Mahaney….Again!: New Evidence from a Black Mat Site in the Northern Andes Supporting a Cosmic Impact 12,800 Years Ago


Source: JOURNAL OF GEOLOGY Volume: 121 Issue: 4 Pages: 309-325 DOI: 10.1086/670652 Published: JUL 2013

Previous work has ascribed a cosmic impact origin to black, high-temperature, carbon-encrusted beds (2–3 cm thick), associated with the Younger Dryas readvance of ice at 12.8 ka during the Late Glacial in the northern Andes of Venezuela. The evidence for this includes carbon spherules, aluminosilicate melt rocks, melted coatings of glass-like amorphous carbon, and Fe-Mn on sands and clasts derived from local felsic gneiss and granite. These sediments have been subjected to renewed investigation using high-resolution scanning electron microscopy and energy-dispersive spectrometry, and new data show that spherules at site MUM7B exhibit unique morphologies and compositions. Molar oxide weight percentages prove the spherules are not volcanic and show little overlap with cosmic materials. Spherule microstructures display quench melting and, thus, could not have formed from slow geological authigenic, diagenetic, or metamorphic processes. Instead, geochemical values for the Venezuelan samples plot within the limits of impact-related materials, including tektites, ejecta, and impact spherules from a number of craters and strewnfields (cf. Chicxulub Crater, Chesapeake Bay Crater, Tunguska, Australasian tektite field, Lake Bosumtwi Crater, Ries Crater, and others). These results are identical to previously reported spherules from the Younger Dryas boundary layer (YDB) on three continents, North America, Europe, and Asia, and the most likely origin is from a cosmic impact/airburst 12.8 ka, as previously proposed. The MUM7B site is one of the two southernmost sites (Venezuela and Peru) in South America, thus extending the evidence supporting the YDB impact event into a new hemisphere on a new continent.

  • Steve; The nuke plant at Dresden is on the bed rock just south of the Illinois River and is an extension of the Dolomite prairie in that area. The Braidwood plant is on the sandy area south (west) of the Kankakee River. In the former coal producing areas. There are a whole slew of strip mine holes all around that region plus some shaft mines none of which are in use any more. Are lake Chicago and Saginaw bay impacts in the same time frame or they totally seperate from each other? Also has anyone looked any further south in this state for any YDB evidence? Either directly or accidently?

  • Han Kloosterman

    Hello Jim, accept my excuses, I have been ill and out of email space, restarting slowly only in August. Your question I find just now, 2 months post posting.

    There are too many things I don’t understand! Of course I know that we’re born on a crazy planet (read The Fortean Times once in a while), but even so I try to make sense of things, seeing regularities and predictabilities. We can’t live without.

    Something I do not understand is why the Late Pleistocene climate around what remained of the Canadian ice cap wasn’t similar to the one in Europe. Here the European Sand Belt was formed around what remained of the Scandinavian ice cap, a sickle-shaped body stretching from England over N.France, Belgium, Holland, N.Germany, Denmark, and Poland to N.Russia.
    Excepting a few sites in the UK, all the Usselo occurrences I know or know about are within the so-called Coversands of this Belt.
    The sites in the UK outside the belt, which I know only per photograph, look more as sites in N.America.

    I don’t know what the Black Mat is, a word coming from Vance Haynes’ Black Algal Mat – but there have never been found any algae in it. So, what are they talking about? Here in Holland and surroundings, the Usselo Layer is a sand layer with sand (granulometrically) similar to the sand underneath and above, but with an enrichment in the smallest fractions – and that is of course wherein are found what the N.Americans call ET proxies. Within the layer, whether 3 or 12 cms thick, this extra material, about 2% by weight, is evenly distributed, vertically.
    At 3 or 4 places there is a thin (~5cm) peat-like layer on top of the Usselo Layer – is that perhaps what they call the Black Mat?

    When I first read about the layer in the UK, in a book by Derek Ager, in 1977, he also mentioned the Twocreekan forest, and I launched the hypothesis of a worldwide conflagraton. And the Twocreekan forest is in Illinois – perhaps it can help you in your research.
    Let me know.



  • Herr Klosterman; Thank you for your time and expertise. The black mat I was referring to is the Younger Dryas Boundary. I was thinking that the YDB was not in this area because of the glaciation removing anything in it’s path. I’m not sure if the ice was advanced or retreated beyond my area 12,900 years ago. I’m thinking it was pulled back because the Kankakee & Illinois rivers had already been formed so there should be evidence of the YDB around here I’m just not sure where to look.

