Greenland Hiawatha Crater Robustly Dated to Late Paleocene

Guest “Missed it by that much” by David Middleton

Following this, Kjaer et al. (2018) report the discovery of a large impact crater beneath Hiawatha Glacier in northwest Greenland. From airborne radar surveys, they identify a 31-km-wide, circular bedrock depression beneath up to a kilometre of ice. They further suggest the impactor was over 1 km wide and unlikely to predate the Pleistocene, i.e. it is less than a few million years old (see Fig. 11). This maximum age is confirmed a year later (Garde et al., 2020). Clearly, this crater is a candidate YD-age impact structure.

Sweatman 2021

“Clearly, this crater is a candidate YD-age impact structure.”

Missed it by that much.

Massive asteroid hit Greenland when it was a lush rainforest, under-ice crater shows
By Stephanie Pappas published 3 days ago

The enormous impact crater dates to 58 million years ago.

Scientists now know the age of an enormous impact crater hidden under Greenland’s ice. 

The Hiawatha crater, which sits under 0.6 mile (1 kilometer) of ice in northwest Greenland, formed 58 million years ago, according to a study published March 9 in the journal Science Advances. Whereas  some initial estimates had gauged the age of the crater at only 13,000 years, the new finding means the impact occurred much earlier, at a time when Greenland was truly green and full of life. 

“Greenland was actually covered with a temperate rainforest when the asteroid hit,” said study co-author Michael Storey, a researcher at the Natural History Museum of Denmark who specializes in dating geological materials. 

[…]

Live Science

The new publication very robustly dates the impact to the Late Paleocene, approximately 58 million years ago (Ma), approximately the same age as the Marquez impact crater. Many of the coauthors also participated in the first publication on the Hiawatha Crater (Kjaer et al., 2018). The full text is available and it is well-worth reading.

A Late Paleocene age for Greenland’s Hiawatha impact structure

Abstract

The ~31-km-wide Hiawatha structure, located beneath Hiawatha Glacier in northwestern Greenland, has been proposed as an impact structure that may have formed after the Pleistocene inception of the Greenland Ice Sheet. To date the structure, we conducted 40Ar/39Ar analyses on glaciofluvial sand and U-Pb analyses on zircon separated from glaciofluvial pebbles of impact melt rock, all sampled immediately downstream of Hiawatha Glacier. Unshocked zircon in the impact melt rocks dates to ~1915 million years (Ma), consistent with felsic intrusions found in local bedrock. The 40Ar/39Ar data indicate Late Paleocene resetting and shocked zircon dates to 57.99 ± 0.54 Ma, which we interpret as the impact age. Consequently, the Hiawatha impact structure far predates Pleistocene glaciation and is unrelated to either the Paleocene-Eocene Thermal Maximum or flood basalt volcanism in east Greenland. However, it was contemporaneous with the Paleocene Carbon Isotope Maximum, although the impact’s exact paleoenvironmental and climatic significance awaits further investigation.

[…]

DISCUSSION

A new age for the Hiawatha structure

Two impact melt rock samples, collected in 2019 from a riverbank less than 10 km downstream from the edge of the Hiawatha structure, contain unshocked zircon with ages indistinguishable from voluminous local felsic intrusions adjacent to—and presumably also under—Hiawatha Glacier. Shocked zircon in the same samples give a robust ~58-Ma U-Pb age, which agrees with the younger of two 40Ar/39Ar mini-plateau ages from the 2016 sand sample recovered even closer to the structure. In sum, these data indicate sample provenance from a Late Paleocene impact event that occurred somewhere upstream but sufficiently proximal that the target geology is indistinguishable geochronologically from that exposed locally where the samples were recovered. Given existing geomorphic evidence for an eroded complex impact structure beneath Hiawatha Glacier, whose apparent rim is breached by the subglacial channel that ultimately becomes the subaerial river channel from which our detrital samples were recovered (1), the simplest interpretation of our observations—which we explicitly accept for the remainder of the discussion—is that the Hiawatha structure is a relatively large impact structure that formed in the Late Paleocene.

When the Hiawatha structure was first proposed as an impact structure, it was also suggested that it post-dated the Pleistocene inception of the Greenland Ice Sheet at ~2.6 Ma (1). The ~58-Ma age for the structure indicates that it formed long before the inception of the ice sheet, and that it is unrelated to the onset of the Younger Dryas cold period ~12,900 years ago as has been speculated (19). 

[…]

Pebble-sized charcoal particles (with cellular structures indicative of conifer wood) and apparently impact-related sand grains rich in organic carbon have been found in Hiawatha Glacier’s glaciofluvial outwash (23). These were assumed to have been derived from organic material in Early Pleistocene deposits and were thus interpreted to support a young impact age (2). However, the new age for the Hiawatha structure indicates that—if these materials are related to the impact—they must instead date to the Paleocene or earlier. Abundant Late Paleocene plant fossils in the Arctic (e.g., on Ellesmere Island, across Nares Strait from Inglefield Land) point to widespread high-altitude coniferous forests at this time (28), providing a plausible source of organic material in impact-related sediments at Hiawatha Glacier.

