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1 PETROLEUM ORIGIN

There is magic in oil, that smelly black liquid which forms
greasy puddles on the garage floor.
Gasoline, the main product of crude oil, or petroleum, runs
our cars, trucks, buses, and boats. Before the day of our swift
transportation, people traveled in horse-drawn vehicles, or by train.
The oil used for heating is another product of petroleum.
Natural gas found with petroleum, is burned in millions of kitchen
stoves. Still other petroleum products, called petrochemicals, are
used to make paints, cleaners, waxes, medicines, and hundreds of
other things.
Crude oil is a black, heavy liquid made up almost entirely of
two elements – hydrogen and carbon. Hydrogen is a gas. Carbon is
a solid which we know best as charcoal or the graphite in lead
pencils. When these two elements are combined in the right
proportion, together with atoms of other elements, a liquid called
petroleum, or crude oil, is formed.
This combination of atoms took place inside the earth
millions of years ago. In prehistoric days, great fires in the centre
of the earth exploded the cooling outside crust into huge piles,
forming continents and mountains ranges. Thousands of years later
the rock was softened and crumbled by wind and rain until plants
could grow. Swamps sheltered strange fish, great scaly snakes,
lizards, and dinosaurs.
The earth’s uneasy surface was still being churned by
earthquakes and volcanoes. Whenever such an eruption occurred,
much vegetation and billions of animals and fish were buried deep
under mud, washed down by violent rains. As time passed and
more sand and mud flowed down, the enormous weight squeezed
the bottom layers until they turned to stone. The partly rotted
animals and plants trapped between the layers of stone were
changed by heat and pressure. In some cases coal was formed. In

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