geologic processes

1. Geologic ProcessesGeologic Processes

2. Core Case Study: The CrucialCore Case Study: The Crucial
Importance of Rare-Earth MetalsImportance of Rare-Earth Metals
 Crucial to the technologies that supportCrucial to the technologies that support
today’s lifestyles and economiestoday’s lifestyles and economies

Used to make LCDs, LED light bulbs, fiberUsed to make LCDs, LED light bulbs, fiber
optic cables, cell phones, and digital camerasoptic cables, cell phones, and digital cameras
 Without affordable supplies of rare earthWithout affordable supplies of rare earth
elements, we could not develop cleanerelements, we could not develop cleaner
technologiestechnologies

3. Core Case Study: The CrucialCore Case Study: The Crucial
Importance of Rare-Earth MetalsImportance of Rare-Earth Metals

4. GEOLOGIC PROCESSESGEOLOGIC PROCESSES
 Earth is dynamic – due to processes on andEarth is dynamic – due to processes on and
below its surfacebelow its surface
 Earth’s interior consists of:Earth’s interior consists of:

CoreCore – innermost zone with solid inner core and– innermost zone with solid inner core and
molten outer core that is extremely hotmolten outer core that is extremely hot

MantleMantle – solid rock with a rigid outer part (+ crust– solid rock with a rigid outer part (+ crust
== lithospherelithosphere) that is overlying melted pliable) that is overlying melted pliable
rock (rock (asthenosphereasthenosphere))

CrustCrust – outermost zone which underlies the– outermost zone which underlies the
continents (continental and oceanic [71% ofcontinents (continental and oceanic [71% of
earth])earth])

5. Fig. 14-3, p. 351
Spreading center
Oceanic crust Oceanic crust
Continental
crust
Continental
crust
Material cools
as it reaches
the outer
mantle
Cold dense
material falls
back through
mantle
Hot
material
rising
through
the
mantle
Mantle
convection
cell
Two plates move
towards each other.
One is subducted back
into the mantle on a
falling convection
current.
Mantle
Hot outer
core
Inner
core
AsthenosphereAsthenosphere

6. GEOLOGIC PROCESSESGEOLOGIC PROCESSES
 Major features of the earth’s crust and upperMajor features of the earth’s crust and upper
mantlemantle

7. GEOLOGIC PROCESSESGEOLOGIC PROCESSES
 Plate tectonicsPlate tectonics - huge volumes of heated- huge volumes of heated
and molten rack moving around the earth’sand molten rack moving around the earth’s
interior form massive solid plates that moveinterior form massive solid plates that move
extremely slowly across the earth’s surfaceextremely slowly across the earth’s surface

Tectonic platesTectonic plates – huge rigid plates moved by– huge rigid plates moved by
convection cellsconvection cells by floating onby floating on magmamagma (molten(molten
rock)rock)

8. The Earth’s Major Tectonic PlatesThe Earth’s Major Tectonic Plates

9. The Earth’s Major Tectonic PlatesThe Earth’s Major Tectonic Plates
 Slow movements of plates causes them toSlow movements of plates causes them to
grind into one another atgrind into one another at convergent plateconvergent plate
boundariesboundaries, move apart at, move apart at divergent platedivergent plate
boundariesboundaries and slide past atand slide past at transformtransform
plate boundariesplate boundaries
Figure 15-4Figure 15-4

10. GEOLOGIC PROCESSESGEOLOGIC PROCESSES
 The San Andreas Fault is an example of aThe San Andreas Fault is an example of a
transform faulttransform fault

11. GEOLOGIC PROCESSES ANDGEOLOGIC PROCESSES AND
NATURAL DISASTERSNATURAL DISASTERS
 EarthquakesEarthquakes – releases pressure at plate– releases pressure at plate
boundariesboundaries
 VolcanoesVolcanoes – at subduction zones when crust– at subduction zones when crust
meltsmelts
 TsunamisTsunamis – walls of water up to 210 feet tall– walls of water up to 210 feet tall
– caused by underwater earthquakes,– caused by underwater earthquakes,
volcanoes, landslidesvolcanoes, landslides

Ex: March 11, 2011 Japan – meltdown ofEx: March 11, 2011 Japan – meltdown of
Fukushima Daiichi nuclear power plantFukushima Daiichi nuclear power plant

Ex: Dec. 26, 2004 Indian Ocean – 221,000 killedEx: Dec. 26, 2004 Indian Ocean – 221,000 killed

12. GEOLOGIC PROCESSES ANDGEOLOGIC PROCESSES AND
NATURAL DISASTERSNATURAL DISASTERS
EarthquakesEarthquakes

13. GEOLOGIC PROCESSES ANDGEOLOGIC PROCESSES AND
NATURAL DISASTERSNATURAL DISASTERS
VolcanoesVolcanoes

14. GEOLOGIC PROCESSES ANDGEOLOGIC PROCESSES AND
NATURAL DISASTERSNATURAL DISASTERS
TsunamisTsunamis

15. GEOLOGIC PROCESSES ANDGEOLOGIC PROCESSES AND
NATURAL DISASTERSNATURAL DISASTERS
Banda Aceh, Indonesia June 23, 2004 (beforeBanda Aceh, Indonesia June 23, 2004 (before
tsunami) and December 28, 2004 (after)tsunami) and December 28, 2004 (after)