A book published in 2006 by Firestone, West, and Warwick-Smith proposed that a cosmic chain of events culminated in the extinction of the megafauna approximately 13,000 years ago. This book established what was later called the Younger Dryas Impact Hypothesis.
The book entitled "The Cycle of Cosmic Catastrophes" has featured two covers with different subtitles. One of them says: Flood, Fire and Famine in the History of Civilization. The second cover design that is more representative of the content of the book illustrates a comet impacting the Earth with the subtitle: How a Stone-Age Comet Changed the Course of World Culture. The authors are Richard Firestone, who has a Ph.D. in nuclear chemistry and worked at the Lawrence Berkeley National Laboratory, Allen West, who heads an international scientific consulting company and Simon Warwick-Smith, who worked as a geologist in Australia and now heads a book consulting firm.
The Cosmic Catastrophes book was followed in 2007 by the publication of a peer-reviewed paper by Richard Firestone and twenty five co-authors that included Allen West, but not Simon Warwick-Smith. The authors of this paper represented a broad spectrum of academic and professional specialties. The paper is entitled "Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling" and was published in the prestigious journal Proceedings of the National Academy of Sciences.
The abstract says: In this paper, we provide evidence for an extraterrestrial impact event 12,900 years ago, which we hypothesize caused abrupt environmental changes that contributed to Younger Dryas cooling, major ecological reorganization, broad-scale extinctions, and rapid human behavioral shifts at the end of the Clovis Period. We propose that one or more large, low-density extraterrestrial objects exploded over northern North America, partially destabilizing the Laurentide Ice Sheet and triggering Younger Dryas cooling. The shock wave, thermal pulse, and event-related environmental effects, such as extensive biomass burning and food limitations, contributed to end-Pleistocene megafaunal extinctions and adaptive shifts among PaleoAmericans in North America.
The scientific community received Firestone's peer-reviewed publication with great skepticism, which culminated in 2011 with the publication of a paper entitled "The Younger Dryas Impact Hypothesis: A requiem" by Nicholas Pinter and six other university professors. The abstract of the requiem paper said: The Younger Dryas (YD) impact hypothesis is a recent theory that suggests that a cometary or meteoritic body or bodies hit and/or exploded over North America 12,900 years ago, causing the YD climate episode, extinction of Pleistocene megafauna, demise of the Clovis archeological culture, and a range of other effects. Since gaining widespread attention in 2007, substantial research has focused on testing the 12 main signatures presented as evidence of a catastrophic extraterrestrial event 12,900 years ago. Here we present a review of the impact hypothesis, including its evolution and current variants, and of efforts to test and corroborate the hypothesis.
The requiem paper says that none of the original YD impact signatures have been subsequently corroborated by independent tests. Of the 12 original lines of evidence, seven have so far proven to be non-reproducible. The remaining signatures instead seem to represent either (1) non-catastrophic mechanisms, and/or (2) terrestrial rather than extraterrestrial or impact-related sources. In all of these cases, sparse but ubiquitous materials seem to have been misreported and misinterpreted as singular peaks at the onset of the YD. Throughout the arc of this hypothesis, recognized and expected impact markers were not found, leading to proposed YD impactors and impact processes that were novel, self-contradictory, rapidly changing, and sometimes defying the laws of physics. The YD impact hypothesis provides a cautionary tale for researchers, the scientific community, the press, and the broader public.
The requiem paper reviewed several sources that discussed the Carolina Bays, including Firestone's 2006 book, his 2007 peer-reviewed paper and a subsequent paper published by Firestone in 2009. The requiem paper provides the following summary: The Carolina Bays include thousands of circular to elliptical depressions across the coastal plain of the southeastern USA. Origin of the Carolina Bays was debated for many years, with some notably odd mechanisms proposed, such as gyroscopic forces and spawning fish. Melton and Schriever in 1933 attributed the Bays to a swarm of oblique impact strikes. In contrast, more recent research has focused on geomorphic origins. Younger Dryas Boundary proponents returned to the impact mechanism for the Bays, based on their elliptical forms, parallel alignment, and purported YD impact markers collected from the bay rims and interiors. Firestone's 2006 book implied that the Carolina Bays formed from impacts of large-scale secondary ejecta from the primary impact site, whereas Firestone's 2009 paper suggested "a high-temperature shock wave that raced across the continent creating the impact debris-rich Carolina Bays as it passed." Research both before and since the YDIH suggests that an impact origin for the Carolina Bays is unlikely. No meteoritic material has ever been recovered from the bays.
