How do dead animals and plants turn into oil (petroleum) under hundred years of pressure and heat in the earth

Answer 1

First of all I wish to Inform you that not all types of animals and plants turn in to oil. Plants turn in to COAL and only plankton's turn in to oil. As you are probably aware oil chemical formula is organic and mainly compose of Hydrogen Carbon Oxygen.
It means the oil origin from organic materials.

Answer 2

An interesting question... A quick, somewhat incomplete answer.

At the mouths of rivers, where fresh river water mixes with the salt water of the sea, there is a constant deposition of freshwater plant material that cannot survive in the salt water. The stuff constantly dies as it enters the salt water and sinks to the bottom.

Over many thousands of years, hundreds or even thousands of feet of this plant material builds up. Storms & floods will cause layers of clay & sand to build up as well.

Heat and pressure over time will press the clays into impermeable layers under which the organic muck will become trapped in layers of oil permeated sands. We drill down into those trapped layers and extract the muck which will have changed over many thousands of years into petroleum & gas.

They call it fossil fuel, but most of the stuff is plant material. There are very very few dinosaurs in the oil sands.

Answer 3

good question

and since we have found oil 5,000 ft below the surface -
how did dinosaurs get that far down?

or does the earth generate oil?

Answer 4

If that were true, couldn't we stuff Fluffy in the gas tank? It's a wonderful life.