Exploring abrupt climate change induced by comets and asteroids during human history

A comprehensive, modern Catastrophist Bibliography



William I. Thomson III is a new friend of the Tusk, and a helpful one at that. With great care and obvious patience Bill has developed a tremendously informative and downright fascinating bibliography of Catastrophism. Anyone interested in reading the variety of publications within, and contributors to, our broad subject will appreciate his hard work. The list is filled with today’s journal articles and working hyperlinks where available.

From Abbott, Baillie and Clube, through Yeomans and Zanner, the list below is to my knowledge the most up-to-date compendium of written work concerning our ancient field. Enjoy.

PPS. This bib is updated as of 1/11/20

81 Responses

  1. That looks like a very useful source.

    I noticed some anonymous author attributions. If I can be of a little assistance, this one:

    Anon. (2012-03-16) ― The Younger Dryas Impact Hypothesis Revisited,‖ In a blog “A Catastrophe of Comets,” [Online:] http://craterhunter.wordpress.com/2012/03/16/the-younger-dryas-impact-hypothesis-revisited/

    Would appear to be Dennis Cox as author, since it is on his blog and no other author is mentioned.

    Also the previous one is also on Dennis’ blog and thus is almost certainly Dennis’:

    r.] Anon. (2011B) ― “A Different Kind of Climate catastrophe”
    In a blog “A Catastrophe of Comets,” [Online:] https://craterhunter.wordpress.com/a-different-kind-of-climate-catastrophe/

    Perhaps three is some reason why William has not assigned authorship.

  2. Steve Garcia’s suggestions have been incorporated into the latest version of the bibliography. Thank You.

  3. On Scribd I can “re-upload” up to six revisions I think, then I am happy to post another “first” and start over. We can have a rolling update from time to time.


  4. Guilty as charged Steve, and thanks. But since writing those two articles I’ve been able to go to the places I wrote about, and spend a little time on the ground there. I’ll be doing a re-write of both of them after I’ve gotten some lab results back on the samples that were collected.

  5. Thanks all, for agreeing, and I only pointed it out so that Dennis would have the credit he deserves.

    And, Dennis, I do again applaud your field work, and I look forward to your updates.

  6. There are no entries for any of the Cambridge Conference materials.

    But then you must know that.

  7. Ed:

    The Second Cambridge Conference Proceedings, not all individual papers, is included:

    Peiser, Benny J., Trevor Palmer, and Mark E. Bailey – Editors – (1998) Natural Catastrophes During Bronze Age Civilisations: Archaeological, Geological, Astronomical and Cultural Perspectives, Proceedings of the Second Society for Interdisciplinary Studies (SIS) Cambridge Conference, 11-13 July 1997, British Archaeological Reports (BAR) 728, Archaeopress, Oxford, ISBN 086054916X [Available as a PDF document.] [I own a hard and PDF copy. See Abstract Below. The Introduction and the list of papers and abstracts of most papers are online: http://www.sis-group.org.uk/cambproc.htm , Cited in Palmer (2003), p. 119. See Abstract below:]
    Abstract: Research in the field of neo-catastrophism and impact cratering has quickened its pace since the early 1980s. An increasing number of astronomers have suggested that a series of cosmic disasters punctuated the earth in prehistoric times. Scholars such as Victor Clube, Bill Napier, Mark Bailey, Sir Fred Hoyle and Duncan Steel claim that a more ‘active’ sky might have caused major cultural changes of Bronze Age civilisations, belief systems and religious rituals. Can the astronomical evidence brought forward by these astronomers be substantiated by the historical, archaeological and climatological records? End

    I may add more if time allows.

  8. Personally I don’t think there are any Catastrophists more dedicated than me, and yet not even a mention. Very disappointed given the following I’m building up. I’ve written two books and have another one on the way (“Extraterrestrial Desert Sands). Even if you disagree with my theories, I would have thought my work was worthy of a mention.

    So much for “A comprehensive, modern Catastrophist Bibliography.”


    Gary Gilligan


  9. Hi Bill –

    Personally, I deal with comet and asteroid impacts, not “catastrophism”.

    That noted, I think that you will need to go back and read the Cambridge Conference archives to complete your bibliography.

  10. Thanks for the link, Barry, but when I read the article, and the paper linked off that, there doesn’t seem to be much there but speculations and caveat words. Compared to, say, the forensics of the YDB folks, this is all very vague and has no substance. Richard Feynman would have a cow at “science” like that, if he was still alive. It is all interesting, but no substance.

    There is a principle in science that, “Correlation does not equal causation.” Trying to tie two 35Mya “cycles” together, when either one might be off by 10-20% and when there is no means of falsifying the conjecture is nothing more than guessing. I am sure the paper got the researcher a little closer to tenure, but it has no teeth.

