Why is there sand at the beach?

Why is there sand at the beach?

Lesson narration:
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DISCUSS (1 of 2):

Why do you think the sand is purple?

DISCUSS (2 of 2):

Imagine you were at Pfeiffer Beach. How could you look for clues to help you solve the mystery of where the purple sand comes from?

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DISCUSS:

Can you think of a way tiny pieces of these rocks could move from the mountains all the way to the beach?

Hint...

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DISCUSS: What do you think would happen if the rocks in the river crashed into each other? Could this explain how there’s sand at the beach?

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ocean


1 of 15

a large area of salt water that covers the Earth
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beach


2 of 15

land next to a large area of water, often covered in sand
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microscope


3 of 15

a tool used to see very tiny things up close
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sand


4 of 15

very tiny pieces of rock, such as what you often see on the ground at a beach
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pebble


5 of 15

a small rock, usually with smooth edges
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rock


6 of 15

a solid natural material that is found on and under the surface of the Earth
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boulder


7 of 15

a large rock
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mountain


8 of 15

a high area of land with steep sides
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slope


9 of 15

where one side is higher than the other
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steep


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something that is very high up on one end and very low at the other end
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river


11 of 15

a long, thin area of water that flows
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flow


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to move along
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erosion


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when tiny bits of rock are moved from one place to another
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downstream


14 of 15

toward the direction that water in a river or stream flows
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model


15 of 15

a pretend version of something that scientists use when the real thing is too big, small, or complicated to work with
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Image & Video Credits

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Exploration
kids at the beach by Image used under license from Shutterstock.com: bikeriderlondon
white sand beach by Image used under license from Shutterstock.com: Rob Marmion
girl on the beach by Image used under license from Shutterstock.com: ori-artiste
sand castle by Image used under license from Shutterstock.com: Kris Wiktor
Southwick Beach State Park by Easchiff
hand in sand by Image used under license from Shutterstock.com: kasidit
kid at Pfieffer Beach by The Offshore Aquaholic
purple sand by The Offshore Aquaholic
purple sand beach by Carson
kid holding sand by Image used under license from Shutterstock.com: Albina Glisic
footprints on purple beach by Image used under license from Shutterstock.com: mhgstan
hand holding purple sand by Akos Kokai
magnifiying glass by Image used under license from Shutterstock.com: underworld
close up of sand by Image used under license from Shutterstock.com: Mr Twister
zoomed view of sand by Image used under license from Shutterstock.com: AlexussK
green sand beach by Image used under license from Shutterstock.com: Alexander Demyanenko
close up of green sand by Brian W. Schaller
cliffs facing the beach by Image used under license from Shutterstock.com: Noradoa
close up of cliff by Image used under license from Shutterstock.com: jennyt
scuba diver by Image used under license from Shutterstock.com: Rostislav Ageev
Lepidolite (purple rock) by Spirit Rock Shop
purple mountains by Gonzo fan2007
falling rocks sign by Image used under license from Shutterstock.com: Michael Leslie
rock crashing down mountain by Joraj Dason
beach flooding by Muhammad Moolla
fast flowing river by Hayk Arakelyan
rocks flowing down river by Internet Geography
big blue waves by Image used under license from Shutterstock.com: bus109
chair and beach umbrella by Image used under license from Shutterstock.com: Aleks Melnik
clouds by Image used under license from Shutterstock.com: nikiteev_konstantin
mountains sillhouette by Image used under license from Shutterstock.com: Alex Ghidan
ocean concept by Image used under license from Shutterstock.com: Nikita Konashenkov
sand texture by Image used under license from Shutterstock.com: Ursa Major
Rainbow Beach by Cassarazzi
green rock by Image used under license from Shutterstock.com: Helen Cingisiz
hornocal by Lahi
close up of rainbow beach by cordyceps
stream on the beach by Humphrey Bolton
Activity
rushing river in Smoky Mountains by GreatSmokyMountains (© GSMA 2010. All rights reserved.)
turtles by Image used under license from Shutterstock.com: Dmitri Ma
rushing river by fccysf
Lesson narration:

Activity Prep

Print Prep

In this lesson, students investigate the effects of rocks tumbling in a river. Based on their observations, they construct an explanation for why there is sand at a beach. In the activity, Rocking the River, students pretend to be a river and tear up pieces of construction paper to model what happens to rocks as they travel along the river.

Preview activity

Exploration

22 mins

Wrap-Up

3 mins

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