Rock+Identification

__ Rock Identification __

Kaari Casey e-mail: kec232@psu.edu Terri Mercer e-mail: tmm5246@psu.edu

This lesson is designed for students grades 5-7 and is focused on the three types of rock and rock identification. The Pennsylvania State Standards that will be addressed are the Earth Sciences standards 3.5.7 A, "Describe earth features and processes," and particularly 3.5.7 B, "Recognize earth resources and how they affect everyday life." These will be used to build off of the corresponding grade 4 standards 3.5.4 A, "Know basic landforms and earth history" and 3.5.4 B, "Know types and uses of earth minerals." In comparing and contrasting the different types of rocks, the Unifying Theme 3.1.7 C, "Identify patterns as repeated processes or recurring elements in science and technology," will also be addressed. And finally, the Inquiry and Design standards 3.2.7 A, "Explain and apply scientific technological knowledge," 3.2.7 B "Apply process knowledge to make and interpret observations," and 3.2.7 C "Identify and use the elements of scientific inquiry to solve problems" will be applied in this lesson. ** Objectives **** : ** 1. Students will be able to define the three main types of rocks. 2. Students will be able to explain how each main rock type is formed in the earth. 3. Students will be able to identify four unknown rocks through collaboration. 4. Students will be able to justify their identifications by using the rock key. ** Content Explanation **** : ** There are three main types of rocks: igneous, sedimentary, and metamorphic rocks. Igneous rocks are formed from magma and molten lava; sedimentary rocks are formed by compaction of sediment (particles of rock and other materials) over time. And metamorphic rocks come from igneous or sedimentary rocks that form as a result of extreme heat, extreme pressure, and/or chemical reactions. ** Materials, Equipment, Set-Up: ** • (1) Dinoscope • (4) Rock samples: granite, sandstone, quartzite, and obsidian • (1) Laptop • (4) Observation sheets (1 per rock sample) • (4) Rock keys (1 per student) • (4) Pencils (1 per student) • (1) Rock cycle poster (may substitute poster for an online rock cycle animation) ** Activity **** : ** ** SAFETY **** : ** Risk of being scraped or cut by the rock samples or the nail used in identification tests. ** Body of Lesson: ** a) Engagement: (4 Minutes) ■ Hi guys my name is _, what are your names? Thanks for coming here today!   ■ // Gesture to the four rock samples // : Which rock here looks the coolest? What do you like most about it?   ■ Have you ever wondered why rocks look the way that they do?   ■ // Brief overview of the rock cycle // : Does anyone know what the three types of rocks are? Do you know how each type of rock is formed in the earth? Could you convert from one type of rock to another?

b) Exploration: How can we identify four different unknown rock samples? (8 minutes)  ■ // Brief overview of rock properties needed for identification // : We will explain to the students how they can identify specific types of rocks by using a rock key. We will give a brief demonstration on how to navigate the key using different rock properties (crystals, grain size, layers, gas bubbles). We will also plug-in the Dinoscope and then show the students how to use it to inspect the samples closely.   ■ Students will collaborate to identify the samples through techniques such as a scratch test. They will record their data and observations on four sheets of paper, one for each rock sample. At the bottom of each sheet, they will record the proposed identity of each sample.

c) Explanation: (3 minutes) ■ After the students fill the sheets, we will ask them to explain to us how they came to classify each of the rock samples. They will be asked to point out any identification disagreements they had amongst their peers and from where these disagreements arose.

d) Evaluation: (5 minutes) ■ The students' identifications will be compared to the actual identifications. We will assess why classifications were either correct or incorrect. We will help the students by addressing any misconceptions in their understanding.

e) Elaboration: (as long as the lesson timing permits) ■ If there is extra time, we will go further into the different rocks within each rock category (i.e. different igneous rocks, different sedimentary rocks, and different igneous rocks) or where different rocks are commonly seen (i.e. obsidian was used by Native Americans to make arrowheads).  ** References **** : **  Academic Standards for Science and Technology. //Pennsylvania Department of Education//. 5  January 2002. 3 March 2011. .   Blueford, Joyce R., Ph.D. Rock Cycle: Understanding the Earth's Crust. Activities and Lesson    Plans, Volume 4. 3 March 2011. .