- Slides: 36
Rocks and Erosion Chapter 8 L 4 and L 5
Lesson 3 Ch 8 Minerals pg 303 �A mineral is a nonliving, naturally occurring solid that has its own regular arrangement of particles in it. 3/12/2021 7: 50: 40 AM
Where are they found? 3/12/2021 7: 50: 44 AM
Where are they found? �Minerals are found in soil and rocks. �Although many different minerals exist, only a few dozen make up most of the rocks on Earth 3/12/2021 7: 50: 45 AM
What does minerals make? 3/12/2021 7: 50: 47 AM
Properties of minerals pg 304 �There are more than 4, 000 kinds of minerals. �Certain properties help scientists identify minerals. �These properties are hardness, luster, color, streak, shape, and magnetism. Sometimes smell. 3/12/2021 7: 50 AM
Hardness �Scientists test a mineral’s hardness by finding out how easily it can be scratched. �Use a chart called the Mohs scale. 3/12/2021 7: 50: 51 AM
Moh’s Scale 3/12/2021 7: 50: 51 AM
Hardness scale �A mineral with a greater number can scratch all minerals with a lesser number. 3/12/2021 7: 50: 56 AM
Reread pg 304 with your shoulder partner and answer questions 3&4 3/12/2021 7: 50: 56 AM
Color pg 305 �Color describes a mineral’s outside appearance. �Elements that make up a mineral may affect its color �The element copper gives malachite a green color. 3/12/2021 7: 50: 56 AM
Streak � Streak is the color of a mineral in its powdered form � To see a mineral’s streak, you rub it on a hard, rough, white surface or black surface. Called a streak plate. � Streak Plate � The powder can be the same as or very different from the mineral’s outside appearance. 3/12/2021 7: 50: 56 AM
Shape �The shape of a mineral’s crystals is not always easy to see �Some minerals have a definite shape that is helpful for identification. 3/12/2021 7: 50: 58 AM
Magnetism �A few minerals have magnetic properties �Pyrrhyotite and certain varieties of magnetite are strongly magnetic. 3/12/2021 7: 50: 58 AM
Identifying minerals �In order to identify an unknown mineral, scientists first make many observations. �Then, they compare their observations with charts of known minerals. �The chart gives the names and properties of several minerals. 3/12/2021 7: 50: 59 AM
Economic significance �Many common products contain minerals. �Minerals are the source of metals such as iron, copper, and silver. �Many minerals are used in foods, medicines, fertilizers, and building materials. 3/12/2021 7: 51: 05 AM
Lesson 4 Rocks �There are three kinds of rocks Igneous Sedimentary metamorphic
Id-ing rocks �By looking at how the minerals in the rock are arranged, it is often possible to determine how the rock was formed
Igneous �Rocks that form when melted rock cools and hardens are called igneous rocks.
Igneous rocks con’d �Igneous rocks can form deep inside Earth or from lava that hardens on Earth’s surface.
Igneous rocks con’d �As hot, liquid rock cools, crystals of minerals form. Melted rock cools slowly results in igneous rocks with large crystals of minerals �Melted rock that cools quickly results in igneous rocks with small crystals.
Sedimentary Rocks �Most sedimentary rocks form when layers of materials and rock particles settle on top of each other and then harden.
Sedimentary rocks con’d �Minerals from water may act like cement. They hold the particles together. �Sandstone and conglomerate are examples of sedimentary rock.
Sandstone �Sandstone can form when layers of sand are buried and put under pressure. Large, rounded particles that have been pressed together form conglomerate.
Metamorphic Rocks �When solid rock is squeezed and heated to very high temperatures, the particles inside the rock can take on different arrangements. �Metamorphic rock is rock formed inside Earth from other rocks under heat and pressure
The Rock Cycle �Rocks are constantly being formed and destroyed in a process called the Rock Cycle. �Rocks may be changed from one kind to another in any order or stay the same for millions of years. �See page 311
Id-ing rocks �Rocks are made of mixtures of minerals and other materials. �Some rocks contain only one type of mineral. �Others contain many minerals.
High. Light IT!!! �Quickly!!!! And Quietly Turn to page 309 Get out a highlighter
Causes of Erosion pg 315 �Materials such as rock particles on Earth move. �Water, wind, and ice can carry particles from one place to another place. �The movement of materials away from a place is called erosion.
Causes of Erosion pg 315 �Erosion is a destructive process. �Gravity is the main force causing erosion. �In a landslide, gravity is the main force causing erosion.
Water Erosion �Moving water causes much of the erosion that shapes Earth’s surface. �Rivers, rain, waves, ocean currents, and glaciers are all forms of moving water.
Rivers �Gravity causes rivers to flow �As rivers flow downhill, they pick up and carry sediments, such as rock, soil, and sand. �The sediments can erode the riverbeds by grinding against the riverbeds again and again.
Rain �Rain can loosen sediments from the soil and carry them away. �Rain cause flooding in low, flat area. �Flooding damages soil, roads, and buildings.