Ph: Earth's Changing Surface - Ch. 2: Weathering & Soil Formation

Front 1

weathering

Back 1

The chemical and physical processes that break down rock at Earth's surface.

Front 2

erosion

Back 2

The process by which water, ice, wind, or gravity moves weathered rock or soil.

Front 3

uniformitarianism

Back 3

The geologic principal that the same geologic processes that operate today operated in the past to change Earth's surface.

Front 4

mechanical weathering

Back 4

The type of weathering in which rock is physically broken into smaller pieces.

Front 5

abrasion

Back 5

The grinding away of rock by other rock particles carried in water, ice or wind.

Front 6

ice wedging

Back 6

Process that splits rock when water seeps into cracks, then freezes and expands.

Front 7

chemical weathering

Back 7

The process that breaks down rock through chemical changes.

Front 8

oxidation

Back 8

A chemical change in which a substance combines with oxygen, as when iron oxidizes, forming rust.

Front 9

permeable

Back 9

Characteristic of a material that is full of tiny, connected air spaces that water can seep through.

Front 10

soil

Back 10

The loose, weathered material on Earth's surface in which plants can grow.

Front 11

bedrock

Back 11

The solid layer of rock beneath the soil.

Front 12

humus

Back 12

Dark colored organic (once living) material in soil.

Front 13

fertility

Back 13

A measure of how well soil supports plant growth.

Front 14

loam

Back 14

Rich, fertile soil that is made up of about equal parts of clay, sand, and silt.

Front 15

soil horizon

Back 15

The layer of soil that differs in color and texture from the layers above or below it.

Front 16

topsoil

Back 16

Mixture of humus, clay, and other minerals that forms the crumbly, topmost layer of soil.

Front 17

subsoil

Back 17

The layer of soil beneath the topsoil that contains mostly clay and other minerals.

Front 18

litter

Back 18

The loose layer of dead plant leaves and stems on the surface of the soil.

Front 19

decomposer

Back 19

Soil organism that breaks down the remains of organisms and digests them.

Front 20

sod

Back 20

A thick mass of grass roots and soil.

Front 21

natural resource

Back 21

Anything in the environment that humans use.

Front 22

Dust Bowl

Back 22

The area of the Great Plains where wind erosion caused soil loss during the 1930s.

Front 23

soil conservation

Back 23

The management of soil to prevent its destruction.

Front 24

contour plowing

Back 24

Plowing fields along the curves of slopes to prevent soil loss.

Front 25

conservation plowing

Back 25

Soil conservation method in which the dead stalks from the previous year's crop are LEFT IN THE GROUND to hold the soil in place.

Front 26

crop rotation

Back 26

The planting of different crops in a field each year to maintain the soil's fertility.