  • E.P. Grondine

    Hi Jim –

    Several years ago I passed on the Osage memories of surviving the Holocene Start Impact Event at the salt lick south of Saint Louis. They came via “Fossil Legends of the First Americans” by Mayor, and they were not “Fossil Legends” but quite explicit in detail.

    I can not find a link to that posting now, and do not have the materials at hand; that is one reason why the Cambridge Conference and Bob Kobres archive of it was so useful. You might want to try one of the internet archiving sites.

    When this kind of thing occurs it is tough not to be paranoid; it is big dollars that are being fought over, and there are a lot of fanatics and insane people out there. If anyone is trying to claim copyright on Osage traditions…

    Back to the subject at hand, the Osage remembered exactly what happened.

    If you are interested in the ice sheets, there is work being done on the float copper distribution.

  • Han Kloosterman

    Jim, I’m not a bloody Herr, part of the Herrenvolk, and when I meet a nice, well-educated German I’d rather describe him as a gentleman. You must be one of those Northamericans who think that phenomenon is the plural of phenomena.
    By all means, study some geography.

    For the geological problems you probably should study the geological map of Illinois, perhaps there are some Late Pleistocene sands anyhow, lateral equivalent of the European Coversands. If so, that would be good place to look for the Clovis Layer. It would have the advantage – as the Usselo Layer has here – that the time sequence can be studied better, from the stratigraphical superposition.
    And then it might turn out that the layer is NOT marking the lower YD boundary sharply.


  • Han; My sincerest apologies, no disrespect intended. There is an area of sands just west of where I’m at. I’ll need to look see if there is any evidence of YDB between the suface and the coal seams approximately 100ft down. Again thank you for your time. Jim

  • JimC

    Han is The Man.

    Check out the Fireplanet link on that site, “An e-mail discussion between Han Kloosterman, Derek V. Ager and Alfred de Grazia concerning Catastrophist Geology.” Han Kloosterman was observing the evidence of the Younger Dryas Lower Boundary and entertaining the concept of Global Conflagration while some of us were still in diapers, or even before….

    The 2007 film “Overturning of the Earth” on that site explains his well founded sensitivities about the evil and (self proclaimed) Nazi Herrenvolk (Master Race). It also details his rigorous scientific method and beautiful wacky genius regarding GeoSpace and Earth sciences.


    TimH (I promise I am not a spammer….)

  • E.P. Grondine

    Hi Hans –

    I have met people trying to locate clovis sites in Illinois.

    Aside from that, at this point in time I focus on data recovery rather than “theories”.

    One piece of current data is that Morrison’s rather constant insult that I am a Velikovsky wannabe really irritates me; Morrison refuses to mention Clube and Napier, even in his insults.

  • Han Kloosterman

    Hello EP, in the German-speaking countries they don’t use Velikovsky to defile your face, but Alexander Tollmann. He was professor of geology at Vienna U. – the prestigious chair of Edward Suess, author of the famous Das Antlitz der Erde (The Face of the Earth), a century ago.
    Towards the end of his academic career, as a uniformitarist, Tollmann became a catastrophist and produced together with his wife their book on the Late Pleistocene impacts, in 1993 I think.
    It was never translated into English.

  • Jim coyle

    TH; Thanks for the link to Han’s site. I’m hoping Han isn’t upset with me after my inappropriate addressing of him. After reading about the various sites and some of the stratas involved it’s possible I might be able to find some indications of YDB in my area. Does anyone know of any maps showing the approximate limits of the wisconsonian ice sheet at the time of the YDB?

  • Hi Jim,

    This paper by David M. Mickelson and Patrick M. Colgan, and titled, The Southern Laurentide Ice Sheet might be the reference you’re looking for. But if you’re digging in a location that was both under the LIS, and then later as the ice retreated was submerged by Lake Agassiz, you may never find a clearly defined YDB layer; only stratigraphic evidence of the transition from sub-glacial to lacustrine conditions

    But if you can find a well defined exposure showing that transition such as a ditch wall, or some other excavation, perhaps a construction site, look for the clay layer that was once the under belly of the LIS, above that you should see a layer of glacial till, and debris, that can be anywhere from a few inches to hundreds of feet thick, and that was laid down as the ice melted. And finally a sand layer of varying thickness that represents the bottom sediments of Lake Agassiz.

