tectonic movement
- Created by: michael-j-inman
- Created on: 10-01-14 10:21
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- tectonic movement
- evidence for tectonics theory
- the evidence of sea floor speading
- mid Atlantic ridge discovered in 1948 during a survey also mountain ranges in the pacific
- analysis in the 1960s created idea of sea floor spreading
- 1960s further rock dating tchneches found the youngest of rocks closest to the ridge and the oldest further away further supoting this
- paleomagnatism shown a pattern of corresponding strips of iron particles must have once been joined together
- earth not getting bigger so plates must be destroyed elsewhere
- mid Atlantic ridge discovered in 1948 during a survey also mountain ranges in the pacific
- continental drift wegneres idea
- geological evidence
- rocks in south west Africa and eastern brazil as well as eastern Canada and northern Scotland are similar type and formation.
- biological evidence
- fossils found in brazil and south east Africa (mesosauraus) must hav been layed down when the continents where once joined
- climatological evidence
- red sandstones and coal formed in different climatological conditions than where they currently are
- continental fit
- continents seemed to fit together the continents today formed through the splitting of Pangaea
- was dismissed at the time as couldn't come up with process in which would cause the movement of the continents
- geological evidence
- convection currents
- the convection currents cause the magma to be more ductile in the athsenosphere
- leads to the spreading forming rift valleys as magma moves more sideways it cools becoming more dense eventually sinking back into the lower mantle
- oceanic plates cooled into the subduction zones forming trenches like Peru chili trench
- leads to the spreading forming rift valleys as magma moves more sideways it cools becoming more dense eventually sinking back into the lower mantle
- the convection currents cause the magma to be more ductile in the athsenosphere
- todays ideas
- what happens on the surface links to activity below
- slab pull
- greater density of the old lithosphere causes it to sink into the mantle at subduction zones sinking deep into the mantle with suction from the asthenosphere as well as gravity
- the evidence of sea floor speading
- structure links to plate movements
- heat left over
- radioactive decay and from creation of earth
- leads to convection currents
- heat left over
- Untitled
- evidence for tectonics theory
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