By Dennis Cox
A couple of years ago, as a hobby, and pass-time, I set out to see if I could work out a better way of identifying potential sites to go meteorite hunting. I had learned to do battle damage assessment from aerial reconnaissance photos a long time ago in the Army. And the blast damage, and ground effects from an explosive event, are pretty much the same, no matter what the source of the explosion might be. It’s only a question of scale, and explosive force. Visually, there is very little difference in the appearance of a bomb crater, and an impact crater of the same size. So the military style forensic technique of reading the patterns of movement in the emplacement of blast effected materials on the ground applies well in the search for potential impact related geology. The quality of the image data now commonly available to anyone with a good PC, an internet connection, and a copy of Google Earth, is excellent. In the past five years, the publically available image data has really come into its own. And today’s 21st century satellite imagery allows us to study the surface of the Earth at a level of detail our fathers could never have imagined.
Almost a century ago, using aerial photography, a geologist named Harlan Bretz noticed evidence for the mega-floods that sculpted the Grande Coulee, and the ‘Channeled Scablands’ of eastern Washington. What he had found, were the patterns of fluid flow, like the ripples you see in the sedimentary deposits of a stream bed, but these ‘ripples’ are hundreds of feet high. He saw them as empirical evidence of a major catastrophic flood event, on a scale that the standard theorists of his day thought was inconceivable.
Harlan Bretz was the first to use Aerial photographs to detect, and map, catastrophic mass movement of the Earth’s surface materials. The aerial views allowed him a perspective from which patterns of fluid flow, and catastrophic mass movement of terrain materials, could be perceived on a scale that had been unimaginable until he described them. And most of the academic community of his time thought he had a screw loose, or two. After all, most geologists by that time had already decided to agree without question that sudden, catastrophic, geologic changes just don’t happen anymore. And that all geomorphology on the surface of the Earth is the result of slow processes we see going on around us today, and requiring millions of years. They believed that “The present is the key to understanding the past”, and that the rocks of that area were all ‘well defined’. They were mistaken.
The trouble we face today, Just as Mr. Bretz did back then, is that through some 19th century process of mutual-inter-assumptive reasoning, and confabulation, instead of sound, experiment-driven, science, and for more that 150 years, the Earth sciences have been founded on that unquestioned ‘Gradualist’ assumption. But gradualism only works until something sudden happens. And if you want to understand, or predict, the nature of the planetary scarring of a geologically recent catastrophic event, especially one that’s different from anything that’s ever been studied before, that 19th century, gradualist-assumptive, reasoning just won’t get you there.
Apparently, being able to see the truth is no guarantee that anyone’s going to bother to look where you’re pointing anytime soon. It wasn’t until 1965 that a report from an independent geologist’s tour concluded that Harlan Bretz was right about the catastrophic geomorphology that resulted from an early Holocene event he’d called ‘The Spokane Flood’. And finally, in 1976, at the age of 96, he was awarded the Penrose Medal of the Geological Society of America. Which is just about the most prestigious award a person can get in the field of geology. Upon receiving the award, Mr. Bretz is said to have complained to his son that he couldn’t gloat properly, because all of his enemies were dead.
The satellites of today have upped the ante. Harlan Bretz could see evidence of catastrophic material movement on a statewide scale. With the imagery now available through Google Earth, we can detect, and read, patterns of catastrophic mass movement of terrains on a continental scale. The event Bretz perceived was only implausible from a standard theory viewpoint because of its size. And yet, by comparison, and in the final analysis, someday it may be seen that his glacial mega flood in the Pacific Northwest was only a minor little footnote in the events of the early Holocene. And some of those events were far more terrible then a glacial flood event.
In June 1908, an explosion rocked a remote, swampy area in central Siberia, in Russia; it came to be known as the “Tunguska event.” And a later expedition to the site found that 20 miles of trees had been knocked down and set alight by the blast. Today, it’s understood that Tunguska’s devastation was caused by a 100-foot asteroid that had entered Earth’s atmosphere, causing an airburst.
Some 13,000 years earlier, just after the end of the last ice age, the Earth’s climate had begun to warm up to temperatures much like what we enjoy today, when an occurrence thought by many researchers to be some kind extraterrestrial impact set off an “impact winter”, and a return to ice age conditions that lasted another 1,300 years, or so. And the event coincided with the end of the prehistoric Clovis culture. And the mass extinction of almost all of the giant animals that lived on North America at the time.
Perhaps the single most important paper on the subject of the Younger Dryas, is the 2007 paper by R.B. Firestone et al, and titled: Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling
The 2007 Firestone paper caused a pretty good stir in the academic community. And it has become the ‘Flagship’, so to speak, of the Younger Dryas impact hypothesis.
In that paper, a team of twenty six scientists, studying sedimentary deposits, presented a whole suite of compelling evidence for a massive impact event of a comet that appears to have broken up, and scattered, fragments all across North America. The multiple, air bursts are thought to have triggered wide-spread bio mass burning on a continental scale. As well as causing a return to ice age conditions, and the extinction of many species. Including the mega fauna, like mastodons, wooly mammoths, and giant sloths. In all, I think something like 35 genera went extinct.
It is by no means, a settled science though. And the debate continues to go around, and around as to the cause of the Younger Dryas. Firestone, and friends, had found evidence in the stratigraphic record that implied some kind of very large impact related catastrophe had occurred to trigger the Younger Dryas Cooling, and the megafaunal extinctions. But it was clear that the event was vastly different from anything that had been studied before. So they could only speculate on just exactly what the nature of the event was, or what had hit us, or where the actual impact zones were. Without an astronomical model that could confidently describe the the nature of the impactor/s, they were were at an impasse. And the biggest weakness in the YD impact hypothesis, as written, is that it’s impossible to construct a model with a four mile wide bolide that has enough time in the atmosphere to break up completely, and scatter fragments, and devastation over a continent sized area, without making a good sized crater somewhere. And “where’s the crater?” became a rallying cry of opponents to the hypothesis.
Meanwhile, astronomers Victor Clube, and William Napier, in their book The Cosmic Serpent, had been talking about the giant comet they described as the progenitor of the Taurid Complex since 1982. Their data is as solid as anything you can dig up with a trowel. But except for them, and a few others like Bob Kobres, no one had connected the the dots, and put the Younger Dryas comet, and the Taurid Progenitor together. Except in private, speculative, emails, and letters. And to the best of my knowledge there was nothing in refereed literature.
Then, In early 2010, Professor Napier published a paper in the Journal Monthly Notices of the Royal Astronomical Society titled, Paleolithic extinctions and the Taurid Complex in it we read:
“The proposition that an exceptionally large comet has been undergoing disintegration in the inner planetary system goes back over 40 years (Whipple 1967), and the evidence for the hypothesis has accumulated to the point where it seems compelling. Radio and visual meteor data show that the zodiacal cloud is dominated by a broad stream of largely cometary material which incorporates an ancient, dispersed system of related meteor streams. Embedded within this system are significant numbers of large NEOs, including Comet Encke. Replenishment of the zodiacal cloud is sporadic, with the current cloud being substantially overmassive in relation to current sources. The system is most easily understood as due to the injection and continuing disintegration of a comet 50-100 km in diameter. The fragmentation of comets is now recognized as a major route of their disintegration, and this is consistent with the numerous sub-streams and co-moving observed in the Taurid complex. The probable epoch of injection of this large comet, ~20-30 kyr ago, comfortably straddles the 12.9 kyr date of the Younger Dryas Boundary.
