The formation of rocks
• There are three kinds of rocks: the igneous, the
sedimentary, and the metamorphic rocks.
• Igneous rocks - are those formed by the cooling and
hardening of molten materials found deep in the crust
or closer to the surface in or near a volcano.
• Sedimentary rocks – are solidified sediments that
originally came from other rocks and were deposited
by water or air.
• Metamorphic rocks – are those formed by great heat
and pressure from igneous and sedimentary rocks.
• About 65% of the earth’s crust is made up of igneous
rocks; 27% is metamorphic; and about 8% is
sedimentary.
Ex. of Igneous:
Ex. of Sedimentary:
Ex. of Metamorphic:
Granite
Limestone
Slate