1. Section Ten Earth Science Sedimentary Rock Fossils

2. As rocks go through the rock cycle, weathering and erosion and other events such as volcanic eruptions change them. Sedimentary rocks cover a great deal of the Earth’s surface and scientists can discover a lot about the history of the Earth and events that have happened by studying them.

3. Sedimentary Rock Many have layers of different colors They are softer than other types of rocks. (they break apart easier). Usually composed of pieces cemented or pressed together. Particles can be all the same size or a variety of sizes Often contain fossils. Formed in places where there once was water. Made of sediments. Sediments are loose Earth materials (sand, soil, rock, silt, pebbles, etc.)

4. Fossils Most fossils are found in sedimentary rock. Fossils are the remains or traces of organisms that lived long ago. The most common way a fossil is created happens when an organism is quickly trapped in layers of sediment. The plant or animal slowly decays and the organism is replaced by minerals that seep through the layers of soil. All fossils are old. Scientists study fossils to discover what life was like on Earth a long time ago.

5. Sedimentary Rocks and Fossil Questions

6. 1.A hiker walks from the upper rim to the bottom of a large canyon. At the bottom of the canyon, the hiker camps for the night. While walking along the trail, the hiker sees a fossil that looks like a shell. Which statement best explains the presence of the fossil in the canyon? A. Lava formed the fossil. B. Wind carved a rock to look like a shell. C. The area was covered by a glacier in the past. D. The area was covered by liquid water in the past. 2. A leaf is covered in mud during a landslide. After one million years, this leaf will most likely be… A. a fossil B. an animal species C. a new plant species D. a non-renewable resource

7. 3.Coral, clam, and starfish fossils are common in South Dakota. These fossils are evidence that South Dakota was once… A. a forest area B. covered by water C. flooded by spring rains D. at the edge of a tectonic plate

8. Questions/Explanations 1. animals with shells usually live in the water. If a fossil of a shell is found in a canyon, the most logical explanation is that the area had been covered by water at some time. 2. if an organism is quickly trapped in sediment before it can decay, over time, due to minerals seeping into the ground, it can change to a fossil. 3. coral, clams, and starfish are aquatic animals. If they are found in South Dakota where there is no oceans, the most logical explanation is that the area was once covered by water.