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39 Cards in this Set

  • Front
  • Back
continental drift
Wegener hypothesis that states continents have moved were once part of a single land mass
"all lands" Single landmass of Wegener's hypothesis. One land mass surrounded by a hugh ocean
"all seas" the huge ocean surrounding the Pangaea
Mid-Atlantic Ridge
undersea mountain range with a steep narrow valley running down its center
mid ocean ridges
entire system of ridges that wind their way around the earth
seafloor spreading
Dietz named it. Valley of MidAtlantic ridge is really a break or rift in the earth's crust and molten rock or magma from inside the earth was coming through the rift causeing the ocean floor to move away from both sides of the ridge
plate tectonics
a theory that describes the continental moovement and possible explanation to why it occurs and why it is continuing
oceanic crust
one of the two types of earth's crust and made from materials on the ocean floor
continental crust
one of the two types of earth's crust made up of the continent's (land) materials
oceanic, continental crust and rigid upper mantle of the earth forming a THIN outer layer of earth
layer under the lithosphere of plastic rock (like putty) made of solid rock that flows when under pressure
Plate Tectonics Theory
the lithosphere is broken and floats on the astenosphere (putty) that is moving when under pressure
broken parts of the lithosphere making up the continents and oceans of the world
Plate boundaries
Edges of the 30 plates
Divergent boundary
two plates moving AWAY from each other
Rift valley
narrow valley in the middle of the mid-ocean ridge formed when plates move away from each other
Convergent Boundaries
Direct collision as plates move away they PUSH into another plate. There are 3 types of convergent collisions
When one plate moves under another plate forming a deep ocean trench
Ocean trench
As a plate moves under another, it melts and becomes part of the mantle material. Some magma rises to the surface and forms volcanic mountains
transform fault boundary
when two plates grind against each other as they pass
transfer of heat through heated fluid material
convection current
warm water rises and cool water sinks to replace it.
theory of suspect terranes
continents are actually a patchwork of terranes
pieces of the lithosphere each with their own distinct geologic history
How terranes differ
different rocks and fossils
major faults at boundaries of terranne
magnetic properties of each are different
Alfred Wegener
proposed existence of Pangaea
climatic patterns
Support Wegener's hypothesis
seafloor spreading
New ocean floor being produced through this process
Mid ocean ridge
underwater mountain chain formed with molten rock from seafloor spreading
Tectonics in Greek
layer of mantle with plastic rock that underlies and moves the plates
Approximately how many plates
30 plates
divergent boundary
plates move away from each other
convergent boundary
formed when there is a collision of one plate with another
subduction zone
where one plate is pushed under another
transform fault boundary
where two plates grind past each other
Convection occurs because heated material is
less dense and rises
Convection currents are responsible for
portions of the ocntinents are made up of separate piences of the lithosphere called what