Monday, March 4, Day 6 Goal: Describe 3 types of rocks 1.Take out HW: Rocks notes 2.Write HW: Do vocabulary and hypothesis for Rock Cycle lab; RILS questions due Wednesday WARM UP 3/4- What is a “Rock?” Define. What are the 3 types of rocks called? Rocks: Natural Materials made of one or more minerals Igneous rocks (FIRE ROCKS) form by cooling and hardening of hot liquid rock Igneous rocks The slower the magma cools, the LARGER the crystal size. Extrusive Igneous Rocks Form when lava cools quickly on earth’s surface Examples: Grain Size: Obsidian (volcanic glass) Glassy-no grains Basalt(most common) Less than 1 mm Rhyolite Less than 1 mm Extrusive Igneous Rocks Earth's Most Abundant Bedrock: Basalt Basalt forms more of Earth's surface than any other rock type. Most areas in ocean basins are basalt. May be on land from lava flows, too. Igneous Rocks Obsidian Obsidian on the side of a volcano Exrusive Igneous Rock - Obsidian Obsidian was used to make knives, arrow heads, spear points, scrapers and many other weapons and tools Intrusive Igneous Rocks Forms when magma cools slowly underground Example Grain Size Granite 1-10mm (coarse grained) Most abundant intrusive rock on Earth’s continents. Forms the core of many mountain ranges. Intrusive Igneous Rocks Granite is used to make many objects Granite is also well-known from its many world- famous natural exposures. These include: Stone Mountain, GA; Mount Rushmore, SD Intrusive Igneous Rocks Example Grain Size Pegmatite Greater than 10mm Very coarse grained) Intrusive Igneous Rocks Texture: coarse-grained Slowly cooling magma forms coarse- grained rock with large crystals REMEMBER: The slower it cools, The larger the crystals! Ex: granite Uses of Igneous Rock Statues, Public Buildings - Granite Uses of Igneous Rocks Cobblestone streets, kitchen countertops – Granite Uses of Igneous Rock Basalt - Gravel for construction Obsidian - Sharp tools for cutting and scraping (Native Am!), Starting vegetable gardens (fertilizer) – it’s called Perlite, which is formed from heating Obsidian Add to your notes: Clues to Identify Igneous Rocks May have crystals, can often be seen easily by eye Crystals are not in band-like patterns If no crystals; may appear glassy or with air pockets how ingneous rocks are formed Mt. St. Helens, March 198 eruption sent plume of volcanic ash 12 miles and spread for 10 hours. It drifted around the globe in about 2 weeks. igneous rock formation summary Rocks, Rocks, and more Rocks - Sedimentary Sedimentary rocks are classified by the types of sediments that make up the rock What are sediments? – Small, solid pieces of material that come from rocks or living things like bones, leaves, stems, etc Sizes of Sediments How do they form? Sediments are carried by wind or water are deposited (dropped). Sediments accumulate in layers and harden into rocks. Those smashed sediments can form into layers like the ones shown. Rock Name Particles Shale ---------------------------- Clay Siltstone------------------------ Silt Sandstone --------------------- Sand Conglomerate --------------- Pebbles Limestone--- Calcite from Seashells Uses: What things have been made from Sedimentary Rock? Flint: Arrowheads Sandstone: Buildings, THE WHITE HOUSE Limestone: Blocks & slabs for building, making cement Uses: What things have been made from Sedimentary Rock? Coal: Electricity generation, heat, fuel Halite: Winter road treatment, Seasoning Possibly the coolest thing about Sedimentary Rock… FOSSILS are always found in Sedimentary Rock ONLY! Why??? Write on top of notes: Clues for Sedimentary Rock Distinct parallel layers Made of rock fragments or one type of sediment (sand, clay…) Shows evidence of life, ex. Fossils, Shells Often dull or earthy http://www.youtube.com/watch?v=9Df4CtlZ0AQ#t=29 Rocks, Rocks, and More Rocks Metamorphic Metamorphic means Change!! How do Metamorphic rocks form? Igneous or sedimentary rocks are changed by heat, pressure or both NEVER ACTUALLY MELT Rocks can be pushed down toward the heat of the mantle or form along plate boundaries Original Rock New Metamorphic Rock Shale Slate Shale (sedimentary) changes to Slate when heated & squeezed by pressure. Original Rock New Metamorphic Rock Granite Gneiss Granite (Igneous) changes to Gneiss when heated & squeezed by pressure. metmorph formation animation Original Rock New Metamorphic Rock Sandstone Quartzite When Sandstone (Sedimentary) is under extreme heat & pressure, Quartzite will form. Original Rock New Metamorphic Rock Limestone Marble Uses of Metamorphic Rocks Slate: Old fashioned chalkboards, roofs, walkways, trim on buildings Marble: *Sculptures – (Lincoln Memorial in Washington D.C.) * Buildings Add to bottom of notes: Clues for Metamorphic Rocks Bands of color Signs of bending and distortion Mineral crystals will be flattened How are the 3 rock types related? THE ROCK CYCLE! interactive cycle bp rock cycle Questions… What processes form Igneous Rocks? How are the 2 types of Igneous Rock different? How can we use Igneous Rocks? How have they been used in the past? Can you describe the most common Intrusive Ign. Rock? Where is it commonly found? Can you describe the most abundant Extrusive Ign. Rock? What area on Earth is mostly made of this type? The Rock To the tune of Row, Row, Row Your Cycle Song Boat Sedimentary rock has been formed in layers Often found near water sources fossils and decayers Then there’s Igneous rock, here since Earth was born Magma, lava cooled and hardened that’s how it is formed These two kinds of rocks can also be transformed With pressure, heat, deep in Earth Metamorphic they’ll become .