TYPES OF ROCKS - IGNEOUS, SEDIMENTARY AND METAMORPHIC

3. 1.IGNEOUS ROCKS
 Some were once liquid magma that
erupted from volcanoes. They cooled up
very quickly (extrusive)
 Others were once liquid magma but they
did not erupt from volcanoes. Instead,
they cooled slowly underground

5. EXAMPLES OF IGNEOUS ROCKS

6. 2.SEDIMENTARY ROCKS
 Clastic sedimentary rocks are made up of
pieces (clasts) of pre-existing rocks loosened
by weathering. These rocks have particles
ranging in size from microscopic clay to huge
boulders; their names are determined by the
clast or grain size. The smallest grains are
called clay, then silt, then sand. Grains larger
than 2 millimeters are called pebbles.

8. EXAMPLES OF SEDIMENTARY
ROCKS:

9. 3.METAMORPHIC ROCKS
 Metamorphic rocks arise from the
transformation of existing rock to new
types of rock, in a process called
metamorphism. The original rock is
subjected to temperatures greater than
150 to 200 °C and, often, elevated
pressure of 100 megapascals or more,
causing profound physical or chemical
change.