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Igneous Rocks Sedimentary Rocks Metamorphic The Rock Cycle Chapter 5 and 6 page 110 - 152
Rocks • Rock: any solid mass of mineral or mineral-like matter that occurs naturally – Can be a single mineral or a mixture • Three major types of rocks: igneous, sedimentary, & metamorphic. – Differ in the way they were formed
http: //www. youtube. com/watch? feat ure=player_detailpage&v=ihf. KNRdl E 2 E
Create a graphic organizer that defines, describes, illustrates, and gives examples each type of rock. Pg 118 - 151 Example Igneous DEFINE: DESCRIBE HOW THEY ARE FORMED: EXAMPLES: Illustration: Metamorphic Sedimentary
Igneous Rocks Chapter 5 page 110
Formation of Igneous Rocks • Igneous = magma or lava cools & hardens – Intrusive igneous: beneath Earth’s surface (magma cools slowly) • “intrudes” into existing rock • Contains high amount of gases • Ex: granite – Extrusive igneous: on Earth’s surface (lava cools quickly) • “extruded” onto the surface • Most of the gases have escaped • Ex: rhyolite
Classification of Igneous Rock • Two characteristics used to classify igneous: – Texture: appearance based on size, shape, and arrangement of crystals – Composition: proportions of light and dark minerals in the rock • Four texture types: – Coarse-grained: slow cooling = large crystals – Fine-grained: rapid cooling = small, interconnected mineral grains – Glassy: extremely rapid cooling = no crystal network (random arrangement) – Porphyritic: mixture of large & small crystals due to extended time as magma
• Two main compositions: – Granitic: light-colored, almost entirely silicate minerals such as quartz and feldspar – Basaltic: dark-colored, made of dark silicate materials and plagioclase feldspar with a high metal content • Other compositions are between granitic and basaltic: – Andesitic: 25% dark silicates, rest is plagioclase feldspar – Ultramafic: almost entirely dark silicates
What are igneous rocks? VIDEO http: //www. youtube. com/watch? feature =player_detailpage&v=7 FLlcc. ELWUo
Igneous Rock Quiz 1. Identify the two ways igneous rocks form. 2. Identify the two characteristics used to classify igneous rocks. 3. What are the two compositions of igneous rocks ?
Igneous Rock Summary (50 pts) • Find an image of an igneous rock on the internet. • Drag the image to a word doc. • Write the name and summary of the rock under the image that includes the following: composition, texture, formation (intrusive, extrusive) • Email your finished product as an attachment to : • [email protected] com Example NAME OF ROCK Dsfnjksdfn jkdfnjkd fnjksfnkdfnksgfnjkgnjksgnjkdg njksgfnksgnkjdfgnjkdfngjkdgnj sgjlkfdgnjsdfgjkdglsdfgnlfdgndf gnkdngfnkgjlfdglsnjkfgdhjf. (4 -5 sentences)
Sedimentary Rocks Chapter 6 page 132
Formation of Sedimentary Rock • 1 st step is always the formation of sediments by the breakdown of existing rock. • Weathering is any process that breaks down rock; can by physical or chemical. • Weathered sediments are usually transported: – Erosion is the process of weathering & removing rock. – When the agent of erosion (usually wind, water, ice, or gravity) loses energy, the sediment is dropped—deposition. • Largest sediments deposited first.
• Two processes cause deposited sediments to become lithified, or turned to rock: – Compaction: sediments are squeezed together, driving the water out, usually under their own weight – Cementation: dissolved minerals are deposited in the tiny spaces among sediments and they act like glue
Classification of Sedimentary Rocks • Two main groups according to how they form: – Clastic: made from weathered bits of rocks and minerals • Further grouped by size of particles: – – – Conglomerate: rounded, gravel-sized or larger Breccia: angular pieces, gravel-sized or larger Sandstone: sand-size grains Siltstone: fine-grains Shale: very fine grains – Chemical: made when dissolved substances precipitate from water solution • Ex: limestone, rock salt, chert, flint, rock gypsum • “Biochemical”—made from shells & skeletal remains of sea organisms; ex: most limestones and chalk
Features of Some Sedimentary Rocks • Unique features give clues to how, when, and where sedimentary rocks formed. – Layers show age. – Ripple marks indicate location on a shoreline. – Mud cracks indicate a dry environment. – Fossils can indicate geography, climate, & age.
