Metamorphic Rocks Aim: How do rocks morph?

1. Metamorphic means… a. “" and “" means to a. “Meta" and “Morph" means to change form b. Any rock can become metamorphic. c. Living organisms undergo metamorphosis to change form at different stages of their lives. (ex. Butterflies and frogs) d. Rocks undergo metamorphism to change form when different processes act upon them.

2. Made by… a. Undergoing extreme heat an pressure b. But NOT enough to melt back to magma

3. Where do they come from? a. Parent rock – the original rock that was changed b. Metamorphic rocks are harder than the parent rock c. Shale (sedimentary) + heat and pressure  Slate  Phyllite  Schist  Gneiss

4. Locations – deep under continents and near magma intrusions Increasing heat and pressure near subduction zone Increasing heat and pressure from depth

5. 2 Types of formation a. Contact metamorphism – rock that touches nearby magma, occurs near igneous intrusions

Magma intrusions… Batholith – big area of “deep rock” Sill – magma forms parallel between rock layers Dike – magma rises through vertical fractures Laccolith – “lake of rock”

What type of rock is….

5. 2 Types of formation b. Regional metamorphism – over large areas, where crust collides or buried deep under continents

6. Categories (based on texture of the rock) a. Foliated – minerals align in bands, usually containing mica, can be fine to coarse texture b. Often the bands look distorted

Foliated Examples…. Schist - Flakes of mica Phyllite – waxy sheen Gneiss – obvious bands

6. Categories (based on texture of the rock) b. Non-foliated – - minerals are not arranged in bands - usually one or two minerals that grow in size and change composition in a process called recrystallization

Nonfoliated Examples….

ESRT Examples: What kinds of metamorphic rock can contain garnet? What kinds of metamorphic rock can contain garnet? How is hornfels formed and from what parent rock? How is hornfels formed and from what parent rock? Which rock is composed of the minerals calcite or dolomite? Which rock is composed of the minerals calcite or dolomite? What is the grain size of slate? What is the grain size of slate? What is quartzite formed from? What is quartzite formed from?

Animations of metamorphic formation ience/terc/content/visualizations/es0607/e s0607page01.cfm?chapter_no=visualizatio n ience/terc/content/visualizations/es0607/e s0607page01.cfm?chapter_no=visualizatio n ience/terc/content/visualizations/es0607/e s0607page01.cfm?chapter_no=visualizatio n ience/terc/content/visualizations/es0607/e s0607page01.cfm?chapter_no=visualizatio n ience_up_close/607/deploy/interface.html ience_up_close/607/deploy/interface.html ience_up_close/607/deploy/interface.html ience_up_close/607/deploy/interface.html

Do NOW: Metamorphics

Type of rock? Order of events?

IgneousSedimentaryMetamorphic Texture – intrusive or extrusive Clastic – sediments compacted and cemented Foliated – banding, sometimes distorted Intergrown crystals Layers Shiny flakes of mica Vesicular – gas holes Organic – coal or fossils Nonfoliated Mafic or felsic Chemical – precipitates or evaporites

Online practice: games/rocks-game.php games/rocks-game.php games/rocks-game.php games/rocks-game.php