lab+4


 * 1)  what fossil fuels are?  :El petróleo y el gas encuentra cerca de la superficie terrestre se los suele describir como los combustibles fósiles.


 * 1)  how are they formed?  :se formaron a partir de la ruptura de las antiguas plantas y de animales

1. Write what you know on the topic in your wiki. If you don't know anything you should after reading this text on Digging deep for fuel: el texto trata de la excavaciones de los combustibles fosiles como lo son el gas y el petroleo que se encuentan en la superficie terrestre, señala experiementos que realizan los cientificos y dan pistas importantes de como comenzo la vida sobre la tierra, su proceso de excavacion, y su formacion que fue dada por la ruptura de antiguas plantas y animales.
 * 1)  how they are extracted from the Earth?: la excavacion del combustible fosil es un gran negocio, el cual se encuentra debajo de la superficie de la tierra en algunos lugares, y en otros en reservorios de planetas principales de fuente de combustible

Scrambled text Copy and paste the paragraphs in their correct order into your wiki:

Digging in dirt and rock is a big business. Oil and gas lie beneath Earth's surface in certain places, and these reservoirs are the planet's main sources of fuel.

Oil and gas found near Earth's surface are often described as fossil fuels. Most scientists favor the idea that these hydrocarbon fuels were formed by the breakdown of ancient plants and animals. However, recent research also shows that methane gas can form in the crust when there are no living creatures around.

The research could provide important clues about how life began on Earth. Some bacteria feed on methane. If methane were present in the mantle, it could support populations of microbes, allowing them to survive in such an extreme environment. It may also be worth looking for underground stores of methane on Mars and other planets when searching for signs of life.

Until now, all the digging has happened only in Earth's outer layer, called the crust. Oil and gas wells normally go no deeper than about 6 kilometers. A new study shows that natural gas, mainly methane, may also form in a much deeper layer called the mantle. This means that new sources of energy could lie at depths of 100 kilometers (62 miles) or more.

The experiment produced tiny bubbles of methane gas, the scientists report. However, no one knows yet how much methane, if any, is actually present in the mantle. And, if it is present, whether any gas might seep up into the crust and emerge from spots on the ocean floor.