Transcript Rocks
*observe color and texture to determine mineral composition Texture- look & feel of rock’s surface Grains- particles of minerals or other rocks. Size Shape Pattern No visible grain Origin • Igneous • Sedimentary • Metamorphic *Most abundant on Earth *Formed from cooling of molten rock *Classified as intrusive or extrusive Animation http://www.classzone.c om/books/earth_scienc e/terc/content/investiga tions/es0603/es0603pa ge05.cfm Intrusive *Cooling of magma below Earth’s surface *slow rate of cooling *Large mineral crystals *Coarse-grained texture *Examples: granite, gabbro, diorite, pegmatite Extrusive *Cooling of lava on Earth’s surface *Fast rate of cooling *Small or no mineral crystals *fine-grained texture if small crystals *glassy texture if no crystals *Examples: basalt, obsidian, pumice, scoria, rhyolite *Some rocks begin to cool deep underground when suddenly magma is forced to the earth’s surface. This rock will have large mineral grains surrounded by fine mineral grains. This texture is called porphyry. *lava low in silica usually forms darkcolored rocks such as basalt *magma that is high in silica usually forms light-colored rocks such as granite http://player.discoveryeducation.com/in dex.cfm?guidAssetId=24F28C84-AB7F4F93-92376FA426079138&blnFromSearch=1&produ ctcode=US Sediment- small, solid pieces of material that come from rocks or living things. 1. Rock fragments and sediments are moved by erosion. 2. Erosion slows down and sediments are deposited. 3. Layers of sediments build up and they become compacted into rock. 4. Minerals in the rock dissolve in water. The dissolved minerals seep into spaces between the sediments and act like a glue, cementing them together. http://www.classzone.com/books/earth_science/terc/ content/visualizations/es0605/es0605page01.cfm?ch apter_no=visualization 1. clastic- formed when rock fragments are squeezed together. shale- clay particles Sandstone sandstone- sand comglomerate- mixture of rock fragments of different sizes Conglomerate Shale 2. organic- from remains of living matter. coal- swamp plants limestone- shells or skeletal remains of living things Limestone Coquina Coal 3. chemical- form when minerals dissolved in solution crystallize. limestone rock salt (halite) Limestone Halite http://player.discoveryeducation.com/in dex.cfm?guidAssetId=36566049-E79142CF-8FE2494F33FA9983&blnFromSearch=1&produ ctcode=US *Formed from heat and pressure deep beneath Earth’s surface. *Form from igneous, sedimentary or other metamorphic rocks. *Results in a change in a rocks texture, crystal structure & mineral content. *Heat comes from rock being pushed down close to the mantle at converging plate boundaries, or by magma rising through the crust. *The deeper the rock, the more pressure. *Classified by the arrangement of the grains in the rock (foliated or nonfoliated) *Foliated- mineral grains are arranged Animation in parallel bands Ex: slate, gneiss http://www.classzone.com/books/earth_science/terc/content/visu alizations/es0607/es0607page01.cfm?chapter_no=visualization Shale Slate Gneiss Granite *Nonfoliated-mineral grains are arranged randomly. Ex: marble, quartzite Limestone Marble Quartzite Sandstone http://player.discoveryeducation.com/in dex.cfm?guidAssetId=CDDA0692-8F8B461C-9F0486D58B7A2A03&blnFromSearch=1&prod uctcode=US Rock Cycle- series of processes on Earth’s surface and inside the planet that slowly change rocks from one kind to another. Constructive and destructive forces move rocks through the cycle. http://player.discoveryeducation.com/in dex.cfm?guidAssetId=4B67887F-E1F14992-A9E11FC91726A237&blnFromSearch=1&prod uctcode=US http://www.classzone.com/books/earth_ science/terc/content/investigations/es06 02/es0602page02.cfm http://www.phschool.com/atschool/phsc iexp/active_art/rock_cycle/index.html