4.1
Monday, November 11, 2024
Plate Tectonics
The Earth's resources were determined when the planet was formed
Earth's Structure
Made of 3 Parts:
Core
Innermost part surrounded by liquid core of molten or semisolid material
Contains Fe & Ni
Mantle
Thick solid zone surrounding core; mostly solid rock but "plastic like"
area nearest core that is partially melted rock that flows slowly.
Largest zone by volume and mass
Asthenosphere: lower mantle - the "plastic" region
Lithosphere: Crust & upper mantle - the "plate" where minerals are mined
Crust
Outermost layer & thinnest zone
Consists of both continental and oceanic crust
Contains Al, Fe, Si, and O 2
Why We Care
The Earth contains a finite supply of mineral resources; we cannot extract resources from the planet indefinitely
Once we have mined the deposits of resources that are most easily obtained, we must use more energy to extract the
remaining resources.
We must incentivize sustainable use, re-use and recycling of our mineral resources
New technologies seek to find alternative materials
The Earth is Dynamic and is Constantly Changing
3 Major Processes
• Tectonic Cycle
Unit 4 Page 1
, • Tectonic Cycle
• Rock Cycle
• Soil Formation
Maps of tectonic plates can be used to determine locations of volcanoes, island arcs, earthquakes, hot spots, and fault
Why Tectonic Plates Move
Heat
Is released in the core due to radioactive decay of K, U, Th
Causes plumes of hot magma to well upward where molten material from the mantle reaches the lithosphere
Creates convection cells in the mantle similar to atmospheric circulation
• Drive continuous change, creation, and removal of earth materials from the lithosphere
Types of Tectonic Plates
2 Types
Oceanic Plates
• Lie underneath oceans
• Dense
• Rich in Iron
Continental Plates
• Lie underneath landmasses
• Less dense
• More SiO2
How Tectonic Plates Interact
3 Types of Plate Boundaries
Divergent Boundaries
Process
Oceanic plates move away from each other, molten rock
flows up the crack and creates new lithosphere
Result
Brings Cu, Pb, & Ag to the surface
Earthquakes
Seafloor spreading
Rift valleys
Volcanoes
Unit 4 Page 2
, Rift valleys
Volcanoes
Convergent Boundaries
Process
Two plates push together
Result
Earthquakes & Volcanoes & Tsunamis
Continental & Oceanic = dense oceanic plate subducts
under continental plate
• Creates an ocean trench on ocean side and a mountain
on continental side
• ex: Andes of South America
Continental & Continental = both plates lifted
• Creates a mid-continental mountain range
• ex: Himalayas in Asia
Transform Boundaries
Process
Plates slide past and grid past one another along a fracture
Result
Tsunami
Earthquake
Unit 4 Page 3
Monday, November 11, 2024
Plate Tectonics
The Earth's resources were determined when the planet was formed
Earth's Structure
Made of 3 Parts:
Core
Innermost part surrounded by liquid core of molten or semisolid material
Contains Fe & Ni
Mantle
Thick solid zone surrounding core; mostly solid rock but "plastic like"
area nearest core that is partially melted rock that flows slowly.
Largest zone by volume and mass
Asthenosphere: lower mantle - the "plastic" region
Lithosphere: Crust & upper mantle - the "plate" where minerals are mined
Crust
Outermost layer & thinnest zone
Consists of both continental and oceanic crust
Contains Al, Fe, Si, and O 2
Why We Care
The Earth contains a finite supply of mineral resources; we cannot extract resources from the planet indefinitely
Once we have mined the deposits of resources that are most easily obtained, we must use more energy to extract the
remaining resources.
We must incentivize sustainable use, re-use and recycling of our mineral resources
New technologies seek to find alternative materials
The Earth is Dynamic and is Constantly Changing
3 Major Processes
• Tectonic Cycle
Unit 4 Page 1
, • Tectonic Cycle
• Rock Cycle
• Soil Formation
Maps of tectonic plates can be used to determine locations of volcanoes, island arcs, earthquakes, hot spots, and fault
Why Tectonic Plates Move
Heat
Is released in the core due to radioactive decay of K, U, Th
Causes plumes of hot magma to well upward where molten material from the mantle reaches the lithosphere
Creates convection cells in the mantle similar to atmospheric circulation
• Drive continuous change, creation, and removal of earth materials from the lithosphere
Types of Tectonic Plates
2 Types
Oceanic Plates
• Lie underneath oceans
• Dense
• Rich in Iron
Continental Plates
• Lie underneath landmasses
• Less dense
• More SiO2
How Tectonic Plates Interact
3 Types of Plate Boundaries
Divergent Boundaries
Process
Oceanic plates move away from each other, molten rock
flows up the crack and creates new lithosphere
Result
Brings Cu, Pb, & Ag to the surface
Earthquakes
Seafloor spreading
Rift valleys
Volcanoes
Unit 4 Page 2
, Rift valleys
Volcanoes
Convergent Boundaries
Process
Two plates push together
Result
Earthquakes & Volcanoes & Tsunamis
Continental & Oceanic = dense oceanic plate subducts
under continental plate
• Creates an ocean trench on ocean side and a mountain
on continental side
• ex: Andes of South America
Continental & Continental = both plates lifted
• Creates a mid-continental mountain range
• ex: Himalayas in Asia
Transform Boundaries
Process
Plates slide past and grid past one another along a fracture
Result
Tsunami
Earthquake
Unit 4 Page 3
