • Rock is ______by physical force, rather than by __________ • Smaller pieces _______to a new location, but remain next to one another until erosion carries them away • There are 4 main types of Mechanical Weathering • • ____________
Ice Wedging • ______ enters the cracks in rocks, and then _________ about 10%. • The ice puts stress on the walls around the cracks and causes cracks to __________. • Water can flow deeper into the rock as _______. As the cycle repeats, rocks grow _______ over time. • Along the cracks, the rock will ____________over time.
Ice Wedging
Exfoliation • Rocks formed _______are under a huge amount of _______. • When the overlying rock ________, _____ is released and the once buried rocks are exposed. • _______ occurs along the outer parts of rocks. This stress will cause fractures to form parallel to the rock surface. • Along the exposed rock fractures, _______will break away.
Exfoliation
Thermal • _______is a result of extreme changes in temperature that causes the expansion or contraction of rock. • Common in ________, where it is hot in the day and cold at night; different minerals expand contract at different rates causing the rock to split • The outer layers ______into thin sheets.
Thermal
Biotic • Biotic weathering is caused by __________. • Most often, _______are the cause. • They act as a ________, widening and extending the cracks. • __________can also cause weathering.
Biotic
Chemical Weathering • __________is the breaking down of rock into smaller pieces because of chemical changes within the rock. • Rock reacts with _______________(may be acidic); these reactions will add or remove elements from minerals. • Rocks fall apart because the ____________are broken down by chemical reactions. • There are 4 main types of Chemical Weathering • • ____________
Oxidation • When oxygen ______________and chemical reaction known as oxidation occurs and new types of rock are formed. • The new types of rock are _____ to break apart because they are much softer than the original substances. • A reddish-brown coloration on the surface is called _______.
Oxidation
Hydrolysis • _______ is the weathering reaction that occurs when ___________________ in a rock meet. • This results in the ___________ of the rock surface by forming new compounds. • Most common reaction is the hydrolysis of feldspars producing clay (kaolinite)
Hydrolysis
Carbonation • When _______reacts with water or rain, carbonation occurs and a weak _______is formed. • This is the same acid found in _______. • The acid is too weak to _______ plants and animals, but slowly causes feldspars and limestone to decompose. • New types of ___________are formed within the rocks.
Carbonation
Biotic • ____________live on the surfaces of rocks. • Plants lower the local ___ to make it ________. • Their _______ give off a ____that _____ rocks and minerals.
Biotic
- Slides: 20