[…]

Kenny et al., 2022
FIG. 6. The new age for the Hiawatha impact structure in the context of early Paleogene chronostratigraphy and carbon and oxygen isotope variations.
Chronostratigraphic column and absolute ages after (75). Carbon and oxygen isotope curves after (76) and references therein. Ages for other impact structures with absolute age constraints from compilation of (42) and references therein, except the age for Boltysh, which was published very recently (77). Age of spherules at P-E boundary from (50). Age of peak flood basalt volcanism in east Greenland recalculated from (33) and age of peak eruption of Paleocene lava piles in west Greenland from (3435). Approximate age of spherule beds in west Greenland is based on their occurrence at low stratigraphic levels of the Paleocene lava pile of western Greenland (34). Uncertainties shown at 2σ. K., Cretaceous; Maas., Maastrichtian; Dan., Danian; Sel., Selandian; Than., Thanetian; Ypr., Ypresian. (Kenny et al., 2022)

The authors dated unshocked and shocked zircon using the 40Ar/39Ar technique. The unshocked zircon dated to 1.9 Ga, consistent with established dating of the target rock formation. The shocked zircon dated to 58 Ma. The U-Pb method also yielded an age of 58 Ma for the shocked zircon. 40Ar/39Ar (argon-argon) is a very versatile and relatively accurate method for geochronological dating. It can date materials from a few thousand to billions of years old. U-Pb (uranium-lead) is one of the most widely used methods for radiometric dating, particular older rocks.

Based primarily on the work of Garde et al., 2020, Christ et al., 2021 and Silber et al, 2021, I had previously bracketed the age of the impact to have been between 1.4 to 0.9 Ma. Silber demonstrated that the impact probably occurred on an ice-free surface and Garde had placed the maximum age at 2.4 to 3 Ma. Garde made the assumption that the charred organic material was related to Late Pliocene to Early Pleistocene deposits containing fossilized material from trees. They didn’t directly date the material or consider that it might be related to much older periods when Greenland was actually green.

The Hiawatha Crater is now categorically ruled out as a candidate for a Younger Dryas impact structure.

References

Christ, A.J., Bierman, P.R., Schaefer, J.M., Dahl-Jensen, D., Steffensen, J.P., Corbett, L.B., Peteet, D.M., Thomas, E.K., Steig, E.J., Rittenour, T.M., Tison, J-L., Blard, P-H., Perdrial, N., Dethier, D., Lini, A., Hidy, A.J., Caffee, M., Southon, J., 2021, “A multi-million-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century”, The Proceedings of the National Academies of Sciences of the United States of America.

Garde, Adam A., Anne Sofie Søndergaard, Carsten Guvad, Jette Dahl-Møller, Gernot Nehrke, Hamed Sanei, Christian Weikusat, Svend Funder, Kurt H. Kjær, Nicolaj Krog Larsen; Pleistocene organic matter modified by the Hiawatha impact, northwest GreenlandGeology 2020;; 48 (9): 867–871. doi: https://doi.org/10.1130/G47432.1

Kenny, Gavin G. et al. 2022. “A Late Paleocene age for Greenland’s Hiawatha impact structure“. Science Advances 8 (10); doi: 10.1126/sciadv.abm2434

Kjær, Kurt, Larsen, Nicolaj, Binder, Tobias, Bjørk, Anders, Eisen, Olaf, Fahnestock, Mark & Funder, Svend & Garde, Adam & Haack, Henning & Helm, Veit, Houmark-Nielsen, Michael, Kjeldsen, Kristian, Khan, Shfaqat, Machguth, Horst, Mcdonald, Iain, Morlighem, Mathieu, Mouginot, Jeremie’ Paden, J., Waight, Tod & MacGregor, Joseph. (2018). “A large impact crater beneath Hiawatha Glacier in northwest Greenland”. Science Advances. 4. eaar8173. 10.1126/sciadv.aar8173.

Silber, E. A., B. C. Johnson, E. Bjonnes, et al. 2021. “Effect of ice sheet thickness on formation of the Hiawatha impact crater.” Earth and Planetary Science Letters566: 116972 [10.1016/j.epsl.2021.116972]

Sweatman, Martin B. The Younger Dryas impact hypothesis: Review of the impact evidence, Earth-Science Reviews, Volume 218, 2021, 103677, ISSN 0012-8252, https://doi.org/10.1016/j.earscirev.2021.103677.

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Kpar
March 18, 2022 2:16 pm

Too bad. I was hoping that it was coincident with the “carbon layer” dating to 12.9 Kyr BP, which appears to coincide with the collapse of the megafauna of North America (and, coincidentally (?) with the disappearance of the Clovis People.

