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Why is there sand at the beach?
Work of Water Unit | Lesson 2 of 5
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Why is there sand at the beach?

Work of Water Unit | Lesson 2 of 5
Lesson narration:
English Spanish
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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


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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


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


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a small rock, usually with smooth edges
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rock


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


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a large rock
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mountain


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a high area of land with steep sides
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slope


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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


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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


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


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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

Mystery Science respects the intellectual property rights of the owners of visual assets. We make every effort to use images and videos under appropriate licenses from the owner or by reaching out to the owner to get explicit permission. If you are the owner of a visual and believe we are using it without permission, please contact us—we will reply promptly and make things right.

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
Credits
Lesson narration:
English Spanish

Grade 2

Erosion & Earth’s Surface

Rocks, Sand, & Erosion

2-ESS2-2

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
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In your Mystery Pack Lesson Bag
Draw the River Rocks printout 1 per student
River (5 sheets) printout 1 per group
Colored Construction Paper 3 sheets per group
Not included in your Mystery Pack
Draw the River Rocks printout 1 per student
River (5 sheets) printout 1 per group
Prep Instructions

We suggest students work in groups of four.

Prepare “Paper Boulders”

Cut or tear each sheet of construction paper into about 12 pieces. We used a paper cutter to cut many sheets at the same time, making irregularly shaped pieces, but tearing or cutting with scissors will also work.

randomly cut paper

Each group should start with 3 sheets worth of boulders (about 36). We recommend providing plenty of boulders at the beginning so that the students will still have large boulders at the end of the activity. That way, students will be able to see how the sizes of the rocks change as they move downstream.

Exploration

22 mins

Hands-On Activity

30 mins

Wrap-Up

3 mins

Grade 2

Erosion & Earth’s Surface

Rocks, Sand, & Erosion

2-ESS2-2

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Credits