Coal and petroleum products (fossil fuels) are a powerful resource of and energy. Following plants and animals are buried and "stored" underground for millions of years leading to the formation of these byproducts.

Carbon AND

DEATH

Explanation:

Carbon containing organic molecules derived from the remains of  dead plants and animals on the earth million of years ago, buried deep under  the sediment and rock layers are called Fossil fuels. Coal,oil,and natural gas are examples.

These underground deposits were formed million of years ago,due to the chemical reactions between  relatively underground  water molecules on one hand,and the  earliest mic organisms  viz algae,bacteria  which inhabited the earth other hand.These decomposition occurred around 540 to 65milion years ago.

However,some million of later chemical reactions in the soil leads to compression of these remains underground.The degradation leads to formation of the fossil fuel precursor called Kerogen. With time Geothermal heat transforms the kerogen precursor to fossil fuel.  some other kerogens are transformed to other natural gas,coal etc.