The hypothesis that terrestrial catastrophes may happen on timescales ~0.1 Myr, due to the Earth running through swarms of debris from disintegrating large comets, is likewise not new (Clube & Napier, 1984). However the accumulation of observations has allowed us to build an astronomical model, closely based on the contemporary environment, which can plausibly yield the postulated YDB catastrophe. The interception of ~1015 gm of material during the course of disintegration is shown here to have been a reasonably probable event, capable of yielding destruction on a continental scale.
The object of this paper is not to claim that such an encounter took place at 12,900 BP – that is a matter for Earth scientists – but to show that a convincing astronomical scenario can be constructed which seems to give a satisfactory match to the major geophysical features of the Younger Dryas Boundary data.
If indeed the YDB event was an astronomical catastrophe, its occurrence bears little relation to current impact hazard assessments derived from NEO surveys.”
With Professor Napier’s work specifically proposing in refereed literature that the Taurid Progenitor was the Younger Dryas comet, he changed the game completely. Because he didn’t just give us a convincing astronomical model of the event. We also have a pretty good picture of the physical properties of the thing that did the disastrous deed. And if you can describe a beast, you can predict it’s footprints.
From Comets, Catastrophes, and Earth’s History by W. M. Napier we read ,
“The evidence that an exceptionally large (50-100 km) comet entered a short-period, Earth- crossing orbit during the upper Paleolithic, and underwent a series of disintegrations, now seems compelling. The idea is not new, but it has been strengthened by an accumulation of evidence from radar studies of the interplanetary environment, from the LDEF experiment, from numerical simulations of the Taurid complex meteoroids and ‘asteroids’, and from the latter’s highly significant orbital clustering around Comet Encke.
The disintegration of this massive Taurid Complex progenitor over some tens of thousands of years would yield meteoroid swarms which could easily lead to brief, catastrophic episodes of multiple bombardment by sub-kilometer bolides, and it is tempting to see the event at ∼ 12,900 BP as an instance of this. Whether it actually happened is a matter for Earth scientists, but from the astronomical point of view a meteoroid swarm is a much more probable event than a 4 km comet collision.
The images of Comet LINEAR , and Comet Scwassmann-Wachmann 3, make it abundantly clear that Professor Napier is probably right. And that total, explosive, fragmentation of a comet can occur at any time. And it can happen before it even gets close to a planet. It doesn’t need the atmosphere to do that.
Both of those objects are typical daughters of the Taurid complex. So they are also typical of the kinds of objects we see in Earth crossing orbits. And while they themselves don’t represent an immediate threat, There is the potential for many more undiscovered Near Earth Objects out there just like them that do. With the Taurid Complex as the astronomical model for the YD impact hypothesis, we don’t need to account for how the YD comet broke up. Because we know it was already a cluster of smaller fragments before it got anywhere near this fair world of ours.
I asked NASA’s David Morison what he thought of the possibility of a cluster impact event. And he expressed his doubts. Saying that he thought it was ‘highly unlikely’. But the fragmented nature of the objects above would seem to say that the opposite is true And the realization that most catastrophic impact events are probably the result of a large cluster, or stream, of smaller fragments, instead of a single, large, bolide as has been assumed in the past, represents a significant paradigm shift in NEO threat assessment, and impact science.
Impact research is an infant science. And thanks to poor funding for Near Earth Object research, and for impact science in general, we don’t have a very good handle yet on the variety or quantity, of objects that might threaten our world, much less a comfortable understanding of the different kinds of devastation that might be released in a catastrophic impact besides what we see in a generic, solid bolide, crater forming, kinetic impact event.
So who is to say what a full suite of impact markers should be? And what of airburst blast effects?
Tunguska of 1908 was the largest impact event in recorded history. And yet, the blast effected materials at ground zero do not qualify it as an impact structure. Indeed, if there hadn’t been any eye witnesses, our impact scientists would be in complete denial of an ET origin for all the violence there that day. There is no reason to think Tunguska was an isolated event. Or even a big one, on the grand scale of such things. And, in a poster by Mark Boslough titled, The Nature of Airbursts and their Contribution to the Impact Threat. we read:
“Ongoing simulations of low-altitude airbursts from hypervelocity asteroid impacts have led to a re-evaluation of the impact hazard that accounts for the enhanced damage potential relative to the standard point-source approximations. Computational models demonstrate that the altitude of maximum energy deposition is not a good estimate of the equivalent height of a point explosion, because the center of mass of an exploding projectile maintains a significant fraction of its initial momentum and is transported downward in the form of a high-temperature jet of expanding gas. This “fireball” descends to a depth well beneath the burst altitude before its velocity becomes subsonic. The time scale of this descent is similar to the time scale of the explosion itself, so the jet simultaneously couples both its translational and its radial kinetic energy to the atmosphere. Because of this downward flow, larger blast waves and stronger thermal radiation pulses are experienced at the surface than would be predicted for a nuclear explosion of the same yield at the same burst height. For impacts with a kinetic energy below some threshold value, the hot jet of vaporized projectile loses its momentum before it can make contact with the Earth’s surface. The 1908 Tunguska explosion is the largest observed example of this first type of airburst. For impacts above the threshold, the fireball descends all the way to the ground, where it expands radially, driving supersonic winds and radiating thermal energy at temperatures that can melt silicate surface materials. The Libyan Desert Glass event, 29 million years ago, may be an example of this second, larger, and more destructive type of airburst. The kinetic energy threshold that demarcates these two airburst types depends on asteroid velocity, density, strength, and impact angle.”
At Sandia Labs, Mark Boslough used their ‘Red Storm’ supercomputer to simulate the airburst, and impact, of a 120-meter diameter stony asteroid. And it represents an example of that second, geo-ablative kind of air burst.
For comparison, an ordinary oxy-acetylene cutting torch in a steel shop uses a thin stream of hot gases at only about 900 degrees C. and 40 PSI. to cut steel. The speed of that stream of hot gasses is only a little bit more than a stiff breeze. But that’s all it takes to ablate solid iron, and to blow it away, into runnels of melt, and heaps of slag.
Dr Boslough tells us that: “Simulations suggest strong coupling of thermal radiation to the ground, and efficient ablation of the resulting melt by the high-velocity shear flow.”
I think Mark Boslough’s simple statement may represent the cusp of another major paradigm shift in the Earth sciences. Especially when you think it through. And when you consider what form the blast effected materials of a geo-ablative airburst like that should be expected to take.