Still, this does NOT provide evidence of the contrary, there may not be a crater associated with that event.

Rud Istvan
Reply to  Kpar
March 18, 2022 3:06 pm

I did a fair bit of research on the Younger Dryas impact theory. Turns out that much of the supposedly supporting data really doesn’t because of wide discrepancies in dates from different sites. Has been debunked academically several times because of this, but the proponents just keep bringing up more ‘new’ evidence that then gets debunked again. It almost made an example in my ebook Arts of Truth but eventually got left on the cutting room floor as too esoteric and not generalizable enough.

Reply to  David Middleton
March 19, 2022 6:36 am

JFK assassination conspiracy theories.
=========
Nixon had been head of CIA.
Nixon was POed over election defeat.
Nixon was in Dallas day before Kennedy assasination.
Assasination was in Dallas.
CIA was very POed with Kennedy over Bay of Pigs.
CIA had history of political assasinations.
Nixon Plumbers were ex CIA.

Similar list exists for LBJ who was also POed with Kennedy and stood to gain the presidency.

Why LBJ didnt run for another term and instead Nixon became president would suggest the assasination was part of a long term strategy.

John Tillman
Reply to  ferdberple
March 19, 2022 7:26 am

Nixon was not head of CIA, nor in Dallas.

JFK was shot by a pro-Cuban Communist.

John Tillman
Reply to  John Tillman
March 19, 2022 4:18 pm

The KGB went to great lengths to convince the CIA that its hit on JFK was not like its hit on Hugh Gaitskell, anti-Communist UK Labour Party leader, in January 1963.

But the evidence is overwhelming.

John Tillman
Reply to  John Tillman
March 20, 2022 12:04 pm

Before k!lling Kennedy and wounding Gov. Connolly, Oswald tried to assassinate MG Edwin Walker. After murdering the president, he k!lled Officer J. D. Tippit.

Ruleo
Reply to  John Tillman
March 20, 2022 12:30 pm

LOL no buddy. FBI killed him. But, whatever suits your programming.

Gary Pearse
Reply to  David Middleton
March 19, 2022 12:57 pm

Well, like the Hiawatha, it could be another hidden impact waiting to be discovered. Something sudden happened for which we have no climate-by-itself precedents known.

John Tillman
Reply to  Gary Pearse
March 19, 2022 1:46 pm

The YD is the very opposite of unprecedented. It was preceded by the Older and Oldest Dryas cold snaps, plus the same phenomenon in previous glacial terminations. They’re caused by fresh water lenses on the Arctic, Atlantic and Pacific Oceans.

Such warming interruptions are related to Heinrich Events during glacial intervals, when iceberg armadas carry freshwater out into the oceans, leading to the coldest stadials.

Nothing the least bit mysterious about the recurrent phenomenon.

https://www.science.org/doi/10.1126/sciadv.aay2935

Sea level fingerprinting of the Bering Strait flooding history detects the source of the Younger Dryas climate event

Last edited 6 months ago by John Tillman
John Tillman
Reply to  John Tillman
March 21, 2022 5:31 pm

It was followed by the 8.2 Ka cold snap, when meltwater from the last of the North American ice sheets was released.

Reply to  Kpar
March 19, 2022 6:32 am

There is no record of the impact in the Greenland ice cores….now we know why.

John Tillman
Reply to  Kpar
March 19, 2022 4:25 pm

No such layer. No such coincidence.

YDIH is the sheerest nonsense, evidence free idle speculation iniciated by a convicted fraudster, but latched onto by third-rate academics seeking easily to publish garbage, lest they perish, as would have been deserved..

Thomas Gasloli
March 18, 2022 2:18 pm

The most interesting thing about this crater is that the impact apparently had no other affect. Something can crash into the earth, cause a 31 km wide crater, and Gaia shrugs.

Rud Istvan
Reply to  Thomas Gasloli
March 18, 2022 2:54 pm

This one hit bedrock. The Chixilub impact was 5x bigger, and it hit thick layers of gypsum so the sulfur aerosols were horrendous.

Martin
Reply to  David Middleton
March 18, 2022 5:36 pm

Humans, on the other hand, are increasingly more fragile…

Clyde Spencer
Reply to  Martin
March 18, 2022 6:36 pm

They melt easily — at least a lot of the newer ones.

Peter Fraser
Reply to  Thomas Gasloli
March 19, 2022 1:07 pm

The same may be said for the Manson Crater in Iowa. Dated at 74 mya with a similar diameter to Hiawatha of 31kms. Before it was accurately dated it was a possible candidate for the dinosaur extinction but was assessed as being ‘too small’.

John Tillman
Reply to  Peter Fraser
March 19, 2022 1:48 pm

Also lacking the particularly nasty geology of the Yucatan site.

