Transcript Unit 1 APES Lecture

Unit 6 APES Lecture
Introduction to Earth Science
Geologic Time Overview
• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic
Questions
• How many extinctions have occurred/are
occuring?
• Where did the oxygen come from about 2.7
bya?
• During what PERIOD was the majority of coal
formed?
• What event proceeded the development of
multi-celled organisms?
Earth Compositon
• Core: Intermost zone;
• Made up of Nickel and Iron.
• Inner Core solid;
• Outer Core Liquid
• Mantle--molten rock or
magma--circulates by
convection currents.
• Asthenosphere: Outer part
of mantle—semi molten—
ductile
• Lithosphere: Brittle,
outermost layer. Includes
the crust.
Theory of Plate Tectonics
• Plate Tectonics--Earth’s
Lithosphere is divided
into plates, most of
which in constant
motion-• This is called the
tectonic cycle--build up
and break down
lithosphere...
• Oceanic plates-primarily oceans
• Continental plates-primarily land masses
Type of Plate Contact
• Divergent Plate
Boundaries: Fig aoceanic plates move
apart.--sea floor
spreading.
• Convergent Plate
Boundaries. Plates
move towards each
other. Oceanic plates
heavier metal--iron
crust...
Plate Contact 2
• Collision of two continental plates--The
Himalayan Mountain Range was formed by
the collision between two continental
plates...
• Transform faults-c--plates slide sideways.
Plate Tectonics 2
• Movement driven by convection cells
• Seafloor spreading
• Subduction--the heavier oceanic plate slides
underneath the lighter continental plate
San Andreas Fault
Consequences of Movement
• As volcanos move over geologic hot spots,
can form volcanoes.
• Hawaiian Islands...
Questions
• What kind of plate boundary formed the
Rocky Mountains?
• What type of boudary would be the San
Andres Fault?
• What type of boundary is formed by the
Himalyas?
• What is an oceanic trench?
The Himalayas
Convection and Earth Layers
Rock Cycle