Geography Terror 😊 Flashcards
Striations
Scratches/parallel grooves on rock from moving ice like glacier/fault movement.
Drumlin
Hills of sediment that streamlined by glacier flow.
Weathering
Breaking down/dissolving of rocks/minerals on the earth. After erosion transports the rocks/minerals away.
Physical weathering
Breaks down rocks/minerals/soil, without changing chemical composition.
Biological weathering
Plants break up rocks with the roots/roots exudates
J. Tuzo Wilson
Sparked interest in the plate tectonics theory. He’s Canadian.
Chemical weathering
Chemicals from rainwater changing minerals in rocks.
Earths composition
Structure of the earth divided into four.
Crust
Rocky outer layer of Earth. Made of basalt/granite. Thinner under oceans.
Mantle
Rocky layer, under crust. Made up of mostly silicates. convection (heat) currents carry heat from hot inner mantle to cooler outer mantle.
Outer core
Molten rock iron-nickel layer surrounding inner core.
Inner core
Solid iron-nickel Center of Earth. Very hot and under great pressure.
Volcano’s
Opening/vents that lava/small rocks/steam erupt to earth’s surface surface.
Earthquake
Two blocks of earth suddenly slip past each other.
Pacific Ring of Fire
Pacific Ocean surrounds pacific plate. It’s the area the plates meet and there’s the weakness that caused earthquakes/volcanoes.
Intrusive Igneous Rock
Made from magma trapped deep in the earth.
Extrusive Igneous Rock
Made from magma that exits, cools above/near Earth’s surface.
Granite
Igneous rock made of mostly quartz/feldspar. It’s an intrusive rock.
Sandstone
Sedimentary rock made from grains of sand compacted/cemented over millions of years. The sands mostly made of quartz/feldspar that was worn off rocks, then grounded into pebbles.
Limestone
Sedimentary rock naturally in earth’s environment.
Magma
Molten rock that’s underground.
Lava
Magma (molten rock) coming out as liquid on Earth’s surface. Or solidified rock after cooling of molten lava flow.
Glaciation
Buildup/movement of ice on Earth resulting in formations/scars left on the ground/mountain ranges.
Moraines
Hills deposited when a glacier retreats. Made of rocks,sand,etc.
Outwash (stratified drift)
Sediments laid down by glacier melt wash.
Till
Material that is deposited directly by the ice.
Erratics
Large, isolated boulders that were left behind by a glacier.
Alfred Wegener
Proposed continental drift theory in 1912.
5 pieces of evidence to support continental drift
- Jig-saw puzzle fit of continents
- Matching rocks/mountain belts
- Similar fossils on different continents
- Evidence of similar past climates
- Matching glacial deposits
Pangaea
Super-continent which included all the earths landmasses.
Folding
Bending/deformation of beds of rocks subjected to compressional forces.
Faulting
Displacement/fracturing that happens between two portions of Earths crust.
Big bang theory
15 billion years ago there was a giant release of energy. It threw gas/rocks/energy across the galaxy. Billions of years later matter slowed down. Material condensed into plants/suns. Scientists believe earth began 4.5-5 billion years ago.
Continental drift
Movement of continents because of motion from tectonic plates.
Plate tectonic theory
Suggests earths outer layer is divided in seven plates that go over earths Rocky inner layer above the soft core (mantle).
Convection currents
Process of heat going from inner core to mantle, then cooling and going back down.
Sea-floor spreading
Process where tectonic plates split from each other.
Mid-Atlantic ridge
Mostly underwater mountain range in the Atlantic Ocean.
Rift valley
Lowland regions formed when earths tectonic plates move apart/rift.
Great African rift valley
Series of contiguous trenches. 7k kilometres approximately in length.
Marianas trench
Deep-sea trench in the floor in the western North Pacific Ocean.
Iceland
Large island located in northern Atlantic. Rugged landscape/scenery.
Subduction
Ocean plate crashes into continental plate, slides under.
Divergent plate boundary
Two tectonic plates move from each other.
Transform plate boundary
Two plates slide past one another, horizontally.
Convergent plate boundary
Area where 2+ lithosphere plates collide.
Oceanic-continental
Ocean is denser, oceanic plate sinks beneath continental . Happens at ocean trench.
Subduction zones
Where subduction takes place.
Continental-continental
Collide and make mountains. Will not go underneath each other because of densities.
Oceanic-oceanic
Collide, both are made of basaltic rock, older will go under younger because older is cooler which equals denser.
San Andreas fault
Strike-slip boundary between two big plates of earth crust. Northern pacific (south/west) and North America (north/east)
Oak ridges moraine
Thickest piece of glacial material in Ontario. Made 13k years ago during last ice age.
Erosion
Materials are worn away and transported by natural forces.
