HNRS 227 Lecture

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HNRS 227 Lecture 18Chapter 19

• The Earth
• presented by Prof. Geller
• 29 October 2002

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Key Points of Chapter 19

• Minerals
• Rocks
• Igneous, Sedimentary, Metamorphic
• The Rock Cycle
• Earths Interior
• Crust, Mantle, Outer Core, Inner Core
• Plate Tectonics

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Telling Rocks Apart

• How geologists tell apart different minerals and
  rocks
• color, luster, texture
• hardness test
• scratching one against another
• diamond is hardest
• acid test
• using weak hydrochloric acid to
• streak test
• form a streak across a ceramic tile

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Minerals(see Table 19.1)

• Characteristics
• naturally occurring
• inorganic
• definite crystalline structure
• The natural resources of industry

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Igneous Rocks

• Rocks formed from hot molten mass of melted rock
  material
• See Figure 19.11 in textbook

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Sedimentary Rocks

• Rocks formed from particles or dissolved
  materials from previously existing rocks.
• See Table 19.2 in textbook

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Metamorphic Rocks

• Previously existing rocks that have been changed
  by heat, pressure, or hot solutions into a
  distinctly different rock.
• See Figure 19.13 in textbook

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The Rock Cycle
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Earths Interior andHow We Know It
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Earthquakes Galore
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Earths Inside Story
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Crustal Rumblings
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Plate Tectonics

• The theory that the Earths crust is made of
  rigid plates that float on the asthenosphere.
• Consider the scientific evidence for plate
  tectonics and what forced scientists to accept
  the theory as fact

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Fossils across an ocean
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Boundaries Galore
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Plates are smashing