Plate Tectonics

Question 1

suggests that all the continents were
joined into a single large landmass called
supercontinent Pangaea

Answer 1

Continental Drift Theory

Question 2

he introduced the continental drift theory

Answer 2

Alfred Wegener

Question 3

name of the ocean surrounding Pangaea

Answer 3

Panthalassa

Question 4

~180 My, it broke off into two large masses called

Answer 4

Laurasia and Gondwana
w/ Tethys sea in between

Question 5

4 continental drift theory proofs

Answer 5

jigsaw fit
index fossils
rock types among continents
paleoclimate evidences

Question 6

suggests that the seafloor moves and carries the crust with it as it
spreads from a central rift axis (oceanic ridge)

Answer 6

seafloor spreading

Question 7

he proposed seafloor spreading

Answer 7

Harry Hammond Hess (1962)

Question 8

name of his proposal/theory

Answer 8

geopoetry

Question 9

the record of the earth
magnetic field through time in rocks

Answer 9

paleomagnetism

Question 10

material from the mantle that rises up through the mid-ocean ridge is basalt
that contains magnetite – a rock mineral that is highly magnetic and aligns with the magnetic field

Answer 10

Vine-Matthews-Morley Hypothesis

Question 11

unifying theory of geology

Answer 11

Plate Tectonics Theory (1968)

Question 11

Major Plates of the Lithosphere (7)

Answer 11

Eurasia, North America, Australia, Pacific, South America, Africa, and Antarctic

Question 12

Small plates in the lithosphere

Answer 12

Philippine sea plate, Cocos, Juan de Fuca, Caribbean, Nazca, Scotia

Question 12

created crustal material in divergent boundaries

Answer 12

mafic igneous rock, Basalt or Gabbro

Question 13

formed when the ridge opens up and a column of magma cools in the
crack. This column is cracked again in the middle due to spreading and is intruded by a new dyke. It can be thought of as a dyke within a dyke
within a dyke (so on and so forth)

Answer 13

Sheeted dykes

Question 13

formed when lava oozes out into the water. The lava cools quickly on the outside since it is in contact with water, allowing a “shell” to form. Pressure is built up inside and it breaks the shell, allowing magma to ooze out again, repeating the process

Answer 13

Pillow Lavas

Question 13

Since Oceanic crust/plate is denser the continental crust/plate, oceanic
crust/plate subducts underneath continental crust.

Answer 13

Oceanic-continental convergent boundary

Question 13

▪ Since both are quite dense, one of them subducts (older and colder plate = denser) and usually forms an ocean
trench

Answer 13

Oceanic-oceanic convergent boundary

Question 13

Happens when the plate has moved so much that continental part of it becomes the one converging with another
continental material.

Answer 13

continental-continental convergent boundary

Question 14

Accumulated sediment on continental slope is thrust up and
forms

Answer 14

accretionary wedge

Question 15

Plates slides across each other without creation or destruction of crustal material.

Answer 15

transform boundary

Question 16

convection cells in asthenosphere

Answer 16

mantle convection/traction

Question 17

upwelling of mantle causes newer and warmer material
to form that will in turn be pushing older and colder material away
from the ridge.

Answer 17

ridge push

Question 18

older and colder plate segments at subduction zones become colder and denser thus goes down further and pulls the rest of the plate attached to it

Answer 18

slab pull

Question 18

plates that move the fastest

Answer 18

plates with subducting parts

Question 19

3 magma forming plate-tectonic settings

Answer 19

divergent - decompression melting convergent - flux melting mantle plume - heat induced melting

Question 20

melting or partial melting of hot rock as pressure on it is reduced

Answer 20

decompression melting

Question 20

Mantle material is melted by simply adding heat

Answer 20

heat-induced melting

Question 20

When subducting plate material is heated, it may force water out of the minerals (heat is not enough to cause melting). The water rises into the rock above it and wets it. Being wet causes partial melting of the rock

Answer 20

flux melting

Question 21

Spot where hot mantle material goes up through the crust and up above the surface

Answer 21

mantle plume

Question 22

elongation/stretching of the crust in some areas resulting to its thinning. Since it is thin, it allows rising of mantle material

Answer 22

continental rifting

Question 22

Regular fracture surfaces of rock masses, usually planar, cutting across the rock at constant orientation and spacing

Answer 22

joints

Question 23

Occurs when plates collide or shear past each other, when intrusions are emplaced, when uplift or subsidence occurs or when earth is stress at specific points

Answer 23

rock deformation

Question 24

Produced from bending of rock strata without rupture

Answer 24

folds

Question 25

Crustal rock failure by shear rupture

Answer 25

faults

Question 26

3 types of faults

Answer 26

dip-slip faults (normal and reverse) strike-slip faults

Question 27

Faults whose movement is parallel to the dip of the fault

Answer 27

dip-slip faults

Question 28

– the rocks are pulled apart (extension)

Answer 28

normal fault

Question 29

– the rocks are pushed together (compression)

Answer 29

reverse fault

Question 30

Faults whose movement is along the strike or length of fault

Answer 30

strike-slip fault

Question 31

– rifted from mainland Asia starting 33 Mya. Includes Palawan and some Panay islands. It existed before PMB and contains the oldest rocks in the country.

Answer 31

Palawan continental block

Question 32

collision of Sunda Plate, Philippine Sea Plate, and Indo-Australian Plate. Most parts of the PH belongs here.

Answer 32

Philippine mobile belt

Question 33

the country’s longest fault that traverses the entire length of the archipelago. It is a left-lateral fault.

Answer 33

Philippine fault

Question 34

how many active volcanoes in the Philippines

Answer 34

24