1Daily Warm-Up Exercises Day 48 What is differential erosion? When a mountain or plateau is made of both weak and strong rock, the weak rock wears away and the strong rock remains. What is correlation? The process of finding connections between rock layers from different locations.

2 Reading Grand Canyon Rocks (Part 4) Investigation 5 Limestone

3 Colorado Plateau Rocks You have now examined most of the rocks that can be seen in the walls of the Grand Canyon. at other locations on the Colorado Plateau How were most of the rocks of the Colorado Plateau formed? Where else can you see many of these rocks? Layers of sediment piled up on top of each other and hardened to form rock.

4 Interpreting Environments type of fossils, particles, crossbedding What are some clues in a rock layer that can tell us about the environment in which it was formed? the remains or trace of an organism preserved in Earth's crust What is a fossil?

5 Key to the Past The idea that the present is the key to the past. Geologists observe modern environments and compare what they see to evidence they find in rocks. What is uniformitarianism?

6 Environments  Turn to Grand Canyon Environments (pages in the lab notebook).  These pages include notes taken by a geologist who studied the Grand Canyon.  Your task is to complete the "Environmental Interpretations" column.  View slide show: Modern Environments

7 Temple Butte  You may have noticed that there is a new layer on this sheet called Temple Butte.  Temple Butte is not a continuous layer. It occurs only in certain locations.  How do you think Temple Butte was formed?

Types of Environments Marine: Aquatic animals, limestone, shells. Beach: Evidence of sand, ripple marks. Coastal: Ripple marks, smooth sand, well sorted. Swamp or floodplain: Lots of plants, trails of animals like worms, snails. Desert or sand dunes: Evidence of reptiles, well sorted sand. Daily Warm-Up Exercises8