ROCKS
What is a Rock? <ul><li>Naturally-occurring mixtures of  minerals , mineraloids, glass or organic matter. </li></ul>
What is a Rock? <ul><li>Rocks are divided into 3 groups based on how they were formed: </li></ul><ul><ul><ul><li>IGNEOUS <...
What is the difference between a rock and a mineral? <ul><li>Rocks are made up of  ONE or MORE  minerals. </li></ul>
Once a rock is formed, does it stay the same rock forever? <ul><li>NO ! </li></ul>
<ul><li>Rocks are  continually changed  by many processes, such as weathering, erosion, compaction, cementation, melting, ...
What is the process through which rocks change? <ul><li>The Rock Cycle—earth materials change back and forth among the dif...
 
 
<ul><li>No set path a rock takes to become another kind of rock </li></ul>
Weathering, Erosion, Compaction, Cementation Recrystallization Weathering, Erosion, Compaction, Cementation Recrystallizat...
How are rocks redistributed? <ul><li>The core, mantle, & crust are one giant rock  recycling machine </li></ul>
***Watch the Rock Cycle by Brainpop <ul><li>What do igneous rocks form from? </li></ul><ul><li>What kind of rock is sandst...
<ul><li>“ Ignis” = Latin for “ fire ” </li></ul><ul><li>Formed from the cooling of either  magma or lava </li></ul><ul><li...
ORIGIN—  Where rocks are formed <ul><li>Below ground = from magma (intrusive igneous rock) </li></ul><ul><ul><ul><li>Usual...
Some have large & small crystals (called porphyritic)
<ul><li>Above ground = from lava (extrusive igneous rock) </li></ul><ul><ul><ul><li>Usually have  SMALL or NO  crystals (t...
Peridotite: Intrusive or Extrusive?  Why?
Granite: Intrusive or Extrusive?  Why?
Porphyry: Intrusive or Extrusive?  Why?
Obsidian: Intrusive or Extrusive?  Why?
COMPOSITION—  What kind of substances the rocks are made of
Basaltic Igneous Rocks  —made from lava/magma that is low in  silica , rich in iron and magnesium.  Rocks are  dark- color...
Granitic Igneous Rocks—made from magma/lava  high  in silica and oxygen.  Rocks are  light -colored.
Andesitic Igneous Rocks—have a composition between basaltic and  granitic .
Diorite
Basalt
Granite
<ul><li>Formed from  sediments  (rock fragments, mineral grains, animal & plant remains) that are pressed or cemented toge...
<ul><li>These sediments are moved by wind, water, ice or gravity. </li></ul><ul><li>Sedimentary rocks represent  7%  of th...
What turns sediments into solid rock? <ul><li>Water or wind  breaks down  and  deposits  sediment (erosion & deposition) <...
<ul><li>The heavy sediments  press down  on the layers beneath (compaction) </li></ul>
<ul><li>Dissolved minerals flow between the particles and  cement  them together (cementation) </li></ul>
How can sedimentary layers help us understand the age of fossils? <ul><li>As sedimentary rocks are deposited, they form ho...
3 Types of Sedimentary Rocks: <ul><li>Clastic (also called Detrial)—made of  broken  pieces of other rocks </li></ul>
<ul><li>Organic—remains of  plants and animals  are deposited in thick layers </li></ul><ul><li>Examples </li></ul><ul><li...
<ul><li>Chemical— minerals  dissolved in lakes, seas, or underground water </li></ul>3 Types of Sedimentary Rocks: Mineral...
<ul><li>Examples </li></ul><ul><li>Limestone  made when calcite mineral precipitates from sea water  </li></ul><ul><li>Roc...
<ul><li>Rocks that have changed due to intense  temperature  and  pressure </li></ul><ul><li>“ Meta” means “ change ” and ...
What occurs in the Earth to change these rocks? <ul><ul><ul><li>Pressure  from overlying rock layers </li></ul></ul></ul><...
<ul><li>*You can think of metamorphic rocks as a squished peanut butter & jelly sandwich in your lunch. </li></ul>
How are metamorphic rocks classified? <ul><li>Foliated—mineral grains are flattened and line up in parallel  bands </li></...
How are metamorphic rocks classified? <ul><li>Non-Foliated— No  bands are formed </li></ul><ul><li>Example : marble formed...
Where do metamorphic rocks usually form?   <ul><li>Where magma  intrudes  relatively cool rock </li></ul><ul><li>Near  col...
 
