Constructive and Destructive Process on the Earth's surface

1. Integrated Science
Unit 10, Chapter 29

2. 29.2 The Surface of Earth
 Earth’s surface is
constantly changing.
 Recall that earthquakes,
volcanoes, mountains, and
the construction of new
lithosphere are events that
occur at plate boundaries.
 These events are changing
the appearance of Earth’s
surface all the time.

3.  *Thefeatures we see on Earth’s surface
represent the dynamic balance between
constructive processes versus destructive
processes.

4. 29.2 Mountain Building
 *Mountain-building is a
major constructive
process.
 *Mountains form in three main ways:
— by folding at convergent plate boundaries
— by movement of chunks of land at faults
— by volcanic activity

6. Mountain Building Processes:
*Fold Mountains: Form as two convergent
plate boundaries collide
Example: the Himalayas (Mt. Everest)

7. Mountain Building Processes:
*Fault Block Mountains- Pressure at plate
boundaries cause the lithosphere to
crack and pieces of it tilt or move causing
a valleys and tilt mountains
Example: mountains around San Andreas
Fault

8. Mountain Building Processes:
*Volcanic Mountains- Extensive layering
of lava and volcanic material builds up
over time to form a dome mountain.
Example: Mount Rushmore

9. Destructive Processes
 *Erosion- (also known as
weathering) is a major
destructive process.
 *Erosion is a continuous
physical and chemical event that
cause land and rock to wear
down.
 The rate of erosion is related to
the height and steepness of the
mountain—the steeper the
mountain is, the faster it erodes
because it is easier to push
material down a steep slope than
a gradual slope.

10. Formation of Soil
 *A soil profile is a
cross-section that
shows the different
layers of soil in the
ground.
 It takes a long time
and a lot of
weathering for soil to
have all the layers.
 Young soil does not
have each of these
layers.

11. Glaciers  *A glacier is a huge
mass of ice that can be
many kilometers thick
and thousands of
kilometers wide.
 Glaciers at the poles are
a frozen form of about 2
percent of all the water
on Earth.
 Glaciers are formed
from the accumulation
of snow over hundreds
or thousands of years.

12. Sometimes you can’t see the whole story:

13. Your turn:
Read section 29.2 pgs 568-575
and add to your notes.

14. Rocks and Rock Cycle
 *Arock is a naturally formed
solid usually made of one or
more minerals.
 Theterms igneous, sedimentary,
and metamorphic refer to how a
rock was formed.
 Therock cycle illustrates the
formation and recycling of rocks
by geological processes.

15. Igneous Rocks
 *IgneousRocks are made of magma or lava
— Intrusive igneous rocks are formed below
Earth’s surface
— Extrusive igneous rocks are formed above
Earth’s surface

16. Sedimentary Rocks
 *Sedimentary Rocks- rocks that form from
sediment that is compressed and cemented over
a long period of time

17. Metamorphic Rocks
 *MetamorphicRocks- a rock that is transformed
by tremendous heat and pressure

18. Answer On Your Paper:
 Is erosion a constructive or destructive force
that shapes the land?
— Explain your answer.