2. Objectives: Describetwo ways rocks have been used by humans. Describefour processes that shape Earthâs features. Describe how each type of rock changes into another type as it moves through the rock cycle. List two characteristics of rock that are used to help classify it.
3. The Rock Cycle Rock naturally occurring solid mixture of one or more minerals or organic matter New rock forms from old rock material constantly 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
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5. The Value of Rock Important natural resource for as long as humans have existed Ancient and modern civilizations used granite, limestone, marble, sandstone, slate and other rocks as construction materials Important ingredient in concrete and plaster, both of which are commonly used in construction Capitol Building Pyramids and Sphinx, Giza, Egypt
7. Processes that Shape the Earth Certain geological processes make and destroy rock These processes Shape the features of our planet Influence the type of rock that is found in certain areas Grand Canyon, Arizona Hawaiian Islands
8. Weathering, Erosion, and Deposition Weathering Process in which water, wind, ice, and heat break down rock Important because it breaks down rock into fragments of which sedimentary rock is made
9. Erosion Process by which wind, water, ice, or gravity transports soil and sediment from one location to another Ice Wind Water
11. Heat and Pressure Sedimentary rock can also form when buried sediment is squeezed by the weight of overlaying layers of sediment If the temperature and pressure are high enough, the rock can change into metamorphic rock If the rock gets hot enough to melt, this creates the magma that eventually cools to form igneous rock
12. How the Cycle Continues Buried rock is exposed at the Earthâs surface by a combination of uplift and erosion Uplift Movement within the Earth that causes rocks inside the Earth to be moved to the surface When uplifted rock reaches the Earthâs surface, weathering, erosion, and deposition begin
14. Rock Classification Three main classes Igneous rock Sedimentary rock Metamorphic rock Each class of rock can be divided further, based on differences in the ways rocks form granite obsidian shale sandstone slate marble
15. Igneous rock can be divided again based on whether the magma from which it forms cools on the Earthâs surfaceor below ground Sedimentary and metamorphic rocks are also divided into smaller groups Scientists study rocks in detail using two important criteria: Composition Texture
16. Composition Chemical makeup of a rock Can describe either the minerals or other materials in the rock Texture Quality of a rock that is based on the sizes, shapes, and positions of the rockâs grains 95% calcite limestone 5% aragonite siltstone sandstone Conglomerate Fine-grained medium-grained Coarse-grained