    If you can find a sequence like that then any YDB materials will be found somewhere between the bottom of the sand layer, and the top of the glacial till. And even then it my be too thin to discern.

  • Steve Garcia

    Jim and Han –

    This Quaternary Deposits of Illinois Map you might like to look at:

    For a bedrock geology map (if needed) of Illinois there seem to be quite a few at

    The first of those has a remarkable pattern that is taken to be the direction the ice sheet flowed, but looks to me like it could just as well have been a pattern from an ice sheet impact. No one KNOWS what the effects of an ice sheet impact would be, so I propose that this is as possible an effect as any.

    I think it is important for all of us to realize that the impact hypothesis for the YDB, if found to be correct, would have ramifications for interpreting all SORTS of things that are currently thought to be gradualism in action. While we spend time talking about the possibility that the Carolina bays are secondary impactors, there may be all sorts of other effects out there being misinterpreted. And until someone looks at them in from an impact perspective, it won’t be possible to learn how big of an effect impacts have beyond the explosive initial impact and the creating of what are currently accepted as impact markers. The work is mostly going on at field collecting and the nano-particle scale and chemistry. Those are good – and necessary, big time – but what about effects in between super-macro and micro?

    The target materials – what happens to not only the ones that Boslough entrains in his conflagration, but the materials much more outboard? ALL of the materials can be melted or vaporized. Farther from ground zero the forces are still incredibly powerful, even if rocks aren’t melting. The Boslough modeling work shows the interior of the plume with lots of heat and pressure, creating all sorts of mayhem at the chemical level. But a bit further away it devolves into simply a lot of Newtonian bang, but on a humongous scale. What is going on “out there”?

    That looks like a possible splash pattern in NE IL. Just like the overkill effect for so long prevented people from considering other possible explanations, is the ice sheet explanation really correct? See the way those patterns flow, from ENE to WSW? That reading of the evidence is NECESSARY in the gradualist paradigm – as opposed to ice simply moving straight southward because there are some spindly rock spires out in western Wisconsin that simply could not have had ice sheets moving over – not without wiping out the spires. Ergo, they had to put this really weird notched area in the southern edge of the Wisconsinan ice sheet in western WI and western IL. That forced them to imagine the ice sheets coming from the EAST, not the north. And the moraines SEEM to agree, so they read the moraines as evidence that their reading of the ice sheets as correct.

    I conjecture that that pattern was instead the result of ice blasted away from the Saginaw impact of Michael Davias. Not ice melted or vaporized, but ice blasted and that never became plasma. It is certain that an ice sheet impact would have cracked the ice sheet (as well as melting much of it). Schultz’s hyper-velocity impact onto ice video was done to look at what the effect would be on UNDER the ice – would there be a crater or not? But what DID happen to the ice? It cracked and large pieces were pushed ahead and outward. His velocity was insufficient to create melting, but it certainly created cracking. Are we supposed to think that no cracking of the ice sheet occurred, beyond the Boslough models showing what was going on within the core of the maelstrom? Why would we think that was all that happened? Schultz’s broken ice sheet showed that large movements of such pieces would likely occur.

    If large pieces were pushed forward (from Saginaw, say) by an impact, then they would have plowed materials ahead of them much like an ice sheet, only with velocities that were magnitudes higher than ice sheets had or have. The evidence would look the same as ice flow, and we would not know the difference.

    End of speculation…

  • Han Kloosterman

    Jim, if I wished and could go and search for the Clovis Layer in Illinois, embedded in hypothetical Late Pleistocene Coversands, I’d look first of all on the Geol.Map. If such a unit exists, my next step would be locating sandpits, and then I’d start visiting these pits.
    The layer here can vary in colour from very white, just bleached sand with a few dark speckles, to very dark where the speckles are predominant. In either case, white or black, the colouring is different from the bottom- and the topsand. Usually there are well-defined under and upper surfaces, defining a layer of 5 to 12 cms.


  • Hi Han

    I don’t know what they’ll find in Illinois. But I’ve been wandering around northern Minnesota for a couple of weeks now; slogging around in giant bogs, digging in the mud, and even presenting myself as a human sacrifice to ungodly swarms of mosquitoes. All in the interest of turning up something that might be pertinent to our favorite hypothesis.

    Here, the late Pleistocene Coversands you speak of are not hypothetical at all. They exist in abundance. And I was able to find a very clearly defined exposure in a ditch on a construction site on the second  day I was here.

