Slide 1 / 107 New Jersey Center for Teaching and Learning Progressive Science Initiative This material is made freely available at www.njctl.org and is intended for the non-commercial use of students and teachers. These materials may not be used for any commercial purpose without the written permission of the owners. NJCTL maintains its website for the convenience of teachers who wish to make their work available to other teachers, participate in a virtual professional learning community, and/or provide access to course materials to parents, students and others. Click to go to website: www.njctl.org Slide 2 / 107 4th Grade PSI The History of Planet Earth www.njctl.org Slide 3 / 107 The History of Planet Earth Click on the topic to go to that section · The Structure of Earth · Rock Layers · Fossils and Relative Time · Rock Formations and Earth Forces · Tectonic Plates · Earth's Visible Features · Patterns of Earth's Features
Slide 4 / 107 The Structure of Earth Return to Table of Contents Slide 5 / 107 The Structure of Earth When you look at the world around you, have you ever asked How did the Earth get to be the way it is today? Slide 6 / 107 The Structure of Earth The things that we see today on the surface of the Earth exist for many reasons, and they can teach us many things. The structures we can see on the surface and things underneath the surface tell us about the Earth's history.
Slide 7 / 107 The Structure of Earth Working with your table, come up with a list of structures on Earth that you think might tell some of the story of Earth's past. Slide 8 / 107 The Structure of Earth The things we see on the surface of Earth today have gotten to be that way over many, many years. The surface of Earth - what we see with our eyes - is the outermost layer of Earth and is called the crust. crust Even though the crust is the outer layer, there are still parts of the crust that are too deep for us to see. Slide 9 / 107 The Structure of Earth Earth has other layers underneath the crust. These are called the mantle and the core . But when we talk mantle about the history of Earth, it is the crust - core the outer layer - that can tell us the most. Why do we rely on the crust to tell us the story and not the mantle or the core?
Slide 10 / 107 The Structure of Earth Most of the crust is made up of rock. Much of this rock is sedimentary rock . Sedimentary rocks are one of the main reasons why the crust tells us so much about Earth's history. Slide 11 / 107 1 Can the things we see on Earth's surface can tell us about Earth's history? Yes No Answer Slide 12 / 107 2 Is it possible Earth's surface has gotten to be the way it is within the past 50 years? Yes No Answer
Slide 13 / 107 3 The outer layer of Earth is called the: A skin B mantle C crust D core Answer Slide 14 / 107 4 We can see all of Earth's crust with our eyes. Yes No Answer Slide 15 / 107 5 Which layer of Earth tells us the most about Earth's history? A the core B the mantle C the outside Answer D the crust
Slide 16 / 107 Rock Layers Return to Table of Contents Slide 17 / 107 Rock Layers Sedimentary rock, which makes up much of Earth's crust, is made from sediment . Sediment is broken down pieces of rock and other solid material that settles to the bottom of a liquid . Sediment is often dirt and rock particles that settle at the bottom of bodies of water, but it also refers to any solid material that settles at the bottom of a liquid, such as these particles in this glass of water. sediment Slide 18 / 107 Rock Layers Sedimentary rock is formed over many years. Can you brainstorm any ways sedimentary rock could come to be? Remember our definition of sediment. Where on Earth might we see evidence of layering? How could that have happened?
Slide 19 / 107 Rock Layers So here's how it happens: Sediments are deposited (usually by water). S ediments build up in layers - a process called sedimentation . Sediments are compacted as the weight of the sediments on top squash the sediments at the bottom. Sediments are cemented by crystals of salt that are left after the water has been squeezed out of the rocks. Slide 20 / 107 Rock Layers deposition sedimentation compaction cementation txstate.edu deposition sedimentation compaction cementation Slide 21 / 107 Rock Layers Sedimentary rocks provide a history of the evolution of Earth, especially within the past billion years. When sediments are deposited and compacted to form sedimentary rock, sediments are accumulated in beds one on top of another - in layers . This means that when cut deep into the crust, below the surface we can see with our eyes, we find layers of different rocks that have formed over a long period of time.