During the event, any ablated materials would be in an atmospheric suspension, in a ‘fluidized’ flow. Similar to a pyroclastic flow. But wind-driven, like the froth, and foam, on a storm tossed beach, not gravity-attracted, like a pyroclastic flow down the flanks of a volcano. For more than 150 years, standard uniformitarian/gradualist geologic theory has assumed without question that only terrestrial volcanism can produce pyroclastic rock. And deposits of sheet ignimbrites have always been seen as conclusive evidence of explosive volcanism. Even when no volcanic vent, or magma chamber can be identified.
The word ‘ignimbrite’ comes from the Latin for ‘Fire Cloud Rock’. So, since geo-ablative airburst melt would be formed and emplaced in a cloud of fire, it’s still a good word to describe airburst melt. Volcanic tuff, and airburst melt, are both ‘Fire cloud rocks’.
An important thing to keep in mind is that, no matter whether a piece of ‘ignimbrite’ is truly volcanogenic, or if after detailed chemical tests, we can conclude an ET origin, either way, such materials are always the product of a violent explosive event. And as the blast effected materials of an explosive event, the patterns of movement, and flow, that get frozen into them during emplacement can reveal much of the true nature of the explosive event that put them there.
I don’t want to digress into a discussion about volcanoes. But it’s important at this point to understand the internal structure of these kinds of materials, and how they move during formation, and emplacement. And why it might be easy to get them confused. It’s time to put on your fluid mechanics hat.
From How Volcanoes Work
The extraordinary velocity of a pyroclastic flow is partly attributed to its fluidization. A moving pyroclastic flow has properties more like those of a liquid than a mass of solid fragments. It’s mobility comes from the disappearance of inter-particle friction. A fluidized flow is best described as a dispersion of large fragments in a medium of fluidized fine fragments. A constant stream of hot, expanding gases keeps the smallest of the fragments (ash and lapilli size particles) in constant suspension. This solid-gas mixture can then support larger fragments that float in the matrix.
In Fluid Mechanics Such a flow is also known as a density current. So, a rock of geo-ablative airburst melt should be expected to be similar in structure to ‘ignimbrite’. And it might be visually indistinguishable from volcanic tuff. The final test for ET origin would be to look at the isotopes. Horton Newsom at NMU tells me that we should expect to see significant siderophile, or platinum group element, enrichment as supportive evidence of ET origin. But there might be a easier way to identify geo-ablative airburst formations, simply by reading the patterns of flow that were frozen into them when they were formed, and emplaced.
Because of the difference in motive forces involved, one wind-driven, the other gravity-attracted, there would be fundamental differences in the way geo-ablative melt, and it’s volcanogenic cousin moves, and flows, during formation, and emplacement. And in satellite images, in ‘orphan’ ignimbrite deposits, we’re looking for wind-driven patterns of movement, and flow. And by ‘orphan’, I mean to say that no volcanic system has been positively identified to account for them. And since the debris of the Taurid progenitor is thought to have hit sometime in the geologically recent past, we should expect those geo-ablative formations to be in very good condition. undisturbed, and on the surface.
But we face a bit of a conundrum. For more than 150 years, standard gradualist geology theory has assumed without question that only terrestrial volcanism can produce the explosive forces needed to make a pyroclastic density current of flash melted stone. And For generations they’ve used sheet ignimbrite deposits as conclusive evidence of explosive volcanism, in spite of often not being able to locate a vent, or magma chamber, it came from; not even with our best 21st century technology. But Since geo-ablative airburst melt would be in the form of a wind-driven pyroclastic flow while it’s in motion, that’s exactly what structural form any geo-ablative material would take as it comes to rest, and cools. And except for its wind-driven patterns of flow which become frozen in at the moment of emplacement, it would be visually indistinguishable from ignimbrite, or volcanic tuff.
The Chihuahuan Ignimbrites of central Mexico are one such orphan deposit. There, and in the Sierra Madre Occidental mountains to the west, there are more than 350,000 cubic miles of random colliding, inter-flowing, sheet ignimbrites, undisturbed, on the surface, in pristine condition, with wind-driven patterns of flow. And less than 15% can be positively attributed to a volcano. The problem with studying them in the past, has been that they cover such a vast, and remote, desert area, that using antiquated surveying techniques of the past, it has been difficult, and time consuming. As a result, except for a 100 km stretch along the roadside between Chihuahua City, Mexico, and El Paso Texas, they are almost completely unmapped. And in refereed literature, all we find of their origin is speculation.
The theorists of the past had to come up with a plausible model of an explosive event powerful enough that it could get hundreds of thousands of cubic miles of rock up in the air into atmospheric suspension, in a pyroclastic density current, at the same time. And if ‘the present is the key to the past’, as they say, there is nothing in recorded history that gives us an example of how something like that could happen. They could not imagine such energies coming down from above. So they invented a theoretical kind of super-giant eruption called an Ignimbrite “Flare Up” event.
It’s thought the event dates to the mid tertiary, when extensional forces in the middle of the continent are thought to have caused fault-grabens in the middle of the continent, hundreds of miles long, to suddenly open up, transforming into vast fissures that belched all those ignimbrites in an unimaginably violent explosive event, and then closed up again. But there are major problems with that theory.
First of all, after decades of geological surveys to catalogue Mexico’s mineral wealth, no seismic, tomographic, ground penetrating radar, or any other data, has ever revealed a single one of those fault-graben-turned-fissures. Much less a magma chamber big enough that almost all of central Mexico must be a supergiant caldera that makes the Yellowstone caldera look like a mouse breaking wind by comparison. And no one can explain the crazy mantel physics required for those giant, magic trap-door vents that are assumed to have opened, and closed, without a trace.
The old gradualist-assumptive model falls apart quickly when questioned closely. But whether volcanogenic, or exogenic, pyroclastic rock is always the signature of a violent explosive event. And if you want to understand an explosive event after the fact, you begin by studying the emplacement motions of the blast effected materials.
Doing so may have been difficult, and time consuming, on the ground with an old fashioned surveyor’s transit. But the satellite technology of the 21st century has made it possible to map the emplacement, and directionality, of those flows to an amazing level of detail. And from the comfort of one’s own desk. Using Google Earth’s ‘save image’ feature, I made a very large, hi-resolution image map of overlapping saved images seamlessly stitched together with Photoshop. I then had the image map printed out professionally in a format that covers a whole wall. A sheet of clear plastic for an overlay, some markers to draw little arrows to indicate the direction of flow wherever they were discernable, and I had a high resolution flow map, that would’ve taken decades of difficult surveying, in the middle of some of the most inhospitable terrains on Earth, to produce the old way.
The problem with the assumed ancient age is that they are all in perfectly pristine condition. And they are the undisturbed capstone of the terrains they’re blanketing. Whatever else they are, geologically old, they’re not. And after a few thousand hours of studying their patterns of emplacement, I can tell you that those are are wind-driven patterns of motion frozen into those pristine pyroclastic rivers of flash melted stone. The heat, and pressure to ablate the surface, and to produce and emplace, the Chihuahuan ignimbrites came from above. The ignimbrites themselves consist of materials from the original surface. But flash melted, and blown around a bit. Just like the froth, and foam, on a storm tossed beach.
