Weathering and Soil

acidic

2

clay, silt, sand

3 particles common in soil

weathered rocks rock fragments decayed organic matter water air

5 components of soil

parental material climate topography biota (all of the organisms that live in a region) time

5 factors of soil formation

Ph

7 is neutral acid is between 0 and 7

NOT acidic

8

sediment

A type of rock that forms when particles from other rocks or the remains of plants and animals are pressed and cemented together

pollutants

Acid rain is caused by ____ in the air reacting with rain water.

volcanoes.

Acid-forming chemicals enter the air from natural sources such as

abrasion

Another effective mechanical weathering process. The grinding away of rock by friction or impact. EXAMPLE: A strong current in a stream can carry loose fragments or rock downstream. The rock fragments tumble and grind against one another. Eventually the fragments grind themselves into smaller and smaller pieces. Glaciers, wind, waves along ocean along lake shores can also cause abrasion.

chemical weathering

Changes the materials that are part of a rock into new materials.

* Plants and living things grow on the outside of the rocks. they slowly break down rock to get nutrients. * Temperature changes/weather, sun, ice, wind, and water (rain) also slowly break rock apart. Small plants can grow in the cracks. Plant roots continue to break the rock apart. * Wind and water move bits of weathered rocks to new places. Later, the bits are part of the well developed soil.

How do the rock and rock fragments in soil get into the soil?

acids (acid rain)

Increase the rate of chemical weathering more than rain or water does. Attracts atoms away from the rock and dissolves them.

causes of mechanical weathering

Intense temperature of forest fires cause nearby rocks to expand and crack.

rock bedrock

It takes a VERY LONG time for soil to form. Soil can develop from _____ that weathered in the same place where the rock first formed. This rock is known as _______.

parental material

It takes a VERY LONG time for soil to form. The starting material of soil is _____. It is made up of rock or sediment that weathers and forms the soil. Broken down by mechanical and chemical weathering.

weathered pieces of rock

It takes a very long time for soil to form. Soil can also develop from ________ that were carried by wind or water from another location.

A Horizon B Horizon C Horizon

List the soil horizons in order from top to bottom.

larger smaller

Mechanical weathering breaks ____ rocks into _____ rocks.

temperature changes

Mechanical weathering requires frequent_____.

soil

Mixture of weathered rock, rock fragments, decayed organic matter, water, and air. Full of live, and life on Earth depends on it. Half the volume is solid materials. The other half is liquid and gases.

iron oxide (rust)

Most familiar type of oxidation.

air

Most of the oxygen needed for oxidation comes from the ___.

layer outside

Oxidation forms as a ____ on the ____ surface.

oxidation

Process that causing chemical weathering. Combines the element oxygen with other elements or molecules.

environment(water & temperature) and rock type

Rate of weathering depends on

greater surface area.

Rock material with _____ can hold more WATER and NUTRIENTS for plants.

normal rain

Slightly acidic pH 5.6

plants and animals

Soil fragments do NOT become good soil until ____ and ____ live in them because they add ORGANIC matter to the rock fragments.

chemical makeup

The ______ of a rock is NOT changed by mechanical weathering. If a piece of granite undergoes mechanical weathering, the smaller pieces that result are still granite.

oxide

The addition of oxygen to a substance produces an _____.

weathering

The mechanical and chemical processes that break rock into smaller pieces over time. The mechanical and chemical processes that change objects on Earth's surfaces over time.

decomposition

The process of changing once-living material into dark-colored organic matter. A chemical reaction that breaks down compounds into simpler products. The resulting product of a chemical reaction when one or more of the reactants are broken down into simpler molecules or elements. A new substance is also formed. the state or process of rotting; decay.

chemical weathering

The process that breaks down rock through chemical changes breaking down of rocks by chemicals, like water, acid, and oxidation

organic matter

The remains of something that was once ALIVE. The solid part of soil. Made up of pieces of leaves, dead insects, waste products of animals.

more surface area

The smaller rocks have ____ than the one large rock.

ice wedging

Water enters or collects in the cracks of rocks and freezes. the frozen water widens the cracks. When the temperature reaches 0 degrees, the water freezes. Water expands as it freezes, and the expansion widens the cracks. Repeated thawing and freezing breaks the rocks apart.

warm and wet

What type of climate does chemical weathering occur rapidly?

mechanical weathering

When physical processes naturally break rocks into smaller pieces.

A horizon

Which horizon has the smallest rock and mineral particles?

horizons

___ are layers of soil formed from the movement of the products of weathering.

plants

___ takes nutrients from the rock. Can cause weathering by crumbling rocks. Roots absorb minerals from the rocks making it weaker. It gets bigger and wider and pushes on the sides of the cracks in the rock causing it to break.

softer rocks

____ are weathered more easily by mechanical and chemical weathering than harder rocks.

weathered parent material

____ can be rock or sediment.

water

____ is important in chemical weathering because most substances dissolve in this. It DISSOLVES minerals in rocks.

animals

____ that live in the soil creates holes in the soil where water can get in and cause weathering. They also burrow through loose rock breaking them.

extreme temperatures

______ cause mechanical weathering.

acid rain

pH 4.5 or less causes much more chemical weathering than NORMAL ran.

A Horizon

the uppermost horizon of soil. It is primarily made up of organic material, including waste from organisms, the bodies of decomposing organisms, and live organisms.