This lesson comes after my students are familiar with rocks and minerals and their properties and uses. I have already briefly introduced the idea that there are three ways rocks can form. Today, we look more closely at igneous rock and how it forms - from volcanoes!
I teach the Essential Standards for science and this lesson aligns to 1.E.2.1, "Summarize the physical properties of Earth materials, including rocks, minerals, soils and water that make them useful in different ways." Click here to hear my Explanation of Essential Standards and Essential Question. Today's essential questions are "How do igneous rocks form and what are some examples?"
*Access to YouTube
*Large brown construction paper (1 per student)
*Red construction paper
*4 printed labels per student with the words 'lava, magma, vent, sill'
*Scissors and glue
First, I show this clip of Bill Nye (everyone's favorite scientist!) showing a model of a volcano and then walking through a door to Mount Saint Helens. I like starting lessons with a video clip because it immerses students in live footage that I cannot provide by reading a text, and this one is even better because Bill Nye explains how much destruction and change can be brought about by different types of volcanoes.
After the clip, I say,
"We have discussed how rocks can form three ways - sedimentary, where they are pressed over time and metamorphic where they are changed over time by extreme heat and pressure. The third way is igneous, which means it came from a volcano. Today we are going to make a diagram together to show how these rocks form. To do that, we have to look closely at the inside and the outside of a volcano".
For the activity, I start by going through this PowerPoint presentation that I made from pictures of the outsides of volcanoes, then the inside of volcanoes and lava flow. As I go through the presentation with my students, I ask questions like 'How are these volcanoes the same? How are they different? What does the exterior look like?' As we engage with the PowerPoint pictures, looking closely and talking about what we see and why it looks that way, students are engaging in Science and Engineering Practice 6 which is learning from media and making observations to account for natural phenomenon. They are also engaging in Practice 8 as they communicate about what they observe.
I want students to see that there is variety to the exterior but that the interiors all have magma and look the same. As I show the slide with the pumice and obsidian, I stop and pass around samples so my students can really feel them and look at them closely.
After we finish the PowerPoint, I say,
"Now, we are going to make a detailed diagram together of both the exterior and interior of a volcano. First, use your brown paper and find the fold. That will be the bottom of your volcano. Watch how I draw up from the bottom to make the shape of a volcano. We saw in the PowerPoint that the basic shape is always the same, so they should all look similar".
Then, I ask what was on the outside of the volcanoes in the pictures - snow, trees, and rocks should all come up. Then I say,
"Choose what you want your volcano to look like on the outside. Take about 5 minutes and use details to draw just the exterior - do not work on the inside yet!"
As students work, I help where I am needed with students who need me. Then after 5 minutes, I say,
"Okay, let's work on the inside. I am going to show you a Volcano Diagram of what the interior looks like. What do you notice?"
I show the diagram and give a detailed Explanation of the Volcano Structure and we talk about the different parts of the volcano and how it works, and I use the vocabulary terms as I talk about the magma, lava, and the different places inside the volcano. Then I say,
"Using the red paper, cut a piece to glue to look like the vent, which comes up to the top of the volcano. Then cut and glue some pieces on to look like the sills and dikes. Those are the places where the magma tries to get out before it reaches the top because it is under so much pressure".
As students add detail to the inside of their diagrams, I help where needed. After they have finished, we meet back on the carpet with our diagrams.
Developing a model in first grade supports Science and Engineering Practice 2 as students create their diagram to represent a volcano.
Once everyone is settled, I say,
"Now we need to add some labels to our diagram so it is complete. I am going to give you 4 sticky labels with the words vent, magma, lava, and sill. Let's work together and look at the diagram again to make sure we put them in the right places!"
After we have put all 4 stickers on the correct places, I say,
"Today we have made a diagram of a volcano. Who can answer our guiding questions for today - Where do igneous rocks form and what are some examples? Everyone turn to a neighbor and answer those questions"
I want my students to be able to verbalize that igneous rocks form from cooled magma or lava and to give examples like pumice and obsidian, so I choose to end this lesson with students telling each other the answer to the question instead of one student addressing the class. Then, I select 3 or 4 students to share with the class. This communication supports Science and Engineering Practice 8.