Download Plate Tectonic Terms

Plate Tectonic Terms
1. Plate Tectonics - The theory that the Earth's crust and
upper mantle (the lithosphere) is broken into a number of
more or less rigid, but constantly moving, segments or
plates.
2. Pangea, also spelled Pangaea, in early geologic time, a
supercontinent that incorporated almost all the landmasses
on Earth.
3. Fault - A weak point in the Earth's crust and upper mantle
where the rock layers have ruptured and slipped. Faults are
caused by earthquakes, and earthquakes are likely to
reoccur on pre-existing faults.
4. Lithosphere - outer solid part of the earth, including the
crust and uppermost mantle. The lithosphere is about 100
km thick, although its thickness is age dependent (older
lithosphere is thicker).
5. Mid-Ocean Ridge - an underwater mountain system that
consists of various mountain ranges (chains), typically
having a valley known as a rift running along its spine,
formed by plate tectonics.
6. Ocean Trench - The oceanic trenches are hemisphericscale long but narrow topographic depressions of the sea
floor. They also are the deepest parts of the ocean floor.
Trenches define one of the most important natural
boundaries on the Earth’s solid surface, that between two
lithospheric plates.
7. Rift - a linear zone where the Earth's crust and lithosphere
are being pulled apart.
8. Rift Valley - a linear-shaped lowland between several
highlands or mountain ranges created by the action of a
geologic rift or fault
9. Seafloor Spreading - a process of plate tectonics where
new oceanic crust is created as large slabs of the Earth's
crust split apart from each other and magma wells up to fill
the gap.