The age estimate is based on assumed slow erosion rates of ordinary wind, and rain. The landforms in the region seem to be worn down to the nubbin. And no one could ever have imagined that ablation from above might be a factor. But an ablative airburst event can be expected to move more material in seconds than ordinary weather can in many millions of years.
If the ignimbrite sheets were laid down before the landforms rising among them began eroding, then the ignimbrite sheets should be as heavily weathered, and eroded, as everything else. And they should be under the alluvium that erosion would’ve produced. But the 25 million years worth of alluvium we should expect to see covering the ignimbrites is missing from the satellite images. And as anyone can see who looks closely, the ignimbrites themselves are almost perfectly pristine.
Good field work, and detailed chemical analysis of field specimens will have the final word. But a very compelling case can be made from satellite image data for the statement that the mountains, and landforms of central Mexico weren’t heavily eroded to their present state over millions of years. They were heavily ablated in a large, multiple airburst, impact storm. And over a period of just a few seconds. The vast, interflowing, ignimbrite sheets are the product of that ablation. And their almost completely unweathered condition, as the capstone of the terrains, disproves the assumption of ancient age. The ablative event must have been only a few thousand years ago.
The real test of any supercomputer simulation, or model, like Mark Boslough’s, is whether or not it is predictive of something we can find in real life on the ground, and in this case, we can. Take a look at that simulation again. Remember, you are looking at a cross-section. Imagine it in 3D. Take a good, close look at the bottom of the down blast vortex. And pay special attention to the patterns of flow at the point of contact with the ground.
In the image below, I’ve chosen an ordinary-typical example from the Chihuahuan “Ignimbrites” to give you an idea of what something like can do. And what I’ve been talking about. The mountain you see in the image below is at 29.702168, -105.686617 about 150 miles south, southeast of El Paso, Texas. And it is not unique. There are many others nearby. Note the radial, outwards flowing curtain of melt. The wind-driven patterns of flow frozen into that curtain at the moment of its emplacement are a perfect match for the patterns of flow at the bottom of the large airburst vortex in Dr Boslough’s simulation. The white line in the bottom of the image is 5 miles long.
Click on the image to view a 3D PhotoSynth of this mountain
As you can see, the radial, outwards flowing curtain of pyroclastic rock is almost perfectly pristine. There is no question but that the mountain is the source location of the materials in the curtain. But the mountain itself is a cuesta that consists of uplifted meta sedimentary strata. It’s not a volcanic vent, or rift, at all.
These are the patterns of movement you see when a fluid is driven across a surface by high velocity atmospheric pressure. Like I said, just like the foam, and froth, on a storm tossed beach. Gravity wasn’t the motive force for the material movement we see evidence of here.
The indication of the speed of the materials in the emplacement of the curtain is the outwards pointing chevrons clearly visible in the patterns of flow.
The shocker here, is that the mountain probably didn’t exist in any form at all at until the moment of the impact. I suspect that it was uplifted as the surface rebounded upwards from the impact shockwave. In other words, in a sense, it ‘bounced’ up after the impact of the shockwave like the surface of a trampoline. But we need to look closely at the ablative patterns of flow in its outer surface.
In the simulation, note the supersonic upwards flow in the center of post impact vortex. The mountain was born almost in an instant as the surface bounced back from pressure of the shockwave, and it rebounded up into the impact vortex. So, at the same time the ablated material in the radial curtain was being ablated, and blown outwards, the rebounding surface at the center was ablated, and the materials that were removed, were drawn up into the impact plume by the upwards flow at the center of the vortex. At this point, it’s hard to say where they might have fallen back to Earth.
And the signature of that supersonic, and ablative, upwards flow in the middle of the vortex is in the deep V shaped excavations that wider at the top, and center of the flow. What has been interpreted as the work of millions of years of erosion is in fact, the work of just few seconds of an ablative airburst. And probably not so long ago at that.
Dr Boslough only simulated the airburst of a single fragment. But the blast effected materials in the giant impact zone this airburst structure is setting in the middle of, describe a cluster consisting of thousands of air bursting fragments that big. And if Comets Linear and SW-3 are any model of the density of the debris cluster, those larger fragments were probably accompanied by clouds of stuff down to the size of dust grains. And all of it falling within seconds. Like a giant shotgun blast.
There are well over 50,000 square miles of geo-ablative terrains like that in central Mexico alone. The zone extends up into west Texas. And the region is unique on the surface of the Earth. The Arid climate has preserved the blast effected materials in context, and in perfect condition. And except for the occasional sage brush, or cactus, most of it is in almost the same condition as it was the first year after the impact storm.
I don’t see anything in the satellite images that would allow one to pin down the exact age of these formations with any degree of confidence. But since these formations are in such good condition, I struggle to understand how anything on the western half of the continent could’ve survived the fires. The entire food chain over a vast area would’ve been compromised. Most of it burned away down to the last blade of grass. So I like it for a suspect in the early Holocene megafaunal extinctions.
A very compelling case can be made that a similar large cluster of comet fragments also hit the Laurentide ice sheet in a region from northern Minnesota to the Arctic ocean. I have to confess to being a climate science wuss though. And I have a hard time imagining what the climate consequences of destroying an ice mass as big as the continental US. And suddenly evaporating a couple of hundred thousand cubic miles of ice directly into the atmosphere. All the while burning the biomass away from the other half of the continent.
I’ll describe the blast effected materials of the Northeast impact zone a little later on. But for now, there is more to show you in the west, and southwest.
There are also thousands of fairly normal craters in New Mexico, and west Texas averaging about 100 meters wide that have never been seriously considered as potential impact structures. And for no other reason than there are too many of them, all the same apparent age. And it has always been assumed that a multiple fragment impact storm, or cluster impact event would be “Highly unlikely”. So, with the exception of the Odessa crater, all of its sister craters that we can clearly see in the satellite images of the Oil fields near Odessa, and Midland Texas have been ignored.
The other day I was watching an episode of the ‘Meteorite Men’. It was the one in which they went to try their luck at the Odessa crater, in Texas. It was a good show. But the guys had a tough time of it. Untold numbers of meteorite hunters, and collectors, have worked that site over the years. And they’ve turned the ground over so much looking for meteorite fragments, it’s barely recognizable as an impact structure anymore.
Geoff, and Steve, worked that site every which way but loose. And they still came up empty handed…, almost.
It wasn’t until they gave up looking, packed up their gear, and started driving away disappointed, that the Meteorite Men found anything. On their way out of the area, in the gravel of the road, they spotted meteorite fragments lying right there in plain sight. So they stopped, took out their metal detectors, and started digging fragments. After giving up on a day of frustration, they made a pretty good haul, right there in the gravel of the road. And they left the area with some really nice Odessa Irons.
