Unit 3: Earth Science

a.Geology: area of science that studies the earth, rocks, and how it has changed over time b.Two pieces of evidence that geology has found about the interior of the earth i. Direct evidence from rock samples 1. Show what type of rock is under the earth’s surface 2. Igneous, Metamorphic, or sedimentary ii. Indirect evidence from seismic waves 1. Seismic Waves are created from earthquakes 2. These wave change direction and speed as they hit new type of rocks under the earth surface I. Earth Interior

c. Three different main layers of the Earth i. Crust: layer of solid rock that forms dry land and ocean floor. 1. Mainly made of: oxygen and silicon 2. Anywhere from 5km-40km thick 3. It is the thickest under mountains and the thinnest under the ocean 4. Oceanic Crust is the crust under the ocean a. Made of a fine-grained rock called Basalt 5. Continental Crust is the crust that makes dry land. a. Made of many different kinds of rocks b. Most continental crust is much like Granite, light in color and has coarse grains I. Earth Interior

i. Mantle: layer of rock that sit right below the crust 1. The rock in this layer is very hot, but still solid 2. 3,000 km thick 3. Split into three parts a. Lithosphere: upper most part and is made of brittle rock. b. Asthenosphere: hotter and increasing pressure. Less ridged but still solid rock c. Mesosphere: Also called the transition zone because it extends into the earths core I. Earth Interior

iii. The core: inner most part of the Earth 1. Made of mostly iron and nickel 2. Two different parts a. Outer Core: dense liquid metal b. Inner core: dense solid metal 3. Core may also contain oxygen, sulfur, and silicon I. Earth Interior

1.What are the three different kinds of rocks? 2.Name the two different types of “crust” that is on our earth and explain how they are different. 3.Name and Describe the three different layers of the mantle. 4.What is the different between the outer core and the inner core? Warm Up #6

e. Earths magnetic field i. Scientists believe it is the liquid outer core that creates the magnetic field effect ii. The earth has a North and South magnetic Pole iii. A compass needle is attracted to the north pole iv. The magnetic north pole and the geographical north pole are not the same place I. Earth Interior

a.Three types of Heat Transfer i. Conduction ii. Convection iii. Radiation b. Mantle uses Convection c. Density changes as an object is heated and cooled d. Changes in density in fluids create a movement called the convection current i. Convection current illustration II. Convection in the Mantle

e. How the Mantle uses the Convection Current i. The core of the earth heats up and causes a Convection current ii. That convection current then begins to heat up the mantle, creating another convection current within the mantle iii. Mantle Convection Current Illustration II. Convection in the Mantle

a.Rocks are made from a mixture of different minerals i. Some rocks only contain one mineral, some rocks contain many different minerals b. Rock forming minerals: 20 different minerals that make up most rocks c. The color of the rock gives clues as to what type of mineral the rock is made out of. d. The texture of the rock gives clues as to what type of mineral is in the rock i. Texture comes from the grain of the rock III. Classifying Rocks

ii. Three different categories for grain 1. Shape 2. Size 3. Pattern iii. Shape of the grain 1. Rounded grain 2. Jagged grain III. Classifying Rocks

1.Describe how the convection current is used on the inside of the earth. (Inlcude the inner core, outer core, mantle, crust and how the heat is moving) 2.Describe the earths magnetic field. Warm Up 7 Rewrite the question and answer in complete sentence

iv. Size of the grain 1. Fine grain 2. Coarse grain 3. No Visible grain v. Pattern of the grain 1. Nonbanded 2. Banded III. Classifying Rocks

e. Origin of Rocks i. Igneous rock: forms from the cooling of Lava or magma 1. Magma cools underground to form rock 2. Lava erupts out of a volcano and cools and hardens on the earth surface ii. Sedimentary rock: forms when small particles of rocks or remains of plants and animals get pressed together 1. This happens under tremendous pressure 2. These are formed in layers that are buried under the earth III. Classifying Rocks

iii. Metamorphic rock: forms when a rock is changed by heat or pressure or chemical reactions 1. Most metamorphic rock forms deep under ground III. Classifying Rocks

a. Igneous rock is classified by origin, texture, and mineral composition b. Origin i. Extrusive rock 1. formed from lava that was erupted 2. Basalt is one of the most common extrusive rocks ii. Intrusive rock 1. Formed underground from the hardening of magma 2. the most common intrusive rock is granite 3. These rocks can take hundreds of thousands of years to form IV. Igneous Rock

