BY Basic processes and major rocks types: - Metamorphic - Sedimentary - Igneous visual.ly/rock-cycle Rock cycle - an idealized cycle of processes undergone by rocks What drives the rock cycle? Any type of rock can change (igneous and metamorphic rocks) External processes powered by energy from the Sun (sedimentary rocks) Earth’s internal heat - subduction melting and metamorphism (References:) - geolsoc.org.uk - scienceblogs.com - lauracrandler.com - rgsenergy.com - weathering, erosion and deposition - Sun moves the wind and water at the surface with enough force to break rocks apart into sand and other types of sediment Metamorphosis (to change form) Metamorphic Rocks Process: intense heat and pressure Pressure 500 bars – 1200 bars Heat 200°C - 850°C Why (References:) - learner.org - mineralogy4kids.org - 1.bp.blogspot.com - upload.wikimedia.org is it important? - aids in the interpretation of the plate tectonic setting in which the metamorphism took place - reconstruction of the geological history How does it happen? - temperature and pressure conditions (metamorphic environment) in which the rock was formed - composition of the original unmetamorphosed, rock This process happens under the surface of the Earth Characteristics (ribbonlike layers, crystals) Metamorphic Rocks Examples (phyllite and marble) (Gneiss) (References:) - sacgeologymuseum.files.wordpress.com/2013/09/gneiss.jpg - sacgeologymuseum.files.wordpress.com/2013/09/anthracite-coal.jpg - sacgeologymuseum.files.wordpress.com/2013/09/phyllite-luster-andmini-undulations.jpg - sacgeologymuseum.files.wordpress.com/2013/09/marble2.jpg - learner.org Phyllite Intense heat and pressure results in ribbon like layers Before, phyllite was slate (also a metamorphic rock) Marble (Anthracite Coal) Shiny crystals, formed by minerals Marble used to be limestone (a sedimentary rock) (References:) - cdn.shopify.com - getfillings.com - learner.org - mineralogy4kids.org Sedimentation (to settle) Sedimentary Rocks Process: weathering, erosion, deposition, lithification (Schleie) Why is it important? - tell us what Earth's surface was like in the geologic past, can contain fossils about the animals, plants or show the climate in an area - because they may contain water for drinking or oil and gas to run our cars and heat our homes How does it happen? - forces of wind, rain, snow, and ice combine to break down and carry away rocks exposed at the surface. - particles eventually come to rest and become hard rock Characteristics (fairly soft, layers of sediment) Sedimentary Rocks Examples (conglomerate and sandstone) (Quartz Sandstone) (References:) - sacgeologymuseum.files.wordpress.com/2013/09/quartz-sandstonebeach.jpg - sacgeologymuseum.files.wordpress.com/2013/09/chert.jpg - sacgeologymuseum.files.wordpress.com/2013/09/conglomerate.jpg - sacgeologymuseum.files.wordpress.com/2013/09/arkose.jpg - learner.org Conglomerate Generally, fairly soft may break apart or crumble easily composed of rounded gravel, pebbles, cobbles, or boulders along with smaller rock pieces. Sandstone (Arkose) (Chert) Sediment accumulates in layers and over time hardens a type of sandstone containing at least 25% feldspar Latin word: ignis (fire) Igneous Rocks Process: magma, lava, crystallization (References:) - 2.chilton.k12.wi.us - bc.outcrop.com - svs.gsfc.nasa.gov - previews.123rf.com - learner.org How does it happen? - formed when magma cools and hardens, magma cools inside the earth, and other times it erupts onto the surface from volcanoes (lava) - lava cools quickly, no crystals form, looks shiny, glasslike, gas bubbles may be trapped rock during cooling, leaving tiny holes and spaces in the rock. Why is it important? - any rock can transform to any rock, but igneous rocks are the very first rocks on Earth. In other words, they are the origin of rocks. Characteristics (shiny surface, gas bubbles) Igneous Rocks Examples (diorite and basalt) (Obsidian) (References:) - sacgeologymuseum.files.wordpress.com/2013/09/obsidian.jpg - sacgeologymuseum.files.wordpress.com/2013/09/pumice.jpg - sacgeologymuseum.files.wordpress.com/2013/09/diorite.jpg - sacgeologymuseum.files.wordpress.com/2013/09/basalt.jpg - learner.org Diorite lava cools quickly, no crystals form and rock looks shiny, glasslike Consists of plagioclase, feldspar, and hornblende or other mafic minerals Basalt (Pumice) gas bubbles are trapped during cooling , leaving tiny holes and spaces composed largely of plagioclase with pyroxene and olivine Thank you for listening! I am ready to answer your questions. (Topic: Rock Cycle) REFERENCES: Slide 1 - Introduction - visual.ly/rock-cycle Slide 2 - What Drives the Rock Cycle? - geolsoc.org.uk - scienceblogs.com - lauracrandler.com - rgsenergy.com Slide 3 - Metamorphic Rocks Process - learner.org - mineralogy4kids.org - 1.bp.blogspot.com - upload.wikimedia.org Slide 4 - Metamorphic Rock Examples - sacgeologymuseum.files.wordpress.com - learner.org Slide 5 - Sedimentary Rock Process - cdn.shopify.com - getfillings.com - learner.org - mineralogy4kids.org Slide 6 - Sedimentary Rock Examples - sacgeologymuseum.files.wordpress.com - learner.org Slide 7 - Igneous Rock Process - 2.chilton.k12.wi.us - bc.outcrop.com - svs.gsfc.nasa.gov - previews.123rf.com - learner.org Slide 8 - Metamorphic Rock Examples - sacgeologymuseum.files.wordpress.com - learner.org Most helpful/most used sources: - learner.org - mineralogy4kids.org - geolsoc.org.uk