April 1

4th Grade Science

Earth’s Features

In the role of geologists, students investigate how a dinosaur fossil found in the fictional Desert Rocks National Park formed, which serves as the anchor phenomenon for the unit. Students make inferences about the history of the park based on the fossil itself and the rock layers in which it is embedded. Investigating how the fossil formed leads students to learn about sedimentary rock formation. Students use books, hands-on investigations, and the Earth’s Features Simulation to figure out how fossils and sedimentary rock form and how different sediments build up in different environments, forming different rock in those environments. This helps them learn how to tell the environmental history of a place by observing the rock layers present. Finally, in an effort to explain a new anchor phenomenon, why two different canyons in the fictional Desert Rocks National Park have different amounts of exposed rock, students figure out that rock can be broken down and layers can become exposed by things in the environment, such as water.

Why?

The Next Generation Science Standards (NGSS) require grade 4 students to use patterns in rock formations to describe the changes in a landscape over time. Additionally, the NGSS require students to observe how water can break down and transport rock material. This unit engages students with these concepts by focusing on something that excites and engages students: the discovery of a dinosaur fossil. Students investigate the fossils and kind of rock in a rocky outcrop to reveal the history of a location. The study of a dinosaur fossil in a rocky outcrop provides a great context for beginning to understand how geologists can use fossils and rock to determine what a place was like in the past.

Most fourth graders can identify and name geographical features of Earth’s surface—mountains, canyons, beaches, and oceans—but few students understand that these seemingly unchanging features have not always existed exactly as they are now. What is currently a rock formation in a desert may have once been a flat floodplain covered by a lush forest. This unit prompts students to think about how these features formed incrementally as sediment deposited, compacted, and cemented into rock over millions of years. Students gain an understanding of the connection between sediment deposition, rock formation, and environment. By understanding that sediment deposits and rock forms in particular environments, students can engage in an authentic practice of geology—making inferences about the past using data from the present. Armed with this understanding, students begin to conceptualize the small changes occurring in an environment that lead to dramatic changes to its landscape over time.

How?

In Chapter 1, students figure out how the mystery fossil formed inside the rocky outcrop at Desert Rocks National Park. In the first part of the chapter, students figure out the process by which fossils form. They then read an informational text about a paleontologist who studies fossils by observing them to make inferences about extinct organisms and their behaviors. They determine what inferences they can make about the mystery fossil and explore fossil formation in a digital app to learn that fossils form when an organism dies and is covered with sediment that turns to rock. In the second part of the chapter, they figure out how sedimentary rock forms. They observe a sample of conglomerate, reread a section of the book, and investigate in the digital app to construct an understanding of sedimentary rock formation. Students then create Sedimentary Rock Formation Models, which demonstrate the sedimentary rock formation process, and the teacher introduces the Class Sedimentary Rock Formation Model, which the class will observe and discuss throughout the unit to model the slow process of sedimentary rock formation over time. Students consolidate their understanding with a discourse routine and, together with the teacher, write an end-of-chapter argument about what Desert Rocks National Park was like in the past.

In Chapter 2, students investigate more about what the environment of Desert Rocks National Park used to be like in the past. Students read a book which models how geologists use rocks and fossils to make inferences about past environments of a place, which sets the stage for students’ own authentic investigation of rocks for the remainder of the chapter. Students observe samples of conglomerate and sandstone to notice differences between the two and to make inferences about the environments in which each of the rocks formed. They then read more information about rocks and why they form in different environments in the unit’s reference book. They return to the Sedimentary Rock Formation Models they made in Chapter 1 and add a different rock layer to apply their understanding that the sediment that makes up different kinds of sedimentary rock is different. Finally, students investigate in the digital app to construct the understanding that different sediments build up in different environments, which enables geologists to use rock to make inferences about past environments. At the end of the chapter, students are introduced to the different kinds of rock in the rocky outcrop in Desert Rocks National Park and to additional fossils found in different rock layers. Students use this data to infer the past environments of Desert Rocks National Park in a written end-of-chapter scientific argument.

In Chapter 3, students are challenged to use evidence from rock layers to consider the order of the past environments of Desert Rocks National Park. Students begin by working together to create a new class model using sheets of paper in order to explore the order in which rock layers are formed. They return to the Sedimentary Rock Formation Models to observe the order in which the rock layers formed. Students then return to the reference book in order to gather additional evidence about which rock layers form first. Students also return to the Class Sedimentary Rock Formation Model to analyze the order in which the layers formed consolidating their understanding that lower rock layers are older than the layers above them. Next, students use a digital modeling tool to communicate their understanding of rock layer formation. Students read a book that models the practice of engaging in argument from evidence and discusses examples of how scientists make convincing arguments using the ideas about the order of rock layers. Students apply what they learned about the age of rock layers to infer the order of past environments by completing a mission in the Simulation. At the end of the chapter, students learn about a new fossil and rock layer and write an argument about the environment of Desert Rocks National Park when that layer formed. Finally, students use this new information to explain the order of past environments of the park.

In Chapter 4, students explore why more rock layers got exposed in Desert Rocks Canyon in comparison to another canyon in the same park. They read a book which provides students with an introduction to erosion using beautiful rock formations from around the world. They then investigate water erosion in the Simulation to determine what factors affect the erosion of a canyon. Based on information in the book and in the Sim, students determine what factors might cause one canyon to erode more than another. They conduct two different River Model investigations using stream tables to construct an understanding of the effect of speed and amount of time a river flows on the amount of rock that it erodes. Students apply what they have learned to complete a digital model of canyon formation. At the end of the chapter, students use evidence from these investigations to support a claim in a written argument about why Desert Rocks Canyon has more exposed rock than nearby Keller’s Canyon.