And then, as happy as can be, they just drove away, richer by a few nice meteorite fragments, (As a matter of fact, a few thousand dollars worth!) and a good episode for their TV show. But in missing the significance of where they found those iron meteorite fragments, they also drove away from what may be the most single most important clue of their careers.
Here’s a Google image of the Odessa Crater, and the Museum at 31.765137, -102.479064.
You see, when those dirt roads in that oil field were graded, they hauled in aggregate to elevate the road surface a few inches above grade for better drainage. That aggregate did not come from inside the crater. It came from a quarry location about 20 miles away. The mystery there was; since the dump truck that brought in that thin layer of aggregate got its load from a quarry miles away, and not the Odessa Crater, how did all those Odessa Irons get into that load of aggregate for the road bed?
The answer, is that that Odessa crater is not alone. It is only one of many thousands in a vast cluster event. Turn on Google Earth, and scan the area carefully from an eye height of about 5 km. Scattered among the oil fields there are too many craters like the Odessa structure to count.
I have heard that ‘most geologists agree’ that the Odessa event was about 60,000 years ago. I don’t believe that for a minute. I want to see proof. I’ve also heard estimates as young as 20,000 years. Until I see some radiometric data, I am working from the postulate that they are much younger than that. Less than 13,000 years old as a matter of fact. And they are all the same age. Give, or take a few seconds.
There are large crater fields of structures like that in a wide band stretching from eastern New Mexico to west Texas. And the famous Odessa Crater is only 1 of many. This one is near Odessa, at 31.617601, -102.271674. It’s a little over a hundred meters wide.
This next one’s at 31.788219, -102.153964, and is 189 meters across.
And there are a few more Odessa craters in this Gallery
There is another type impact structure I’ve been told is highly Unlikely. And that’s oval craters caused by oblique impacts. But in the early Holocene sediments of a dry lake bed in northern Nevada at 39.739717, -115.388916 we can find a place where a cluster of oblique impacts hit the submerged sediments of what would’ve been a shallow lake at the time.
Here’s the north end of the lake from an altitude of about 45 km.
Unlike the airburst formations in central Mexico, there are good visual cues here to establish an age, give, or take a few centuries.
I did a few crude impact experiments with a low powered rifle, and a mud puddle. Not exactly laboratory conditions. But good enough to determine that the weird, feather shaped ejecta plumes downrange to the northeast from the points of impact are consistent with a low angle impact of about 30 degrees into a submerged surface, and are probably the result of the ejecta’s interaction with the water of the lake. And to determine that the strangely distorted beach lines that correspond to that lake level are the result of some of the lake sediments being splashed out of it banks.
On the north end of the lake, and the cluster of oblique craters, we see where, as the lake returned to its banks after the impact event, the beach lines criss-crossed some of the ejecta plumes. Beach lines in a dry lake are like bathtub rings. And they give us an age. That set of beach lines represents the lake’s last, and lowest, shore line before it dried up completely. Which puts it sometime in the early Holocene, maybe less than ten thousand years ago. I don’t know if an impact scientist has been on the ground there yet, probably not. But I do know that a 600 gram, carbonaceous chondrite, meteorite fragment was found in a neighboring dry lake bed. Carbonaceous chondrite meteorites are the rarest of the rare. And the thing is worth about $1,000 per gram. These dry lakes in Northern Nevada are considered by many meteorite collectors as a happy hunting ground. It’s no wonder to me why.
But it gets better. The direction of those plumes points to about 24 degrees north by northeast. If we go looking downrange from there, we can find another field of oblique craters with the same direction, and trajectory, in the early Holocene sediments of the Red Rock River Valley in southwest Montana.
We also have good visual cues to date this fall. Look in the upper left of the image map above. The ejecta splash from the oval crater at 44.642265, -112.077185 was blown over the top of, and is blanketing, one of the ancient meanders of the river.
And at 44.644033, -112.076880, the ejecta that’s covering that late Pleistocene/Early Holocene meander provides an excellent stratigraphic horizon for dating the event. The two crater fields were probably formed in the same fall of fragments.
Remember Harlan Bretz’s catastrophic flood event in Eastern Washington? The cause of that flood is now well known. During the ice age, a tongue of the Cordilleran Ice Sheet had extended far enough south into northern Idaho that it formed an ice dam that was blocking the Clark Fork river. That ice dam backed up the waters of a huge glacial lake in western Montana called Lake Missoula. The dam failed many times during the last ice age and then reformed again. The resulting repeated torrents of water, and ice, hundreds of feet deep, are what gouged the terrains of the Grande Coulee, and the ‘Channeled Scablands’.
The Northeast Impact Zone, and the destruction of the Laurentide Ice Sheet
The distribution of the blast effected materials found in the Younger Dryas Boundary layer imply that the Laurentide Ice Sheet took a major hit. Firestone and friends thought that the most likely target zone was in the Great Lakes region.
From Evidence for an extraterestrial impact 12,900 years ago that led to the megafaunal extinctions and the Younger Dryas cooling. by R.B. Firestone et al, 2007 we read:
“Toon et al. suggest that an impact capable of continent-wide damage requires energy of 10^7 megatons, equivalent to an impact by a 4-km-wide comet . Although an impactor that size typically leaves an obvious large crater, no such late Pleistocene crater has been identified. The lack of a crater may be due to prior fragmentation of a large impactor, thereby producing multiple airbursts or craters. Hypervelocity oblique impact experiments (Peter. H. Shultz , unpublished data) indicate that a low-impedance surface layer, such as an ice sheet, can markedly reduce modification of the underlying substrate if the layer is equal to the projectile’s diameter. These results suggest that if multiple 2-km objects struck the 2-km-thick Laurentide Ice Sheet at 30°, they may have left negligible traces after deglaciation. Thus, lasting evidence may have been limited to enigmatic depressions or disturbances in the Canadian Shield (e.g., under the Great Lakes or Hudson Bay), while producing marginal or no shock effects and dispersing fine debris composed of the impactor, ice-sheet detritus, and the underlying crust.”
Peter Shultz’s hypervelocity ice sheet impact experiments indicated that we can expect the ice to explode on impact like the reactive armor on a battle tank. So we don’t necessarily expect to find any shocked minerals. Because all of the kinetic energy gets translated to heat. In fact, we aren’t looking for any of the normal features we would expect to find in an impact structure. The ice sheet impacts didn’t produce a single crater. But the violence of those impact induced hydro-thermal explosions, and all that inconceivable heat in the presence of a lot of water most certainly left its mark.
