Maths, Physics Revision Physicss Maths Physics Physics A Level Physics Home Maths Maths Revision hut Energy resources Oil and Gas were formed when animals and  plants living in the seas died and were covered in mud. The mud was compressed in the same way as dead plants were compressed to form coal Coal, Oil and Gas are known as Fossil  Fuels and because they were formed  hundreds of millions of years ago they cannot be  replaced as they get used up, they are known as Non Renewable Energy Resources useful link