Chapter 4- Rocks: Mineral Textures By Samantha Pereira

Chapter Summary This chapter will tell you about the rock cycle, and the different types of rock and how they are formed. This chapter will tell you about the rock cycle, and the different types of rock and how they are formed.

Lesson 1: The Rock Cycle

Lesson 1 Vocabulary Rock cycle- the series of processes in which a rock forms, changes from one type to another, is destroyed, and forms again by geological processes Rock- a naturally occurring solid mixture of one or more minerals or organic matter Erosion- the process by which wind, water, ice, or gravity transports soil and sediment from one location to another Deposition- the process in which material is laid down Composition- the chemical makeup of a rock; describes either the minerals or other materials or other materials in the rock Texture- the quality of a rock that is based on sizes, shapes, and positions of the rock’s grains

Summary of Lesson Rock has been an important natural resource as long as humans have existed. Early humans used rock to make tools. Ancient and modern civilizations have used rock as a construction material. Rock has been an important natural resource as long as humans have existed. Early humans used rock to make tools. Ancient and modern civilizations have used rock as a construction material. Weathering, erosion, deposition, and uplift are all processes that shape the surface of the Earth. Weathering, erosion, deposition, and uplift are all processes that shape the surface of the Earth. The rock cycle is the continual process by which new rock forms from old rock material. The rock cycle is the continual process by which new rock forms from old rock material. The sequence of events in the rock cycle depends on processes, such as weathering, erosion, deposition, pressure, and heat, that change the rock material. The sequence of events in the rock cycle depends on processes, such as weathering, erosion, deposition, pressure, and heat, that change the rock material. Composition and texture are two characteristics that scientists use to classify rocks. Composition and texture are two characteristics that scientists use to classify rocks. The composition is determined by the size, shape, and positions of the grains that make up a rock. The composition is determined by the size, shape, and positions of the grains that make up a rock.

Lesson 2: Igneous Rock

Lesson 2 Vocabulary Intrusive igneous rock- rock formed from the cooling and solidification of magma beneath the Earth’s surface Extrusive igneous rock- rock that forms as a result of volcanic activity at or near the Earth’s surface

Summary of Lesson Igneous rock forms when magma cools and hardens. Igneous rock forms when magma cools and hardens. The texture of igneous rock is determined by the rate at which the rock cools. The texture of igneous rock is determined by the rate at which the rock cools. Igneous rock that solidifies within Earth’s surface is intrusive. Igneous rock that solidifies within Earth’s surface is intrusive. Shapes of common igneous intrusive bodies include batholiths, stocks, sills, and dikes. Shapes of common igneous intrusive bodies include batholiths, stocks, sills, and dikes.

Lesson 3: Sedimentary Rock

Lesson 3 Vocabulary Strata- layers of rock Stratification- the process in which sedimentary rocks are arranged in layers

Lesson Summary Sedimentary rock forms at or near the Earth’s surface. Sedimentary rock forms at or near the Earth’s surface. Clastic sedimentary rock forms when rock or mineral fragments are cemented together. Clastic sedimentary rock forms when rock or mineral fragments are cemented together. Chemical sedimentary rock forms from solutions of dissolved minerals and water. Chemical sedimentary rock forms from solutions of dissolved minerals and water. Organic limestone forms from the remains of plants and animals. Organic limestone forms from the remains of plants and animals. Sedimentary structures include ripple marks, mud cracks, and raindrop impressions. Sedimentary structures include ripple marks, mud cracks, and raindrop impressions.

Lesson 4: Metamorphic Rock

Lesson 4 Vocabulary Foliated- the texture of metamorphic rock in which the mineral grains are arranged in planes or bands Nonfoliated- the texture of metamorphic rock in which the mineral grains are not arranged in planes or bands

Lesson Summary Metamorphic rocks are rocks in which the structure, texture, or composition has changed. Metamorphic rocks are rocks in which the structure, texture, or composition has changed. Two ways rocks can undergo metamorphism are by contact metamorphism and regional metamorphism. Two ways rocks can undergo metamorphism are by contact metamorphism and regional metamorphism. As rocks undergo metamorphism, the original minerals in rock change into new minerals that are more stable in new pressure and temperature conditions. As rocks undergo metamorphism, the original minerals in rock change into new minerals that are more stable in new pressure and temperature conditions. Foliated metamorphic rock has mineral crystals aligned in planes or bands, whereas nonfoliated rocks have unaligned mineral crystals. Foliated metamorphic rock has mineral crystals aligned in planes or bands, whereas nonfoliated rocks have unaligned mineral crystals. Metamorphic rock structures are caused by deformation. Metamorphic rock structures are caused by deformation.

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