Tom Halla
March 18, 2022 2:54 pm

A beautiful theory destroyed by an ugly little fact.

John Tillman
Reply to  Tom Halla
March 18, 2022 4:56 pm

It’s an ugly hypothesis as well.

Rud Istvan
March 18, 2022 3:00 pm

That Greenland 58mya was truly green is thanks to plate tectonics. It’s present central latitude is about 72N. Back then it was about 50N (inferred from Iceland drift over 500my, footnote 5 to recognition chapter of Arts of Truth, inspired by a Lindzen question to me after he kindly reviewed not only the climate chapter but the whole book draft). Today’s Olympic Peninsula temperate coniferous rain forest in Washington State is about 48N.

John Tillman
Reply to  Rud Istvan
March 18, 2022 4:59 pm

Greenland then was farther north than that. It was verdant because Earth was in a Hothouse climate during the Paleocene.

Last edited 6 months ago by John Tillman
Rud Istvan
Reply to  John Tillman
March 18, 2022 5:12 pm

JT, please check your ‘Continental drift’ plate tectonics. The poles were always cold. The lands now over them we’re not then.

Ron Long
Reply to  Rud Istvan
March 18, 2022 6:20 pm

Guys, the first thing I did was look at Greenland projection 58 mya and it appears, in the data I found, the Hiawatha impact site was around 20 degrees latitude further south than today. However, the Earth was hotter then, so the Greenland rain forest was really lush. So, in 58 my we went from rain forest to one kilometer of glacial ice cover. Wonder where the continents are going now? Is there a race between continental drift and global warming? Judging from the trace of the Yellowstone hot spot, the North American Plate is moving northwest, into cooler climates. CAGW? Forget about it.

rah
Reply to  Ron Long
March 19, 2022 3:26 am

What? If the hotspot that now lies beneath the Yellowstone Caldera is static that means the shift of the plate is to the SW not the NE.

Track of Yellowstone hotspot | U.S. Geological Survey (usgs.gov)

comment image?itok=GEiVyNOw

Ron Long
Reply to  rah
March 19, 2022 3:44 am

rah, look at the arc of the downwarp, it is concave north, requiring plate movement west of Yellowstone to be trending NW (not NE). I prefer to plot the arc of the hotspot scribed into the North America Plate by the trend of actual felsic calderas, matched by Columbia River Basalt Flows to the north and Rift basalts to the south.

rah
Reply to  Ron Long
March 19, 2022 4:47 am

So if plate is rotating and the western portion is moving NE then the eastern portion is moving SW?

ATheoK
Reply to  rah
March 19, 2022 8:00 pm

Perhaps this will help.

The picture includes an arrow depicting plate direction, to the SW.

Yellowstone hot spot path 2000-rbs-1.jpg
John Tillman
Reply to  Rud Istvan
March 19, 2022 7:47 am

Please take your own advice. In the Paleocene, Greenland was mostly in its present latitudes:

https://www.nature.com/articles/s43247-021-00249-w

John Tillman
Reply to  John Tillman
March 19, 2022 11:58 am

Please see Pat Frank’s comment below for a Paleocene reconstruction.

Scotese doesn’t have a Paleocene map, but here’s the Eocene, just eight million years later:

http://www.scotese.com/newpage9.htm

And here’s the end of the Late Cretaceous Epoch and beginning of the Paleocene. eight million years before the probable age of the Hiawatha Crater:

http://www.scotese.com/K/t.htm

Please note the high latitude of Greenland.

The early Eocene was even toastier than the PETM, but then rearrangement of the Gondwanan continents led to global cooling and drying. Antarctic ice sheets formed in the early Oligocene, thanks to the Southern Ocean.

Last edited 6 months ago by John Tillman
Gary Pearse
Reply to  Rud Istvan
March 19, 2022 1:14 pm

How about the “over 50 million year” old redwood logs preserved at 300m depth in the Ekati diamond mine at the Arctic Circle in Northern Canada.

https://www.livescience.com/23374-fossil-forest-redwood-diamond-mine.html

Maybe the impact caused the emplacement of diamond pipes from Saskatchewan to Quebec and up into the Canadian Arctic Archipelago

https://www.livescience.com/23374-fossil-forest-redwood-diamond-mine.html

Nelson
March 18, 2022 4:15 pm

The Younger Dryas is an interesting period. I find it amazing that there isn’t an agreed upon explanation.

John Tillman
Reply to  Nelson
March 18, 2022 5:05 pm

The cause of the Dryas is agreed upon by every student of it, except for the few who’ve made a career out pushing the YDIH nonsense.

It’s cause was the same as the previous Dryas events, and other such cold snaps during prior glacial terminations, ie pulses of cold, fresh water from outburst floods and iceberg armadas (as in Heinrich events).

