Plate Tectonics - Chapter 1

Question 1

Trench

Answer 1

Long, narrow deep depression in the ocean bed running parallel to a plate boundary and marking a subduction zone

Question 2

Terrane

Answer 2

Fragment of crust broken off from one tectonic plate and stuck to another plate

Question 3

Tectonic cycle

Answer 3

Continuous collision and separation of tectonic plates causing destruction and formation of earths crust

Question 4

Subduction

Answer 4

Geological process at convergent boundaries here one plate sinks under another and is forced into mantle. Regions where occurs are called subduction zones
Eg. Nazca under South America

Question 5

Sea floor spreading

Answer 5

Geological process at mid ocean ridges. Plates split apart causing formation of sea bed. Sea floor spreading is result of mantle convection

Question 6

Rift Valley

Answer 6

A steep sided valley formed by downward movements of a block of the earths surface between nearly parallel faults
Eg. East African rift

Question 7

Plate tectonics

Answer 7

Study of the processes that cause the movement of the earths crustal plates and resulting landforms

Question 7

Plume

Answer 7

An up welling of unusually hot magma in the mantle. Form volcanic hotspots

Question 8

Plates

Answer 8

Huge slabs of rock made of oceanic and continental lithosphere

Question 9

Passive plate margin

Answer 9

The transition between oceanic and continental lithosphere. earthquakes and volcanic activity doesn’t occur here

Question 10

Pangaea

Answer 10

The giant super continent containing all the landmasses on earth that existed 200-300 million years ago

Question 11

Pacific Ring of Fire

Answer 11

Horse-shoe shaped zone around the edge of the Pacific. A lot of earthquake and volcanic eruptions. Lots of oceanic trenches, volcanic islands, arcs and volcanoes

Question 12

Oceanic crust

Answer 12

Thin part of the earths crust which forms seabed. Made of basalt covered with ocean sediments.

Question 13

Mid Ocean Ridge

Answer 13

Range of undersea volcanic mountains in the ocean. Forms when 2 tectonic plates separate. Associated with shallow earthquakes.

Question 14

Lithosphere

Answer 14

Rigid outer layer of the earth. Includes crust and upper mantle

Question 15

Laurasia

Answer 15

One of the 2 continents that formed after Pangaea around 200-300 million years ago. included North America, Europe and Asia

Question 16

Island arc

Answer 16

Curved line of volcanic islands located at a destructive late margin with a deep ocean trench on convex sides. 2 oceanic plates collide

Question 17

Hotspot

Answer 17

Place where magma pushes up through the crust in the middle of a tectonic plate to form a volcano. Form from plumes of magma rising from the mantle
Eg. Hawaii in the Pacific Plate

Question 18

Gondwanaland

Answer 18

One of the continents formed after Pangaea around 200-300 million years ago. Included Antarctica, Australia, Saudi Arabia and Madagascar

Question 19

Fold Mountains

Answer 19

Mountains formed by collision of 2 plates
Eg Alps or Himalayas

Question 20

Fault lines

Answer 20

Cracks in crust along which movement happens. Fault lines can be big/ small
Eg. San Andreas Fault (Between Pacific and North American plate)

Question 21

Exogenic

Answer 21

A force that occurs on the surface
Eg weather and erosion

Question 22

Destructive / convergent plate boundaries

Answer 22

A region of earth where plates collide

Question 22

Endogenic

Answer 22

A force the occurs on the inside, driven by heat from earths core
Eg. convection currents

Question 23

Constructive / divergent plate boundaries

Answer 23

a region where new oceanic crust is formed when 2 plates separate
Eg. junction between Eurasia and North America

Question 24

Continental drift

Answer 24

Slow movement of the continents across earths surface over millions of years

Question 25

continental crust

Answer 25

The crust that forms the continents and the shallow area of seabed close to their shores

Question 26

Conservation / transform plate boundaires

Answer 26

Junction between 2 plates that slide past each other without forming or destroying lithosphere
Eg. San Andreas Fault between Pacific and North American plate

Question 27

Asthenosphere

Answer 27

Part of the mantle. Below lithosphere and made of partly melted rock. 180 km thick