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Geografia English Rocks

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Geografia English Rocks

  1. 1. ROCKS
  2. 2. What is a Rock? <ul><li>Naturally-occurring mixtures of minerals , mineraloids, glass or organic matter. </li></ul>
  3. 3. What is a Rock? <ul><li>Rocks are divided into 3 groups based on how they were formed: </li></ul><ul><ul><ul><li>IGNEOUS </li></ul></ul></ul><ul><ul><ul><li>SEDIMENTARY </li></ul></ul></ul><ul><ul><ul><li>METAMORPHIC </li></ul></ul></ul>
  4. 4. What is the difference between a rock and a mineral? <ul><li>Rocks are made up of ONE or MORE minerals. </li></ul>
  5. 5. Once a rock is formed, does it stay the same rock forever? <ul><li>NO ! </li></ul>
  6. 6. <ul><li>Rocks are continually changed by many processes, such as weathering, erosion, compaction, cementation, melting, and cooling </li></ul><ul><li>Rocks can change to and from the three types </li></ul>
  7. 7. What is the process through which rocks change? <ul><li>The Rock Cycle—earth materials change back and forth among the different types of rocks </li></ul>
  8. 10. <ul><li>No set path a rock takes to become another kind of rock </li></ul>
  9. 11. Weathering, Erosion, Compaction, Cementation Recrystallization Weathering, Erosion, Compaction, Cementation Recrystallization Melting, Solidification Melting, Solidification IGNEOUS SEDIMENTARY METAMORPHIC
  10. 12. How are rocks redistributed? <ul><li>The core, mantle, & crust are one giant rock recycling machine </li></ul>
  11. 13. ***Watch the Rock Cycle by Brainpop <ul><li>What do igneous rocks form from? </li></ul><ul><li>What kind of rock is sandstone? </li></ul><ul><li>What are metamorphic rocks formed by? </li></ul>
  12. 14. <ul><li>“ Ignis” = Latin for “ fire ” </li></ul><ul><li>Formed from the cooling of either magma or lava </li></ul><ul><li>The most abundant type of rock </li></ul><ul><li>Classified according to their origin and composition </li></ul>Igneous Rocks
  13. 15. ORIGIN— Where rocks are formed <ul><li>Below ground = from magma (intrusive igneous rock) </li></ul><ul><ul><ul><li>Usually have LARGE crystal grains (they cooled slowly ) </li></ul></ul></ul>
  14. 16. Some have large & small crystals (called porphyritic)
  15. 17. <ul><li>Above ground = from lava (extrusive igneous rock) </li></ul><ul><ul><ul><li>Usually have SMALL or NO crystals (they cooled too quickly ) </li></ul></ul></ul>
  16. 18. Peridotite: Intrusive or Extrusive? Why?
  17. 19. Granite: Intrusive or Extrusive? Why?
  18. 20. Porphyry: Intrusive or Extrusive? Why?
  19. 21. Obsidian: Intrusive or Extrusive? Why?
  20. 22. COMPOSITION— What kind of substances the rocks are made of
  21. 23. Basaltic Igneous Rocks —made from lava/magma that is low in silica , rich in iron and magnesium. Rocks are dark- colored .
  22. 24. Granitic Igneous Rocks—made from magma/lava high in silica and oxygen. Rocks are light -colored.
  23. 25. Andesitic Igneous Rocks—have a composition between basaltic and granitic .
  24. 26. Diorite
  25. 27. Basalt
  26. 28. Granite
  27. 29. <ul><li>Formed from sediments (rock fragments, mineral grains, animal & plant remains) that are pressed or cemented together or when sediments precipitate out of a solution. </li></ul>Sedimentary Rocks