Just one of many papers presenting the incontrovertible evidence:

https://www.nature.com/articles/nature08954

Identification of Younger Dryas outburst flood path from Lake Agassiz to the Arctic Ocean
There is no mystery surrounding the YD. Megafauna went extinct before, during and after it, whenever humans arrived. Large animals did better in Africa, where they were hip to human tricks, but even so, anatomnically modern people wiped out many big game species there as well. Same as in Australia, Asia, Europe, the Americas, Hawaii, New Zealand, Reunion Island. You name it.

The YDIH is easily shown false. Caribbean megafauna didn’t go extinct until thousands of years after the YD and after their kin on North and South America were wiped out by humans.

Last edited 6 months ago by John Tillman
John Tillman
Reply to  John Tillman
March 18, 2022 5:43 pm

The only reason there was ever any question about the YD was because scientists were looking in the wrong places, a la “Raiders of the Lost Ark”. Other glacial termination cold snaps, and Heinrich Events during glaciations, all showed sediment or ice-rafted debris of the right age. Sediments down the St. Lawrence and Mississippi didn’t include YD age layers.

This gave the YDIH kooks an opening, and they ran with it. But soon after they began their scam, YD-age sediments were found in the Arctic Ocean. At that time, proglacial Lake Agassiz drained to the north, not the south or east. This discovery has been repeatedly confirmed in the Atlantic and Pacific.

The YDIH is dead but lurches on, zombie-like, because some journals still publish its few advocates, who of course pay for their breathless “work” to be printed.

agimarc
Reply to  Nelson
March 18, 2022 5:07 pm

Its because it is relatively new and we’re still in the arm waving and chair throwing stage of the discussion. David is doing God’s Work (though I disagree with his conclusion that the impact model for the YD doesn’t work) in relentlessly bringing things that don’t fit that model to WUWT. Many thanks, David. For my part, I think something happened, though there is not enough bulletproof data as yet. The YD guys make their money with the discussions of what happened in the interval following the YD and today. There was a LOT of very well documented catastrophic events between the YD and 535 AD yet to be tied together. Cheers –

Rud Istvan
Reply to  Nelson
March 18, 2022 5:13 pm

I agree. Tried to sort it out over a year a decade ago. Gave up.

Steph
Reply to  Nelson
March 18, 2022 7:59 pm

All of you are much more knowledgeable than myself, so my wonder is has anyone looked up to the big ball o’ fire in the sky that may have changed Earth’s climate so precipitously ?

March 18, 2022 4:21 pm

It appears that “Greenland was truly green and full of life” at about 65 degrees north.

Greenland appears to be surrounded by spreading rifts. Maybe all that thermal activity had something to do with the green.

Paleocene 60 Ma.png
Smart Rock
Reply to  Pat Frank
March 18, 2022 5:30 pm

No Pat, it was just a “normal” time in earth history. It seems anomalous to us because we live in an ice age, which is an “abnormal” time. Even the present interglacial that contains all of recorded human history is several degrees colder than the normal times, when there were no polar ice caps.

It seems more than likely that, without the ice age and the need to adapt to rapidly changing climate and environment as the earth slopped back and forth between glacial and interglacial periods, we wouldn’t have evolved much beyond our great ape ancestors. We’d still be hanging around the jungle and not thinking about much except where to get the best bananas. We are the children of the ice age.

John Tillman
Reply to  Smart Rock
March 18, 2022 5:44 pm

Both Icehouses and Hothouses are normal.

Duane
Reply to  John Tillman
March 18, 2022 7:15 pm

Yes – “Normal” is a value judgment, not a scientific analysis. The planet constantly cycles through varying climatic and geologic eras, and that is simply what the Earth does, and has always done, and will continue to do until we are absorbed by our sun turning into a Red Giant star.

Duane
Reply to  Smart Rock
March 18, 2022 7:08 pm

It is correct that human ancestors – hominins as opposed to hominids – evolved away from modern apes because their climate and vegetation evolved from dense wet tropical rain forests to open temperate drier savannas, whereas the hominids remained as apes in the tropical rain forests.

That climate shift made it necessary for our ancestors to come down from the forest canopy to pursue life on the ground. That caused our evolution to bipedalism, while having exposure to greater risk from ground based predators, successful hominins needed to grow larger brains and opposed thumbs that promoted more sophisticated tool-making and more complex behaviors such as language and artistry. Thus we eventually became Homo Sapiens Sapiens. And the apes stayed as apes.

The former warmer, wetter climate that preceded the “ice age”, when it transformed into a cooler and drier, climate, birthed modern humans.

Last edited 6 months ago by Duane
rah
Reply to  Duane
March 19, 2022 3:34 am

I don’t know why you got a down mark on that. What you stated is the current accepted hypothesis from what I have read.

ATheoK
Reply to  rah
March 19, 2022 8:47 pm

successful hominins needed to grow larger brains and opposed thumbs that promoted more sophisticated tool-making”

That is not an evolution process.

