What is the Ocean Crust made of?
Basalt— a thin, dense rock that is approximately 10km.
What is the Continental Crust made of?
Granite— a lighter rock, thicker than basalt and is approximately 64km.
Define Divergent
Plates that move away from each other allowing magma to come to the surface and cool, forming a new crust.
Define Convergent
Plates that move towards each other.
Define Subduction
When the heavy Ocean Crust crashes with the Continental Crust, in which the Ocean Crust dives under the Continental Crust; the edge of the Continent Crust is dropped down.
Define Folding
When the Continental Crust crashes with the Continental Crust; the same density causes no subduction but buckles instead.
Define Transform
Plates that are moving past each other.
What is Pangaea?
A supercontinent— the continents once formed a supercontinent (all land) during the Paleozoic Era.
Define Erosion
Gradual destruction involving wind, water, debris, etc.
give an example of erosion
Eroded material from The Canadian Shield was deposited into ancient seas and was hardened into rock. This later became the bedrock under the continent.
What are fossils?
Based on fossil evidence, the organisms that lived during the Paleozoic Era were organisms with shells in which later there were fish, insects, amphibians, plants and trees.
What is the Canadian Shield?
The geographic foundation of Canada— the rocks that form most of the shield are igneous and metamorphic, containing large quantities of valuable minerals such as lead, gold, copper, zinc and nickel.
Define folding
Over a long period of time along with conditions of high temperature and pressure, rock layers slowly bend rather than break.
Define faulting
Fractures or cracks in bedrock along with movement that has taken place in which they are producing the Earth’s crust by the stress that convection currents create in the mantle. If the rock is brittle, the forces cause the rock to move faster than it can bend causing it to fracture.
What is Igneous rock?
Made from molten rock which originates in the core when magma joins with crystals as it cools to become mineral crystals.
How is Basalt made?
When magma cools quickly and small crystals are joined.
How is Granite made?
When magma cools slowly and large crystals are joined.
What is Sedimentary rock?
Made from rock that is broken up into smaller pieces by weathering (constant heating + cooling; freezing and melting) and when different sediments are deposited and compressed by weight of other sediments.
How is Shale made?
From fine particles of rock.
How is Limestone made?
From particles of rock and animal skeletons.
What is Metamorphic rock?
Made from igneous and sedimentary rock that is exposed to heat and pressure.
How is Gneiss made?
From granite that is exposed to heat and pressure.
How is Slate made?
When shale is exposed to heat and pressure.
How is Marble made?
When Limestone is exposed to heat and pressure.