    Even the Abstract begins with mealy-mouth words:

    “Although statistical evidence is not overwhelming, possible support for an approximately 35 million year periodicity in the crater record on Earth could indicate a nonrandom underlying enhancement of meteorite impacts at regular intervals.”

    “Not overwhelming” could mean anything from no support to moderate support.

    “Possible support” means even less.

    “Approximate 35 million year periodicity” means they saw two 35MYa numbers and are speculating on some tie-in between them – but they don’t even speculate on what mechanism in the galactic periods might affect meteors within the inner solar system – and how that applies to the Earth itself, as opposed to, say, Venus or Mars. All they do is use the numbers to suggest. Are they somehow suggesting that more meteors materialize? That they take aim on terrestrial planets better when certain galactic plane effects exist?

    They even admit:

    “Recent analyses of the crater data usually find that a period of about 35 MYr is most consistent with the data, although the statistical evidence is weak and disappears completely when the look elsewhere effect is taken into account.”

    In terms of the “nonrandom underlying enhancement of meteorite impacts at regular intervals,” the gravitational variations inherent at such vast distances within the galaxy due to wanderings up and down from the galactic plane are incredibly small. Anyone who has ever done sine and cosine calculations on very small angles knows that the sine or cosine values for these angles change so little as to be insignificant. Add to that the fact that such vertical components as are discussed cannot be projected back to the inner solar system as significant increases in the very weak force we call gravity. A tiny wobble in the orbit of Jupiter would be able to create many more magnitudes of effects than the gravity coming from the galaxy’s masses. A passing other meteor would have more effect.

    I would argue that all of this is just playing with numbers/statistics and hearken to Mark Twain again: “There are three kinds of lies – lies, damned lies, and statistics.”

    In addition, a variation of just a few hundred thousand years in either 35 Myr cycle or both (well within the uncertainty of both) would negate even whatever correlation the author was trying to establish.

    As well, the article is a mish-mash of nothings, speculations, and using big words to sound like science.

    That is my two cents. No offense meant, Barry.

  11. BTW, One of the founders of the Royal Society in England, Robert Hooke (the equal to and intense opponent of Newton and his ego on many fronts), was adamant that the Royal Society focus ONLY on such science as could be shown and proved through empirical and experimental means.

    I date the start of real science from the foundation of the Royal Society – methodical and consistent and quantifiable analyses. Prior to that scientific thought was a mix of experiment and philosophy. The philosophical part was a carry over from Aristotle’s and Plato’s time, when experiment had mostly not even been thought of. As we all know, following Aristotle held back science for 2000 years. All of his work was reasonable-sounding but misleading in many critical ways.

    Reasonable-sounding is not in itself science. It is only guesses, no matter how reasonable those guesses are. It only becomes science when experiments are derived from the reasoning and then are tested and not proven wrong (falsified).

    That was Hooke’s insistence, but the very philosophical Newton sabotaged that premise almost from day one. Newton was into religion and alchemy and all sorts of things. Hooke died not long after and his work was mainly lost, and his enemy Newton made sure Hooke got little to no credit for much of his findings. There was no such thing then as peer review; that is what the Royal Society eventually led to, with the lectures and presentations before the Society. But Hooke had Newton fighting him tooth and nail, and Newton as a posthumous reviewer left Hooke’s legacy in tatters.

    As famous as Newton is for gravity, here we are 350 years later and still don’t have any idea what gravity is. Newton recognized the lack at the time and hoped that later generations would fix the problem. They have not. Hooke would find that unacceptable. I do, too.

  12. Dennis; I have a ? for you if you are out there. Is there a physical difference in craters if they are airburst or solid impact created? The answer could possibly help me out with a theory I’m working on. Also, Did you get the pics I sent you 2 weeks ago? If not let me know and I will try again to send them off.

  13. There most deffinately must be. What we haven’t proven yet though, is what the planetary scarring of an ablative airburst should be expected to look like. The simulations done at Sandia indicate that we are looking for places where the fireball reached all the way to the ground with temps hot enough to melt silcate rock, and with sustained supersonic winds at those temps ablating the surface for twenty seconds or more. There are plenty of “pseudoexplosion structures” in the southwest to compile a rather long suspect list.
    Most of those I’ve visited have a lot of geomorphology that looks suspiciously volcanic, although volcanism has been ruled out there. So the trick will be to be to find something in the make up of those rocks that could only have happened during a very large ablative airburst.

  14. Dennis –

    In your visits to the suspect locations, have you grabbed any samples of the suspicious materials that you can run by a geologist or two? His feedback should be worth something, even as a first impression. It might help to inform him first who has ruled out vulcanism, so that he doesn’t go off in that direction – or that he has reason to think in other directions, too.

