Actually dinosaurs contributed little if any to our petroleum deposits. Any organic matter (plants and animals) can be converted to petroleum once buried deep enough and subjected to just the right range of temperature and pressures (called the oil window). Swamps and coastal marshes did contribute to our petroleum deposits as organic matter died and was buried deeper and deeper but; in fact, the majority of our petroleum came from marine plants and animals. Millions of years ago these plants and animals died and settled to the seafloor. There are so many of these tiny marine creatures and plants that it's almost like a continuous rain of material (called pelagic rain), covering the seafloor with a think ooze even today. Eventually these layers are buried under so much sediment (thousands of feet) that the temperature and pressure is high enough to turn them into oil. The layers of material from this pelagic rain turn into shales and the hydrocarbon is generated from shales. During other time periods conditions were different and sands may have made it out to the deep sea bottom on the continental slope near where rivers emptied into the ocean. These eventually form layers of sandstone several hundred feet think. Alternating cycles of sandstones and shales (from times when sand can't make it out that far and all that is deposited is the pelagic rain) being deposited eventually end up as layers within the earth. Each layer can be from a few feet to hundreds of feet think. The shale layers generate the oil which can then migrate upward into the sandstones where it will be stored (in the pore spaces between the grains of sand). Oil is lighter than water so it will move upward until it is trapped by some layer or structure it can't get through. This can be, for example, where the rocks have folded into a dome shape and a sandstone layer is covered by a layer of clays or shales that stop the oil from moving higher. It becomes trapped in the top of the dome.
So really, the answer to your question as to why oil isn't found in more places has as much or more to do with adequate traps being available than it does with source rocks to generate the hydrocarbons. You really need several things working together to end up with an oil reservoir that we can use. You need a source of hydrocarbons (organic material), (2) buried deep enough to turn it into oil, (3) a reservoir rock like sandstone that can hold the oil within it's pore spaces and is close enough to the shales that are generating the oil for it to be able to migrate into it, and (4) for the rocks to have been folded or faulted in such a way as to form a trap to keep the oil from just migrating all the way to the surface and being lost (if it gets too shallow microorganisms literally eat it and turn it into tars and asphaltenes). Really, when you consider everything that has to work together just right it's a wonder we have as much trapped as we do have!
2007-02-11 17:09:55
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answer #1
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answered by GatorGal 4
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Their are vast petroleum deposits still in many places on Earth.
The dreaded country of Iraq is still largely untapped, as is parts of North America and the Gulf of Mexico.
Methane is believed to be frozen under sediment in the worlds oceans.
The problem is that the easy to get oil is mostly depleted.
Political and environmental concerns are hampering efforts to open new fields.
Iraq is obviously at war.
North America has passed many environmental protection laws that prohibit oil exploration.
Oil in the Gulf of Mexico has proven difficult to extract and with hurricanes slamming the drilling platforms, really expensive and dangerous.
Methane (natural gas) is a greenhouse gas.
Sooooo...there you have it. Yes there is still plenty of oil out there,
but it's really hard to get.
We also can't forget that OPEC sets the prices of crude oil and
adjusts production levels when ever they "feel like it".
So your petroleum prices and supply can be altered on a whim.
This is the part where I write that I am not taking sides on the political and environmental issues associated with oil.
I'm just answering your question.
2007-02-12 00:55:05
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answer #2
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answered by welder guy 2
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Some of the petrochemicals come in the form of oil. Some in the form of coal and natural gas. It is pretty much all over in areas that are relatively flat. (Not in the middle of a mountain range for example.) The problem is we are using up the stuff that is easy (and cheap) to get and what will remain is the expensive stuff.
Imagine having to pay $100 for a gallon of gas. You will still be able to buy the gas, but do you want to pay that price?
We need to start moving towards forms of energy that can be renewed, such as solar, wind, tidal, hydro, and bio power. We also need to get going on nuclear fusion power.
If we continue the course we are on, life will be like presented in the movie SOYLENT GREEN...
2007-02-12 00:16:07
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answer #3
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answered by forgivebutdonotforget911 6
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Petroeum is formed from the remains of ancient swamps. It includes dead dinosaurs, trees, plants, smaller animals, insects, etc. So it's found in places that formerly supported swampland. There are a great many such places in the world, but some are easier to get to than others, in terms of drilling, mining, and transportation. In addition, some oil producting countries don't consume very much oil, so they have more for export.
2007-02-12 00:09:18
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answer #4
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answered by Joni DaNerd 6
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she-nerd is correct. oil is an organic based substance. it can be found in may places but right now we are only using the easiest pools to get at for it. as the supply dwindles we Will be forced to put more money into drilling for the harder to reach pools.
2007-02-12 00:18:40
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answer #5
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answered by Anonymous
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Apparently not. Also the earths surface shifts and moves around.
2007-02-12 00:09:31
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answer #6
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answered by Anonymous
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