Lecture 3: Plate Tectonics Flashcards

1
Q

1858: Snider – existence of a great region of *
1890: Edward Suess – *
1915: Alfred Wegener – * {Challenge: not able to provide the mechanism on how continents drifted apart}

A

dry land before the Great Flood
breakup of supercontinent; Gondwanaland
Continental drift

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2
Q
  • – existence of a great region of dry land before the Great Flood
  • – breakup of supercontinent; Gondwanaland
  • – Continental drift
A

1858: Snider
1890: Edward Suess
1915: Alfred Wegener

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3
Q

Challenge for continental drift

A

{Challenge: not able to provide the mechanism on how continents drifted apart}

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4
Q

All lands

A

Pangaea

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5
Q

All water

A

Panthalassa

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6
Q

Pangaea Breakup:
Laurasia {}
Gondwanaland {
}

A

(North America, Europe, Asia)

South America, Africa, India, Australia, Antarctica

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7
Q

Evidence for Continental drift

A
  1. Global geography
  2. Rock sequences
  3. Fossil
  4. Paleoclimate
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8
Q

Clue from global geography

A

Continental fit

Coastlines of Africa + South America

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9
Q

{Challenge: coastlines are constantly modified by erosion and deposition}
What did Edward Buller use?

A

– used continental shelf

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10
Q

Clues from Rock Sequences

A
Mountain Ranges
Appalachian Mountains (N America), 
British Isles, Caledonian Mountains (Scandinavia)
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11
Q

remains, trace, imprints of organisms that have been preserved in the Earth’s crust for 10,000 years +

A

Fossils

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12
Q

Fossil Distribution

A
  1. Mesosaurus – aquatic reptile; eastern South America and South Western Africa
  2. Lystrosaurus – strictly land-dwelling reptile; (Africa, Antarctica, Inda)
  3. Glossopteris “fossil seed fern” – too large to be carried by wind (Africa, Australia, India, South America)
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13
Q

aquatic reptile; eastern South America and South Western Africa

A

Mesosaurus

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14
Q

strictly land-dwelling reptile; (Africa, Antarctica, Inda)

A

Lystrosaurus

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15
Q

too large to be carried by wind (Africa, Australia, India, South America)

A

Glossopteris “fossil seed fern”

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16
Q

Glacial deposits – SA. Africa, India, Australia {tropical countries = rocks related to glaciers}; Coal fields in the northern hemisphere
Southern continents are joined together and located near the South Pole (Antarctica, Arctic}

A

Paleoclimate

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17
Q

Glacial deposits in

A

SA. Africa, India, Australia

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18
Q

Proponent of seafloor spreading

A

Harry Hess

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19
Q

Place of continuous generation of oceanic crust;

A

Mid-oceanic ridge:

ridge crest

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20
Q

7 major plates

A
African Plate
Indo-Australian Plate
Antarctic Plate
Eurasian Plate
North American Plate
Pacific Plate
South American Plate
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21
Q

MINOR PLATES

A
Somali Plate · Nazca Plate
Philippine Sea Plate · Arabian Plate
Caribbean Plate
· Cocos Plate
Caroline Plate · Scotia Plate
Burma Plate · New Hebrides Plate
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22
Q

Elaborate Plate Tectonics:

A

Continental drift + seafloor spreading

*Earth is composed of lithospheric plates

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23
Q

Further Evidence of Plate Tectonics

A
  1. Hotspots
  2. Paleomagnetism
  3. Seismic Activity
24
Q

area of high temperature

*Examples: Hawaii, Emperor Seamount chain

A

Hot spots

25
Q

Hawaii, Emperor Seamount chain

* interacts with *

A

*Pacific Plate interacts with Eurasia

26
Q

form magnetic stripes depending on Earth’s polarity. Record magnetic mineral; generate oceanic lithosphere.

