what is oil in the ground made from?

Answer 1

Crude oil is composed of a mix of molecules composed of hydrogen, carbon, and oxygen atoms in many different forms. These can range from simple compounds like methane (CH4) or ethane (C2H6) to long complicated molecules such as paraffins like C8H18, also known as octane that is used to rate motor fuels.

The initial source of the crude oil is the accumulation of the dead bodies of phytoplankton and zooplankton which are microscopic plants and animals that live in the sea and fresh water lakes. Adding to this organic matter that accumulates on the sea floor is the material that is carried into the ocean by rivers, such as pollen, spores, and plant material. To be preserved, all of this organic matter must fall into a zone of the water that is low in oxygen, otherwise it will decay rather than be preserved. Mud and silt coming from rivers will often bury this material before it can be consumed by living organisms. Near the mouths of rivers there are often rapid rates of deposition of mud and silt that will bury organic material, and over time it may be buried by several miles of sediment. For example, the Mississippi River Delta, which is a prolific oil producing area, has deposited sediments several miles thick over the last 66 million years.

As these deposits of organic matter are buried deeper and deeper they begin to warm from the heat of the earth's interior. When they reach a temperature of about 140 degrees F, they begin to undergo "catagenesis" which is a molecular change that makes oil. If they reach a temperature of about 250 degree F, they will begin to form more natural gas than oil. If they get too hot it is possible to change them to graphite, and no oil or gas will be produced.

In other types of depositional environments the plants and animals that become oil also form the rock. Carbonate mudstone (which is simply a type of limestone) of the Hanifa Formation in the Middle East formed much of the oil in Saudi Arabia. These carbonate mudstones are composed of huge accumulations of lime muds made from the breakdown of marine algaes and other organisms. These deposits of the remains of marine organisms also must undergo burial and and heating by the deep earth to generate oil and gas.

So when you burn oil, you are really burning solar energy that was stored by plants and animals thousands or millions of years ago and buried in the earth.

Every time I answer this question someone comes along and points out that there may be oil that is not from living organisms. Thomas Gold, a respected physicist at Cornell proposed that oil may be abiotic; that is just another type of deposit of the earth. This may in fact be possible, but if it is, it is likely to be a very minor source of the oil on Earth. The reasons are complicated, but the fact that the rocks where Gold predicted this abiotic oil should be found do not contain oil is pretty conclusive proof that this type of oil is not significant, if it exists at all.

Here is my previous answer to this question:
http://answers.yahoo.com/question/;_ylt=AqkzP9amgCudYabOz20w2YIjzKIX?qid=1006022109950

Answer 2

Oil formed from the remains of marine organisms, mostly planktonic, that died & fell to the bottom of the sea where they were covered w/ sediments.

Over millions of years these sediments continued to cover the remains creating great pressure. This led to the formation of what we know as petroleum.

Coal, on the otherhand, is made up of the remains of plants, more specifically land or terrestrial plants.

Both are hydrocarbon compounds that contain the elements carbon & hydrogen.

Where did the hydrogen & carbon come from? From living things. All living things are carbon-based.

In organic chemistry, petroleum is considered to be a liquid alkane which is just a really long chain of carbons linked together w/ single bonds.

Answer 3

Oil like coal is made from the remains of living organisms mostly
vegetation. There is a geological period called the carboniferous, many millions of years ago when the Earth was warmer, had lots of shallow seas and more carbon dioxide in its atmosphere. The remains of these organisms did not completely break down, thus they retained some of the energy, originally derived from the sun in chemical form. Through tectonic geological changes these deposits were buried, hence subject to pressure and changed to fossil fuels. Oil particularly formed under basins (shallow seas).

Answer 4

It's a complex mixture of different chemicals that have formed from the mass of biological material (plant and animal matter) that became buried over millennia and just happened to be in the right regions of the world for temperature and pressure of the earth to exert an effect on them, transforming them into a slurry of organic chemicals that combine and recombine over millions of years to form the chemical goo that we call crude oil. It has simple organic chains starting with methane and ethane, with some all the way up to ten or fifteen carbon atoms, in addition to nitrates, sulfates, other organic and inorganic gases, and water (it's in there)

Answer 5

oil is formed from the decayed fossil $ decomposition of plants under high pressure and temperature .

Answer 6

Decomposed billion year old compressed matter, i.e. fish, dinosaurs, plankton...depends on where it is in the world.

Answer 7

The broken down plants that died there.

Answer 8

oil- its a nonrenewable resource

Answer 9

What Theyuks said .....his answer pretty much says it right and pretty much so you can understand it. Come vote time ...... Theyuks gets my vote.

Answer 10

how much older you are?