erosion
The breaking down and carrying
away of rock and soil caused by
such forces as wind and flowing
water. The pounding waves caused
erosion of the sandy shoreline.
crust
The outer layer of the Earth; it is
covered by water, sand, soil and
plants. The earth’s crust is a thin
layer of rock (10-65 kilometers (km),
depending on location). It is broken
into plates.
mantle
inner core
outer core
sedimentary rock
The second layer of the earth, under
the crust. The mantle is solid
igneous rock, especially closest to
the crust, but changes into a solid
rock that has some properties of a
liquid. It is the thickest layer of the
earth (2,900 km).
The innermost layer of the earth
composed of solid iron and nickel.
The center is very hot, and is solid
because of the extreme pressure
pushing on the center of the earth.
The radius of this sphere is 1,206
km.
the molten (melted rock) layer of the
earth surrounding the inner core.
Temperatures inside the core are
nearly as hot as the sun. It is 2,250
km thick.
A type of rock that forms when
sediments harden. Most
sedimentary rocks form in layers.
igneous rock
A type of rock that forms from
melted rock that cools and hardens.
Obsidian is an igneous rock that
forms when lava cools quickly.
metamorphic rock
A type of rock that forms from
existing rocks because of changes
caused by heat, pressure, or
chemicals.
Slate is a metamorphic rock that
forms from the sedimentary rock
shale.
magma
Melted rock material that forms deep
within Earth. Some igneous rocks,
such as granite, form from magma.
lava
liquid rock that reaches the surface
of the earth, through vents called
volcanoes
minerals
A solid element of compound from
Earth’s crust that has a definitive
chemical composition and crystal
structure.
plate tectonics
the process of crustal plate
movement
volcano
places on the earth’s surface where
hot, liquid rock seeps or explodes
out.
earthquake
a shaking of the ground caused by
plates moving under the surface of
the earth.
plates
the huge slabs of rock that make up
the earth’s crust (like pieces of a
puzzle)
fossil
The remains or traces of a living
thing from the past, preserved in
rock. Fossils can include imprints of
animal skeletons pressed into rock.
fault lines
points at which the earth’s crust
cracks
Pangaea
the theory that shows how once all
the continents were connected and
have drifted apart over time.
tsunami
an enormous ocean wave caused
by earthquakes or volcanoes.