Intro

Objective 10/14/2011Describe the three major types of folds and faults by modeling them.

Does rock bend or break or both?

Deforming the Earth’s Crust

Folds Folding –

the bending of rock layers due to stress

Folds:

Take the layered clay in both hands, and slowly bend upwards (do not break the clay!) until a fold appears. Draw what you see:

Folds:

Take the layered clay in both hands, and slowly bend upwards (do not break the clay!) until a fold appears. Draw what you see:

Folds: Anticline –

upward arching folds

Folds:

Take the layered clay in both hands, and slowly bend downwards (do not break the clay!) until a fold appears. Draw what you see:

Folds:

Take the layered clay in both hands, and slowly bend downwards (do not break the clay!) until a fold appears. Draw what you see:

Folds: Synclines –

down-ward folds

Folds:

Take the layered clay in both hands. While keeping both hands horizontal, move one hand upwards slowly, until a new fold appears. Be careful not to break the clay! Draw what you see:

Folds:

Take the layered clay in both hands. While keeping both hands horizontal, move one hand upwards slowly, until a new fold appears. Be careful not to break the clay! Draw what you see:

Folds: Monocline –

rock layers are folded so that both ends of the fold are horizontal

Faults Fault – a

break in a body of rock along which one block slides relative to another

Faults

With each piece of clay in your hands, model a normal fault by moving your right hand downwards and your left hand upwards. Draw what you see:

Faults

With each piece of clay in your hands, model a normal fault by moving your right hand downwards and your left hand upwards. Draw what you see:

Faults Normal

Fault – causes the hanging wall to move down relative to the footwall

Faults

With each piece of clay in your hands, model a reverse fault by moving your right hand upwards and your left hand downwards. Draw what you see:

Faults

With each piece of clay in your hands, model a reverse fault by moving your right hand upwards and your left hand downwards. Draw what you see:

Faults Reverse

Fault – causes hanging wall to move up relative to the footwall

Faults

When rocks are pulled apart

One slab of rock slides DOWNWARD

When rocks are pushed together

One slab of rock slides UPWARD

Normal Fault Reverse Fault

Faults

With each piece of clay set on the table in front of you, model a strike-slip fault by pushing one piece of clay forward while pulling the other piece towards you. Draw what you see.

Faults

With each piece of clay set on the table in front of you, model a strike-slip fault by pushing one piece of clay forward while pulling the other piece towards you. Draw what you see.

Faults Strike-slip

Fault – opposing forces cause rock to break and move horizontally (like at a transform boundary)

Folds and Faults Folding = bending Fault = breaking

Summary When stress is put on rocks, they can

either bend (fold) or break (fault). Syncline, Anticline and Monocline are three types of folds. Normal, Reverse and Strike-Slip are three types of faults. Each play a role in creating the different types of landforms around us.

Objective 10/14/2011

Outro

Describe the three major types of folds and faults by modeling them.

The diagram shows a profile of rock layers.Which point indicates the oldest exposed layer?

A B C D