Download 15 mts and erosion handout

# _________ Handout
Name __________________ 6___ Class#:___
UDC7L4 – Mountains and Soil D44-D53, UDC8L5 Erosion and Deposition D56-D65
Objectives:








Explore what produces mountains
Identify the forces that make and shape landforms
Compare and contrast kinds of weathering
Explain how soil is produced and transported
Explore why sediment moves downhill
Explain how erosion and deposition work with gravity and wind
Describe how running water changes the land
Describe how glaciers change the land
Mountain Formation
1) Fold Mountains:

Fold mountains:
Formed when _____________________________________________
o At _______________________________
o e.g. Himalayas, Andes
2) Fault-Block Mountains:

________________________________________________________
o At _______________________________
Soil Formation
o When rocks, animal life, plant life, air, water, and chemicals interact
o
A very SLOW process, takes ______________________________
1) Breaking up of rock
Weathering: ___________________________________________________________________
o _____________________ weathering

Step 1:
Example: water and gas in the air combine to form a weak acid that
eats away at rock
o _____________________ weathering

Example: water and gas in the air combine to form a weak acid that
eats away at rock
2) Continued weathering: thin soil layer
a. Small stones/fragments + moss  sand, silt, clay
Step 2:
b. As the moss and plants die, they add to the soil
c. Insects, worms, ____________, ____________ start to live among the
rock particles and plant roots
d. Grass begins to grow
Weeks 13-14: Making Mountains and Soil, Erosion and Deposition
1 of 4
e. As animals and plants die, they form humus: ________________________________________
______________________________________________________________________________
f. ________________________ burrow in the soil which mixes the humus around
3) Weathering continues: organic matter builds
Step 3:
a. The humus-rich soil can support a greater variety of plant life
b. Soil becomes richer and richer.
Layers of Soil:
1) Topsoil (Horizon A)—only 30cm deep
o Dark-colored soil
o Rich in
o Includes organic litter, such as
2) Subsoil (Horizon B)
o Has some of the same
(filtered down with
as topsoil
)
3) Soil parent material (Horizon C)
o
rock
o Just beginning to change into
4) Bedrock
How Soil is Related to Groundwater:
1) Groundwater:
Formation:
a. Precipitation falls to the Earth
b. Some of this sinks into the ground through the soil (seeps)
c. It keeps sinking and then ____________________________________________
d. Travels all the way down to a layer of rock that it can’t pass through
o This layer is considered _____________________________ (
)
2) Aquifer: ______________________________________________________________________
o People can get drinking water by drilling wells into an aquifer (rock)
o Because water collects in an aquifer, we can infer two things:
 the bottom of these wells must be below the__________________________________
 there must be a layer of
Weeks 13-14: Making Mountains and Soil, Erosion and Deposition
rock under the well
2 of 4
3) Water table:
___________________________________
o Sometimes visible at the surface -
4) Caverns (_______________)
o When groundwater seeps through limestone it
dissolves calcium and other minerals in the
limestone
o This process can carve HUGE caverns
o Usually at or below the water table
In the end, most rivers and some groundwater will empty in the ocean.
o Brings sediments
o Sea animals use this sediment to form shells or form bones
o Other sediment forms minerals on the ocean floor that humans can use
The Earth’s surface changes because of gravity, wind, water, and ice.
Erosion and Deposition by Gravity
o Erosion:

Mass Wasting: ______________________________________
 Depends on steepness of a hill (steeper = _________ mass wasting)
o Deposition:__________________________________________

Sediment: ___________________________________
Erosion and Deposition by Wind
o Deposition

Wind can pick up particles and drop them off

Depends on speed of the wind (faster = _________ particles that can be carried)
o Weathering

Wind blows sediment against rocks  _________________________________
Weeks 13-14: Making Mountains and Soil, Erosion and Deposition
3 of 4
Erosion and Deposition by Water
o Deposition

Faster flowing water carries __________ particles

When water slows down, _________________________________
o Weathering

Fast-moving particles can ___________________________________________________
Characteristics of Streams and Rivers
Faster Flow
Slower Flow
Erosion and Deposition by Ice
Glaciers: ______________________________________

Formed by build-up of snow over years  thick ice

Can move slowly over land
o Erosion

Drags ___________ and ___________ with it

Scrapes and digs away sides of a valley

Over time, V-shaped valleys  U-shaped
o Deposition

When glaciers melt: __________________________________________________________

Till: ____________________________________________________________

Moraine:
 Composed of _________
 Sediment collects
of glaciers
 Are mounds and ridges left behind when the glacier melts
Weeks 13-14: Making Mountains and Soil, Erosion and Deposition
4 of 4