It is true that no significant meteoritic material has been recovered from the bays, but if the Carolina Bays were created by the secondary impacts of glacier ice ejected from an extraterrestrial impact on an ice sheet, the bays would not be expected to contain any meteoritic material because glacier ice is a terrestrial material.
Why were the critics of the cosmic catastrophe so harsh? The requiem paper provides three main reasons. The first one is the catastrophic vs. the non-catastrophic mechanisms, where the Younger Dryas impact research avoids using gradual uniformitarian explanations for the claim of catastrophic wildfires triggered by the purported impact. The second objection is the terrestrial vs. extraterrestrial mechanisms, where the Younger Dryas Impact Hypothesis attributes terrestrial material to purported extraterrestrial sources. The third and most severe objection relates to the impact signatures at the Younger Dryas Boundary.
Firestone proposed that magnetic spherules found in the Clovis-era sediments were evidence of a comet explosion, but the requiem paper stated that such spherules are consistent with the diffuse, non-catastrophic input of micrometeorite ablation fallout, probably augmented by anthropogenic and other terrestrial spherular grains.
The requiem paper stated that impact cratering studies are part of mainstream geological research, and that diagnostic criteria have been developed for the identification and confirmation of impact structures and ejecta on Earth. These criteria are clearly defined: only the presence of diagnostic shock-metamorphic effects and, in some cases, the discovery of meteorites, or traces thereof, are generally accepted as unambiguous evidence for an impact origin. Shock deformation can be expressed in macroscopic form, such as shatter cones, or in microscopic forms like the distinctive planar deformation features in quartz. None of these have been found in the Younger Dryas deposits.
The Cycle of Cosmic Catastrophes book proposes that the Younger Dryas cataclysm was triggered by a supernova explosion close to the Earth 41,000 years ago. The burst of radiation caused widespread extinctions in Australia and Southeast Asia. Then, 34,000 years ago, the first shock wave of the supernova buffeted the Earth, and 16,000 years ago, the second shock wave of the supernova arrived. Finally, 13,000 years ago multiple impacts of comet-like objects hit the Northern Hemisphere. The Cycle of Cosmic Catastrophes book proposes a complicated hypothesis that is very difficult to prove. There is no convincing way of proving that a supernova exploded close to Earth 41,000 years ago, and that the shock waves reached the Earth 34,000 and 16,000 years ago. This is why the 2007 peer-reviewed paper only focused on the purported impacts in North America 13,000 years ago for which it was easier to provide corroborating evidence.
The Cycle of Cosmic Catastrophes book has a chapter entitled "The Carolina Bay Craters" that starts with the following question: Many scientists believe the bays formed, not from impacts, but from wind and water action alone. What evidence is there supporting the impact theory? The book says: One of the strongest arguments supporting the impact theory is this: the bays seem to be unique on the entire planet, and whatever process formed them is not creating any new bays. In other words, if common agents like wind and water had formed the bays instead of an impact, then wind and water should still be producing more bays at this moment somewhere on the vast land areas of our planet. However, we want to point out that nearly all researchers agree that wind and water have modified the shapes and rims of existing bays; the only disagreement is whether wind and water created the initial bay depressions.
The chapter about the Carolina Bays says that the best explanation for the overlaps is that they result from the impact of multiple objects. After the first ones landed, others fell on top of them, creating the overlaps. Firestone provides an image of a cluster of bays in North Carolina where one bay overlaps in nearly all compass directions, a fact impossible to explain with the wind and water theories, which propose that the strong bay-forming winds blew only from either the northwest or the southwest, varying according to the particular version of the theory. Either direction is insufficient to explain how the bays could expand backward for miles against the prevailing winds.
Firestone chose a good example to illustrate the overlaps of the bays. A LiDAR image of his example shows these overlaps very clearly. The geological law of superposition indicates that several small bays were emplaced first. Then, a large bay overlaid the small bays. Later, another large bay overlaid the large bay and some of the small bays. LiDAR images provide a view of the Carolina Bays that is unobstructed by vegetation and greatly improve our ability to study them.
