Sorting of Earth’s Materials:
Beaches, Streams and Road
Cuts.
What is Sorting?
Sorting is
arranging things
according to class,
kind, or size;
classify.
 Density affects
the sorting of
natural materials
in a mixture.

Jar Activity
Before
Shaking/Mixing
What do you
observe?

After
Shaking/ Mixing
What do you
observe?

Sorting in General


Density affects the sorting
of naturally occurring
materials in a mixture.
For example, in the stream
to the right dense objects
like heavy and large rocks
stay at the bottom while
less dense objects like
light and small silt and dirt
can be carried away by the
flow.
What is density?



Density =
Mass/Volume
Mass = The amount of
matter in something.
Volume = The amount
of space occupied by
something. It is the
size of something.
How does density affect sorting?

Knowing that some things float while
others sink gives us a good idea
about how density relates to things
around us. Not only does density
determine when something will sink,
it also is responsible for the different
layers of the Earth and the sorting
of natural materials on the Earth!
How does density affect sorting?

Below you will find photographs to represent the different
layers of the Earth. At the right of each photograph you will
find the density for that layer. What layer would each of
these objects represent based on the density given.
B
A
C
Density =
.0013
g/cm3
Density
Density =
Close to 2.7
to 3 g/cm3
Density =
1 g/cm3
D
4.5 g/cm3
E
Density =
11.5 –
13.0
g/cm3




Does particle size affect
sorting?
Does the size of particles
matter in how they will
sort in a river, road cut
and beach?
Have you ever heard of the
saying “The whole
enchilada”?
Have you ever heard the
saying “the bigger they are
the harder they fall”?
Large particles are often more
heavy and difficult to move just
because of overall size. The large
particles may in fact be less
dense per cm3 than smaller
particles that get washed away in
a river. However, because of
overall size they don’t move as
easily.
Robert Wadlow
(1918-1940) holds
the record for the
world's tallest
person at 8 feet
11.1 inches tall.
The tallest living
person is Sultan
Kosen of Turkey,
at 8 feet 1 inch
tall.
How will Earth particles made with the SAME
MATERIAL or Matter but different sizes sort?
Below are pictures of six different-sized particles of rock that are made of
the same basic stuff that could be found on Earth. Imagine that you put
them in a large container filled with water and then shake the container
vigorously to model sorting of a river. The particles are labeled A, B, C,
D, E and F. Which particle would go to the bottom 1st? 2nd? 3rd? ……. Why?
How will Earth particles made with the
DIFFERENT MATERIALS or Matter but
EQUAL sizes sort?
Do you remember our 4 – Color
Column Demonstration? Will Earth
materials do the same when mixed
up?
 Clear Air (gas) 0.0013g/cm3 Density
 Yellow Fluid 0.93g/cm3 Density
 Green Fluid 1.01g/cm3 Density
 Red Fluid 1.38g/cm3 Density
Imagine if …..
Sand
Origins
Imagine if you traveled around the
world and collected sand samples
from different beaches that you
visited. The sand grains you collect
end up being roughly the same size.
 Does this mean that the density of
the sand grains will also be the
same?
 How will the sand of different
types/densities sort if placed in a jar
and shaken up?

Sorting according to density in
Nature
Can you think of any examples of
sorting by density and/or size in
nature?
 Beaches
 Streams
 Road Cut

Sorting: The Beach

Have you ever walked
along a beach and
wondered why the sand
particles are all in one
basic area and the grains
are all about the same
size?
Sorting: Stream or River

Try and think of the
rocks you have
observed in a river or
stream. Why do you
not see small sized
and low density
particles like sand and
silt being deposited in
fast moving water?
Why are the big rocks
staying in place?
Action of Streams
Tubing Story
Sorting Evidence in Road
Cuts? Slightly different story.

http://www.mgs.md.gov/esic/brochu
res/sideling.html (Best Road Cut)
Sorting in Utah: Capital Reef

See Trip Picts.
Quiz

Pat puts items into a jar and shakes it up. Pat lets the jar
settle for 5 minutes. What would be the expected order of
the items going from the top of the container to the
bottom?
a.
b.
c.
d.
rock, sand, water, metal
metal, rock, sand, water
water, sand, rock, metal
sand, metal, water, rock
Quiz

A streambed contains round rocks, all about the
same size. Why are there no smaller particles of
sand and clay? The sand and clay…
A. are too small to see
B. are denser
C. have washed away
D. were never there
Quiz

A beach is composed of particles of sand of the
same size. Why doesn't the beach have materials
of all sizes? The particles have…
A. been placed there by humans
B. come to the beach at the same time.
C. been found in underwater canyons
D. been sorted by size and density
Quiz

Sand with particles of the same size
was gently shaken in a jar to see if
layers would form. What variable
was being tested?
A. particle size
B. particle density
C. particle color
D. particle type
Quiz
Where would the smallest particles of rock
be deposited in a streambed?
a.
b.
c.
d.
Where the water is moving the fastest
Where the water is moving the slowest
Near the middle
At the beginning
Quiz
In an experiment, students shook jars of
water with soil and rock in them. What
could the shaking model in nature?
a.
b.
c.
d.
A lake environment
A stream current
Living things in an environment
A rainstorm
Quiz
A student shakes a jar with a mixture of
sand types. Instead of mixing, the sand
grains separate into layers. Why?
a.
b.
c.
d.
The grains are different colors.
The grains have different shapes.
The grains have different densities.
The jar has a round shape.
Quiz
In the spring, rivers in Utah are cloudy or
murky. A sample of the water shows it
contains very small particles of silt. Why
is silt suspended in the water?
a. The water is moving rapidly.
b. Silt is small with low density.
c.
Water has a high density