Presentation on theme: "Weathering and Soil Formation Chapter 6. WARM-UP #1 The breaking down of rocks and other materials at Earth’s surface is."— Presentation transcript:
Weathering and Soil Formation Chapter 6
WARM-UP #1 The breaking down of rocks and other materials at Earth’s surface is
WARM-UP #2 Freezing and thawing cause
ANSWER Ice wedging
VOCABULARY Weathering Erosion Uniformitarianism
weathering and erosion Weathering – the process that breaks down rock and other substances at the Earth’s surface. Erosion – forces of erosion carry the pieces away…..weathering and erosion work together to break down and carry away rocks on Earth’s surface.
vocabulary Uniformitarianism – principles that operate today operated in the past
WARM-UP #3 Which is a cause of chemical weathering?
ANSWER Acid rain
WARM-UP #4 Mechanical weathering is faster in a climate that is
MECHANICAL WEATHERING Mechanical weathering – weathering where the rock is broken into smaller pieces….each piece is still the same composition….mechanical weathering is a slow process
EXAMPLES Freezing and thawing, release of pressure, plant growth, actions of animals, abrasion Abrasion – grinding away of rocks by rock particles carried away by wind, water, ice, or gravity Ice wedging – water seeps into cracks – expands when it freezes – ice is like a wedge that breaks the rock apart
WARM-UP #5 When dead plants and animals decay, they form
WARM-UP #6 A solid layer of rock under the soil is called
VOCABULARY Chemical weathering Oxidation Permeable
Chemical weathering Process that breaks down rock through chemical changes………..causes are the action of water, oxygen, carbon dioxide, living organisms, and acid rain.
VOCABULARY Oxidation – when iron combines with oxygen in the presence of water………….rust Permeable – rock that is full of tiny holes…allows water to seep through easily….permeable rocks will weather quickly when exposed to chemical weathering.
WARM-UP #7 In the United States, most of the eastern states are covered with
ANSWER Forest soil
WARM-UP #8 Living things that break down dead organisms are called
VOCABULARY Soil Bedrock Humus
VOCABULARY Soil – loose weathered material on Earth’s surface where plants can grow Bedrock – solid layer of rock below the soil Humus – decayed organic material in soil
WARM-UP #9 Soil fertility is a measure of
ANSWER how good soil is for growing plants.
WARM-UP #10 Farmers leave dead plants in their fields in the soil conservation method called
ANSWER conservation plowing.
VOCABULARY Fertility Loam Soil horizon
VOCABULARY Fertility – measure of how well the soil supports plant growth Loam – soil made up of equal parts of sand, clay and silt Soil horizon – is how the soil develops into layers ………the layers differ in color and texture
WARM-UP #11 The movement of rock pieces and other materials on Earth’s surface is called ______________________ ______.
WARM-UP#12 The kind of weathering that breaks rocks into smaller pieces is _____________weathering.
VOCABULARY Topsoil Subsoil Litter Decomposers
TOPSOIL AND SUBSOIL Topsoil – is horizon A ….crumbly, dark brown soil that is a mixture of humus, clay and other mixtures Subsoil – is horizon B….clay and other particles washed down from horizon A…little humus
LITTER AND DECOMPOSERS Litter – is what is left of the plant before it adds to humus…..leaves, roots, and the plant itself when it dies. Decomposers – organisms that break down the remains of dead organisms into smaller pieces and digest them with chemicals.
WARM-UP#13 The scraping of rock by wind- blown pieces of rock is called _________________________ _.
WARM-UP#14 The material on Earth’s surface in which plants can grow is ___________________.
VOCABULARY Sod – thick masses of tough roots at the surface of the soil……..keeps the soil in place and held onto moisture. Natural resource – anything in the environment that humans use
WARM-UP #15 The B horizon is also called _____________.
WARM-UP #16 In ______________ weathering, the makeup of rock changes.
VOCABULARY Dust Bowl – ruined farmland on Oklahoma and parts of the surrounding states…..caused by years of droughts and lots of plowing tuned the top soil to dust and it blew away. Soil Conservation – management of the soil to prevent it’s destruction.
WARM-UP #17 Different kinds of rock weather at different ___________.
WARM-UP #18 The last layer of soil to form is the _____ horizon.
PLOWING Contour Plowing – plow the fields along the curve of the slope….slows runoff and preserves the soil from erosion. Conservation Plowing – disturb the plant cover and soil as little as possible…dead weeds and stalks are left in the ground to help return soil nutrients.
CROP ROTATION Farmers plant different crops in the field each year………helps maintain the nutrients in the soil
WARM-UP #19 Loss of _____________ causes soil to lose its fertility.
WARM-UP #20 One way to keep soil fertile is to grow a __________________ kind of plant every year.