John Tillman
Reply to  ATheoK
March 20, 2022 2:47 pm

The mutations that permitted larger brains were selected for, so growth of the organ was entirely an evolutionary process. Indeed, classic darwinian evolution via natural selection.

Here is one of the mutations enabling bigger brains.

https://www.discovermagazine.com/planet-earth/found-the-genes-behind-big-human-brains

And another one:

https://www.science.org/content/article/weak-jaw-big-brain

Last edited 6 months ago by John Tillman
Reply to  Duane
March 19, 2022 6:48 am

A cooler drier climate doesnt explain why humans are almost hairless.

We should have thick fur because a naked human dies of exposure outside the tropical jungles.

If we argue that clothind was the causr of hair loss it can equally be argured that clothing was an adaptation to lack of hair and changing climate.

But still unanswered. Why are humans almost hairless. What other mamals are hairless and why?

John Tillman
Reply to  ferdberple
March 19, 2022 7:38 am

Mole rats. Some dog breeds.

Humans grow short body hair because of our cooling system by sweating. We have the same number of follicles per square inch of skin as chimps.

Outside the tropics, we need fire and clothes.

Reply to  John Tillman
March 19, 2022 12:30 pm

I’ve read that explanation as well, John. Archaic humans ran down their prey. Becoming hairless caused efficient skin cooling while running in a tropical climate.

I don’t believe there’s an animal that can run farther than a human. I have met people who run the hundred miler Western States Ultra over the Sierra Nevada.

The race used to be on horseback. In 1974 amateur marathoner Gordy Ainsleigh ran the race and beat the horses. Men and women have been running it ever since.

John Tillman
Reply to  Pat Frank
March 19, 2022 1:39 pm

Slow and steady wins the race!

H. erectus was an aerobically fit monster long-distance runner. Wound your prey then relentlessly track it.

Plus scavenge megafaunal long bones with your multitool hand ax.

Instead of fur for protection from tropical UV light, H. erectus evolved melanin rich skin. When his descendants migrated into temperate zones, melanin became less adaptive, due to the need for vitamin D and lowered selective advantage of skin cancer protection.

ATheoK
Reply to  Pat Frank
March 19, 2022 9:29 pm

Several additions to your theory.
A) Native Americans used to chase deer until they collapsed. Usually several NA participated to keep the deer moving.

B) Apaches, despite movie depictions were able to outrun a horse over distance. A horse could only catch a human early in a race.

Instead of the big battles emphasized on TV, Apaches were famous for letting a cavalry patrol to pass by where they are hidden, jumping up and shooting the last soldier with an arrow.

Then the Apache would run over the nearest hill. By the time, the cavalry figured out what happened, turned around and tried to follow, when they got to the top of the hill, no Apache in sight.

C) Walking and running are by far, most efficient means of travel for humans. Worse, the body learns and improves that efficiency as a person walks or runs more.

ATheoK
Reply to  ferdberple
March 19, 2022 9:03 pm

But still unanswered. Why are humans almost hairless. What other mamals are hairless and why?”

Pigs, elephants, Rhinos, Hippos, Whales, Porpoises, Dolphins (mammals), Dugong, etc.

What they have in common are warm wet/muddy environments.

Human ancestors’ fossils are frequently found along watercourses, lakes, oceans, estuaries, etc.
Many of the waters have abundant easy to subdue and consume animals.
Mosquitos are a major problem in those areas. Wildlife far and wide understand the benefit of mud baths to prevent blood loss and near insanity.

Life alongside water goes far to explain why human hair grows so long on the head, yet nowhere else on a human body does hair grow longer endlessly.

Does anyone actually know?
Nope!

John Tillman
Reply to  ATheoK
March 20, 2022 11:40 am

Pigs, elephants, rhinos and hippos all have hair. So do pinnipeds, while sea otters have the densest fur of any mammal. The integument of pinnipeds, sea otters, and polar bears generally has two layers of hair.

Cetacean skin is hairless except for a few vibrissae or bristles occurring mostly on the rostrum or around the mouth. These are usually lost before or soon after birth.

Sirenians have widely scattered hairs.

Humans by contrast have the normal number of body hairs for apes. They just grow shorter than on our heads, armpits and groins.

Our ancestors did not go through an aquatic evolutionary phase. Like all animals, they needed water, and they hunted and gathered aquatic resources.

John Tillman
Reply to  Duane
March 19, 2022 7:34 am

Humans are still hominids and apes. We are African great apes, to be more precise.

All apes have opposable thumbs. Chimps’ precision grip is to the side of the index finger rather than the tip.

Reply to  Smart Rock
March 19, 2022 12:14 pm

Thanks SM. I knew about the warm times past.

The periodic ice ages began after the Isthmus of Panama closed about 3 million years ago, shutting off the Atlantic-Pacific current.

Thinking is that the newly formed Gulf Stream delivered the Arctic moisture that stimulated glacial growth.

