Lesson 3-4 - TeacherWeb

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Transcript Lesson 3-4 - TeacherWeb

The Cycling of Matter
Ch. 3 Lesson 4
Key Concept:
Over time, matter- such as rock, water,
carbon, and nitrogen- is transferred
between organisms and the physical
How fast does the earth change?
Did you know that the Earth recycles?
 Since not much new matter comes into
the Earth system, much that is here has
to be recycled.
 Water, carbon, nitrogen, phosphorus,
and even rocks move through cycles on
As matter moves through the Earth, it
 Some changes are fast, like a flood
moving a rock.
 Other changes are slow, like a tall
mountain taking millions of years to
Since Earth is so old, even the slow
changes affect Earth a great deal.
What are the Different Kinds of
Rocks are grouped by how they are
There are three groups:
Sedimentary Rocks
Igneous Rocks
Metamorphic Rocks
Sedimentary Rocks
 Sedimentary
rocks form when pieces of
rock stick together to form a hard rock.
 Small pieces of rock that are moved
from place to place by wind, water, ice,
and gravity are called sediment.
Three types of Sedimentary
Clastic Sedimentary Rocks are formed
when sediment hardens under pressure.
Chemical Sedimentary Rocks are formed
when minerals that are dissolved into
water formed crystals.
Organic Sedimentary Rocks are formed
when pieces of dead organisms stick
together and form a rock.
Igneous Rocks
 Igneous
rocks form when melted rock
cools and hardens.
They can be grouped based on the size
of the crystals in the rock.
Igneous Rocks, continued
 Coarse-grained
igneous rocks are
formed when rock cools slowly and
forms large crystals.
 Fine-grained igneous rocks form when
rock cools quickly and only small crystals
form or there is no time for crystals to
form at all.
Igneous Rocks, continued
 Igneous
rocks can also be grouped by
the types of minerals in them.
Some, like granite, are made mostly lightlycolored minerals and found on Earth’s
crust, in the continents.
Others are made of mostly dark-colored
minerals and are found mostly in Earth’s
mantle and in the crust under the oceans.
Metamorphic Rocks
 Metamorphic
rocks form when rock
changes because of heat or pressure.
 Most are deep within Earth’s crust,
where the depths, temperature, and
pressure can be much higher than at the
Earth’s surface.
Metamorphic Rocks, continued
 Grouped
according to how the minerals
in them are related.
In foliated metamorphic rock, the minerals
form bands or stripes within the rock.
In non-foliated metamorphic rock, the
minerals do not form bands or stripes.
How Do Rocks Change from One
Kind to Another?
 The
Rock Cycle is made up of all the
ways that rocks can change from one
kind to another:
Increasing pressure
 Weathering
happens when a rock is
broken into smaller pieces.
 Erosion happens when sediment is moved
form one place to another.
How Rock Moves Through the
Rock Cycle
 Rock
can take many paths through the
rock cycle, depending on the forces that
act upon the rock.
 The forces change, depending on where
the rock is located.
Example: metamorphic rock usually forms
deep beneath Earth’s surface, where
temperature and pressure is high.
How Water Moves Through
Earth’s Systems
 The
water cycle is the constant
movement of water between the
atmosphere, the land, and the oceans.
 Most of the energy that drives the
water cycle comes from the sun.
How Elements Move Through the
Earth’s Systems
 Many
chemical elements, such as carbon,
nitrogen, and phosphorus, are important
for life on Earth.
 These elements are constantly moving
from one place to another.
 They move between living things and
nonliving things through many different
The Carbon Cycle
 Carbon,
an important part of many of
the chemicals that make up living things,
is found in the atmosphere, the land,
and in water.
 The Carbon Cycle is the way the carbon
moves between living and nonliving
The Carbon Cycle, continued
Some parts of the carbon cycle happen
fairly quickly.
Example: Plants turn carbon dioxide
from the atmosphere into food. Other
organisms get food from plants. When
plants and other organisms break down
the food, the carbon dioxide moves
back into the atmosphere. This process
can take as little as a day or two.
Some parts happen very slowly.
Example: Dead plants and tiny sea creatures can
be buried by sediment before they decay.
After millions of years, the remains can turn
into fossil fuels, such as coal, oil, and natural
gas. The carbon in the organisms is stored in
the fossil fuels. People can burn the fossil
fuels for energy. When people burn the fossil
fuels, the carbon moves back into the
The Nitrogen Cycle
The movement of nitrogen through the Earth
system is called the nitrogen cycle.
Nitrogen can be found in several different ways.
In the atmosphere, it is mostly found as a gas, but
since most living things cannot use nitrogen gas,
special bacteria change it into a form of nitrogen
that plants can use. Other organisms get their
nitrogen from plants.
When organisms die, the nitrogen in them can be
returned to the environment. Bacteria can change
the nitrogen in the dead organisms back into
nitrogen gas. The nitrogen gas then moves back
into the atmosphere.
The Phosphorus Cycle
 Like
carbon and nitrogen, phosphorus is
found in living things.
 It is also found in soil, rock, and water.
 Plants take up phosphorus through their
roots from the soil.
 Animals take in phosphorus when they
eat the plants.
 When plants and animals die, the
phosphorus returns to the soil.
Other Cycles in Nature
Many other forms of matter also move through the Earth in
Almost all the elements that living things need to survive are
cycled through Earth’s systems. When living things die, every
element in their bodies is recycled.
Every cycle in nature is connected to every other cycle.
Example: water can carry nitrogen and carbon through the
Living things are also important to keep the cycles moving.