What Is Weathering Weathering is the process that

What Is Weathering? • Weathering is the process that breaks down rocks into smaller and smaller pieces • Weathering wears down mountains and breaks down statues

What Is Weathering? • There are two types of weathering: mechanical and chemical weathering

What Is Mechanical Weathering? • It breaks apart rocks without changing them chemically • There are 5 types

What Is Mechanical Weathering? • Rocks formed under pressure expand contract when pressure is released

What Is Mechanical Weathering? • Ice Wedging occurs when water seeps into cracks in rock & freezes…the rock expands and finally breaks • This type of weathering causes potholes in the road

What Is Mechanical Weathering? Abrasion is the collision of rocks with one another & agents such as gravity, water & wind

What Is Mechanical Weathering? • Organic Activity known as root pry • As roots of plants can work their way into cracks of rock and break them apart

What is Mechanical Weathering? • Temperature changes from hot to cold may aid in weathering • Rocks expand in hot weather and contract in cold

What Is Chemical Weathering? • It breaks apart the rock when substances chemically react with the minerals in the rock, changing it into a different substance. • There are 4 types of chemical weathering

What Is Chemical Weathering? • Hydrolysis – minerals change into new compounds when exposed to water

What Is Chemical Weathering? • Oxidation – Oxygen combines with minerals

What Is Chemical Weathering? • Carbonation – change in minerals when they react with carbonic acid…CO 2 + water – Dissolves limestone forming caves

What Is Chemical Weathering? • Decaying Plants – Produce acids that break down rocks – Especially mosses and lichens

What Affects the Rate of Weathering? • Rock Composition: igneous and metamorphic rock weather more slowly • Amount of Exposure: the longer a rock is exposed the faster it will weather

What Affects the Rate of Weathering? • Climate: variable weather conditions accelerate weathering processes • Topography: on steep slopes, rocks are weathered more quickly