iclicker assignments pick yours up 001 Abreu 003 Agena 004 Albert 006 Araki 091 Atiburcio 008 Buck 082 Byce 011 Clements 012 Colle

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1 iclicker assignments pick yours up 001 Abreu 003 Agena 004 Albert 006 Araki 091 Atiburcio 008 Buck 082 Byce 011 Clements 012 Colle 013 Comilla 014 Cuadrado 015 Dang 016 Duncan 080 Fujihara 018 Ganther 021 Guerrero 022 Haupt 025 Hedden 027 Higa 028 Hipolito 090 Inserra 031 Jadu 030 Johnasen 034 Kaaihue 036 Keanini-White 037 Kipi 089 Lee 039 Lockett 040 Manion 041 McTigue 042 Meyers 043 Mitamura 044 Morikawa 047 Nassiri 048 Ota 088 Pavao 067 Peahu 068 Santiago 069 Shigemitsu 070 Soares 084 Teramura 086 Tomaszek 073 Wu 074 Yamamoto 075 Yanagi 077 Yokota 079 Zoller

2 Lecture 8: Metamorphic Rocks! 1. Read: Chapter 9 2. Homework #8 due Tuesday 12pm 3. Midterm #1 Thursday, September 24 iclicker assignments pick yours up 001 Abreu 003 Agena 004 Albert 006 Araki 091 Atiburcio 008 Buck 082 Byce 011 Clements 012 Colle 013 Comilla 014 Cuadrado 015 Dang 016 Duncan 080 Fujihara 018 Ganther 021 Guerrero 022 Haupt 025 Hedden 027 Higa 028 Hipolito 090 Inserra 031 Jadu 030 Johnasen 034 Kaaihue 036 Keanini-White 037 Kipi 089 Lee 039 Lockett 040 Manion 041 McTigue 042 Meyers 043 Mitamura 044 Morikawa 047 Nassiri 048 Ota 088 Pavao 081 Peahu 068 Santiago 069 Shigemitsu 070 Soares 084 Teramura 086 Tomaszek 073 Wu 074 Yamamoto 075 Yanagi 077 Yokota 079 Zoller

3 Learning Objectives (LO) Lecture 8: Metamorphic Rocks" ** Chapter 9 **" What we ll learn today:" 1. Describe the process of metamorphism" 2. Compare/contrast regional and contact metamorphism" 3. Describe the role of water in metamorphism" 4. Describe the metamorphic grades and how they are identified "

4 Metamorphosis = a transformation (in appearance, character ) migmatite

5 Fundamental Rock Types Igneous Rocks: form when magma solidifies Sedimentary Rocks: form when sediment becomes cemented into solid rock Metamorphic rocks: form when heat, pressure, or hot water alter any preexisting rock

6 The Rock Cycle

7 Metamorphic Rocks Metamorphism: process of rising temperature & pressure, or changing chemical conditions, that transforms rocks & minerals Ways: 1. Heat 2. Pressure 3. Fluid activity

8 Metamorphic rocks are composed of sedimentary, igneous, or metamorphic minerals that have recrystallized Marble from Carrara, Italy

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10 Metamorphic rocks form when crustal rocks are exposed to heat and pressure

11 Metamorphism: Temperature Heat a mineral: 1. becomes unstable at higher temperatures 2. atoms recombine to form new mineral bake Clay (soft) Ceramic (hard)

12 Metamorphism: Pressure Apply a higher pressure to mineral: 1. becomes unstable at higher pressures 2. atoms recombine to form new mineral

13 Metamorphism: Fluid Activity Interaction with fluids: 1. Fluids carry new chemicals to mineral 2. Chemicals react to form new mineral Water Olivine Basalt Serpentinite

14 Metamorphic Grade Def.: intensity of metamorphism that formed the rock As you go deeper in the Earth, it gets hotter, pressure increases Rocks evolve through a sequence of metamorphic grades

15 Metamorphic Grade Metamorphism tells us a rock s tectonic history slate phyllite schist gneiss

16 Index Minerals tell us a rock s temperature and pressure history They serve as geothermometers and geobarometers

17 Metamorphic Changes Textural changes: grain size, shape, alignment - Deformation: tectonic forces that squeeze rock - Foliation: parallel alignment of minerals Deformation Foliation Mineralogical changes: formation of new minerals Quartz sandstone Quartzite

18 Types of Metamorphism Contact Regional separate processes, but can same time Hydrothermal

19 Contact Metamorphism = Thermal

20 Contact Metamorphism when magma comes in contact with basement rock at shallow depth and heats it up magma also brings reactive fluids

21 Contact Metamorphism Limestone changed into marble & various types of minerals Contact metamorphism forms: Quartzite Hornfels Marble

22 Regional Metamorphism When major crustal movements build mountains and deform rocks Rocks deformed & heated at same time regional metamorphism

23 Regional Metamorphism Usually occurs across wide areas.

24 Regional metamorphism often results from directed stress Directed Stress: Pressure is greatest in one direction

25 Directed stress results in folding of rock layers

26 Directed stress also results in foliation of rock texture

27 Regional Metamorphism = stress = foliation

28 Magma + silca-rich liquid (with iron) = amethyst crystals In addition to heat and pressure, chemically active fluids transport heat and promote recrystallization

29 Hydrothermal Metamorphism Heat and pressure release chemically active fluids from rocks. These fluids transport heat, ions dissolve in hot water Reactions promote recrystallization Water Basalt Serpentinite

30 Hydrothermal Metamorphism Metasomatism can also produce gold, silver and other valuable ores. Vein of gold ore in metamorphic rock

31 Gold and silver from a mine near Oatman, AZ:

32 Common Metamorphic Rocks Slates Phyllite Schists Gneisses

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34 Common Metamorphic Rocks sandstone quartzite

35 Common Metamorphic Rocks limestone marble

36 Common Metamorphic Rocks shale schist

37 Common Metamorphic Rocks claystone slate

38 Metamorphic rocks are used as building materials Slate roof schist marble countertops

39 Geology Kitchen: Metamorphism

40 Plate Movement Powers the Rock Cycle Igneous Sedimentary Metamorphic

41 Action Items for Tuesday, Sept Read Chapter 9 2. Complete homework assignment #8 What you should know from today:" 1. Describe the process of metamorphism" 2. Compare/contrast regional and contact metamorphism" 3. Describe the role of water in metamorphism" 4. Describe the metamorphic grades and how they are identified "