Sunspot wrote:Sigh...To repeat, I'm quite sure it was Deffeyes who said there is little liklihood of significant oil deposits in Antartica. The primary reason HE GIVES is the "pounding" of the underlying strata by repeated glaciation.
Ever been in an earthquake?? The ground is not solid, it is plastic, technically. Pile two or three miles of ice on top, over an entire continent, and you're going to press down pretty hard on that land. Doesn't that make sense? If an elephant sat on your chest, you'd feel considerable pressure, don't you think??
The opinion of Kenneth Deffeyes holds much more weight than anyone on this website. I know at this point I'm supposed to provide a specific reference, but I don't have the time to track it down.
Oh, and Deffeyes is also tho person who describes the "Oil Window", 7500 ft. to 15,000 ft. Below that it turns to gas. And yes, it's not exactly the same everywhere on the planet, maybe you can still get oil somewhere deeper than that, but generally it will turn to gas. Read "Hubbert's Peak"!
To repeat, I'm quite sure it was Deffeyes who said there is little liklihood of significant oil deposits in Antartica. The primary reason HE GIVES is the "pounding" of the underlying strata by repeated glaciation.
Ever been in an earthquake?? The ground is not solid, it is plastic, technically. Pile two or three miles of ice on top, over an entire continent, and you're going to press down pretty hard on that land. Doesn't that make sense? If an elephant sat on your chest, you'd feel considerable pressure, don't you think??
Oh, and Deffeyes is also tho person who describes the "Oil Window", 7500 ft. to 15,000 ft. Below that it turns to gas. And yes, it's not exactly the same everywhere on the planet, maybe you can still get oil somewhere deeper than that, but generally it will turn to gas. Read "Hubbert's Peak
Also, high pressure of natural gas will produce oil and not the other way around.
...there is an "oil window" that depends on subsurface temperatures. The rule of thumb says that temperatures 7,500 feet down are hot enough to "crack" organic rich sediments into oil molecules. However, beyond 15,000 ft the rocks are so hot that the oil molecules are further cracked into natural gas. The range from 7,500 ft to 15,000 ft is called the "oil window".If you drill deeper than 15,000 ft, you can find natural gas but little oil."
Straight from the man, Mr. Deffeyes.
Note that he leaves open room for exceptions to these numbers - they aren't set in stone - but this is the general picture. According to someone who has participated in the oil industry and studied the subject his whole life.
Sunspot wrote:re: oil window
"Hubbert's Peak" page 8:
...there is an "oil window" that depends on subsurface temperatures. The rule of thumb says that temperatures 7,500 feet down are hot enough to "crack" organic rich sediments into oil molecules. However, beyond 15,000 ft the rocks are so hot that the oil molecules are further cracked into natural gas. The range from 7,500 ft to 15,000 ft is called the "oil window".If you drill deeper than 15,000 ft, you can find natural gas but little oil."
Straight from the man, Mr. Deffeyes.
Note that he leaves open room for exceptions to these numbers - they aren't set in stone - but this is the general picture. According to someone who has participated in the oil industry and studied the subject his whole life.
Haven't come across the Antarctic reference, like I said, maybe it wasn't from Deffeyes. I just threw out something I know I read somewhere from what I consider to be a reliable source.
The effects on the substrata of repeated glaciation are over the last 100 million years or so. And if you still think that a three mile thick layer of ice doesn't push down on the land then you must think ice is made of helium.
Haven't come across the Antarctic reference, like I said, maybe it wasn't from Deffeyes. I just threw out something I know I read somewhere from what I consider to be a reliable source.
The effects on the substrata of repeated glaciation are over the last 100 million years or so. And if you still think that a three mile thick layer of ice doesn't push down on the land then you must think ice is made of helium.
actually Campbell says something pretty similar, that the weight of the current icecaps turns liquid petroleum to gas
rockdoc123 wrote:
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Irrespective of how long the ice has been there what I said was that 2 km of ice is much lighter than 2 km of rock (heres a experiment go to the fridge pull out an ice cube hold in one hand then walk outside pick up rock of same size and hold in other hand....which is heavier?). Oil is found at depths well over 3 km when it is covered in rock so why should ice be any worse? In actual fact with the cold thermal insulating layer there is a good chance that the geothermal gradient in Antartica is somewhat lower than other cratonic areas suggesting the oil window could even be lower. If ice is such a bad thing then how do you explain the tens of billions of barrels in the Arctic?
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