    I suppose I should give it a name. So we’ll just name it for the farmer who owns the place, and call it The McMillan Exposure.

    At the bottom you see the clays that were once the underbelly of the LIS. That layer goes down another 10 to 15 feet or so and ends at the bottom with a 3 to 5 foot layer of blue clays. But it’s the stuff that rests on top of the glacial clays that’s the most exiting to me.

    Note that we have 4 to 5 inches of dark debris, and glacial till above the grayish clays, above that about a foot of light colored coversands, and finally a very dark, almost black layer of sandy, peaty topsoil. There is also about 8 inches of gravely fill material on the very top that was brought in by the property owner to bring the surface up to grade for construction on the site.

    The dark debris layer between the clays of the LIS, and the light colored sands covering it all that were laid down as bottom sediments in Lake Agassiz is our “hypothetical” Clovis layer. And you’ll note that it is punctuated by a thin band of rusting particles.

    We have to wait for analysis of the rust to be positive it is extra terrestrial or not. But it sure looks promising.

  • E.P. Grondine

    Re: The Tollmans,

    It was the usual case of combining together separate impact events, along with ignoring data that showed separate times/impacts, an adding in data that was not impact produced.

    Very similar to the mistakes made by Alain and Delair.

    It is too bad the Cambridge Conference no longer exists, as the first of the craters from the Holocene Start Impact Event would be publicly documented by now, along with geological features from several other impacts.

    My thinking is that with a really good clearing house the fossil phytolith series from around the world would also be correlated by with accurate 14C dates by now, along with the HSIE bediasite layers.

    Speaking about fascists, we have a lot of theosophist nonsense being promoted in the US right now.

    Also, did you ever meet and talk with Otto Muck?

  • Han Kloosterman

    Dennis, let me know when you have the results of the analyses.

    EP, I have read Muck a long time ago, and now I tend to confound him with Spanuth, the nazi pastor who placed Atlantis at Heligoland. If I remember well, Spanuth tells that Odusseus when with the Phaiakiens heard the words deichos for dyke, and purgos for burg.
    That’s Germanic! And Sp. concluded that the Sea Peoples who invaded Egypt were proto-Teutons.
    I haven’t looked up the words in Homer.
    It sounds ineresting, Odusseus as precursor of Pytheas of Marseille.

  • George Howard

    Thanks, Han. Glad you are up and at them!

  • Hi Han,

    I’ll write up a full report of this trip when I get done. My next study location may not be related to the YD event. In fact it’s probably much older. The geologic formations I’m going to see next are down in Texas on the Mexican border. While I’m there I want to see the Solitario formation in Big Bend Ranch State Park. The gradualists, and catastrophists have radjcally different explanations for the geomorphology there and I need to see it fo myself.

  • E.P. Grondine

    Hi Han –

    It is interesting that only today, some 80 years after the events, are historians realizing that Nazism was a cult. How each German dealt with it or made their way through it is always interesting.

    Did you attend the S.I.S. meetings? Are they still active?

  • Dennis and Steve; I read up on the Mickleson and Colgan paper Southern Laurentian Ice Sheet and found a chart giving approximate lobe locations at a specific time frame. (YDB) The Lake Michigan lobe had retreated to about the mid city point of Chicago. There would have been a smaller glacier lake at the end of the ice. If there was an impact in the Chippewa Basin the western side of the lobe most certainly would have broken off and been thrust against the nearest morraine probably plowing up a lot more debris at that point. I guess any impact on the sourthern portion of the ice sheet would have the potential to dislodge large bergs of ice as the ice is thinner and in decay.

  • Han Kloosterman

    EP, nazism was an overgrown cult and a manipulation system, just as some so-called world religions – the missionary ones. To try forcing what you believe upon somebody else leads to mass murder.

    I have been to some SIS conferences. I have only contact now with Ian Tresman, and with a Dutchman I met there, Rens van der Sluys, independant researcher.
    What I don’t understand at all is that I figure in their Encyclopedia, but Peter Warlow does not. That’s nonsensical! Physicist and SIS-member Warlow was the one who with his tippetop model made sense of Velikovsky’s Earth reversals, which Vel. himself hadn’t understood.
    I have my own contribution there, from the 20-odd reversal myths Vel. collected, I jump to over 100. But that’s not published yet. Moreover, I have unearthed some geological arguments.