We can use the predicted location in the Archaean bedrock of the Canadian Shield to our advantage for a positive identification of the impact sites. The region is some of the most stable continental crust on Earth. And the last time there was any volcanic activity in the Canadian Shield was more than two, and a half billion years ago. That’s really deep time! It’s more than half the age of the Earth. And it is almost too ancient to grasp. But during that time, super continents like Gondwanaland, and Pangaea, have come together, drifted apart, come together again, and drifted apart yet again to become the world we know today. Giant mountain ranges like the Himalayas have been raised up to dizzying heights, crumbled to dust, washed out to sea, and then raised up again too many times to count. Entire ecosystems, the dinosaurs, and countless other species have evolved, flourished successfully for eons, and gone with barely a fossil to remember them by. More than half the age of the Earth is an awfully long time. So any evidence whatsoever of a geologically recent surface melting event is a major red flag. And by ‘geologically recent’ I mean any age since melt that is measured in millions of years our less.
We don’t have to look very far to find our surface melt formations. Just northeast of Upper, and Lower Red Lakes, Minnesota we see clearly legible patterns of movement, and flow, in surface melted stone. And the flows are almost in perfect condition It’s the lighter pink, almost white stone. And it’s the marks of titanic hydrothermal explosions in the ice sheet. The heat source was hot enough to burn all the way down through the ice and partially melt the surface of the stone below. And the story told in the rivers of flowing stone is as easy to read as following spilled paint back to the can.
The whole region is as level as a parking lot. Drainage is poor. And, for the most part, where you see green in these images you are looking at peat of varying depths. And here the ice seems to have provided enough of a heat sink to quench, and preserve, some of the extra terrestrial material that brought all the heat. You see it in the black arrowhead splash of molten material blown off to the side, and framed so nicely by the lighter native rock.
Below is a false color radar image depicting elevation. It’s graded from darkest-lowest to lightest-highest elevation. The deference in elevation for the area of the black splash from lowest to highest is only a couple of feet. The region is as flat as a parking lot. But the ghostly image of the splash and it’s associated rivers of melted stone show up clearly as raised features in the terrain.
The area is sometimes referred to as “The Patterned Peat Lands of Northern Minnesota”. Drainage is poor. And peat bogs are everywhere. But contrary to some of the old literature. The Laurentide ice sheet didn’t form the patterns. And the peat didn’t either. It only conforms to them, and fills in the low spots with green color; the deeper the peat, the darker the green. So in these image maps the depth of color of the peat bogs in the area is a good proxy for the contours of the depressions. The darker the green, the deeper the depression.
The rock composition for the general area of the black splash is labeled on the USGS’s geologic maps as:
“Para gneiss and schist-rich migmatite -grades into undivided meta sedimentary rocks.”
Migmatite is a rock of both metamorphic, and igneous, origin that exhibits characteristics of both rock types. Migmatites form under extreme temperature conditions during metamorphism through the heating (but not quite melting) of rocks in the presence of a lot of water. And where partial melting occurs in pre-existing rocks. They aren’t crystallized from a totally molten material, and are not generally the result of solid-state reactions. Migmatites are composed of a new material crystallized from incipient melting, and an old material that resisted melting. Exactly the kind of rock we would expect in the burn scars of comet induced, hydrothermal explosions in the ice sheet.
And the meta sedimentary rocks are further described as:
‘Meta sedimentary rocks-undivided-greywacke, slate, local units of conglomerate, arentite, graphic slate, fine-grained felsic volcanogenic, and volcaniclastic rocks, lean oxide iron-formation and its metamorphic equivalent. Includes the Knife Lake Group and the Lake Vermilion Formation in northeastern Minnesota.’
So the full range of temperatures, and conditions we should expect of an impact in the ice sheet, from hydrothermal to pyroclastic, is represented by the rock of the blast burns in the area.
The only examples we’ve had in recorded history of the emplacement of a pyroclastic density current is in an explosive, ‘Plinian’ eruption. So the standard model assumes volcanic activity as the source of all clastic rock. And just as in Mexico, some unrecoverable flaws in that assumption are revealed here. And the problem with the words “volcanogenic”, and “volcaniclastic”, is that there is no volcano there. We are looking at an area of the Canadian shield. The bedrock is Archaean. There hasn’t been any volcanic activity there in 2.5 billion years And, without a volcanic system, you can’t make a case for volcanism as the heat source for the pyroclasts, and metamorphic facies, unless you can show that the materials themselves are that old.
As we’ve noted before, a pyroclastic density current does not move slowly like lava. While in motion, the particles, and fragments, of super heated rock are in atmospheric suspension. And the material is in a cloud of fire that’s typically moving at hundreds of miles per hour. That’s where we get the word ‘ignimbrite’, which comes from the Latin for ‘Fire Cloud Rock’. The motive force for a standard model, volcanogenic, pyroclastic flow is provided by gravity as the ash column collapses, and the materials are pulled downslope away from the vent.
The most glaring discrepancy is the lack of any volcano whatsoever; no vent, no magma chamber. The pristine flows of “volcaniclastic” rock could not have come out of the ground. The other problem with using the standard model here is the lack of slopes to flow down. On such flat, and level, ground, we cannot assume gravity as the motive force for these pyroclastic flows.
The lines of movement in the melted, flowing stone in the area are clear, and well preserved. Also, they, and the nature of the rocks in the area, are consistent with being the burn marks of tremendous hydrothermal explosions in the ice sheet. They are the grayish to pinkish, sometimes blurry looking areas with flowing lines of once fluid, and moving,’ stone in them. And the number, and spacing of the hydrothermal burns is exactly what we would expect from many pieces of a large, fragmented, comet exploding in the Ice sheet.
Note the the inclusions of black material in the flows of fine grained clastic rock like the inclusions of till in a flowing glacier of ice. It is the fine grained, high carbon, material defined on the list as slate, and graphic slate. But that stuff was flowing with the melt at the time it was emplaced. And that doesn’t jibe with the well observed explanation for the sedimentary formation of a normal slate deposit. Whatever the inclusions of black, high carbon, material are made of, it isn’t slate.
Most of the old literature on the region focuses a lot of attention in the peat depressions and their possible formation. The area is also known as “The Patterned Peat Lands of Northern Minnesota”. There is speculation that Multiple glaciations caused the patterns. Or Lake Agassiz, and related glacial mega floods may have had something to do with it.
But the profoundly simple fact is that ice sheets, and glacial lakes don’t make pyroclasts, or blast melt, or any other igneous rock form for that matter. They can only erode away some of the surface detail. And if you look closely you will see that there is no missing surface detail in those flows. The solidified flows show show almost no exfoliation, or decomposition. There is no glacial scaring on them at all. And Except for some peat growing here and there in the cracks, and depressions, the melted flows of felsic “volcaniclastic” rock are almost as pristine as the day they first cooled. And yet we know there hasn’t been any volcanic activity there in more than half the age of the Earth.
By its very nature, the fine grained felsic “volcaniclastic” and “volcanogenic” rock on the list was a fluid, in rapid motion at the moment of its emplacement. And here, as in Mexico, those motions are as easy to read as flowing paint. The ice did play a major role here in the formation of these patterns. But not in the manor that has been assumed. The depressions are the footprints of obstacles the melt was flowing around, and through, when it was emplaced. Those obstacles are no longer there because they were icebergs that were the comet blasted remnants of a shattered Laurentide ice sheet.
