Plate Tectonic Theory

Question 1

plate techtonics is what

Answer 1

• a theory describing the origin, movement and recycling of lithospheric & continental plates
• unifying theory of geosciences

Question 2

plate techtonic theory was formalized in

Answer 2

1967

Question 3

what does plate techtonic combine

Answer 3

combines continental drift and seafloor spreading

Question 4

who was the continental drift guy and when was the first proposal

Answer 4

alfred lothar wegener

1912 was the first formal proposal of continental movement

Question 5

how do the mountain support continental drift theory

Answer 5

there were mountains that contained the same rocks/size that were separated but they were clear that they were once together..

Question 6

how do fossils (plant) support continental drift theory

Answer 6

glossopteris (seed fern with tounge shaped leaves were found in south america, africa, india, antartica, aurtralia and new zealand.
the overall question is how they got to continent to continent, they were too big to be picked up by wind. 200-300 MA

Question 7

how do fossils (reptile) support continental drift theory

Answer 7

Mesosaurus
freshwater atlatic reptile
found in south america and southern africa (across the pacific ocean from eachother) since it is a freshwater reptile, it can not possibly get across the ocean ~300 MA

Question 8

how do fossils support continental drift theory (herbivore)

Answer 8

lystrosaurus
found in africa, australia, india, china, mongolia, and russia. cannot get across the ocean again because it is a land animal ~250 MA

Question 9

how do fossils support continental drift theory (Mammal)

Answer 9

cynognathus
~350 MA
south americ and africa
cannot get across the ocean

Question 10

how do glacial tillites support continental drift theory

Answer 10

the mapped out straitens are confusing in current locations

Question 11

tillites def

Answer 11

glacial sediment deposits

Question 12

striations def

Answer 12

scratches in rock, used to determine glacier movement

Question 13

what is Pangaea

Answer 13

supercontinent (AKA all lands, all earth, whole land)

200-330 MA

Question 14

what are 4 disagreements with the continental drift theory

Answer 14

• lots of evidence in south america, but a lack of evidence in North America
• NA geologists reject Wegener’s ideas
• called it a “poor mechanism” = rejection
• wegener dies of a heart attack, therefore the theory forgotten

Question 15

what is SONAR

Answer 15

Sound navigation and ranging

Question 16

when did SONAR start

Answer 16

WWI, however its use was continued throughout WWII to detect submarines and its use expanded after.

Question 17

what is bathymetry

Answer 17

measurement of the oceans depths and the charting of seafloor

Question 18

who is behind the seafloor spreading hypothesis

Answer 18

harry hess in 1962

Question 19

what are some key takeaways from the seafloor spreading hypothesis

Answer 19

• new crust forms at the mid oceanic ridge

- crust is recycled at oceanic trenches

Question 20

what is the driver of the seaafloor spreading hypothesis

Answer 20

mantle convection (warm mantle rises, cooler mantle sinks)

Question 21

additional factors to seafloor spreading hypothesis

Answer 21

• ridge push
• slab pull (90)
• mantle drag
• slab roll back
• trench suction

Question 22

layers by physical state

Answer 22

• lithosphere
• asthenosphere
• lower mantle
• outer core
• inner core

Question 23

what is paleomagmetis, of seafloor (support of seafloor spreading theory)

Answer 23

• iron particles are mobile in magma
• align with the current fields
• locked in after cooling

Question 24

what is the terrestrial palemagnetic record in support of seafloor spreading theory

Answer 24

• created from lava flows,

- there are normal and reversed intervals

Question 25

what is the marine paleomagnetic record in support of seafloor spreading theory

Answer 25

• correlates to terrestrial record
• symmetrical patterns acroos the mid oceanic ridge
• predictive tool

Question 26

how does creating marine magnetic record support the seafloor spreading theory

Answer 26

-

Question 27

where do rocks become older

Answer 27

rocks become older with distance from the mid oceanic ridge

Question 28

when do sediments become thicker

Answer 28

with distance from the mid oceanic ridge

Question 29

how many major lithospheric plates

Answer 29

14

Question 30

what does plate techtonic theory explain

Answer 30

explains distribution of landforms, biosphere, natural disasters,
- explains long term climate change