Aerial views of the Carolina Bays always show them encircled by a raised rim of white sand. On page 121, the Cosmic Catastrophes book has an explanation on how to make sand turn white. "If the white sand was the product of bay genesis, then what could have caused tan sand to turn white? Two things typically do that. The first is chemical action, such as when acid etches quartz, removing the reddish iron-stained surface to reveal the white quartz sand beneath it. The other is very high temperature, usually above 1,500 degrees Fahrenheit, which burns off the reddish iron impurities from the surface of the quartz. White sand and acid? Searing heat? Either of those solutions seemed difficult to believe, and the acid was the least plausible. High temperatures were more likely, since a huge explosion of some kind could have created the temperatures necessary to turn the sand white. According to the impact theorists, that is what one would expect of an impactor arriving at a low angle from the northwest. The force of the impact would superheat the sand instantly, turn it white and blast it out toward the southeast. All that was still theoretical, and we lacked hard evidence either way. We thought, however, that no matter what had happened, the white sand was one clue that might help solve the riddle of the bays."
One of the weaknesses of Cosmic Catastrophes book is that it proposes an idea and then quickly dismisses it. After suggesting that an explosion of some kind could have created the temperatures necessary to turn the sand white, the next paragraph says that the explanation was theoretical and it lacks hard evidence. This type of back-and-forth speculation undermines the confidence of the reader. The explanation is also weak because explosions create circular craters, which are incompatible with the elliptical geometry of the bays. Also, the book does not even consider the idea that the raised rims of the bays could have turned white after the formation of the bays, instead of during their formation, perhaps by rainfall over thousands of years.
It is not surprising that the requiem paper criticized the impact processes in the Cosmic Catastrophes book as self-contradictory, rapidly changing, and sometimes defying the laws of physics. The monograph on impact cratering by Professor Jay Melosh explains that an extraterrestrial impact goes through the stages of compact and compression, excavation, and modification.
But the Cosmic Catastrophes book says that the crash of the bottom half of a dustball-comet exploded and shattered the upper portion of the impactor. This is clearly wrong. In a real impact of a comet with a speed of 50 km/s, the whole comet would have penetrated the target before exploding and starting the excavation stage.
An extraterrestrial impact ejects debris in ballistic trajectories, but the Cosmic Catastrophes book describes icy debris hurtling through the air or skipping across the landscape. Both of those statements are wrong. The distance from the proposed impact point in Hudson Bay to South Carolina is approximately 2,800 kilometers. Using ballistic equations, we can calculate that the trajectories of the ice boulders would have reached heights of 700 kilometers above the surface of the Earth. Since the Earth's atmosphere is only 100 kilometers thick, the icy debris would have traveled in suborbital space flights above the atmosphere in the vacuum of space. It would not have gone hurtling through the air or skipping across the landscape.
Something else that is wrong with the Cosmic Catastrophes book is the disregard for the thermodynamics of water. The book says that a rain of incandescent debris and chunks of steaming ice showered down across most of North America, Europe and Asia. There is no such thing as "chunks of steaming ice". Water has three phases: solid ice, liquid water, and gaseous steam. Some ice might evaporate during its re-entry through the atmosphere, but if it reaches the ground, it will be in its solid phase just like ordinary hail. The statements in the book that the low-flying lumps of ice exploded into fireballs and that ice bombs torched entire forests are merely dramatic expressions of imaginary events that disregard the laws of thermodynamics.
The Cosmic Catastrophes book proposes that following an extraterrestrial impact in Hudson Bay by a giant dustball-comet, the secondary impacts of low-flying lumps of glacier ice crashed into the eastern seaboard, exploding into fireballs and gouging out the Carolina Bays. Even though we know that glacier ice chunks cannot explode into fireballs, the book says that the bays are craters and compares them with the craters in Mars.
The book illustrates similarities between the Carolina Bays and Martian impact craters. Many images of elliptical craters in Mars, including those that overlap, are compared side-by-side with Carolina Bays. The comparisons are convincing because many Martian craters have flat bottoms like the Carolina Bays.
The Cosmic Catastrophes book does not seem to have a firm concept of the characteristics of Carolina Bays. The elliptical geometry, the raised rims, and the orientation toward a convergence point are considered, but not the type of terrain. Carolina Bays are only found on unconsolidated ground close to the water table. They are not found on hard terrain, but the book proposes that a ring fifteen miles in diameter centered on Elizabeth, New Jersey is the largest Carolina Bay ever found.