  • Trent Telenko

    >>It is interesting that only today, some 80 years after the events,
    >>are historians realizing that Nazism was a cult.

    Nazism was only one of two death-cults loosed upon the world in the 1930s-to-1940s.

    The Neo-Samurai death-cult of Japan was the other.

    Robert Pape’s analysis of modern terrorist death-cults from a strategic, social, and psychological point of view in his “Dying to Win: The Strategic Logic of Suicide Terrorism” is the closest the social sciences can bring themselves to look at the political-sociological issues of Death-cults.

    There are good career reasons academics of the WW2 Diplomatic and Military history schools won’t go there, because of the adverse impact on tenure that bucking the accepted narratives causes.

    Funny how that adverse career pattern repeats across the physical sciences with the YDB event, as well as the social sciences with WW2.

  • Han Kloosterman

    Trent, thanks for the reference to the Pape book.

    But what I’m most concerned with are the movements that started full of hope and then deteriorated. The French Revolution turns into the Terreur; Marxism becomes Stalinism; Anabaptism, the left wing of the Reformation with such ideas as equal rights for women, soon became the horror of Munster under Jan van Leiden. (The cages high on the church tower in which the leaders slowly died are still hanging there).

    Michel Tournier in Le Roi des Aulnes calls it L’Inversion Maligne.
    I have just ordered the book Maschinenkinder by Christian Bloess, in the hope to find something in it on the change from XVIIIth century Enlightenment to post-Romanticist Positivism, which suddenly around 1860 took hold over the whole political spectrum.
    That was when the dichotomy Mainstream – Fringe was created, by the dogmatism of the academic mainstream.

    I know a bit about the Japanese movement; at Utrecht U. in the 1950s several students and 2 professors (Von Koenigswald, palaeontology, Van Bemmelen, economic geology) had spent WW II in a camp.
    But especially after seeing the Kubrick movie Paths of Glory, with Kirk Douglas, I promised myself to try to avoid being maneuvered into a Befehl-ist-Befehl situation.
    I didn’t always succeeded.

  • R. Harmon

    I sent this to George Howard, but in case he missed it, I’d like to share it with everyone here.

    I recently watched a documentary by Peter Marsh titled “Cousins Across The Sea” which is about the origins of the Eastern Polynesians and their cultural/possible genetic relationship with the Northwest Native populations.

    In the third part of the film, comparisons are made between their various origin stories. Here’s a link to the specific segment:

    The sky and the earth were the same color, no stars or sun could be seen, it would only lighten or darken. The documentary references the YDB Theory and ties it into the oral history of various cultures throughout the regions.

  • Anyone out there know how the “jets” on a comet work? I got the impression that comets rotate as they travel forward. also if they do inded rotate do theyturn in just one direction or do others rotate opposite.

  • Cevin Q

    Hello R. Harmon,
    The origins of Polynesians has been a fave subject of mine for a few years now. I was introduced to the alternative theory of their origins through Mr. Marshes website.
    As I have progressed through my own research, and through conversations with others, I have to take some of his work with a grain of salt.
    But you can’t throw out the baby with the wash water.
    So, that being said, here’s what I have to add on that subject,
    The austronesian/Polynesian split comes several thousand years after the YDB event. But that doesn’t negate the Polynesian/native American connection.
    The striking cultural similarities between Hawiian mythology and that of certain people of the island northwest is hard to deny.
    Also the other cultural aspects, show a deep connection, such as the use of mats for “currency” , sexually related mortars and pestles and canoe construction draw a definate link between these seemingly separated people.
    As I see it the proto austronesians/Polynesians had to leave their Taiwanese home lands around 8k years ago.
    One of the big questions is what caused them to leave the area? I believe it was volcanism, there are several well documented eruptions at this time horizion, but according to Saboba myth.a great captain called his people together to “leave this land” in a collection of canoes. The people rowed through the darkness, with only the singing from people in other canoes, being able to keep the group together as they journeyed east.
    The Saboba were an inland tribe, from the tehachapi area, that were linguistically related to the chumash of the southern ca coast.
    What I find so interesting is that there are no navigable water ways within their range, so how did they come by the idea of a great journey upon the oceans.

  • E.P. Grondine

    Hi Cevin –

    While I am not intimately familiar with materials from the West Coast, my guess would be that the release of the glacial melt waters and rise in sea level around 8,350 BCE may have led to the migration you mention.

