Respuesta :
Answer: The lifecycle for oil fields begins with a deep, slow biological process. Different species of plants and animals die, gather into collectives, and settle over long periods of time. Wind, water and living organisms move those organic deposits (dead plants and animals) into new positions.
Eventually, rivers deposit the biomass into early lakes or seas, where they accumulate further, possibly smothered by more sediment. The cycle for making oil fields is a long one. Outside of the very early geological history, biological agents are the initial catalysts that begin the process. The exception could be diamond formation. The oldest diamonds are, of course, a billion times older than the oldest fossils, but all diamonds – possibly even the pre-Cambrian rocks – were created at depth by biological catalysts. Eventually, the organic content of all these formations will be affected by huge masses of overburdening sediments.
Fossilised plants and animals will increase the organic content of formations. Even in modern times, lots of organic material falls into the sea each year. Sediment and wind and water will diffuse these fossil-bearing sea deposits almost anywhere on the continents, so that they cover hundreds of meters of land. As the sediments pile up, the overburdening weight exerts immense pressure on the subsurface formations. The enormous pressures and temperatures caused by these tectonic forces lead to diagenesis, as mentioned above. Heat is a crucial input for this process. Chemical reactions within the buried organic matter are sped up by heat, which initiates the creation of hydrocarbons. Heat is generated by the Earth’s internal temperature, as well as by the burial of sediments over periods of many millions of years. Landsurface-melting and freezing are active in these cases, but they are not directly relevant to the formation of oil fields – the heat in the crust is crucial for the creation of the useful resource. Rocks undergo various changes to their chemistry when heated by the Earth’s crust. We call that thermal cracking, and it’s what leads to millions of oil fields underneath the Earth’s surface.
