Download IE 2.1 Earth`s Crust in Motion

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

History of geology wikipedia, lookup

Age of the Earth wikipedia, lookup

Geophysics wikipedia, lookup

Large igneous province wikipedia, lookup

3D fold evolution wikipedia, lookup

Composition of Mars wikipedia, lookup

Plate tectonics wikipedia, lookup

Geochemistry wikipedia, lookup

Geology wikipedia, lookup

Algoman orogeny wikipedia, lookup

Paleostress inversion wikipedia, lookup

Transcript
Earth’s Crust
in Motion
Inside Earth Chapter 2.1
Pages 54-61
Stress(ed)?
• Stress is the measure of the
amount of force applied to a
given area.
Effect on Rocks
• Stress is the force that acts on a rock to change
its shape or volume
• Adds energy to the rock.
Deformation
• Deformation: Any change in the shape or
volume of Earth’s crust (caused by stress)
• Crust deforms from the force of plates
colliding
– Transform boundaries.
Relieving Stress
• Over time, stress builds up in the plates
• Eventually, the stress is released…
Earthquakes
• The shaking and trembling that results from the
movement of rock beneath Earth’s surface.
• Releases MASSIVE amounts of energy
• Generates seismic waves
Compression
• Definition: Squeezing
• Effect on Rock:
• Makes rock layers thicker and shorter
• Associated Fault Type:
– Reverse Fault
• Associated Plate Boundary:
– Convergent Boundary
Tension
• Definition: Pulling apart
• Effect on Rock:
– Stretches making rocks longer and thinner
• Associated Fault Type:
– Normal Fault
• Associated Plate Boundary:
– Divergent Boundary
Shear
• Definition: Moving in opposite directions
– Think of shears or scissors
• Effect on Rock:
– Stress distorts the shapes of rocks.
• Associated Fault Type:
– Strike-Slip
• Associated Plate Boundary:
– Transform
Faults
• A fault is a break in the lithosphere
• Usually occur along plate boundaries, where
the motions of plates compress, pull or shear
the crust so much that the crust breaks.
• 3 Types of Faults
– Strike Slip Fault
– Normal Fault
– Reverse Fault
Hanging Wall
• Above the fault plane.
Hanging (head) Wall
Foot Wall
Foot Wall
• Below the fault plane
Hanging (head) Wall
Foot Wall
• Hanging Wall
– Lantern
• Foot Wall
– Path
Friction along Faults
• How rocks move determines how much
friction there is between opposite sides of the
fault
• Friction: a force that opposes the motion of
one surface as it moves across another
What about the surfaces causes friction?
– It exist because surfaces are not perfectly smooth.
Normal Fault
• Force: Tension
(diverging)
• Hanging wall: Moves
down (with gravity)
Reverse Fault
• Force: Compression
(converging)
• Hanging wall: Moves up
(against gravity)
Strike-Slip Fault
• Force: Shear (transform)
• Rocks on both sides of the
fault slide past each other
Landforms
• Topography: determined by
its elevation, relief and
landform
• All landforms have elevation
and relief
• A landform region is an area
where the topography is
similar.
Elevation
• The height above sea-level
on Earth’s surface.
Relief
• The difference between
the highest point of
elevation and the lowest
parts of an area
– Mountains have high relief
– Plains low relief.
Plateaus
• Have high elevation and relief
– Perfectly smooth on top
• May be really thick (1,500m),
streams or rivers can cut through.
Plains
• Flat or gently rolling land
with low relief and
varying elevation.
• Depends on location…
– Coastal Plains have low
elevation at or near sea
level along the coast.
– Interior Plains are away
from the coast, causing
varied elevation.
Mountains
• A landform with high elevation and relief
• Mountain Ranges are groups of mountains
that are closely related in shape, structure and
age.
Mountains formed From Faulting
• Normal Faults uplift blocks
of rock and the hanging wall
drops.
Mountains formed From Folding
• When continental plates collide, stress can
cause rock layers to fold.
• Creates bends in the rock layers
– Himalayas Mts.
– Appalachian Mountains
Anticline
• A term used to describe folds in rocks
• An arching fold in the rock layers or “apex”
Syncline
• A downward pointing fold or “slump”
Anticline/Syncline
Anticline/Syncline
What to Work On
• Read Section 2.1 (pages 54-61)
• Answer section review questions
(page 61, #1-4)