Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Provenance (geology) wikipedia , lookup
Marine geology of the Cape Peninsula and False Bay wikipedia , lookup
Large igneous province wikipedia , lookup
Composition of Mars wikipedia , lookup
Geology of Great Britain wikipedia , lookup
Geochemistry wikipedia , lookup
RAP 12/17 pg 94 1. What is a rock? 2. What are the three types of rocks? Topic: Rocks —Chapter 6 6.1 How Rocks Form 6.2 Igneous Rocks 6.3 Sedimentary Rocks 6.4 Metamorphic Rocks How Rocks Form In this section, we will be answering two questions: • What is a rock? • What is the rock cycle? ? What is a rock? =group of minerals bound together. A. Rock Cycle link Rock Cycle Diagram Tape the Rock Cycle onto page 95 in your notebook. Rocks! Metamorphic Sedimentary Igneous B. Rock Types 1. Igneous Rocks a. form from crystallization of magma _____ b. Classification i. Type of magma -Felsic or Granitic or Rhyolitic-rocks are light colored and have high silica content - Mafic rocks are dark colored, have lower silica Felsic or Mafic? Mafic ________ http://www.pitt.edu/~cejones/GeoImages/2IgneousRocks/IgneousCom positions/7Rhyolite/RhyoliteCUp.jpg Felsic ________ http://itc.gsw.edu/faculty/tweiland/gabbro.jpg RAP 12/18 (pg 96) 1. The rock shown is composed primarily of large crystals that were formed by a. Cooling magma b. Compacting shells c. weathering d. faulting 2. What word would describe the type of magma that formed this rock? 3. Why? Classifying Igneous Rocks ii. Grain size or texture - Extrusive rocks are fine-grained. - Intrusive rocks are coarse-grained http://core.ecu.edu/geology/harper/igneous/I15lg.gif Classifying Igneous Rocks • two types: Extrusive -______________-lava cools quickly on Earth’s surface, small crystals (fine-grained) Intrusive -________________-lava cools slowly underground, large crystals (coarse-grained) Intrusive or Extrusive? ___________________ ________________ volcano.und.nodak.edu/.../volcanic_rocks.html http://cc.usu.edu/~sharohl/glossary.html 1. What are the two main ways petrologists classify igneous rocks? 2. If you find a rock that is dark with large grains, what 2 terms would you use to describe it? 3. If you find a light rock with large crystals, what 2 terms would you use to describe it? 4. If you find a light rock with small crystals, what 2 terms would you use to describe it? RAP 1/2 pg. 96 Welcome Back! 1. What two processes would occur to change a metamorphic rock to an IGNEOUS rock? 2. RAP 1/3 pg. 96 1. How do metamorphic rocks form? 2. What two ways are metamorphic rocks classified? (hint-use your essentials) 2. Metamorphic heat a. changed by ___________ and pressure ___________ Types of metamorphism 1. Regional 2. Contact 3. Hydrothermal 1. Regional Metamorphism •affects large regions of the Earth’s crust •most often generated by the compressive forces of mountain building www.gly.fsu.edu/.../ 7_Rocks/7_Rocks_index.htm 2. Contact Metamorphism •occurs when solid rock comes in contact with molten rock solid rock, igneous usually from an ________ intrusion. http://enterprise.cc.uakron.edu/geology/natscigeo/ Lectures/smrocks/metafig.gif 3. Hydrothermal Metamorphism •occurs when very hot water reacts with rock. http://www.uoguelph.ca/~sadura/metref/met19.gif Places where metamorphic rocks can form. Formation of metamorphic rocks Pressure from the weight of overlying rocks b. Textures i. Foliated ii. Nonfoliated i. Foliated • foliated : wavy layers and bands of minerals • high pressure during metamorphism, can cause flat or needle-like crystals to form Gneiss Ex_________: alternating bands of light and dark Gneiss Rocks! Photo courtesy of Claude G. Genest, University of Quebec at http://www.uqtr.uquebec.ca/relief/Terme/Photo/IMG0054.jpg Gneiss Gneiss Mineral Changes During Foliation , Diagram courtesy of Dr. Jürgen Schieber Indiana University, at http://www.indiana.edu/~geol105/images/gaia_chapter_5/foliation.jpg Foliation: Slate Photo courtesy of David L. Ozsvath, University of Wisconsin, at http://www.uwsp.edu/geo/faculty/ozsvath/images/slate.jpg You don’t know schist! Granite schist with garnet porphyroblasts http://www.otago.ac.nz/geology/features/rocks-minerals/schist-gnt.jpg Schist happens! http://www.gc.maricopa.edu/earthsci/imagearchive/DK_MICA_SCHIST_big.jpg ii. Nonfoliated -Blocky crystal shapes Example: Quartzite http://www.physci.wsc.ma.edu/young/pgeol/g eoinfo/images/rocks/quartzite.jpg Shale Slate Phyllite Schist Parent rocks and their metamorphic babies. Do Now 12/17 Using the chart above: 1. Rocks subjected to high temperature and pressure during metamorphism, can form ______. 2. What are two possible parent rocks of gneiss? 