Weathering and Soil Formation
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Weathering and Soil Formation Chapter 6
description
Weathering and Soil Formation. Chapter 6. WARM-UP #1. The breaking down of rocks and other materials at Earth’s surface is. ANSWER. weathering. WARM-UP #2. Freezing and thawing cause. ANSWER. Ice wedging. VOCABULARY. Weathering Erosion Uniformitarianism. weathering and erosion. - PowerPoint PPT Presentation
Transcript of Weathering and Soil Formation
Weathering and SoilFormation
Chapter 6
WARM-UP #1
•The breaking down of rocks and other materials at Earth’s surface is
ANSWER
• weathering.
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
ANSWER
• warm
VOCABULARY
•Mechanical weathering•Abrasion• Ice wedging
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
ANSWER
• humus
WARM-UP #6
•A solid layer of rock under the soil is called
ANSWER
• bedrock
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
ANSWER
• decomposer
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 ____________________________.
ANSWER
• erosion
WARM-UP#12
• The kind of weathering that breaks rocks into smaller pieces is _____________weathering.
ANSWER
• mechanical
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 __________________________.
ANSWER
• abrasion
WARM-UP#14
•The material on Earth’s surface in which plants can grow is ___________________.
ANSWER
• soil
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 _____________ .
ANSWER
• subsoil
WARM-UP #16
•In ______________ weathering, the makeup of rock changes.
ANSWER
• chemical
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 ___________.
• rates
WARM-UP #18
•The last layer of soil to form is the _____ horizon.
• C
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.
• topsoil
WARM-UP #20
•One way to keep soil fertile is to grow a __________________ kind of plant every year.
• different
