2. Lesson 2 Reading Guide - Vocab luster streak cleavage fracture crust 13.2 The Geosphere Pages 480 - 488 mantle lithosphere asthenosphere core

3. Lesson 2-1 The basic building blocks for soil, rocks, and metals are minerals. Minerals combine in different ways, forming the other materials in the geosphere. Materials in the Geosphere

4. Lesson 2-1 A mineral is a naturally occurring, inorganic solid with a crystal structure and definite chemical composition. Properties such as color, crystal shape, luster, streak, hardness, cleavage, and fracture can be used to identify minerals. Materials in the Geosphere Mark Schneider/Getty Images

5. Lesson 2-1 Luster is the way a mineral’s surface reflects light.Luster Streak is the color of a mineral’s powder. It is observed by scratching a mineral across a tile of unglazed porcelain.Streak The hardness of a mineral can be ranked on a scale of 1 to 10 on the Mohs scale, with 10 being the hardest. Materials in the Geosphere (cont.) DEA/A.RIZZI/Getty Images

7. Lesson 2-1 Cleavage is the tendency of minerals to break along smooth, flat surfaces.Cleavage Fracture is the tendency of minerals to break along irregular surfaces.Fracture Some minerals tend to break apart and combine with other substances, while other minerals are more stable and durable. Materials in the Geosphere (cont.)

8. Mineral Properties

9. Lesson 2-1 A rock is a naturally occurring solid composed of minerals and other materials. Rocks are classified according to how they form. The three main types of rocks are igneous, metamorphic, and sedimentary. Materials in the Geosphere (cont.)

10. Lesson 2-1 Earth systems interact in the rock cycle.

11. Lesson 2-1 Igneous rock forms when molten rock material cools and hardens. Metamorphic rock forms when sedimentary, igneous, or other metamorphic rocks are subjected to high temperatures and extreme pressure. Sedimentary rocks form when sediment is eroded by water, wind, ice, or gravity and deposited in layers. Materials in the Geosphere (cont.)

12. Lesson 2-1 The formation of sedimentary rocks involves interactions among all Earth systems. Rocks can be broken down by physical and chemical weathering. Materials in the Geosphere (cont.)

13. Lesson 2-1 Soil is the loose, weathered material in which plants grow.

14. Lesson 2-1 Soil layers form as rock is slowly transformed into soil. Soil formation begins when rocks weather into sediment and water dissolves minerals and other materials to form sediment.

15. Lesson 2-1 Wastes from organisms and the decaying bodies of dead organisms provide soil with nutrients that makes it more fertile. A major part of the organic matter in soil is carbon that plants obtain from the atmosphere through photosynthesis. Soil plays a major role in the phosphorus and carbon cycles. Materials in the Geosphere (cont.)

16. Lesson 2-1 Interactions among all Earth systems take place in soil because soil contains minerals, water, air, and organisms, all in close contact.

17. Lesson 2-2 The geosphere has three main layers: the crust, the mantle, and the core. The densest layer of the geosphere is the center, or core, and the least dense layer is the outer crust. Structure of the Geosphere

18. Lesson 2-2 Scientists hypothesize that Earth’s layers formed early in the planet’s history. Ancient Earth was much hotter than it is today and thermal energy melted some of the rock. Gravity pulled denser materials through the melted rock toward Earth’s center, forming layers. Structure of the Geosphere (cont.)

19. Lesson 2-2 Each of Earth’s layers has a different density. Most of the geosphere is made of solid rock, but some of it is made of metal. Structure of the Geosphere (cont.)

20. Lesson 2-2 Scientists know about the makeup of Earth’s deep inner layers from gathering data by analyzing earthquake waves. When the waves travel through Earth, they change speed and direction when they pass through materials with different densities. Structure of the Geosphere (cont.)

21. Layers of the Earth

22. Lesson 2-2 The crust is the thin outer layer of the geosphere.crust Oceanic crust is made of the dense igneous rocks basalt and gabbro.

23. Lesson 2-2 Continental crust, which is thicker but less dense than oceanic crust, is made of igneous, metamorphic, and sedimentary rock.

24. Lesson 2-3 The mantle is the thick, rocky middle layer of the geosphere.mantle The mantle has the largest volume of any layer of Earth, and much of it is made of the rock peridotite.

25. Lesson 2-3 The crust and the uppermost mantle form a brittle outer layer called the lithosphere. lithosphere The weak, partially melted layer of the mantle is called the asthenosphere.asthenosphere

26. Lesson 2-3 The dense, metallic center of Earth is called the core.core The core is made mainly of iron with some nickel and traces of other elements. Due to the high temperatures near the center of the Earth, the outer layer of the core is liquid. Structure of the Geosphere (cont.)

27. Lesson 2-3 Scientists theorize that the movement of liquid iron in the outer core produces Earth’s magnetic field.

28. Lesson 2-3 Inside the outer core is a sphere of solid metal. Despite the scorching heat, the metal in the inner core is not melted. The high pressure from the masses of all Earth’s layers compresses the inner core, making it solid. Structure of the Geosphere (cont.)

29. Bill Nye Video

30. Lesson 2 - VS Minerals are the basic building blocks for materials in the geosphere, including soil, rock, and metal. The three main layers of the geosphere are the crust, the mantle, and the core.

31. Lesson 2 - VS The layers of the geosphere have different densities and chemical compositions.

32. Lesson 2 – LR1 34. What is the color of a mineral’s powder, observed by scratching a mineral across a tile of unglazed porcelain? A.cleavage B.fracture C.luster D.streak

33. Lesson 2 – LR2 A.mantle B.soil C.geosphere D.rock fragments 35. What is the loose, weathered material in which plants grow?

34. Lesson 2 – LR3 A.asthenosphere B.core C.lithosphere D.oceanic crust 36. What is the weak, partially melted layer of the Earth’s mantle?

35. Lesson 2 - Now 37.The inside of Earth is mostly solid rock. 38. Rock makes up minerals. 39. Living things help make soil. Do you agree or disagree?