    One major question is the slower development of advanced cultures in that area, which may be tied to Pacific Ocean impact mega-tsunamis as well as the seismic tsunamis. Aside from the large impact mega-tsunami in the 1400’s CE, which appears to have led to the destruction of Nan Madol and the Chinese ocean fleet, I am ignorant of them.

    Good luck

  • Trent Telenko

    >>Aside from the large impact mega-tsunami in the 1400′s CE, which appears to have led to
    >>the destruction of Nan Madol and the Chinese ocean fleet,…

    Care to expand upon that?

    That China-Pacific impact tsunami event comes under the “first I heard of it” column for me.

  • E.P. Grondine

    Hi Trent –

    You can find some of Ted Bryant’s original work on the Aboriginals’ Great Wall of Water in the Cambridge Conference archives.

  • Trent Telenko


    Based on my internet search, this link seems to be the current index for the Cambridge Conference:

    Using the Cambridge Conference search engine at the link above you find the following:


    The following text is an extract from Edward A. Bryant’s new book TSUNAMI:
    THE UNDERRATED HAZARD, to be published by Cambridge University Press
    (publication c. July 2001).

    0 521 77244 3 Hardback £55.00/$74.95
    0 521 77599 4 Paperback £19.95/$27.95

    For more details and how to order, please visit the CUP website at


    In the past decade over ten major tsunami events have impacted on the
    world’s coastlines, causing devastation and loss of life. Evidence for past
    great tsunami, or ‘mega-tsunami’, has also recently been discovered along
    apparently aseismic and protected coastlines. With a large proportion of the
    world’s population living on the coastline, the threat from tsunami can not
    be ignored. This book comprehensively describes the nature and process of
    tsunami, outlines field evidence for detecting the presence of past events,
    and describes particular events linked to earthquakes, volcanoes, submarine
    landslides and meteorite impacts. While technical aspects are covered, much
    of the text can be read by anyone with a high school education. The book
    will appeal to students and researchers in geomorphology, earth and
    environmental science, and emergency planning, and will also be attractive
    for the general public interested in natural hazards and new developments in

    Chapter Contents

    Preface; Acknowledgments; Part I. Tsunami as Known Hazards: 1. Introduction;
    2. Tsunami dynamics; Part II. Tsunami-Formed Landscapes: 3. Signatures of
    tsunami in the coastal landscape; 4. Coastal landscape evolution; Part III.
    Causes of Tsunami: 5. Earthquake-generated tsunami; 6. Great landslides; 7.
    Volcanic eruptions; 8. Comets and meteorites; Part IV. Modern Risk of
    Tsunami: 9. Risk; 10. Epilogue; References; Index.

    >Much snipped<

    Is this your reference?

  • E.P. Grondine

    Hi Trent –

    You may want to keep in mind that China’s national symbol, the Dragon, first appears after the Holocene Start Impact Event.

    You may also be interested in the transition from yayoi culture to jomon culture in Japan:

  • E.P. Grondine

    Hi Han –

    It is funny to watch how some people try to view me through a Velikovskian perspective.

    It is as funny as having manned Mars flight “enthusiasts” lecture me on dealing with the impact hazard, or George lecturing me on “success”, or D.C. lecturing me about air bursts, impact mechanics, scaling laws and geology.

    It is as though Clube and Napier do not exist and did not exist. “Denial” takes many forms

  • E.P. Grondine

    Hi Trent –

    Yes, that book is essential. While you wait for it to arrive you may read some of his team’s worknotes in the Cambridge Conference archives, and later materials elsewhere on the web.

    While our host is interested in the Carolina Bays, he glides right by some of their later fill materials.

    Essentially, any sizable impact in the Atlantic Ocean has had an effect and will have an effect on major population centers in the US that lie along the east coast. See Dallas Abbott’s work in this regard.

  • Ed,

    Regarding the mention of my recent trip to Minnesota; there is no confirmations required. When one is standing in a ditch in northern Minnesota a couple of hundred miles north of the terminal moraines of the Laurentide Ice Sheat, and looking at an exposure of the clays that were once the underbelly of the LIS, and those clays are topped off by the sediments of Lake Aggasiz, it does not take a geology major to recognize that the transition between them contains any materials scattered on top of the ice by the still hypothetical YD event. As for whether that layer contains any ET chemistry, or impact markers, the locations where specimens were taken from are well documented, we shall see.