Fossil Fuel Formation

How did fossil fuels form?

Fossil Fuels •three major forms of fossil fuels: coal, oil and natural gas.

•all formed 360 to 286 million years ago

•most before the time of the dinosaurs

•the land was covered with swamps filled with huge trees, ferns and other large leafy plants

•the water and seas were filled with algae - the green stuff that forms on a stagnant pool of water. (Algae is actually millions of very small plants.)

COAL • formed from the remains of vegetation

• most of our coal was formed about 300 million years ago, when much of the earth was covered by steamy swamps

• as plants and trees died, their remains sank to the bottom of the swampy areas, accumulating layer upon layer and eventually forming a soggy, dense material called peat

• most important element in the plant material is carbon, which gives coal most of its energy

COAL

NOT Charcoal –

that comes

from burned

wood

Don’t confuse

coal and

charcoal!

land material washed into the

sea from the land

sea

living material dies

remains of plankton –

tiny forms of sea life

layers of sediment form

when sand and other

materials settle on the

ocean floor

parts of the dead materials

change to hydrocarbons

mixed with other

sedimentary materials

layers become

more and more

compressed as

further layers

settle on top

new material depositing sediment

forms a layer that cannot be

penetrated,

called cap rock

gas

oil

gas,

oil,

and

water

Earth movements cause

folds in Earth’s crust

Cross section of porous sandstone. The dark shading

indicates the spaces that contain oil.

OIL • also formed more than 300 million years ago

• scientists believe that tiny diatoms are the source of oil

• diatoms are sea creatures the size of a pin head

• like plants they convert sunlight directly into stored energy

• as the diatoms died they fell to the sea floor and were buried under sediment and other rock

• the rock squeezed the diatoms and the energy in their bodies could not escape

• the carbon eventually turned into oil under great pressure and heat

•About three-quarters (3/4) of the oil used in the United States comes from outside the Persian Gulf in the Middle East. That's due to large North American producers like the U.S. itself, Canada and Mexico. The U.S. is among the world's leaders in oil production.

•Almost 40% of the oil we consume is produced here at home, primarily in Texas, Alaska, California, Louisiana, and Oklahoma

Natural Gas

• most scientists believe that natural gas was formed from the remains of tiny sea animals and plants that died 200-400 million years ago

• main ingredient is methane, a natural compound that is formed whenever plant and animal matter decays

• after a long period of time concentrations of natural gas became trapped in the rock layers much like a wet household sponge traps water

Natural Gas

•don't confuse natural gas with "gasoline," which we call "gas" for short.

“Gas” is a petroleum

product and comes

from oil

Natural Gas comes from

pockets of gas deep in the

Earth

Tiny sea plants and

animals died and were

buried on the ocean

floor. Over time, they

were covered by layers

of silt and sand.

Over millions of years,

the remains were buried

deeper and deeper. The

enormous heat and

pressure turned them

into oil and gas.

Today, we drill down

through layers of sand,

silt, and rock to reach the

rock formations that

contain oil and gas

deposits.

Natural Gas Use

Oil & Gas industry

operations

4.9%

Pipeline

Fuel

2.6%

Vehicle

fuel

0.1%

Saving Fossil Fuels

• Fossil fuels take millions of years to make. We are using up the fuels that were made more than 300 million years ago before the time of the dinosaurs. Once they are gone they are gone.

• So, it's best to not waste fossil fuels. They are not renewable; they can't really be made again. We can save fossil fuels by conserving energy.

What did you learn?

1. Which one of these is NOT a fossil fuel?

A. natural gas

B. coal

C. oil

D. charcoal

2. How was most of our fossil fuel formed?

A. from dead dinosaurs

B. from dead plants and animals

C. from oil wells

D. from sedimentary rock

3. Why are oil, coal, and natural gas called “Nonrenewable” fuels.

A. because they are hard to find

B. because people don’t use them

C. because it takes millions of years to make more

D. because they are buried underground