To sum up, the surface rock of the blast burns in the northeast impact zone grades from migmatites, which were formed from ordinary sedimentary deposits that were heated almost to the melting point under terrific heat, and pressure. And in the presence of a lot of water. To “volcaniclastic”, and “volcanogenic” rock which was probably the same stuff. But heated all the way to a fast flowing state, and fluffed up a bit with hot gasses. So in the recipes, and conditions, needed for the formation of the rocks of each of the blast burns we see the signatures of the full range of conditions and temperatures from hydrothermal to “volcanogenic”, we should expect in the planetary scaring of an ice sheet impact. Those hydrothermal burn scars can be found in large numbers all the way to the Arctic. And, as the blast effected materials of an explosive event, they describe the almost complete destruction of the Laurentide Ice Sheet is a mater of minutes.
The Carolina Bays
All along the eastern seaboard we see the Carolina Bays. They date to the Younger Dryas boundary layer. And currently, no terrestrial process has been identified to account for them. But if you draw a line through the long axis of any one of them, you will see that the line crosses one of the Hydrothermal burns in Minnesota, and Canada to the north. My own theory is that they were formed by an impact event. But don’t go looking for remnants of the bolides. The impact induced hydrothermal explosions in the ice sheet tossed impactites of ice that formed the bays. So the bolides that made all those oval craters simply evaporated.
Imagine along with me for a moment. What say we take a great big comet, say 50 to 100 km wide, out of the Oort Cloud, or the Kuiper belt, and inject it into the inner solar system. And we park it an elliptical, Earth crossing orbit, and break it up into not so little pieces. Let’s give it enough time for tidal forces to break it up completely, and stretch it out a bit. Our average fragment Should be about the size of the Tunguska object. But they ranged from more than a half mile wide, all the way down to clouds of dust.
As the Earth’s orbit brings it across orbital path of the giant, fragmented comet’s debris streams , the fragments begin to fall into the atmosphere from the south at a low angle. And more than 30 km/sec. The first fragments to hit will produce atmospheric temps well over 100,000 degrees C. And they are just cheerleaders, twirling batons in front of a parade. The rest fall into already superheated impact plasma, and just crank up the heat, and pressure. In this way, almost 100% of the kinetic energy of the fragments gets translated to heat, and pressure in the atmosphere. And that heat, and pressure, hit’s the ground as an almost continuous, supersonic, stream of airbursts, hotter than the surface sun.
With just a few short minutes of that, I’ll bet we could sterilize the whole lush, African Savanna, and make it look just like central Mexico, and the American Southwest. And in fact, according to the fossil record, every mega-faunal ecological niche we see in the African Savanna, and more, is represented in the fossils below the Younger Dryas Boundary layer. But not above it. All that astonishing biodiversity was burned, and blown away in seconds.
Sound Crazy? Not so fast. The 2007 Firestone paper cited Toon et al when they proposed temps as high as 107 o C. There’s that exponential thing again. That’s 10 million degrees Celsius. But Professor Napier pointed out for me that even if a bolide hits the atmosphere at 30 kilometers per second, and all of it’s kinetic energy is translated to heat in the atmosphere, it is difficult to get more than 100,000 o C. But that’s ok. Because either way, even with the more conservative figure, we are still describing temperatures that are more than enough to vaporize any known substance on the surface of the Earth. And to blow it away like wax under a high pressure blowtorch.
A compelling, almost conclusive, case can be made for the argument that the Younger Dryas cooling, the mega faunal extinctions of the early Holocene, and the demise of the Clovis people were all caused by the same event. It was the multiple, thermal airburst, impact showers of the fragments of the Taurid Progenitor soon after its complete breakup. And the thermal explosive catastrophe its debris stream brought, was more violent than anything ever imagined. There are still a lot of different theories as the trigger event for the Younger Dryas cooling. And the cause of the megafaunal extinctions. As for me, I am firmly in the camp that’s convinced it was an impact event. But I perceive a vastly different kind of impact event from anything studied before, or even imagined as possible. And if you’ll imagine along with me a little more, I’ll try to summarize, and describe, the event as I think it might’ve happened.
Some time between 20,000, and 30,000 years ago a great comet 50 km to 100 km wide was thrown into the inner solar system. And it immediately began to break up. That disintegrating comet was the progenitor of the Taurid Complex. A family of objects in related, short period, Earth crossing orbits. And 12,900 years ago, just after the end of the last ice age, two large clusters of fragments from that monster, both with the fragment size, density, and distribution we see in comets Linear, or SW-3. Had a celestial train wreck with this fair world of ours. The individual fragments of each cluster were so close, that in the heart of their respective impact zones, only the first fragments to fall, fell into cold atmosphere. The rest fell into the already superheated impact plumes of those that had gone before. And they just cranked up the heat And pressure.
Something like 1.1 billion tons of material fell in those two clusters. And the event lasted a little over an hour. The progression of the event was a result of the Earth’s movement along it’s orbital path, as it crossed through the orbital path of the giant comet’s debris stream. Not a product of the Earth’s rotation. So that, in a daytime event, the fragments are outbound from perihelion. The airburst storms would begin in the west, and progress to the east. As the Earth Crosses the debris stream. In a night time event, the debris stream would be inbound towards their perihelion, and the opposite would be true. You get a better idea of the progression of the event if you consider how fast the Earth itself is traveling.
Assuming that the Earth’s orbit is roughly circular, we can work out it’s orbital speed with some fairly simple algebra. Since the average distance from the Earth to the Sun is 149,597,890 km., the Earth travels a distance of 2*Pi*(149,597,890), or 949,951,264.43 km per year. But I can’t wrap my brain around that number when you write it that way. I need it broken down a little more. There are 365 days in a year, and 24 hours per day. So we get a velocity of 107,300 km/h, or if you prefer, 67,062 miles per hour. So what? How do we put that into a scale that makes some sense? We need to put that number into some kind of subjective context to make sense of it.
Consider this: Earth’s Diameter at the Equator is something like 7,926.28 miles, or 12,756.1 km. Which means we’re riding the Earth through space along her own orbital path at a little more than 8.41 times her own width every hour. So, as the Earth crossed the orbit of the Taurid progenitor’s still concentrated debris streams, she would have only been in the path of that stuff for about an hour. And the two large clusters of fragments would have fell within a few short minutes of each other.
The eastern end of the Laurentide Ice sheet got hit in an area from Northern Minnesota, and the Great Lakes to the Arctic Circle. When the down-blasts of thermal impact plasma hit the Laurentide Ice sheet, they caused titanic hydrothermal explosions (steam) that lofted huge icebergs hundreds of miles in all directions. In a matter of minutes, much of the eastern end of the LIS was obliterated. Much of which probably went into the atmosphere as steam. And a few short minutes later, those flying chunks of ice were the impactites that formed the thousands of oval depressions all over the eastern side of the continent called the “Carolina Bays”.
