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FORMATION OF COAL.
◇ Most of the world’s coal was formed in
Carboniferous age (350 million years ago.)
◇ Name Carboniferous refers to
coal-bearing strata.
◇ Coal formed
millions of years ago when the earth was covered with
huge swampy (marshy) forests. ◇ As plants grew, some
died and
fell into the swamp waters. ◇ New plants grew up to take their places and when these died more grew.
◇ In time, there was
thick layer of dead plants rotting in the swamp. ◇ Surface of the
earth changed, and
water and dirt washed in, stopping the decaying process.
◇ More plants grew up, but they too
died and
fell,
forming separate layers.
◇ After millions of years many layers had formed, one on top of the other.
◇ W
eight of the top layers and the
water and
dirt packed down the lower layers of plant matter.
◇
Heat and
pressure produced chemical and
physical changes in the plant layers which forced out oxygen and
left rich carbon deposits. In time, material that had been plants became coal.