Model Sediment Layering How do layers form in sedimentary rocks? Sedimentary rocks are usually found in layers. In this activity, you will investigate how layers form from particles that settle in water. Simply Sediments LAB
Sedimentary Rock VIDEO http: //www. youtube. com/watch? feature =player_detailpage&v=yd. Z 4 SWiq. Gik
4. After you sediment bottle has been allowed to stand undisturbed overnight, what do you observe? (a) Draw and label what you see on the diagram of the sediment bottle (b) Describe your observations (c) Predict what will happen after your sediment botle is allowed to sit undisturbed for one week. 5. Which type of sediments float? Which ones move along the bottom? 6. If you were to continue moving the bottle for a long time, what would happen to the large sediments 7. Would you find fossils in sedimentary rocks? Why
Sedimentary Rock Quiz (Write the ANSWER ONLY…. . 40 points) 1. What are the two main groups of how sedimentary rocks form? 1. Define weathering. 1. What are the two processes cause deposited sediments to become lithified, or turned to rock? 1. In sedimentary rocks, layers are proof of ______.
Metamorphic Rocks Chapter 6 Page 145
Formation • Metamorphism is changes in rock due to heat and pressure. – These conditions are found a few kilometers below Earth’s surface and extend into the upper mantle. • Two settings for metamorphism: – Contact: low-grade metamorphism when hot magma moves into rock (EX: limestone becomes marble) – Regional: large-scale deformation and high-grade metamorphism when large areas are subjected to extreme pressures and temperatures such as during mountain building
3 Agents of Metamorphism • Heat: – Comes from magma or changes in depth – Causes recrystallization of minerals – Can provide the energy to drive chemical reactions • Pressure (stress): – Causes spaces between mineral grains to close, giving a more compact rock with higher density – Can cause recrystallization of minerals
• Hydrothermal solutions: – Hot, water-based solutions that escape from magma – Aid in recrystallization of minerals by dissolving original minerals and depositing new ones – Can result in a change in composition
Classification • Can be classified by composition or texture • Two main textures: – Foliated: layered or banded appearance • Form when minerals realign as a result of pressure from opposing sides • EX: gneiss, schist – Nonfoliated: does not have a banded texture • Contain only one mineral • EX: marble, quartzite, anthracite
Metamorphic Rock VIDEO http: //www. youtube. com/watch? feature =player_detailpage&v=Urim. Db. TUalg
Metamorphism • Draw an example of a foliated and nonfoliated rock and list three characteristic of each. • Make a data table listing the characteristics of the three types of metamorphism.
Metamorphic Rock Quiz 1. List the 3 agents of metamorphism. ___________, ______ 2. Metamorphic rocks can be classified by _____
THE ROCK CYCLE
The Rock Cycle • The rock cycle is the interactions among Earth’s water, air, and land which cause rocks to change. – Powered by energy from the sun (which powers almost all Earth processes) and processes deep within the Earth • Key points in the rock cycle: – Magma forms – Magma cools to form igneous rock – Weathering breaks down rocks via chemical or physical means to form sediments
– Sediments are compacted and cemented to form sedimentary rock. – Extreme heat and pressure can change sedimentary rock into metamorphic rock. • Alternate paths to rock formation can be taken. – Ex: metamorphic is weathered to sediments to become sedimentary. – Ex: sedimentary is buried deeply, melts, becomes magma, which forms igneous.
Rock Cycle diagram (44 points) • DRAW, COLOR, LABEL and DESCRIBE (in your own words DO NOT copy from the book) each phase in the rock cycle. (24 points) • At the bottom of your diagram answer the following question: (20 points) Apply the concept of the rock cycle and explain how the three main types of rocks are classified. • Page 151