3. What does limestone turn into when it undergoes metamorphism? Metamorphic Mini lab RAP 1/4 pg. 98 1. Schist is a type of _______ metamorphic rock. 2. Marble is a type of ______ metamorphic rock. 3. Granite is a type of _______ igneous rock. 4. Pumice is a type of ______ igneous rock. 3. Sedimentary Rocks a.formed from sediments, dissolved minerals, and/or organic materials b. Process of formation: i. Weathering -the breaking down of rock into smaller pieces by physical and chemical processes ii. Erosion -the movement of sediments iii. Lithification- process of turning sediments into rock - compaction of sediments by overlying layers squeezed out excess space and water and cementation occurs as dissolved minerals cement sediment grains together c. Types of Sedimentary Rock 1. Clastic 2. Nonclastic i. Clastic -formed from fragments of other rocks or organic material - classified by size and shape of fragments Sediment Gravel Sand Silt Clay Size 2mm 0.063 – 2mm 0.004 – 0.063mm <0.004mm Rock Example Conglomerate or breccia Sandstone Siltstone Shale Clastic Formation Animation • http://www.classzone.com/books/earth_sci ence/terc/content/visualizations/es0605/es 0605page01.cfm?chapter_no=visualizatio n ii. Nonclastic -form from dissolved minerals coming out of solution by precipitation or evaporation -fine-grained unless they are crystallized Limestone (chalk) Precipitated Mineral: Death Valley RAP 1/7 pg. 98 1. What are the two types of sedimentary rocks? 2. A rock made of pieces of sand would be which type of sedimentary rock? By the end of class I will… 1. Be able to use sedimentary, metamorphic and igneous features to describe past environments. 2. Be able to sort rocks into their rock type based on their characteristics. Tuff • One other by-product of a volcano is tuff. – Tuff is formed when volcanic ash from a volcano is buried and compressed. Rock Features A. Igneous i. Dike – A dike is a sheet of igneous rock that cuts across rock layers vertically at a steep angle. – A dike forms when magma intrudes into angled cracks. – A dike can be hundreds of kilometers long, and anywhere from a centimeters to many meters thick. Igneous Formations ii. Sill – A sill is a sheet of igneous rock that lies parallel to the layers it intrudes. – A sill is formed when magma is forced between, not across, rock layers. – A sill can be hundreds of meters thick, and many kilometers long. Sill iii. Batholiths -large mass of rock that form the core of many mountain ranges. • Batholiths are usually made of granite. • Batholiths are exposed through the uplift and erosion of overlying rock layers. Batholith Igneous Formations • Laccoliths – A laccolith occurs when magma bulges upward to form a dome Laccoliths Igneous Formations • Volcanic Neck – A volcanic neck is left after an inactive volcano erodes – A volcanic neck is the central plug of hardened magma Volcanic Neck What formations do you see? 3 4 1 2 6 5 Sedimentary Features! *** Sedimentary rocks often have evidence of past life, or . Fossils!!! http://alpha.dickinson.edu/departments/geol/rennie/fish_2.jpg Importance of Sedimentary Rocks 1. Sedimentary rocks are important for reconstructing Earth’s past life and climatic conditions. 2. Sedimentary rocks contain valuable resources such as petroleum, coal, iron, uranium, and others. Sedimentary Features! a. Horizontal layering called bedding – Two types of bedding include: 1. Graded bedding 2. Cross-bedding Sedimentary Features! Type 1.Graded bedding : contains progressively coarser sediments toward the bottom layers Sedimentary Features! Type 2.– Cross-bedding: contains inclined layers of sediment moving forward against a horizontal surface http://faculty.uaeu.ac.ae/~afarrag/physical%20geology/cross%20beddi ng%20copy.jpg Ripple Marks with embedded halite crystals. Mudcracks found in Death Valley. www.geosci.unc.edu/.../ SedStructures.html RAP 1/8 pg. 98 1. What is the difference between a dike and a sill? 2. What underlies the Blue Ridge Mountains? By the end of class, I will … 1. Show what I know on my rocks quiz 2. List rock types of each Virginia province using a geologic map and describe how plate tectonics helped form these rocks Rocks in Virginia RAP 1/9 pg 98 1. Extrusive rocks have small grains because they a. harden underground. c. contain rare minerals. b. have a rough mixture. d. cool quickly. 2. Metamorphic rocks result from the a. b. c. d. erosion of rocks recrystallization of rocks cooling and solidification of molten magma compression and cementation of soil particles 3. Lava that cools quickly forms _____ rocks. a. extrusive metamorphic b. extrusive igneous c. intrusive metamorphic d. intrusive igneous