Petroleum is a naturally occurring fossil fuel that forms from the remains of ancient microscopic aquatic organisms. Over millions of years, the organic matter from these organisms is transformed by heat and pressure into kerogen and then into hydrocarbons like petroleum. Petroleum forms within a specific temperature and pressure range in geologic formations underground and is eventually extracted and used as an energy source. However, burning petroleum releases the stored carbon back into the atmosphere, disrupting the natural carbon cycle.

2. • Petroleum comes from the Latin words petra which means “rock”, and
oleum which means “oil”.
• It is a naturally-occurring liquid composed of complex hydrocarbons and
is found in geologic formations underneath Earth’s surface.
• It is a fossil fuel derived from large quantities of microscopic aquatic
organisms such as algae and planktons.
• The remains of these organisms remain settled to the sea or lake bottoms
millions of years ago and were buried beneath fine sediments anoxic
conditions.

3. • With increasing pressure and temperature due to continuous burial, the
organic matter in these organisms transform into a waxy material known
as kerogen and eventually into hydrocarbons through the process of
catagenesis.
Kerogen is the insoluble organic portion of sedimentary rocks. It is a
waxy mixture of different organic materials (like algae and pollen)
and is insoluble in organic solvents because of the high molecular
weight of the compounds present.

4. •Petroleum forms within a specific depth, pressure, and
temperature range known as “oil window”.
•Below this temperature range (50ºC to 150ºC) kerogen is not
transformed into hydrocarbons.
•On the other hand, if the temperature increases beyond oil
window, oil is converted into natural gas in a process called
thermal cracking.

5. •Natural gas is a hydrocarbon mostly made up of
methane (CH4).
•Methane is a simple chemical compound that is
made up of carbon and hydrogen atoms.
•This gas is lighter than air and is highly
flammable.

6. •Deposits of fossil fuels are carbon storage areas. Carbon that is
locked in the fossil fuels does not cycle through Earth. However,
when fossil fuels are burned, the stored carbon is released into the
atmosphere as carbon dioxide. The carbon is then free to cycle
though Earth and affects the natural balance of the carbon, as well
as the process associated with it.

8. • Carbon is the chemical backbone of
life on Earth.
• It is found in all living (organic matter)
things on Earth
• It can be found in rocks, oceans,
atmosphere • Carbon compounds
regulate the Earth’s temperature,
make up the food that sustains us, and
provide energy that fuels our global
economy.

9.  The same carbon atoms
are used repeatedly on
earth, cycling between the
earth and the atmosphere.
 Carbon moves from one
storage reservoir to another
through a variety of
mechanisms.

10. Plants pull carbon dioxide from the atmosphere into the
biosphere, using it to make food through the process of
Photosynthesis.
The carbon becomes part of the plant and is stored as Starch the
leaves, stems or roots of the plant.
Thus, entering the food chain.

11. When organisms eat plants, they take in the carbon and some of it becomes
part of their own bodies.
All Animals that eat plants digest the sugar molecules to get energy for their
bodies.

12. •Respiration, excretion, and
decomposition release the
carbon back into the
atmosphere or soil, continuing
the cycle.
•When humans consume
plants and animals we add to
this cycling of matter.