    While I myself agree with you that ablation is a strong candidate, I’d personally phrase my opinion as less than “could only have….”

    My own main caveat about ablation is that I don’t see how the radiant heat could only go so far down the slopes and not also melt the surrounding flat terrain. The heat energy density should not drop off that rapidly, so I am not sure what to make of that. The only mechanism I can envision would be a ball of heat traveling essentially horizontal low over the terrain and right through the upper portions of the peaks. I know, that sound silly, but it seems odd that only the peaks (from what I saw a while ago) are melted while the lower slopes and flat terrain are not. So, basically, though I think you have ALMOST got it, I think there might be more to it, a complication.

  15. Steve; I saw a graphic showing the exact thing you are describing. A fireball is coming in at an extremely low flat trajectory as it passes over peaks and other higher terrain it melts these structures with it’s intense heat and blows off the melt in the direction of travel. From what I understand when the airburst occurs it travels more or less on the same angle as the incoming object. I would guess that that the shallower the angle the more surface area is impacted. Conversely the steeper the angle the less surface area is effected but a deeper crater is excavated?

  16. Steve, the radiant heat is only part of it. Since the simulations show winds scouring the surface for a good long time with rotational speeds in the vortices exceeding supersonic, then the wind itself
    can be expected to move around an awful lot of loose material, and never mind if it got melted first.

  17. Dennis – What you describe seems eminently probable, I agree. But do you see melt at the flat ground level? As I recall I did not see any.

  18. Jim –

    Cool! Interesting. Do you recall where you saw that graphic? (It wasn’t in a sci-fi movie, was it? . . . hahah)

  19. Steve; No sci-fi movie, sorry! Don’t have time for movies,besides the popcorn is too expensive. I believe it was on a TV program (same thing) about cosmic impacts and why they aren’t a big problem. Just not enough of them to worry about. But what I described is what they said has happened before. When it comes on again (and it will) I’ll try to get more info for desemenation.

  20. Steve; In my browings I came across an article by Prof Ron Jahnke about the Indiana Sand Islands. As I was reading through this I found that the vast sand areas across Indiana into Illinois were laid down before the Kankakee Torrent. Also the sand composition is almost exclusively Lake Michigan sand not Saginaw sand. At the time (14-20,00yrs ago)this sand was supposedly laid down the area was supposed to have been under the ice sheets. Could this be a sign of Lake Michigan impacts. On a couple of relief maps of Indiana I’ve noticed that there appears to be an area in extreme Northwest Indiana that looks like flowage markings coming out of Lake Michigan and heading south along the Ill-Ind border. Just another tidbit to think on.

  21. Jim –

    Can you point me to the Indian relief map that shows that? Did you actually mean a relief map? They don’t show much on the ones I find.

    I have seen the IL bedrock geology map, and it shows a flow pattern to the WEST of the IN-IL border, quite wide. That was the first thing that pointed me to the Kankakee Outwash/Torrent. That “flow” pattern must actually lie under the Indiana sand islands, so it must also predate them. How it all fits I don’t know. There is insufficient evidence at this time to attempt explanations, even though I’ve speculated before, like a fool. Patterns will do that to your mind – as you try to make sense of what you are seeing. That pattern certainly aligns well, though, with the Kankakee Outwash, the Union City drumlin field, and the proposed Saginaw Bay impact, as well as the centroid of the Michigan Basin.

    Yes, I was clear in my head that the Indiana sand islands are sand that matches Lake Michigan sand. While it may be a stretch, though, that doesn’t mean that the Lake Michigan sand is necessarily native to Lake Michigan. I am non-geologically familiar with the sands around the bottom end of Lake Michigan. My son even works right on the edge of the Indiana Dunes, only a few hundred yards from the shore. What the sand’s history is might be very different in the eyes of a gradualist and myself. Their assumptions I leave as open questions.

  22. Steve; I found the relief maps by going on Internet explorer and typing Indiana relief maps. You will get a couple of choices, But look throughthe bunch and see if you can find the ones Grafic leftovers, Shutterstock 162 or Arid ocean. theses names are ghosted over the maps themselves. If you find one look in the extreme Northwest corner ofthe state and you will see an area of the Valparaiso Morraine that appears to have been washout or overrun. Most of the flowage seems to have gone straight south or slightly west into Illinois. The image from shutterstock is quite dramatic as it shows all the Morraines from the huron and Erie lobes of the galciers and their outflows. My thought (speculation) on the Lake Michigan sand is that if there was an impact in the lake there would have been a tsunami of sorts that could have overwashed the morraine and flooded down state Indiana. Also as you mentioned the lake Michigan sand may not have come from Lake Michigan originally but from the the Sasginaw Impact that laid ejecta over the lake area. just another thought. Also Dr Jahnke mentioned specifically that the Sand Islands sand was not from the Saginaw flows but from lake Michigan. The proposed time frames for each event are fairly close together, maybe they are connected.