Atrato Seaway.jpg
ATheoK
Reply to  Smart Rock
March 19, 2022 8:44 pm

Proto humans were already eating flesh before the ice ages.

Without ferocious strength, claws or teeth, proto humans had to deal with a short semi-erect relatively weak very smelly body.

Survival depended on memory and seriously improved patterning ability. The smartest were often the fittest for learning, improving and eating better. Those that ate better were healthier, stronger and bigger.

When proto-humans crossed the tool barrier early in their evolution, that accelerated brains overcoming challenges.

commieBob
March 18, 2022 4:48 pm

So, are we in a position yet where we can blast space rocks away from the Earth?

Dave Fair
Reply to  David Middleton
March 19, 2022 12:22 am

God, I remember drinking beer and playing ‘Stroids.

Dave Fair
Reply to  David Middleton
March 19, 2022 2:54 pm

On the tip of my tongue but I can’t remember the name of the beer and burger joint with sawdust on the floor in Sacramento, CA 1979-1982. At night it turned into a druggie biker’s bar.

MiloCrabtree
Reply to  commieBob
March 19, 2022 2:52 am

We might be, if we stopped wasting so much money on the stupidity of global warming.

Rud Istvan
March 18, 2022 5:11 pm

Please check your plate tectonics. The poles were always cold. The lands over them used to be elsewhere. Gross example, Antarctica moved over the South Pole about 35mya. It’s coal seams (like Iceland’s) prove it didn’t used to be there.

John Tillman
Reply to  Rud Istvan
March 18, 2022 5:46 pm

The poles are always cooler, but during Hothouses, they’re warm enough for forests to grow there and reptiles to live there.

You are mistaken. Antarctica was already over the South Pole during the Mesozoic Era. You are confusing the formation of deep channels around it at the onset of the Oligocene with its movement over the Pole.

https://en.wikipedia.org/wiki/South_Polar_region_of_the_Cretaceous

Isolating the continent by the Southern Ocean, thanks to oceanic channels between South America and Australia is what caused Antarctica’s glaciation and the onset of the Cenozoic Icehouse climate.

Continental ice sheets spread to the Northern Hemisphere with the closure of the Inter-American Seaway by the formation of the Isthmus of Panama, about three million years ago. Before that, in the Pliocene, boreal forests grew in Arctic Canada and Greenland, which were in about their present high latitude.

Last edited 6 months ago by John Tillman
Jeff
March 18, 2022 6:03 pm

When an asteroid hits there’s usually flood basalts that occur on the opposite side of the world. So if we have dating for the asteroid we have approx dating for the corresponding flood basalts, and when we have the dating for the flood basalts we also have the approx dating for the corresponding asteroid.

ATheoK
Reply to  David Middleton
March 19, 2022 9:43 pm

Metamucil and Kahlua?

Rud Istvan
Reply to  Jeff
March 18, 2022 6:42 pm

That theory depends on stuff not true because of planet tectonics. The India hotspot is a classic example.

John Tillman
Reply to  Rud Istvan
March 19, 2022 2:24 pm

It’s the Reunion Island Hotspot. India happened to be passing over it in the latest Cretaceous. It had nothing whatsoever to do with the Yucatan impact.

The Indian Plate’s journey from separation with Antarctica across the IO to collision with Eurasia set a tectonic speed record. In the process, it split off from the Australian Plate. They now move independently.

John Tillman
Reply to  John Tillman
March 20, 2022 2:49 pm

It wasn’t even antipodal to the impact site.

John Hultquist
Reply to  Jeff
March 18, 2022 9:08 pm

The Columbia River Basalt Group eruptions were mostly from 17–14 million years ago, but less extensive eruptions continued 14–6 million years ago. So says Wikipedia, and numerous other sources.
Can you tell me when the corresponding asteroid hit?

rah
Reply to  John Hultquist
March 19, 2022 3:45 am

The Columbia River basalt floods is a baby compared to the Siberian traps and Deccan in India.

There are so many of them though, that is one heck of a lot of large asteroid hits.

comment image

But I would sure like to know what caused the massive and long lasting volcanic activity in what we now call Siberia 255 mya.

Last edited 6 months ago by rah
Jeff
Reply to  rah
March 19, 2022 10:34 am

Here is the paper so it will be there.
http://www.mantleplumes.org/WebDocuments/Antip_hot.pdf

Because of subduction of the Earth’s mantle it’s often difficult to pinpoint exact locations. It’s unlikely that every single Large Igneous Province and every large meteorite impact will have a 1 to 1 correspondence, but the theory could explain a great many of them.

Regarding the Siberian Traps, this is quoted from the paper: “During the subsequent end-Permian event, an even greater mass extinction occurred as the Siberian Traps were erupted, and Holser and Magaritz have inferred that sea level dropped, and then returned, by perhaps the largest amount in Phanerozoic time. For both the Siberian and Emeishan traps their antipodal sites during the P/T transition would have been on oceanic crust in the Southern Hemisphere. Thus, two large oceanic impacts close together in space and time might have triggered the end-Permian LIPs, and caused the apparent changes in sea level and shifts in ocean chemistry.”