A

Paleomagnetism

27
Q

– temperature at which a mineral’s magnetism is lost

A

Curie point

28
Q

Curie point of Magnetite

A

585 C

29
Q
  • deep earthquakes –> trenches

* shallow earthquakes –> boundaries of plate

A

Seismic Activity

30
Q

Divergent plate boundary

centers, margin, where?

A

{Spreading centers}
*Constructive margin
Mid-oceanic ridge

31
Q

Process involving divergent plate boundary

A

*Magma upwelling –> Rifting Event –> produce body of water

32
Q

Convergent plate boundary

margin, where?

A

Destructive margin

  • subduction zones – trenches
  • orogenic belts – mountain
33
Q

O-C Convergence
Float:
Sink:
Product:

A

Float: C
Sink: O
Product: Continental volcanic arc, trench

34
Q

O-O Convergence
Sink:
Product:

A

Sink: Denser, older, faster
Product: Island Arcs

35
Q

C-C Convergence

Product:

A

Product: Mountains

36
Q

Collision of * to * forming the Himalayas

What type of convergent boundary?

A

India, Eurasia

C-C

37
Q

Transform

Define, Margin, Example

A

Two plates slide past each other
Conservative margin
San Andreas Fault; East Pacific Rise

38
Q

Driving mechanism of Plate Tectonics

A

Plate-Mantle Convection,

Slab pull and ridge push

39
Q
  • is the underlying driving force for plate movement

* models

A

Convective flow
(Plate-Mantle Convection)
TWO LAYER MANTLE CONVECTION MODEL
WHOLE MANTLE CONVECTION MODEL

40
Q

Results from the sinking of a cold, dense slab of lithosphere

A

Slab pull

41
Q

Gravity driven force that results from the elevated position of the ridge
where

A

Ridge push

oceanic ridge

42
Q

Philippine Tectonics

seismically active island arc origin

A
  1. Philippine Mobile Belt
43
Q

aseismic continental origin

A
  1. Palawan Microcontinental Block
44
Q

Oceanic-Oceanic Convergence

West and East

A
{West}
1.	Manila Trench
2.	Negros Trench
3.	Sulu Trench
4.	Cotobato Trench
{East}
1.	East Luzon Trough
2.	Philippine Trench
45
Q

Marginal Basins

A
  1. West Philippine Sea
  2. Sulu Sea
  3. Celebes Sea
  4. Philippine Sea
46
Q

Oceanic Bathymetric Highs (emerged, elevated sea floor)

A
  1. Scarborough Seamounts

2. Philippine Rise

47
Q

Another distinct feature of Philippine Tectonics

A

Philippine Fault Zone

48
Q

The concept of a floating lithosphere in gravitational equilibrium with the Earth’s asthenosphere such that the tectonic plates “float” at an elevation which depends on their thickness and density.

A

Isostasy

49
Q

Isostasy is the concept of a * in gravitational * with the Earth’s * such that the tectonic plates “*” at an elevation which depends on their thickness and density.

A

floating lithosphere, equilibrium, asthenosphere

float

50
Q

Isostasy is the concept of a floating lithosphere in gravitational equilibrium with the Earth’s asthenosphere such that the tectonic plates “float” at an elevation which depends on their *

A

thickness and density.

51
Q

Mountains have “roots” which extend down into
the mantle. Thus, elevation is proportional to
the depth of the underlying “root”.

A

Airy-Heiskanen Model

52
Q

Elevation is inversely proportional to density.
Thus, the higher the mountain, the lower is its
density; that is, light rocks “float” higher.

A

Pratt-Hayford Model

53
Q

the lithosphere acts as an elastic plate and its
inherent rigidity distributes local topographic
loads over a broad region by bending.

A

Vening Meinesz/Flexural Model

54
Q

Height is proportional to depth

A

Airy-Heiskanen

55
Q

Elevation is inversely proportional to density

A

Pratt-Hayford

56
Q

Weight of the load bends or flexes the lithosphere/asthenosphere

A

Vening Meinesz/Felxural Model

57
Q

concept that explains a floating crust in a gravitational balance

A

Isostasy