4.1 - 4.2 apes

The Earth’s rigid outer layer made of the crust and upper mantle is called the _____.

lithosphere

The semi-molten layer beneath the lithosphere that enables plate movement is the ______.

asthenosphere

The theory that Earth’s surface is broken into two moving plates is called the ______ theory.

plate tectonics

When two plates move away from each other, it is a ____ boundary.

divergent

When plates collide or move toward each other, it is a _____ boundary.

convergent

When two plates slide past each other, they form a _____ boundary.

transform

The Mid-Atlantic Ridge is an example of a _____ boundary.

divergent

The San Andreas Fault is an example of a _____ boundary.

transform

Subduction occurs when a ____ plate sinks beneath another plate.

oceanic

The Himalayas were formed by two _____ plates colliding.

continental

Volcanoes often form at _____ boundaries where one plate subducts.

convergent

New oceanic crust is formed through the process of _________.

seafloor spreading

A deep valley created where plates diverge on land is called a ____ valley.

rift

The Ring of Fire is located around the ________.

Pacific Ocean

Earthquakes commonly occur along _____ boundaries due to friction.

plate

Hot spot volcanism occurs when a plate moves over a stationary _____ in the mantle.

hot spot

The Hawaiian Islands were formed as the Pacific Plate moved over a ______.

hot spot

Rock breakdown at or near Earth’s surface is caled ______.

weathering

The movement of weathered materials from one place to another is called _____.

erosion

The accumulation of organic matter on the soil surface forms the ____ horizon.

O

The topsoil layer rich in minerals and humus is the ____ horizon.

A

The zone of leaching, often light in color, is the ____ horizon.

F

Minerals such as iron and aluminum accumulate in the ____ horizon.

B

The partially weathered parent material belongs to the ____ horizon.

C

Unweathered bedrock is represented by the _____ horizon.

R

Soil texture is determined by the percentage of sand, silt, and _____.

clay

A soil that has balanced amounts of sald, silt, and clay is called ______.

loam

The organic component of soil made from decomposed organisms is called ______.

humus

The process by which water carries dissolved nutrients downward through soil is called _____.

leaching

Soil formation is influenced by five factors: parent material, climate, organisms, topography, and _____.

time

Weathering that changes chemical composition of rocks is called _____ weathering.

chemical

Weathering that breaks rocks into smaller pieces without changing position is _____ weathering.

physical

Soil erosion increases significantly when vegetation is removed through activites like ______.

deforestation

The ability of soil to retain water is highest in soils with high _____ content.

clay

The fastest-draining soil type is ______.

sand

The slowest draining soil type is ______.

clay

Soil particles that are medium-sized and hold moderate water are called _____.

silt

The parrent rock that contributes to soil minerals is also called ______ material.

parent

Wind-driven erosion of topsoil is especially common is -____ regions.

arid

When famrers plow land at steep angles to reduce erosion, the practice is known as _____ plowing.

contour