Natural Systems: What Is Fixed?

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Natural Systems: What Is Fixed?

Geological Eras

Cenozoic

-The era that we are living in -The continents take on their present shape -Humans emerge and develop

Mesozoic

-The third oldest era -Dinosaurs and reptiles ruled -Mammals first appeared -The asteroid ended this era

Paleozoic

-The second oldest era -The first organisms appeared on land (reptiles, insects) -The Appalachian Highlands were formed

Precambrian

-The Oldest Era -The first multi and single celled organisms (in the water) -The Canadian Shield was formed

Forces Building Up and Down

Glaciation

-Snow falls faster than it melts creating a fern (hard ice) -Its heavy weight causes it to move, creating new land forms like valleys and waterfalls -A form of erosion

Weathering

-Rocks and other parts of the geosphere are broken -Weathering and erosion go hand in hand; weathering makes a mess and erosion cleans it up

Erosion

-Carries away broken parts of the geosphere -Wind, water, and ice cause this -Lots of mountains have been eroded, like the Appalachian mountains and the Canadian Shield

Faulting

-Where two tectonic plates rub together (Transform Boundary) -Friction causes seismic waves, which result in earthquakes -Mountains can form, one side being steep along the fault line

Folding

-Happens when convergent boundaries push against each other and wrinkle -The highest mountains were made by folding -The Western Cordillera was formed by folding

Natural Regions

Western Cordillera

-Consists of all rock types -Located on the Pacific coast -Formed from folding when the Pacific Plate converged with the North American Plate

Appalachian Highlands

-Consists mostly of sedimentary rock -Formed in the Paleozoic era -Heavily eroded; used to be mountains, now only hills

Canadian Shield

-Covers a little less than half of Canada -Consists mostly of igneous rocks -Made in the Precambrian era

Natural Disasters

Tornadoes

-Occurs when high air pressure and low air pressure winds meet -Winds circulate and create a tunnel, which makes an updraft which makes the tornado reach the clouds

Earthquakes

-Happens due to tectonic plate movement -Strongest around fault lines -Mostly happens at transform boundaries

Volcanoes

-They usually stand alone and are symmetrical -Forms due to subduction -Can form on divergent boundaries

Plate Tectonics

Transform

-Two pate rubbing against each other -This makes seismic waves which results in earthquakes

Divergent

-Two plate tectonics moving apart -Volcanoes can form along these boundaries

Convergent

-Two plate tectonics pushing together -"Subduction" is when an ocean plate get pushed below a continental plate

Rock Cycle

Metamorphic

-"Metamorphic" means "Changed" -Used to be sedimentary of igneous rock -Changed due to heat and pressure -Examples include marble and gneiss

Sedimentary

-Formed in a process that starts with weather and ends in lithification -Forms in layers -Examples include sandstone and limestone

Igneous

-"Igneous" means "Fire" -Rocks made from cooled magma -Mostly found around volcanoes -Examples include granite and obsidian