iii. Differences between Intrusive and Extrusive Rocks 1. Grain size a. Intrusive: Large Grain b. Extrusive: Small Grain iv. Mineral composition 1. Magma has a lot of Silica but Lava does not 2. Silica usually forms light colored rocks IV. Igneous Rock

a.A Rock that forms from another rock due to tremendous pressure and heat b.Metamorphic rock can come from igneous rock, sedimentary rock, or other metamorphic rock c.Classification of Metamorphic Rock i. Classify according to the arrangement of the grain ii. Foliated Rocks: they have grain that goes in parallel layers or bands 1. Granite turned to Gneiss V. Metamorphic Rock

iii. Non-foliated Rock: the grains are arranged randomly 1. Limestone to Marble V. Metamorphic Rock

a.Sediment is small, solid pieces of material that come from rocks or living things. b.Sedimentary Rock is formed when sediment is deposited by water and wind. c.Most sedimentary rock is formed through several different processes i. Weathering: the effect of freezing, thawing, plant roots, and acids ii. Erosion: process of running water, wind or ice that carry away broken up rock iii. Deposition: process of sediment settling out of the water or wind that is carrying it. iv. Compaction: When the weight of other rock compresses settlement together v. Cementation: process of dissolved minerals crystallize and glue particles of sediment together VI. Sedimentary Rock

d. Three major groups of Sedimentary rock i. Clastic rocks 1. A sedimentary rock formed from rock fragments that are squeezed together 2. The fragment size can be so small that it cannot be seen without a microscope to very large fragments 3. Clastic Rocks are grouped by their fragment size 4. Examples: Shale, Sandstone, Conglomerate, Breccia VI. Sedimentary Rock

ii. Organic Rocks 1. These form from remains of living things 2. These form when plant or animals remains are deposited in layers 3. Example: Coal forms when the remains of swamp plants are buried in water. As the layers build up it squeezes the decaying plants together 4. Example: Limestone forms from living things in the ocean and the mineral calcite are combined and compaction and cementation occur to put the rock together VI. Sedimentary Rock

iii. Chemical rocks 1. These are formed when minerals dissolve in water to form crystals e. Uses of Sedimentary Rock i. Sedimentary rocks have been used for tools and building ii. Example: Sandstone and Limestone have been used for buildings for thousands of years. These are soft enough to be cut into blocks. 1. The White House is made out of sandstone 2. Limestone is used in making cement and steel VI. Sedimentary Rock

 In the space below, write a description or draw a Venn diagram that compares and contrasts the way Igneous, Metamorphic, and Sedimentary rocks are made and where they are found. VII. Compare and Contrast

iii. Example: Flint has been used to make tools and weapons for thousands of years. 1. It is a hard rock but can be shaped into a sharp point good for spear heads and building tools VI. Sedimentary Rock

a. The Rock Cycle Basics i. Occurs on the Earths Surface, in the mantle and the crust ii. This cycle is the pattern of pathways that result from: 1. Weathering and erosion 2. Deposition 3. Earthquakes and volcanic activity 4. Tremendous heat and pressure 5. Melting VIII. The Rock Cycle

b. Rock Cycle Events i. Surface events: Weathering and erosion and deposition of rock can all lead to sedimentary rock 1. This may occur through freezing or thawing or water moving broken particles 2. The weight of the sediment begins to form sedimentary rocks. VIII. The Rock Cycle

ii. Subsurface Events: has to do with the movement of the tectonic plates 1. These plates are believed to move due to convection in the mantle 2. When these plates collide we get mountains 3. Earthquakes can push up new rock exposing it to go through the rock cycle 4. These colliding plates also produce volcanoes a. Magma pushes its way to the surface through the cracks VIII. The Rock Cycle

5. These collisions also cause a great amount of heat and pressure under the surface a. This increase in heat and pressure can cause rock to change into metamorphic rock c. Rock Cycle Diagram VIII. The Rock Cycle

a.Relative Aging: a rocks age compared to the age of other rocks b.Absolute Aging: the actually number of years it has been since the rock was formed c.Law of Superposition: in undisturbed horizontal sedimentary rock layers the oldest layer is at the bottom. Each higher is younger than the layer below. IX. Aging of Rocks

d. Extrusion: when younger rock is below older rock i. comes from volcanic activity e. Intrusion: when magma pushes up from the inside of the crust and is younger than the layers around and below it IX. Aging of Rocks