Igneous
Igneous rock: Rock formed from the cooling and hardening of magma.
Igneous rocks are formed from molten magma.
There are 2 categories of Igneous Rock:
plutonic and volcanic
Igneous rocks are formed
by the cooling of molten rock, or magma. Granite is an example of igneous
rock. You probably have seen granite. It’s used for headstones in cemeteries.
In other parts of the country, buildings are made from granite.
The first rocks on Earth were igneous rocks.
Basalt
 
Some famous examples of basalt formations are
the Columbia Plateau overlooking the Columbia River
near Portland
the Giant's Causeway in Northern Ireland
and the Devils
Postpile National Monument in California.
The Isle of Staffa in Scotland.
It's a small uninhibited island that is famous for its hexagonal basalt
formations and the caves shown in the next couple of pictures.
Obsidian
 
 Obsidian
Flow in Oregon
Obsidian is used in
cardiac
surgery, as well-crafted obsidian blades have a cutting edge up to five times
sharper than high-quality steel surgical scalpels, with
the edge of the blade reaching veritable molecular thinness. It produces a
cleaner cut and less tissue trauma,
which translates to faster healing and less scar tissue.
Gabbro
 
Gabbro Falls in Michigan
Pumice
 
 Pumice Canyon,
Lipari Italy
Rhyolite
 
South Iceland
Iceland
Granite
It is the world's
largest exposed mass of granite.
At its summit, the
elevation is 1,683 feet and 825 feet.
Stone
Mountain in Georgia
Granite
in Aberdeenshire,
Scotland
Words clues for Igneous Rocks:
Processes: melting and solidification
Sedimentary
Sedimentary rock: Rock formed from compressed and solidified
layers of organic or inorganic matter.
Sedimentary rocks come
from other rocks and minerals that have been worn down by weather or
dissolved in ocean water. Most of the rocks found in Kentucky are sedimentary. They include
limestone, sandstone and shale. Limestone is crushed to make gravel for roads
and other uses.
Limestone
Limestone formations in Ha long Bay, Vietnam
Notch Peak in Utah
Shale
Shale
in the Lake District, England
Shale in Ohio
full of fossils!
Phacops fossil
Phacops rana can be recognized by its large eyes (which remind
some observers of a frog's eyes), its fairly large size (up to 6 inches
long), and its habit of rolling up into a ball like a pill bug. In order to
protect themselves from predators, Phacops
rana would roll into a ball with its hard exoskeleton on the
outside as protection. Many other trilobites possessed the same ability, but Phacops rana nearly perfected it. The
slightest amount of sediment would trigger their senses, and Phacops rana would be hidden in a tiny
shelter made of its own body. Although this safety feature often helped them
to evade predators, occasionally it backfired and the trilobite would be
buried under heavy sediment. Their fossils can still be found in balled-up
positions 400 million years later.
Sandstone
Sandstone Antelope Canyon, Arizona
Word Clues for Sedimentary Rocks:
sediments
particles, fragments
grain size
clastic, bioclastic,
chemical
* fossils
*
evaporites, precipitates
layers
horizontal
layers
mud
cracks
underwater, seawater, inland sea
Processes: compaction and cementation
Processes: evaporation, precipitation
Metamorphic
Metamorphic rock:
Rock formed by transformation of preexisting rock through changes in
temperature and pressure.
Metamorphic rocks have
been changed by heat and pressure to form a different type of rock.
Limestone, a sedimentary rock, becomes the metamorphic rock marble. Shale
becomes slate.
Granite, an igneous rock,
becomes gneiss.
Arizona
Amethyst
Cobalt
blue
crystal of chalcopyrite
Azurite
Garnet in Gabbro
recrystallization
crystalline
dense, hard
intergrown crystals
new minerals present
distortions,
folds
banding
enlarged minerals
(enlarged mica, garnet minerals common in schist)
foliation
Processes: heat and pressure
Marble
Slate
Slate
in North Wales
Rock cycle: Processes through which rocks change from one
type to another, typically through melting, metamorphism, uplift, weathering,
burial, or other processes.
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