Oil is a fossil fuel that has been formed from a large amount tiny plants and animals such as algae and zooplankton. These organisms fall to the bottom of the sea once they die and over time, get trapped under multiple layers of sand and mud.

How is oil formed short answer?

The formation of oil begins in warm, shallow oceans that were present on the Earth millions of years ago. ... This material then lands on the ocean floor and mixes with inorganic material that enters the ocean by rivers. It is this sediment on the ocean floor that then forms oil over many years.

How is oil really formed?

Millions of years ago, algae and plants lived in shallow seas. After dying and sinking to the seafloor, the organic material mixed with other sediments and was buried. Over millions of years under high pressure and high temperature, the remains of these organisms transformed into what we know today as fossil fuels.