Rocks, Minerals and the Rock Cycle Tanya Furman, Department of Geosciences, Pennsylvania State University General Comments • I hate the rock cycle as taught typically – MemorizaCon – Black box / no processes • I hate rocks and minerals as taught typically – MemorizaCon – Nothing familiar to the student • I’ll propose a contextualized approach: Plate tectonics This is THE BEST WAY I know to teach the rock cycle. When I added this lab to my classes, test scores soared! Have students bring wax crayons from home, which are your building blocks for a great simulation of the entire rock cycle! CAPSULE: Weathering: shave crayons, Erosion: pick up crayons and move them, Deposition: drop crayon shavings onto aluminum foil & fold into packet. Compaction to form Sedimentary Rocks: put packet into vise & apply light pressure. Heat & Pressure to form Metamorphic Rocks: put packet into vise & apply heavy pressure. Melting and Cooling to form Igneous Rocks: melt crayon shavings, pour over ice cubes to form "pumice," into ice water to form "obsidian," and over warm/hot water to form intrusive rocks, such as "diorite" and granite." THIS PROCESS MAKES SENSE TO NORMAL PEOPLE InstrucConal Barriers to Overcome • • • • • • • Volcanoes, earthquakes = dynamic planet Mountains = staCc landforms Rock / mineral kits easy to obtain Vocabulary, idenCficaCon easy to assess Process understanding more challenging IntegraCon of ideas more challenging Life contexts challenging but criCcal Making a context for learning • • • • Students of all ages can make observaCons Some observaCons are important Some observaCons are not important Geology is about the explaining the natural world… even if you live in a city Geologic map of Pennsylvania Topographic map of Pennsylvania Working with maps builds curiosity* • What paUerns do you see on these maps? • What do the colors represent? • Do geologic-‐map colors translate uniformly into topographic-‐map colors? • Why are some rocks at high elevaCon? • Why are some rocks at low elevaCon? • What are the rocks and elevaCon at home? * And lots of other skills, too! What do Pennsylvania’s rocks say? • Most of the bedrock is sedimentary • Small porCons of the state are igneous • Very small porCons have metamorphic rock (let’s think about that first statement) • Most of the bedrock is sedimentary… – There used to be warm ocean over Pennsylvania – Where did the ocean go? – Where did the mountains come from? – When did all of this geology happen? Resources on this Topic • Tectonic Geomorphology: Weathering and Erosion • An InstrucConal Unit on the Marcellus Shale for Middle School Students • Mountain building using GeoMapApp All curricula available in the PAESTA Classroom hUp://paesta.psu.edu/classroom Comparing Ancient / Modern Mountains Appalachians Himalayas Think about rocks in context • Sedimentary rocks require: – Water (river, seashore, deeper ocean) – Topography • Igneous rocks require: – Tectonic se_ng with volcanism – Divergent plate se_ng (ocean or conCnent) – Hot spot se_ng (ocean or conCnent) • Metamorphic rocks require: – Tectonic se_ng with mountain-‐building – Convergent plate se_ng (ocean/conCnent) Resources on these Topics • Grand Canyon straCgraphy • Hawaii / Indonesia • SubducCon zone geometry All curricula available in the PAESTA Classroom hUp://paesta.psu.edu/classroom Rock types record tectonic se_ng Sedimentary Igneous Sedimentary Igneous Metamorphism occurs here Ancient rocks record Earth history • Limited range of possible tectonic se_ngs • Rocks exist over large spaCal scales (mostly) Sedimentary Pennsylvania New York Georgia Metamorphic Igneous Pennsylvania’s mountains: Folded sedimentary rocks 400-‐500 million years old Metamorphic rocks visible north (VT) and south (VA, NC) People o6en wonder why we can find metamorphic rocks at the surface of the planet. Teaching PA Rocks & Minerals • Explore maps for distribuCon of rock types – Rock types are found in specific areas – We learn geological history from those rocks – We learn human history from those rocks • Discuss rock types associated with resources – Energy resources (Marcellus shale gas, oil, coal) – Building and farming resources • Describe mountain building as a process – Mountains indicate where an ocean closed – Mountains eventually erode over Cme The Rock Cycle can be Helpful • Plate tectonics provides the missing process pieces for rock cycle representaCons Closing Comments • • • • Rocks, minerals and the rock cycle are not trivial Good vehicle for learning Pennsylvania history Good vehicle for learning geography The vehicle for understanding Earth processes
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