Bellringer • K= know about rocks already • W= Want to learn about rocks • L= Learned about rocks
Rocks are composed of 1 or more minerals There are 3 types of rocks: igneous, sedimentary, and metamorphic Rock cycle describes how the elements that make up rocks are redistributed transforming one rock into another
4 parts of Earth • Inner core: mass of iron 7000 degrees Fahrenheit. Immense pressure keeps iron solid • Outer core: mass of molten iron. Electric currents produce Earth’s magnetic field • Mantle: slow moving molten rock or lava • Crust: sand and rock
Composition of Magma • Mix of molten rock, gases, and mineral crystals • Elements: O, Si, Al, Fe, Mg, Ca, K, Na • Compound most abundant: Silica • Silica content affects melting temperature and impacts how quickly magma flows
Independent Work • Make a Venn Diagram comparing and contrasting minerals and rocks • Composition • Formation • Group • Elements Present
Bellringer • Make a list of how you think rocks are used in everyday life
Magma Formation • Factors: temperature, pressure, water content, and mineral composition. • Temperature increases with depth in Earth’s crust • Pressure increases with depth. Due to weight of overlying rock • Small percentages of water are in rocks and minerals. Water content increases, melting point decrease. • Different minerals have different melting points.
Igneous Rock • Forms from crystallization of magma (molten rock below Earth’s surface) • 2 types of igneous rocks • Extrusive: fine grained, cools quickly on Earth’s surface. Example: Rhyolite • Intrusive: coarse grained, cools slowly beneath Earth’s surface. Example: Granite
Igneous Rock as a Resource • Useful as building materials • Interlocking grain= strength • Minerals in igneous rocks are resistant to weathering • Example: Granite • Ore deposits
Independent Work • 1. What are the 2 different types of igneous rocks and describe how each forms? • 2. What are the factors that affect the formation of magma? • 3. Why do you think magma is usually a slushy mixture of crystals and rock. • 4. Make a Frayer model: 1. 4 parts of the Earth. 2. How is magma formed. 3. Describe igneous rocks. 4. How can igneous rocks be used.
Bellringer • Make a list of things you know about fossils
Sedimentary Rocks • Igneous rocks are the most common on Earth’s crust • Do not see igneous rocks on the ground • Earth’s surface is covered in sediments • Sediments= pieces of solid material that have been deposited on Earth’s surface by wind, water, ice, gravity, or chemical precipitation • Sediments cement together to form sedimentary rocks. • Formation begins with weathering and erosion.
Types of Sedimentary Rocks • Clastic: Most common: Loose sediment: Varying sizes. Sandstone, shale • Chemical: Formed from evaporation. Limestone, Rock salt • Organic: Remains of once living things: Limestone, coal
Bellringer • Referring to last week’s KWL, make a list of things you have learned about rocks so far under “L”
Importance of Sedimentary Rocks • Form fossils: provide information about past animals and plants • Understand geologic change over time: flow of rivers, wave/wind directions, shorelines • Sources of oil, natural gas, and coal • Uranium mined from sandstone: nuclear power • Limestone: cement for construction
Weathering • Weathering= physical and chemical processes that break rock into smaller pieces • Chemical weathering=rocks are dissolved or chemically changed • Physical weathering= minerals remain chemically unchanged. Rock fragments break off along fractures.
Illustrate the Rock Cycle • Terms to be used: igneous, metamorphic, sedimentary, magma, sediment, melting, heat, pressure, weathering, erosion, deposition, cementation, burial • Do not simply use the terms, you need a picture to show the process. You can refer to your rock cycle worksheet.
Erosion and Transport • After rock fragments have been weathered, they are transported to a new location • Erosion- movement of surface materials from 1 location to another. • Agents of erosion= wind, moving water, gravity, and glaciers • Examples: muddy water, dust, fine sand
Deposition • Deposition= sediments are laid down on the ground or sink to bottom of bodies of water. • Sediment deposited when transport stops. • Fast-moving water can transport large particles. • As water slows, largest particles settle, then next-largest. Settles in layers • Wind moves small grains: Ex: sand dunes • Glaciers move all sizes easily: large boulders, sand, mud
Metamorphic Rock • Heat and pressure form metamorphic rocks • Heat: derived from Earth’s internal heat • Pressure: derived from vertical pressure by weight of overlying rocks or compressive forces
Independent Work • Make a concept Map with Rocks in the middle. • From there, you need 3 legs for each of the types of rocks • Make bubbles for how formed, how used, examples, types. • Describe each further