Slide 22 / 107 Rock Layers Which layer of rock in this diagram do you think is the youngest? Which is the oldest? Label the top and bottom layers and then move the boxes to reveal the answers. This is called the Law of Superposition . move for answer move for answer Slide 23 / 107 Rock Layers Geologists study ancient sedimentary rocks to determine what environment they formed in. Determining ancient environments is very important to understand the history of Earth. It helps geologists understand how Earth's surface has changed over time. One way to study this is to compare the sedimentary structures in ancient rocks with sedimentary structures in modern environments. Slide 24 / 107 6 The most important characteristic of a sediment is: A that it settles to the bottom of a liquid B that it floats in liquid C its color Answer D that it is small
Slide 25 / 107 7 Order the following steps from first to last in the process of sedimentary rock formation (enter all 4 letters on your responder in the correct order): A compaction B deposition Answer C cementation D sedimentation Slide 26 / 107 8 Sedimentary rocks form in layers. Yes No Answer Slide 27 / 107 9 The Law of Superposition says: A rock layers that are closer to the surface are old B old and new rocks are found in the same place C rock layers get older as you go further down D rock layers that are deep down are the most recent Answer
Slide 28 / 107 10 Geologists study ancient rocks to learn about: A people B environments C sediments D cementation Answer Slide 29 / 107 LAB: Rock Layers In this lab, we will look more at how sedimentary rocks form, focusing on the questions: How are different sediments deposited differently? How do sedimentary rocks form? Slide 30 / 107 Fossils and Relative Time Return to Table of Contents
Slide 31 / 107 Fossils and Relative Time Sedimentary rocks not only contain sediments such as dirt, sand, and pebbles, but also fossils - preserved remains of plants or animals . Fossils come in many forms. They can be bones, tracks, plants, or bodies of animals, among other things. Slide 32 / 107 Fossils and Relative Time Rocks of the same age contain the same, or very similar, fossils. So, for example, very recently formed rocks may have a lot of these fossils, while in rocks from an older time period there may be none of those fossils, but many of these fossils, and in rocks from an even older time period, there may be lots of these fossils, but none of the types found in the more recent rock. Slide 33 / 107 Fossils and Relative Time When the same kind of fossils are found in rocks in different places - for example, fossils of an organism that no longer exists - we know that the rocks are the same age. How? So if fossils of this organism are found in these three places, then the rocks they were found in are all the same age.
Slide 34 / 107 Fossils and Relative Time This means that the age of a rock can be determined by the fossils that are found in it. A rock can also be compared to other rocks by the fossils the rocks contain. The types of fossils in the rocks being compared will show which rock is older than the other. Slide 35 / 107 Fossils and Relative Time When we compare fossils, we can form a general timeline of organisms that existed throughout history! very long time ago long time ago recent Slide 36 / 107 Fossils and Relative Time The kinds of fossils found in rocks from different time periods change because animals and plants change through time. These patterns of fossils exist globally. But in certain places, fossils are also found in different rock layers because the environment of that particular place changed throughout history.
Slide 37 / 107 Fossils and Relative Time For example, imagine that a long time ago there was a lake, and many fish and shell fossils were left in that rock. Many years later, something happened in that area and the rocks from that later time had many plant fossils, but no fish or shell fossils. What do you think scientists would be able to tell happened in that place based on what they learned from the fossils? Come up with an idea in your group you can share with the rest of the class. Slide 38 / 107 Fossils and Relative Time Fossils can tell us many things about the the history of: one place, one region, or the entire planet. Slide 39 / 107 11 Fossils are: (choose all that apply) A found in sedimemtary rocks B living organisms Answer C able to help determine how old rocks are D preserved remains of plants and animals
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