  28. 30. <ul><li>These sediments are moved by wind, water, ice or gravity. </li></ul><ul><li>Sedimentary rocks represent 7% of the Earth’s crust, but they cover 70% of the Earth’s surface. </li></ul><ul><li>Sedimentary rocks are fossil -carrying rocks. </li></ul>Sedimentary Rocks
  29. 31. What turns sediments into solid rock? <ul><li>Water or wind breaks down and deposits sediment (erosion & deposition) </li></ul>
  30. 32. <ul><li>The heavy sediments press down on the layers beneath (compaction) </li></ul>
  31. 33. <ul><li>Dissolved minerals flow between the particles and cement them together (cementation) </li></ul>
  32. 34. How can sedimentary layers help us understand the age of fossils? <ul><li>As sedimentary rocks are deposited, they form horizontal layers </li></ul><ul><li>Scientists know that the layers on top (and the fossils in the top layer) are YOUNGER than the fossils in lower layers. </li></ul>
  33. 35. 3 Types of Sedimentary Rocks: <ul><li>Clastic (also called Detrial)—made of broken pieces of other rocks </li></ul>
  34. 36. <ul><li>Organic—remains of plants and animals are deposited in thick layers </li></ul><ul><li>Examples </li></ul><ul><li>Fossil rich limestone is made from the shells of ocean animals; used to make chalk </li></ul>3 Types of Sedimentary Rocks:
  35. 37. <ul><li>Chemical— minerals dissolved in lakes, seas, or underground water </li></ul>3 Types of Sedimentary Rocks: Mineral crystals are made as the shallow water that has flooded the bottom of Death Valley evaporates. Click on image for full size ( 66K JPG ) Courtesy of Martin Miller, University of Oregon
  36. 38. <ul><li>Examples </li></ul><ul><li>Limestone made when calcite mineral precipitates from sea water </li></ul><ul><li>Rock Salt —made from evaporation of sea waters </li></ul>
  37. 39. <ul><li>Rocks that have changed due to intense temperature and pressure </li></ul><ul><li>“ Meta” means “ change ” and morphosis means “ form ” in Greek </li></ul><ul><li>Igneous, sedimentary and other metamorphic rocks can change to become metamorphic rocks </li></ul>Metamorphic Rocks
  38. 40. What occurs in the Earth to change these rocks? <ul><ul><ul><li>Pressure from overlying rock layers </li></ul></ul></ul><ul><ul><ul><li>High heat , but not enough to melt the rock </li></ul></ul></ul><ul><ul><ul><li>Rocks may be flattened or bent or atoms may be exchanged to form new minerals. </li></ul></ul></ul>
  39. 41. <ul><li>*You can think of metamorphic rocks as a squished peanut butter & jelly sandwich in your lunch. </li></ul>
  40. 42. How are metamorphic rocks classified? <ul><li>Foliated—mineral grains are flattened and line up in parallel bands </li></ul><ul><li>Example : gneiss formed from rearrangement of minerals in granite into bands </li></ul>
  41. 43. How are metamorphic rocks classified? <ul><li>Non-Foliated— No bands are formed </li></ul><ul><li>Example : marble formed from limestone </li></ul>
  42. 44. Where do metamorphic rocks usually form? <ul><li>Where magma intrudes relatively cool rock </li></ul><ul><li>Near colliding plates (near mountain ranges) </li></ul><ul><li>Places that are covered miles thick with other rock causing pressure </li></ul><ul><li>When hot water intrudes rock </li></ul><ul><li>Where a meteorite strikes Earth (rare) </li></ul><ul><li>Where lightning bolts strike rocks (rare) </li></ul>

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