APES Geology chp 14



What makes the Earth dynamic? (geology and earth's resources)

  • A constantly changing layered sphere 



Solid Part:



Core

  • 2 layers of dense, intensely hot metal, mostly iron. Generates magnetic fields around the earth. 

  • Inner Core: extremely hot, solid sphere of mostly iron and nickel 

  • Outer Core:  only liquid layer of the earth – a sea of mostly iron and nickel.



Mantle

  • Hot, pliable layer surrounding the core. Less dense than core. 

  • 2 layers, outer layer (Lithosphere)  and Asthenosphere



Crust

  • Cool, lightweight, thin hard and rigid outermost layer. Floats on top of the mantle. 







Tectonic Mosaic



Tectonic Plates: huge blocks of earth crust sliding slowly around, pulling apart to open new ocean basins or crashing into each other to create new larger landmasses. 



Subducted: process of which one tectonic plate is pushed down below another as a plate crashes into each other 



Crust is a patchwork of sliding tectonic plates floating on the magma convection currents of the mantle below it. 



Constant circulation of molecules (cool and warm molecules) moving by the heat from the core.



Being heated through the core and rising causing the plates to move. Plates colliding works by the more dense one are pushed below. 



Magma: molten rock forced up through the cracks forms new oceanic crust



Mid-ocean ridges: Mountain ranges on the ocean floor created molten magma is forced up through cracks in the planet's crust



Alfred Wedgner: German Scientist, 



Pangea: supercontinent, Wedgner believed all earth's continents were once one large mass. It broke off 200 million years ago.



Plates Tectonic Theory: earth's outer layer (lithosphere)  is broken into several large slabs (plates). These plates, which hold the continents and oceans, are slowly but constantly moving 

around the planet.



Continental Crust: crust that underlies the continents, 20-40 miles thick



Oceanic Crust: crust found under the oceans, 4-6 miles thick





Convergent Boundaries:

  • two plates are pushing toward each other.

  • Ex. mountains







Divergent Boundaries:

  • two plates that are moving apart from each other.

  • Ex. lakes 







Transform Boundaries:

  • two plates slide past each other.

  • Ex. earthquakes











Earth's constructive and destructive processes 



Mineral

  • Naturally occurring, inorganic, solid element or compound with a definite chemical composition and regular i



Rocks

  • Solid, cohesive, aggregate of one or more minerals 



Anything can be a rock but not everything can be a mineral. 



The Rock Cycle

  • Cycle of creation, destruction, and metamorphosis (change) of earth's crust. 







Types of Rocks



Igneous rock: Most common type of rock

  • Solidified from magma.

  • Fine grained + quick cooled, most common 



Metamorphic Rock

  • Preexisting rocks are modified by heat, pressure, and chemical agents. 



Sedimentary Rock

  • Formed by erosion/weathering. (mechanical or chemical). Compacted into stone

  • Deposited materials that remain in the same place



Many rocks/minerals have economic importance 

  • Precious metals have economic value to us (gold, gems, coal, sand, limestone), therefore changing the landscape. 



Metals are important to human affairs as in technology and a heavy impact on broad implications for both our  culture and environment



Metals are useful due to their light, strong, easily shaped, and can conduct electricity 



Environmental Impacts of Extraction And Processing 



Mining

  • Disturbed habitat/mining

  • Ex. Placer, underground (coal mining), open pit/strip, mt. top removal

  • Processing methods/purifying  (smelting, heap-leaching)

  • Can affect water quality 

  • Mining tunnels can collapse



Geologic Hazards

  • Earthquakes: Sudden movements of earth's crust that occur along faults where one rock mass slides past another

  • Tsunami: As series of waves causes by an earthquakes, or some other abrupt disturbance

  • Volcanoes: Undersea magma vents. 

  • Mudslides

  • Monsoons 

  • Floods 

  • Meteorite strikes 



Conservation can help extend earth supplies, can help reduce the effects of mining and processing, which includes water use and contamination, air pollution, and energy use. 



ON THE TEST!

Understand dynamic of tectonic plates, colliding and dividing, 

Back page of volcano lab 

Some math