I looked at a LiDAR image of Elizabeth, New Jersey, and I marked the features that supposedly correspond to Carolina Bays. However, these are not Carolina Bays. The terrain is too hard to allow the formation of Carolina Bays. This is another instance where the Cosmic Catastrophes book proposes an idea and then quickly dismisses it. The same page that has the image proposing huge Carolina Bays in New Jersey has a paragraph that says: Most scientists believe that the rim around the Elizabeth, New Jersey bay is actually glacial debris, called end moraine, which meltwater shaped into mounds and ridges when the last glacier retreated. This may be true, or it may be an impact, since it has every one of the usual bay features, and because it is more regular than the typical ice-sheet moraine. Saying that the rim encircling Elizabeth has every one of the usual bay features is a false claim because Carolina Bays only occur on unconsolidated soil.
In addition to proposing an extraterrestrial impact in Hudson Bay, the Cosmic Catastrophes book tries to add support for multiple comet impacts by examining the orientation of the Carolina Bays that point to the Midwest and concludes that Lake Michigan could be the site of a pair of comet impacts. The book illustrates two rough ellipses in the center and southern end of Lake Michigan, and says that if a comet actually landed in Lake Michigan, it should have sent a shower of ejected debris in many directions, not just to the southeast.
The Nebraska Rainwater Basins were first compared to the Carolina Bays in a conference presentation by Zanner in 2001. The Cosmic Catastrophes book mentions the Nebraska Rainwater Basins and describes them as elliptical, shallow and flat-bottomed, with rims that overlap just like the Carolina Bays. The one feature about the Nebraska basins that is very dissimilar is their orientation. The basins point to the northeast rather than to the northwest. This actually strengthens the impact theory since the axis direction of these basins typically points toward the northern part of Lake Michigan.
The Cycle of Cosmic Catastrophes book and other papers by Firestone about the Younger Dryas Impact Hypothesis caused such a great outrage in the geological community that a large number of scientists, like the ones who wrote the requiem paper, tried to disprove the hypothesis. One of the attempts to disprove the Younger Dryas Impact Hypothesis tested the Greenland ice cores for siderophile elements, and to everyone's surprise, found a large platinum anomaly characteristic of an impact by an iron meteorite at the Younger Dryas Boundary. The widespread platinum anomaly is now recognized as marking the Younger Dryas Boundary and the extinction of the megafauna. The platinum anomaly provides a firm basis for the occurrence of an extraterrestrial impact at the Younger Dryas Boundary, but it does not provide the location of the impact.
In 2010, Davias and Gilbride published a paper correlating an impact structure with the Carolina Bays and the Nebraska Rainwater Basins. After compensating for the rotation of the Earth, the impact point was identified as Saginaw Bay in the Michigan peninsula.
In 2017, I published a paper entitled "A model for the geomorphology of the Carolina Bays". I was able to show that well preserved Carolina Bays and Nebraska Rainwater Basins have a mathematically elliptical geometry and that the secondary impacts of glacier ice had enough energy to liquefy unconsolidated ground to allow the formation of inclined conical cavities.
The confirmation that the Carolina Bays are geometrical ellipses or conic sections provides support for the hypothesis that the bays originated as inclined conical cavities, and this can be demonstrated experimentally by oblique impacts of ice projectiles into a viscous clay target.
The geometric analysis of the Carolina Bays made it possible to establish a physics-based model for the extraterrestrial impact that created the bays. The width-to-length ratios of the bays are used to determine the launch angles of the secondary ice projectiles. Ballistic equations use the distance from the convergence point to the target and the launch angle to determine the projectile speed, the height and the flight time of the trajectories. Yield equations correlate the speed of the projectiles and the bay sizes to calculate the energy of the impacts. Using the law of conservation of energy, it is possible to estimate the size of the extraterrestrial projectile from the energies that formed the bays.
Our knowledge of the Carolina Bays and their origin has increased substantially over the last fifteen years, but there are still many barriers for the acceptance of the Carolina Bays as impact structures. The dates that have been published for the bays vary significantly, and it will be necessary to convince geologists that the Optically Stimulated Luminescence dates correspond to the dates of the terrain and not the time of emplacement of the bays. Another problem is that the Carolina Bays are usually not covered in geology books although they are the most prevalent geological structures in the Atlantic Coastal Plain. For this reason, I titled my book "The Neglected Carolina Bays – Ubiquitous Geological Evidence of a Cataclysm". I think that the convergence of the major axes of the Carolina Bays and the Nebraska Rainwater Basins by the Great Lakes provides the best clue about the location of the extraterrestrial impact that killed the megafauna and the Clovis people 12,900 years ago.
