Download Terms and Definitions 2017 File

Year 10 Geology Terms and Definitions
Geology Terms
Tectonic plates
Definitions
Large pieces of the earth’s crust that are moving at
different speeds and in different directions.
Oceanic crust
The thin part of the earth's crust which lies underneath
the oceans.
Continental crust
The thicker part of the earth's crust which forms the
large land masses.
Convection currents Circular movements of molten rock in the mantle
caused by magma, that has been heated by the core,
rising and the cooler magma sinking.
Magma
Molten (liquid) rock beneath the crust.
Lava
Molten (liquid) rock above the crust.
Fault
A crack in the earth’s crust.
Strike slip fault
Where one side of the crust moves sideways past
another piece of crust.
Earthquake
The sudden movement of tectonic plates caused by the
build-up of pressure along the edge of the plates.
Focus
The place in the crust where the pressure is released in
an earthquake.
Epicentre
The area of land directly above the focus.
Richter scale
The scale used to measure the magnitude (size) of an
earthquake.
Subduction
When one plate is forced downwards underneath
another plate.
Volcano
Where liquid rock rises up through a crack in the crust.
Igneous rock
Rock formed from cooled molten rock eg basalt.
Sedimentary rock
Rock formed from grains of eroded rock, plant and
animal material, that has been pressed together eg
limestone.
Metamorphic rock Rock formed when sedimentary rock is buried deep in
the earth’s crust where the temperature and pressure is
very high eg slate and marble.
Erosion
The movement of soil, small stones and other material
from one place to another by wind, water etc
Weathering
The breaking down or wearing down of rocks by
natural processes such as ice, plant roots, chemicals,
rain etc.