Daily Warm-Up Exercises1 Day 3 What’s the same and different about sand, silt, and clay? They are all made up of a lot of small grains, but the size of the grains is different. Silt has much finer grains than sand, and clay’s are very, very fine.

Compare Rock Types2 Contrasting Case Activity 1, Part 3 Earth History, Investigation 8

Compare Rock Types3 Conclusions about Igneous Rocks What features are shared by both igneous rocks? Formed on Earth’s surface from molten rock released by a volcano Grain size is fine to medium Contains a lot of small air pockets Usually feels lighter than other rocks of its size Granite Only Pumice Only Both Granite & Pumice Made of minerals Formed when molten rock cools and hardens Rough and dull Formed deep beneath Earth’s surface Most grains are coarse Usually fairly light in color It is hard and has shiny, smooth crystals Made of volcanic glass

Compare Rock Types4 Conclusions about Metamorphic Rocks What features are shared by both metamorphic rocks? Schist Only Quartzite Only Both Schist & Quartzite Made of minerals Formed when a rock changes due to heat and/or pressure Rough Formed deep beneath Earth’s surface Fairly shiny Medium to coarse grain size Crystals are flat and arranged in layers Formed from slate, a metamorphic rock Dull, and hard Fine grain size Formed from sandstone, a sedimentary rock Grains appear to be fused together

Compare Rock Types5 Conclusions about Sedimentary Rocks What features are shared by both sedimentary rocks? Shale Only Sandstone Only Both Shale & Sandstone Made of minerals Formed when something gets compacted and cemented together Dull and hard May form on or below Earth’s surface Smooth Very fine grain size Grains are arranged in layers Formed from particles of silt or clay Rough Medium to coarse grain size Formed from grains of sand May contain fossils

Compare Rock Types6 Look at the center sections of all three diagrams. Is there anything that all three rock types have in common? no Is there anything that two of the three rock types have in common? Metamorphic and sedimentary rocks are both made of minerals.

Compare Rock Types7 Look at the igneous diagram. Is either of these rocks made of minerals? granite is; pumice is not Look at the last Venn diagram. This one has three circles, one for each rock type. How would you show that most rocks are made of minerals? What can we conclude from this? Most rocks are made of minerals.

Compare Rock Types 8 Rock Types Most rocks are made of minerals Igneous MetamorphicSedimentary

Compare Rock Types9 Is there anything else that is true about two rock types but not true about the third? Igneous and sedimentary rocks may form on or below Earth’s surface. Metamorphic rocks only form below the surface. How would you show this in the diagram?

Compare Rock Types 10 Rock Types May form on or below Earth’s surface Only form below Earth’s surface Most rocks are made of minerals Igneous MetamorphicSedimentary

Compare Rock Types11 Compare Rock Types Fill in the diagram by entering at least one feature that is true about igneous rocks only. Do the same for metamorphic and sedimentary rocks.

Compare Rock Types 12 Rock Types Form when something gets compacted & cemented together May contain fossils Form when a rock changes due to heat and/or pressure Form when molten rock cools & hardens May form on or below Earth’s surface Only form below Earth’s surface Most rocks are made of minerals Igneous Metamorphic Sedimentary

Compare Rock Types13 Concluding Discussion Based on your diagram, what do most rocks have in common? They are made of minerals. Suppose a previously unknown rock is discovered, and scientists categorize it as sedimentary. What can you say about this rock? It probably formed when something got compacted and cemented together. It could have formed on or below Earth’s surface. It may contain fossils.

Compare Rock Types14 Concluding Discussion Suppose they categorize the unknown rock as metamorphic. What can you say about it then? It probably formed deep beneath Earth’s surface, when a rock changed because of heat and/or pressure. What if they categorize it as igneous? What can you say about it then? It probably formed when molten rock cooled and hardened. It could have formed on or below Earth’s surface.