Rocks

3 Types of Rocks Sedimentary Metamorphic Igneous

Sedimentary Small, Solid pieces of material that comes from rock or living things Formed through a series of processes Erosion-particles carried away by water, wind, ice Deposition- process which sediment settles Compaction- pressing of sediments together Thick layers build and press down on layers under them The weight compacts the layers tightly together Cementation- dissolved minerals crystallize and glue sediment together Dissolved minerals seep into spaces between particles and harden

3 types of sedimentary rocks Clastic -rock fragments squeezed together Grouped by size of rock fragments of which they’re made Ex) shale, sandstone, conglomerate, and breccia Organic- Forms where the remains of plants and animals are deposited in thick layers Ex) coal and limestone Chemical Formed when minerals that are dissolved in a solution crystallize Ex) rock and salt

Sedimentary Rocks This Photo by Unknown Author is licensed under CC BY-SA-NC This Photo by Unknown Author is licensed under CC BY-SA

Sedimentary Rocks can have….. Impressions of: Ripples Raindrops This is because, many times, rocks are carried by water and wind downstream then deposited where compression and cementation occurs. Over time, they form layers and make sedimentary rock. This Photo by Unknown Author is licensed under CC BY-SA

Metamorphic Means “change shape” Rocks where structure, texture, or rock have changed Happens deep within Earth

Textures of Metamorphic Rock Foliated Mineral grains arranged in planes (slate) or bands (gneiss)/aligned The amount of heat and pressure applied to the rock determines which foliated rock it changes or “morphs” into. Ex) slate can become phyllite and then change again into schist Non-foliated Not arranged in planes or bands/minerals not aligned Made of only one or a few minerals Crystals may change in size or composition under heat and pressure (rechrystallization)

Foliated metamorphic rock This Photo by Unknown Author is licensed under CC BY This Photo by Unknown Author is licensed under CC BY This Photo by Unknown Author is licensed under CC BY

Non-foliated Metamorphic Rock This Photo by Unknown Author is licensed under CC BY-SA This Photo by Unknown Author is licensed under CC BY-SA-NC

Metamorphic Rock Structures Metamorphic rock, like sedimentary and igneous, has features that show its history. For a metamorphic rock, it’s called “deformation”. Deformation is the change in rock caused by the force placed on it. Squeezed or stretched This Photo by Unknown Author is licensed under CC BY-NC-ND

Igneous “fire” Classified according to Origin Texture Mineral composition Forms on OR beneath Earth’s surface

Igneous (continued) Extrusive (formed from lava erupted onto Earth’s surface) Intrusive (formed when magma hardens beneath Earth’s surface) Ex) granite Texture is dependent on size and shape of its minerals in its make up

Igneous (continued) Lava that cools rapidly forms fine grained igneous rock with SMALL crystals extrusive Magma that cools slowly forms course grained rock with LARGE crystals intrusive

Lava VS Magma Think of lava as OUTside the Earth’s surface and magma as INside the Earth. Lava that is low in silica forms dark colored rocks (extrusive) Magma that is high in silica forms light colored rocks (intrusive)

Igneous Rock This Photo by Unknown This Photo by Unknown Author is licensed under CC BY This Photo by Unknown Author is licensed under CC BY-SA