Plate Tectonic Theory
What is Earth's Crust/Lithosphere made of ?
Plates
What was described that the plates fit like?
a puzzle
very hot, acidic (low pH), emits hydrogen sulfide, high pressure, no light, and very rich in minerals such as copper, zinc, iron, maganese, etc.
physical characteristics/features/ properties of a hydrothermal vent.
buoyant properties of layering rocks, which float on other layers, according to their density and thickness.
what is isostasy
State what happens during a convergent/divergent plate boundary, where it happens, stress type and features.
(plates move apart of each other) Constructive plate boundaries occur when two plates move away from each other.
North American and Eurasian Plate
Tension
Features: earthquakes , ocean ridges, volcanoes
What does plate movement cause?
earthquakes, mountain building and volcanic erruptions.
What is paleontology?
Related fossils on continents separated by ocean shows they were once joined.
Where do hydrothermal vents form?
typically on mid ocean ridges, where Earths tectonic plates are spreading apart and where magma wells up to the surface or close beneath the seafloor.
What does isostasy explain?
why the earth's crust floats on the denser, underlying layer.
Destructive (subduction zone)
Destructive plate boundaries occur when an oceanic plate is forced under (or subducts) a continental plate
Pacific plate and the Eurasian plate
compression
earthquake, oceanic trenches, volcanoes, destructive with 2 oceanic plates, island arcs
What do plates move due to?
convection currents in the asthenosphere
how were mountain ranges evidence for the plate tectonic theory?
stratification/layering of mountain range match of mountains found on different continents indicating continents were once joined together.
how many steps are in the formation of hydrothermal vents?
5
What does the principle of isostasy show?
The principle of isostasy shows that the Earth’s crust is generally higher where it is thicker and less dense; lower where it is thinner and denser.
Conservation (transform)
conservative plate boundaries occur when 2 plates slide past each other
North American plate and the pacific plate
shearing
earthquake, faulting
What do continents lie on?
Plates
Mapping of the seafloor
what is sonar
how do hydrothermal vents form?
1. crack in the seafloor where water seeps in
2. water is superheated by the underlying hot magma
3. hot water builds up pressure, causing it to rise out of cracks
4. dissolves minerals on the way out
5. some minerals precipitate out along edge of crack forming a vent.
Which crust is less dense between continental and oceanic.
Continental crust is less dense as compared to oceanic crust (at convergent boundaries, oceanic will subside – go under cont.).
collision
collision plate boundaries occur when 2 continental plates move towards each other
indo-australian and the Eurasian plate
compression
earthquake, fold mountains
What boundaries do plates meet at?
convergent, divergent and transform
what is seen at mid ocean ridges that provides us with evidence for the plate tectonic theory?
magnetic reversal of rocks
why are hydrothermal vents important ?
support unique ecosystems and their communities of organisms in the deep ocean.
how do boundaries form
plates move apart, magma rises and cools to make new crust