ATheoK
Reply to  Jeff
March 19, 2022 10:19 pm

There’s a major problem with the whole concept.

Try pushing a wood dowel through a peach. soft pear or even an apple. Hammer it through if that makes you happy. Or try a slow bullet, except the result is not clean.

Hitting a point on Earth and popping a volcano zip out an antipodal is impossible.
Earth’s structure is layered with a hard shell exterior. A 100 kilometer (62 miles) exterior. Then more layers of various levels of plasticity with a mostly solid core.

Any impact on the surface is spread locally, making for an enormous area push on the first semi-molten and molten layers.

As further proof, earthquakes varying sizes of areas. Keep in mind those areas are 3 dimensional, not strictly confined to the most exterior surface.
Yet no earthquake causes volcanism. Rather, volcanism itself always causes earthquakes as do tectonics.

The Hilina Pali on Kīlauea Volcano’s south flank is visible evidence of the steep Hilina Fault System. Beneath this system lies the flat-lying décollement fault that has no visible surface expression, but has produced several large earthquakes in the past 200 years. Photo courtesy of Ingrid Johanson.”

Len Werner
March 18, 2022 6:24 pm

David, you have to watch those statements about how good K-Ar is at age dating–read this, it’s short but hilarious:

https://virily.com/science-nature/the-problem-of-potassium-argon-dating/

For those who would hit the down-vote button, you don’t know me; I’ve personally conducted a fair number of age datings, from collecting the samples to running the mass spec. This is one of the key statements from a university publication–

“…only trained geologists should collect the samples in the field. ”

If you haven’t done the entire process from collection to calculation, you might not understand just why.

Johne Morton
March 18, 2022 6:38 pm

“Abundant Late Paleocene plant fossils in the Arctic (e.g., on Ellesmere Island, across Nares Strait from Inglefield Land) point to widespread high-altitude coniferous forests at this time (28)”

Do they mean “high-latitude”?

March 19, 2022 1:23 am

The zombie-hypothesis of the Younger-Dryas impact dies yet again.

DiggerUK
March 19, 2022 4:03 am

When the early searchers for the Arctic North West passage lifted seabed samples on board, they were taken aback to find remains of corals in their trawls.

The poor corals can’t win, too hot they suffer, too cold they suffer. Coming back as a coral must be a recurring nightmare for Buddhists…_

Once again, can I ask all Buddhists and UK citizens to sign and circulate this parliamentary petition on NetZero.
p.s. I’m nothing to do with Nigel Farage…_
https://petition.parliament.uk/petitions/599602

Last edited 6 months ago by DiggerUK
March 19, 2022 8:16 am

“Two impact melt rock samples, collected in 2019 from a riverbank less than 10 km downstream from the edge of the Hiawatha structure.”
Is that all that’s needed for a “robust dating” these days? We have better samples from the Moon.

Gary Pearse
March 19, 2022 11:59 am

At Ekati diamond mine near the Arctic Circle in northern Canada: Latitude: 64° 42′ 29.39″ N
Longitude: -110° 37′ 5.99″ W

Redwood chunks dated at “over 50 million yrs were found at 300m depth in the mine. Obviously the pipe exploded at surface in the midst of a redwood forest (a “temperate rain forest”) and the trees fell in to the temporarily open crater, infilled with hot rock falling back and the last gasps of the intrusion from below.

comment image.webp

https://www.livescience.com/23374-fossil-forest-redwood-diamond-mine.html

John Tillman
Reply to  Gary Pearse
March 19, 2022 1:33 pm

Even in the Pliocene, just 3 Ma, the Arctic Ocean was ringed by boreal forest, not tundra.

Michael S. Kelly
March 19, 2022 11:26 pm

Just to convey a feel for the size of a 1 km wide asteroid, it’s equivalent to about 164 giraffes.

https://www.dailymail.co.uk/sciencetech/article-10610491/Asteroid-half-size-giraffe-strikes-Earth-coast-Iceland.html

When you are writing about an object with which your audience has no experience, and trying to convey to them an idea of that object’s size, the technique of comparison has value. But honestly, comparison of an object with which your audience has no experience to an object with which they have even less experience just seems like a bad strategy.

Last edited 6 months ago by Michael S. Kelly
Bob boder
March 20, 2022 6:47 am

Better title

Just a bit outside

Ruleo
March 20, 2022 12:29 pm

Gotta push the narrative impact craters never occurred during human existence.

I bet in 10 years we’ll be told Chelyabinsk was just an errant ICBM. All the Corp Media gotta to is pull the same Plannedemic and Ukrainian psy-ops. It would take just a week.

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