Origin of Permafrost

When and how did permafrost originate?

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Origin of Permafrost

#1  Postby AlanF » Oct 23, 2019 5:37 pm

When I was young and part of a creationist cult, a major talking point 'proving' Noah's Flood was that "palm trees have been found in Arctic permafrost with intact fruit", which supposedly indicated a pre-Flood 'hothouse climate'. I later learned that this idea was borrowed by the cult from Henry Morris' "The Genesis Flood" and from George McCready Price's writings. I also was told several decades ago that the palm tree trunks were actually mummies (what exactly is mummified wood?), and that the claim of frozen fruit was nonsense.

In recent years geologists have found the Eocene thermal maximum of about 45 million years ago, and that roughly 25 million years ago the Arctic and Antarctic began to freeze. Another creationist staple was that the substantial numbers of large animals found in permafrost or recently melted permafrost were 'quick frozen' in mysterious ways. I recently saw information on the melting of a big hole in Siberian permafrost that shows that large parts of the Arctic during glacial times became rather strange places where spotty melting of permafrost resulted in semi-melted ponds dotting the landscape, which became traps for all manner of animals such as mammoths, so the 'quick frozen mammoths' of Henry Morris et al are now satisfactorily explained.

Given all that, can anyone point me to sources that speak of the above in detail? In particular, that explain how up to a kilometer or more of permafrost accumulated in the Arctic? Especially when Eocene sea levels were up to 60 meters higher than today? I'm especially interested in tracking down where all the now-frozen mud came from. In areas where mountains have eroded and dumped sediments, the sources are fairly well known. How about for Arctic permafrost sediments?

What got me thinking about this stuff was an article on the increased rate of melting of permafrost:

https://www.dailykos.com/stories/2019/1 ... n=trending

I'm somewhat grateful that I'll probably be dead by the time the shit hits the fan big time.
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Re: Origin of Permafrost

#2  Postby felltoearth » Oct 23, 2019 6:48 pm

This is a pretty good explanation.

Permafrost | geology | Britannica.com
The permafrost layer will become thicker each winter, its thickness controlled by the thermal balance between the heat flow from the Earth’s interior and that flowing outward into the atmosphere. This balance depends on the mean annual air temperature and the geothermal gradient. The average geothermal gradient is an increase of 1 °C (1.8 °F) for every 30 to 60 metres of depth. Eventually the thickening permafrost layer reaches an equilibrium depth at which the amount of geothermal heat reaching the permafrost is on the average equal to that lost to the atmosphere. Thousands of years are required to attain a state of equilibrium where permafrost is hundreds of feet thick.
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Re: Origin of Permafrost

#3  Postby AlanF » Oct 23, 2019 8:21 pm

Thanks, but that in no way answers my questions. I want to know where a kilometer or more of sediments came from.
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Re: Origin of Permafrost

#4  Postby newolder » Oct 23, 2019 8:31 pm

More from Brittanica.com
Oceanic crust adjacent to the continents can be deeply buried by several kilometres of sediment.
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Re: Origin of Permafrost

#5  Postby Macdoc » Oct 23, 2019 11:22 pm

I want to know where a kilometer or more of sediments came from.


Glaciers move massive amounts of sediments around - a strong up thrust of new mountain building will see huge amounts of material carried into river valleys....this can also occur underwater and then be upthrust.

https://www.britannica.com/science/marine-sediment

Arctic: Geology
…have been long periods of marine sedimentation, and consequently the shields are partly buried. In some areas thick sediments were subsequently folded, thus producing mountains, many of which have since been destroyed by erosion. Two main orogenies (mountain-building periods) have been recognized in the Arctic. In Paleozoic times
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Re: Origin of Permafrost

#6  Postby AlanF » Oct 24, 2019 5:30 pm

Yes, I understand all that, but the Britannica article does not cover the situation I describe. Between the Eocene thermal maximum, when the Arctic was semitropical and palm trees grew there, and sometime during the following Oligocene, climate cooled a lot. Glaciers in the north formed around the Eocene-Oligocene boundary. The sediments I'm wondering about contain semi-tropical vegetation, so they were not glacial sediments, and glaciers did not exist in the Arctic in the Eocene.

I don't know whether anyone has drilled down through the thick permafrost sediments, so I don't know where a boundary occurs between various sediment layers. Perhaps sediments were laid down in the Cretaceous, followed by the semitropical Eocene layers, followed by what? Some of these obviously Eocene sediments are at or near the surface, which poses another question: what is the history of sediment deposition/erosion in permafrost regions?
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Re: Origin of Permafrost

#7  Postby felltoearth » Oct 24, 2019 6:03 pm

"Walla Walla Bonga!" — Witticism
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Re: Origin of Permafrost

#8  Postby felltoearth » Oct 24, 2019 6:10 pm

There were inland seas and erosion of older mountains that would explain deposition to a certain extent. Pangaea was in the final final throes of breaking up at the time so there would be a lot of rifts and mountain forming moving and possibly concentrating sediments all over the place. I’m not a geologist so I can’t speak to the arctic or antarctic particulars.
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Re: Origin of Permafrost

#9  Postby Macdoc » Oct 24, 2019 8:41 pm

I'm wondering about contain semi-tropical vegetation, so they were not glacial sediments, and glaciers did not exist in the Arctic in the Eocene.


Glaciers moved and folded the deposits....that's why seashells are found on the top of the Rockies

Sub-Tropical deposits are laid down ....
Glaciers then plow them into piles/strata of varying thickness
Then they were also caught in mountain building which further distorts them
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