The ice sheet impacts evaporated millions of acre feet of ice directly into the atmosphere as steam. There was probably much more of the ice sheet that went up as steam, only to rain down in the days, and weeks, that followed than was melted to flow into the sea. As North America burned, the storms around the world raged. There were probably torrential rains everywhere in the northern hemisphere for weeks afterward. How long exactly? Who knows? We can only estimate. But for a good ball park figure to start from, the biblical 40 days, and 40 nights, sounds about right to me.
And the signs of massive flooding that have been attributed by generations of geologists to the bursting of ice damns holding back Glacial lake Agassiz are, in fact, the flood effects of the flash melting of major portions of the eastern end of the Laurentide ice sheet. And the outflows from the resulting floods would’ve been to the north into the Arctic ocean, and the North Atlantic. There would also have been armadas of icebergs after the event in both areas. And I expect that the glacial till in those bergs must have been deposited on the ocean floor below as they melted. I’d expect to see some evidence of that armada of icebergs in ocean cores.
Sea levels rose as the blasted, and melted ice sheet flowed in mega floods to the sea. And just as today, most of the larger populations would have been in low lying areas. The seas rose too fast or anyone, and anything, living in coastal areas anywhere in the world, to escape. Every coastline all over the world was effected. And everywhere it would have been much like a giant tsunami. But this time, the flood waters rose and never receded.
Much of an ice sheet bigger than the Continental United States was destroyed. The whole world was shaken to the core. And, like taking weight from a floating barge, the sudden shift of the weight of so much ice caused a massive uplift of the middle of the continent. Coupled with the powerful detonations of so many exploding comet fragments , it caused earthquakes, and volcanic eruptions all over the world. And global seismic activity was the worst in many millions of years.
Out of tens of thousands of large, air-bursting, fragments there is not one single impact structure the northeast that bares any resemblance to what standard impact theory might expect. There are a few hundred normal craters averaging about 100 meters width, in the southwest, on the outskirts of the primary impact zone there. And that have been pretty much ignored by the academic community. But for the most part, all of the planetary scarring of the event has been mis-defined as ancient volcanogenic. And most of the ages of those blast effected materials have been over estimated by orders of magnitude.
The other much larger cluster of fragments hit in central Mexico, and the American southwest. And it produced the most devastating geo-ablative effects of the two.
The Mexican cluster was approximately 500 miles wide. As the first of the fragments hit, they detonated high in the atmosphere. But the explosions retained their downwards momentum. And they hit the ground as devastating supersonic down blasts hotter than the surface of the sun. And as I said, Only the very first fell into cold atmosphere. The rest of the fragments just piled on in, and added to the heat, and pressure. Mexico didn’t have an ice sheet to protect the surface by exploding on impact like reactive armor on a battle tank. And there, the overpressures from the blast waves were so powerful they blasted whole mountain ranges aside like clumps of flour on a bakers table.
As the comet’s debris continued to pile in, the heat, and overpressures, continued to build. In seconds all of central Mexico was pulverized into a surreal, and blasted, landscape of heavily ablated, and melted terrains, like a Salvador Dali painting. It generated a post impact storm front. Like a mega tsunami of thermal impact plasma taller than the atmosphere, hundreds of miles wide, and hundreds of miles from front to back. And it rushed downrange to the northwest at supersonic speeds, sterilizing the western half of the continent on a swath from Mexico to the Arctic, along a storm front extending from California to the great plains.
The blast wind incinerated everything it passed over. In the hottest part of the impact zone, vast quantities of stone were vaporized, and whipped up, into the storm, where the atmosphere worked like a refining tower. And in a fiery rain, the materials precipitated out of the impact storm, down wind according to their condensation temperature, and specific gravity. This was like nothing ever imagined in our most frightening nightmares of disaster, or catastrophe. During the impacts, and for a few minutes after, most of North America from Mexico to the Arctic, and from California, to the plains of the Midwest, was engulfed in a firestorm like something we should only expect to find on the surface of the sun. And there is not one square inch of the surface terrains of western North America in its path that doesn’t bare the scars of that blast of heat.
In fact, look closely in modern satellite images. You’ll see that all of the high ridges of the mountain ranges of California, Colorado, Utah, Wyoming, and Montana that had glaciers at the time bare clear and obvious signs of the heat. And a profound feature that is easy to spot is melted glacial ridges, blown over to the north, and northwest, like runnels of melted wax on the side of a candle. And we typically see high glacial valleys below those deformed, and melted, glacial ridges that have all of the material that was once suspended in the Glacier lying exactly below where it was in the glacier. Indicating that the glacial till dropped out so fast it’s as if the ice just vanished in a quick puff of steam.
While the mega floods from the blasted ice sheet were still flowing into the sea. Much of the biomass of western North America was burned away. And much of the resultant smoke, and soot, was blown high above the atmosphere where it blocked sunlight for years. There was an immediate sharp drop in temperatures world wide. And it was the worst kind of ’Perfect Storm’. Made all the worse because at the same time the destruction of the LIS caused a sudden rise in sea levels world wide. It it may have caused a shutdown of the thermal haline cycle which brings tropical warmth to the North Atlantic. Be that as it may, Northern Europe quickly cooled to arctic temperatures. And the cold remained for something like 1,300 years.
The Clovis people, and whole species, and ecosystems, were annihilated in seconds. Most of the western half of the continent was incinerated, and sterilized. The other half was devastated. The food chain of the entire northern hemisphere was severely compromised. And except. for rare, and random, patches here, and there, that remained somehow unscathed like the one surviving undamaged house in a neighborhood hit by a tornado. The lush savannah the giant animals of North America depended on for food was gone down to the last blade of grass. Those giant animals that survived in the southeast corner of the continent faced a drastically altered, and reduced food supply. And they simply starved. The specialist predators that depended on those animals for food perished as well. The species that survived extinction were the most adaptable, the smaller ones that didn’t eat much, and those that were just plain lucky.
If there were any human survivors of that day, anywhere in the western hemisphere, they were hiding in a deep cave somewhere well south, and east, of the impact zones. And they were cringing in terror as their world was erased and made new again. Any who peeked out of the cave without getting themselves killed, may have told stories of fire breathing dragons remaking the world with breath so hot it could melt mountains.
All that might sound like the product of an overactive imagination. But using modern satellite imagery, a very compelling case can be made that the scenario described above is very close to the exact truth. The remaining debris of the Taurid Complex is still out there. And there are still fragments of significant size in Earth crossing orbits. It is almost a certainty that the next major impact event will be an airburst. And it is a certainty that we haven’t seen the last catastrophic impact event of the Taurid Complex.
Something wicked this way comes. It’s been here a few times before. It’s caused extinctions before. It’s even killed humans before. And apparently in large numbers. Next time it comes back, it would be good to see it coming in time to get people out of the way. And yet congress would rather whiz away 70 million dollars trying to convince us a trace gas that’s important for life to flourish on this planet should be thought of as a pollutant. All the while giving funding for impact research, and the search for Near Earth Objects, little more than lip service.