R O C K S Chapter 4 p. 108

Lesson 1 The Rock Cycle p. 110 Rocks are everywhere-mountains, valleys, seafloor, north, south, east, west Rock-Natural, solid, mixture of minerals, Processes on Earth cause rocks to break into tiny grains used to classify rocks Some rocks have decayed remains of organisms Geologist-scientist that study rocks and landforms

How do geologist classify rocks? TEXTURE- how tiny grains/pieces fit together creates the overall feel COMPOSITION-which grains/pieces are in a rock tells where a rock formed Tools like maps, journal, compass, and hammer are used by geologist interpret rocks (physical and chemical characteristics)

What are the 3 major types of rocks? IGNEOUS-form from cooled magma/lava crystals; connect much like jigsaw puzzle, form in subduction zones, ocean ridges, and hot spots around the world SEDIMENTARY-form from sediment from wind, water, ice and gravity; form near water (beach,rivers, streams), deserts and valleys METAMORPHIC-form from extreme heat and pressure near plate boundaries; often twist grains into layers

The Rock Cycle Rocks change slowly all the time. The processes that change rocks is called the rock cycle. Pic p. 115 Caused by natural forces inside and on the surface of Earth Processes that change rocks: weathering/erosion, compaction, extreme temperatures, pressure, cooling, crystallization, melting, and uplift Uplift is a tectonic process that forces rocks up to Earth’s surface

Lesson 2 Igneous Rocks p. 118 Viscosity describes the tendency or lack of tendency of flow of liquids. Magma and lava have different viscosities based on what minerals are present in the magma/lava. Enjoy Viscosity Lab Magma-melted rock below Earth’s surface Lava-melted rock on top of Earth’s surface Stone Mountain, Georgia is a igneous rock that formed from magma that cooled underground over a long period of time

Classification of Igneous Rocks If crystals are too small to see without a magnifying glass, the rock was formed ON Earth’s surface (extrusive) If crystals are large enough to see without a magnifying glass, the rock was formed In Earth’s crust (intrusive) The amount of silica, magma composition, location of crystallization, helps geologist classify igneous rocks. Common Igneous Rocks: granite, basalt, rhyolite, gabbro, diorite, andesite

Lesson 3 Sedimentary Rocks p. 125 Water, glacier ice, gravity, and wind can cause rocks to break into smaller pieces, dissolve, or form new minerals. These smaller pieces, sediments are eventually deposited (laid down) and compacted into layers. The weight of the layers of sediment forces out fluids and decreases the space between grains in a process called compaction-can lead to a process called of crystallization of sediments called cementation. Common minerals that cement sediment: quartz, calcite, clay

Classification of Sedimentary Rocks Broken pieces of rock are called clasts and are referred to as clastic rocks. Geologist use clast size and shape to classify sedimentary rocks. Sediment near glaciers can be as large as a car so shape helps determines environment. Shape gives more detail. Sediment in water will appear and feel rounded and smooth. Sedimentary rocks can form during evaporation when minerals crystallize from water or when organisms remove minerals from water to make their shells or skeletons.

Chemical Sedimentary Rocks Water can flow through porous rocks and dissolve and wash away minerals which eventually arrive to the ocean. Particles can crystallize out of the water Chemical rocks form when minerals crystallize directly from water - have interlocking crystalized texture Forms from ONE mineral and are one color Examples: rock/Epson salt, limestone, and gypsum Pic p. 128

Biochemical Sedimentary Rocks Bio = life Biochemical sedimentary rocks are formed by organisms or the remains of decayed organisms Some biochemical rocks are Carbonate rocks and will will fizz Examples: fossiliferous limestone, chert, coal

Lesson 4 Metamorphic Rocks p. 133 Metamorphism is a process that affects the structure or composition of a rock in a solid state as a result of changes in temperature, pressure, or the addition of chemical fluids. Form deep in Earth’s crust under high temps and large amounts of pressure-bend and twist into wrinkly layers

Classification of Metamorphic Rocks Texture of metamorphic rocks is either foliated or nonfoliated. Foliated contain parallel layers of flat elongated minerals Pic p. 135 Examples: slate, phyllite, schist, gneiss Unfoliated contain interlocking mineral grains Pic p. 136 Examples: marble, quartzite

Review for Test Foldable Activity Mineral Escape Room Read and study pics, summaries, and vocab on p. 140 Chapter Review p. 142-143 Study Quizlet Make an A! :)