Monday February 6, 2012 (The Rock Cycle; Igneous Rocks) The Launch Pad Monday, 2/6/12 Identify the type of rock in each picture. sedimentary metamorphic igneous Assignment Currently Open Summative or Formative Date Issued Date Due Date Into Grade Speed Last Day Lab Fossils F4 1/12 Quiz 16 S3 1/201/231/202/6 Lab Rock Identification 1/24 Video Quiz Rocks and Mineral 1/26 Quiz 17 S4 1/27 2/10 Activity Rock and Mineral Properties F 1/30 Quiz 18 S5 2/3 2/17 Announcements I will be available after school today until 4:45 Latest Newsm/releases/2008/10/ htm Arctic Sea Ice Is Suddenly Getting Thinner As Well As Receding. Read article here: The Rock Cycle The Rock Cycle is the Earth system that depicts the interrelationships among the three general categories of rocks. The Rock Cycle Molten magma in the upper mantle rises into the lithosphere, where it cools and crystallizes to form igneous rock. Over time, this igneous rock is weathered (eroded) by liquid water, ice and/or wind into sediment. The sediment is eventually deposited in layers, which are compacted by the weight of the layers above. The process of cementation forms sedimentary rocks. This is called lithification. Over time heat from below and pressure from above can cause these sedimentary rocks to change form and change into metamorphic rock. If subjected to continuing heat and pressure, the metamorphic rocks can melt to become magma again and the cycle begins again. The Rock Cycle The full cycle does not always take place due to shortcuts or interruptions. Sedimentary rock melts Sedimentary rock is weathered Igneous rock is metamorphosed Metamorphic rock weathers The Rock Cycle Check Which types of rocks can be weathered into sediment? Igneous, metamorphic, or even sedimentary rocks can all be weathered into sediment. Describe the process of lithification. Lithification occurs when sediment is deposited in layers, which are compacted by the weight of the layers above. The pressure on the sediment layers cement them into sedimentary rocks. Igneous rocks form as magma cools and crystallizes. Rocks formed on the surface are formed from lava (a material similar to magma, but without gas) are called volcanic or extrusive rocks. Rocks that are formed inside the Earth are called plutonic or intrusive rocks. When magma crystallizes, its ions are arranged into orderly patterns. The size of the crystal is determined by the rate of cooling. Slow cooling rates form large crystals. Fast cooling rates form microscopic crystals. Very fast cooling rates form glass. Classification of igneous rocks is based on the rocks texture and mineral constituents. Texture refers to the size and arrangement of the crystals in the rock. Types of igneous rock textures: Coarse-grained slow rate of cooling Fine-grained fast rate of cooling graniteandesite Classification of igneous rocks is based on the rocks texture and mineral constituents. Texture refers to the size and arrangement of the crystals in the rock. Types of igneous rock textures: Glassy very fast rate of cooling Porphyritic (two crystal sizes) two rates of cooling obsidianpumice porphyritic granite Figure 3.5 Figure 3.5 A Figure 3.5 B Figure 3.5 D Glassy (obsidian) Figure 3.7 Figure 3.8 pumice