6th grade Interactive Science Chapter 4 Earthquakes: Lesson 1

When two normal faults cause valleys to drop down on either side of a block of rock, what type of landform results?

A fault-block mountain or valley.

What is a Transform Boundary?

A stike-slip fault that forms the boundary between two plates.

What is the relationship with tension and normal faults and what is the result?

As tension forces pull the crust apart, two normal faults can form a fault-block mountain range and valley.

When enough stress builds up in brittle rock, the rock breaks, causing a ____________ to form.

Fault

Describe a Reverse Fault

It has the same structure as a normal fault, BUT blocks move in the REVERSE DIRECTION. Force causing stress = Compression Movement along the fault = Hanging Wall moves UP Footwall Wall moves DOWN Direction of stress - 2 plates push together

What are the 3 main types of Faults.

NORMAL REVERSE STRIKE-SLIP

A geologist sees a fault along which blocks of rock in the footwall have moved higher relative to blocks of rock in the hanging wall. What type of fault is this?

Normal Fault

How does plate movement create new landforms?

Over millions of years, the forces of plate movement can change a flat plain into landforms, like: FAULT BLOCK MOUNTAINS OR VALLEY ANITCLINES AND SYNCLINES FOLDED MOUNTAINS PLATEAUS

Forces deforming the crust uplifted it to create ______________.

Plateaus

Define Compression

Stress force that SQUEEZES rock until it folds or breaks. (Kind of like a giant trash compactor)

How does stress change Earth's Crust?

Stress is a force that acts on rock to change its shape or volume. Because stress increases as force increases, stress adds energy to the rock. The energy is stored in the rock until the rock changes its shape or breaks.

Define Shearing

Stress that PUSHES a mass of rock in two opposite directions. It can cause rock to break and slip apart or to change its shape.

List the 3 kinds of stress that can occur in the crust.

TENSION COMPRESSION SHEARING They work over millions of years to change the shape and volume of rock.

True or False. Stretching the Earth's Crust forces the creation of Fault Block Mountains

TRUE

Define TENSION

Tension is the stress force that PULLS on the crust and THINS the rock in the middle.

What Mountains clearly show Anticlines and Synclines?

The Central Appalachian Mountains in Pennsylvania are folded mountains made up of anticlines and syclines

What 3 type of plate movements cause new landforms to form?

The Earth's plates STRETCH - tension FOLD - compression UPLIFT

What is an example of real Fault Block Mountains.

The Great Basin. You would cross over the Great Basin if you traveled from Salt Lake City to Los Angelos. This region contains many mountains separated by broad valleys, or basins. The mountains form from tension in Earth's crust that causes faulting.....giving you Fault Block Mountains.

What's another famous mountain that is an example of a folded mountain?

The Himalayas in Asia Also....the Alps, not pictured, are folded mountains

An example of a Plateau is ________________.

the Colorado Plateau in the "Four Corners" region of Arizona, Utah, Colorado, and New Mexico. Also, Kaibab Plateau forms the North Rim of the Grand Canyon. It has a flat top.

The 3 main types of Faults are defined by __________.

the direction in which rock moves along the fault

Describe a Normal Fault.

the fault cuts through rock at an angle, so one block of rock sits over the fault, while the other block lies under the fault. Force causing stress = Tension Movement along the fault = Hanging wall slips DOWN, and Footwall moves UP Looks like a step Direction of stress - 2 plates pull apart and move away from each other

Describe a Strike-Slip Fault

the rocks on either side of the fault SLIP PAST EACH OTHER sideways, with little up or down motion. Force causing stress = Shearing Direction of stress = 2 plates move sideways in opposite directions

How do Anticlines and Synclines Form?

the upward and downward folds in rock. The ARCH = Anticline DOWNWARDS "V" shape BEND = Synclines

How do Folds Form?

they are bends in rock that form when compression SHORTENS and THICKENS the Earth's crust. (Bends without breaking) Have you ever skidded on a rug that wrinkled up as your feet pushed it across the floor? Sometimes plate movements can cause Earth's crust to fold much like the rug.

How do Faults form?

when enough stress builds up in rock, the rock breaks, creating a fault

Where do Reverse Faults form?

where compression PUSHES the rock of the crust together

Where are most Anticlines and Synclines found?

where compression forces have FOLDED the crust.

Where do fault block mountains typically occur?

where two plates move AWAY from each other.

Where does Shearing occur?

Where two plates slip past each other

What is a fault?

a break in the rock of the crust where rock surfaces slip paast each other.

Describe a plateau.

a large area of flat land elevated high above sea level. Some plateaus form when forces in Earth's crush PUSH UP a large, flat block of rock.

Where do most faults occur?

at plate boundaries

Here is a picture of a Real Reverse Fault

The Rocky Mountains

An example of a Transform Boundary.

The San Adnreas Fault split the hilly plains in southern California. Here, shearing has produced a stike-slip fault.

How are Folded Mountains formed?

The collision of two plates can cause compression and folding of the crust over a wide area.