  23. Jim –

    Thanks for those relief maps.

    You being an Illinoisan, I don’t think I have to explain to you that, even though those patterns are obviously connected with Lake Michigan, the prevailing winds do NOT go in that direction (toward the SW), so, whatever the coloration represents, it is not wind-blown.

  24. Steve; I realize that the wind does usually go to the southwest but I believe that at one time there was a great deal of water spilled over the valpo morraine. That section in the NE corner of Indiana appears to have had the top washed off and from Chicago Heights,Ill to around Valparaiso,Ind the Morraine is spread out to over 17 miles wide. When looking at the same style map of Michigan you’ll see the flow pattern coming out of the Saginaw Bay Area and going south behind the Valparaiso Morraine across Ind. You will also see a clear channel due east into Lake Michigan through the Valpo Morraine. I’m of the opinion that the Kankakee Torrent also went into lake Michigan and probably drained out the south west corner of Lake Michigan into Ill and Ind. How’s that for speculation? Ones speculation is someone elses thought spark.

  25. George,

    You may want to put this up as a separate post:

    Blast Sensors Detect More Asteroid Strikes Than Expected

    Short story — there have been 26 one-kiloton plus asteroid impact blasts detected by the world wide nuclear blast detectors since 2001.

    The hard scientific data about the rate of asteroid impacts on Earth for the last 13 years pretty much shoots down every single impact model I have seen, by orders of magnitude.

  26. Trent – My posted comment on that article’s web page:

    “It is good that we have this data, though by itself it tells us little that is of any use at this time.

    “…The fact that none of these asteroid impacts shown in the video was detected in advance is proof that the only thing preventing a catastrophe from a ‘city-killer’-sized asteroid is blind luck.”

    Not true at all. The atmosphere burns up over 90% of each large incoming objects such as the Chelyabinsk meteor. This means that we have a miraculously effective defense system – and it is all natural.

    A 1-kt explosion is not a city killer.

    The stated kilotonnage of any object depends on what moment they are talking about. With 90% energy losses between the time of atmospheric entry and the airburst, are they talking about 1-kt when it explodes or when it entered the atmosphere. The best info I have on Chelyabinsk is that the 500-kt of the “explosion” (actually it was a final disintegration due to the atmospheric resistance and turbulance) was using the original size, not the size at explosion. Deducting 90%, that was a 50-kt explosion. The 1-kt objects probably started out as 10-kt – about 1/50th of Chelyabinsk.

    In addition, even Chelyabinsk one exploded well over 25-km in the air, so the effects on the ground were minimal, especially in terms of “city killer.” Broken windows? Oh my! People cut by glass is not even remotely a city killer.

    So if what is left of a 500-kt incomer explodes at >20 km up, these 1-kt things don’t really tell us anything whatsoever about city-killers. That is only one data point. Perhaps it is good that they realize that THAT sized meteor is more frequent, but ANY kind of curve (steep, shallow, moderate) can be speculated on from that information, which means basically they’ve learned nothing about city killers.

    Most people with their imaginations get all hyped up about any kind of “end of the World” scenarios. We can credit at least some of that to religion and “End Times” silliness. Those people seem to have deaeth wishes and hopes that they will be part of some really big catastrophe. However, they really do NOT want to be part of such an event. Not anymore than they want to be apart of a nuclear war.

    But their is all “death-wishful thinking”. The reality is that if a 500-kt made it intact to the ground it would be close to a city killer, at least a small city. That would mean starting out as a 5-megaton object.

    The Earth’s atmosphere is like a force field in its results. In that regard, I’d point people to the fact that nearly all observed incoming objects arrive at a low entry angle (probably something to do with the size of the Earth’s gravity well versus the direct Earth target size needed for a steep angle entry), meaning that the object spends a LOT of time in the atmosphere, and for each second within the atmosphere massive amounts of potentially explosive energy are being shed through the process called “ablation.” The rock melts and flows off as droplets, which then vaporize (the bright trail we see). Each bit ablated makes for less energy left to do damage on the ground or in a low airburst.

    Those 1-kt explosions were all WAAAAY up in the atmosphere, where they couldn’t do any damage. 20 meter objects like Chelyabinsk are not city killers. Even the 1908 Tunguska object would not have killed a city, even though it knocked down a lot of trees. Tunguska was probably about three times as wide as Chelyabinsk. It also was absorbed by the Earth’s atmosphere – it never made it to the ground. This should tell people that it does take a rather large object to become any threat to cities. We almost certainly would detect a 60-meter object before it arrives – even if we presently cannot do anything about it.

    But even if we don’t detect an object, the atmosphere is massively shrinking every one of the buggers. The actual risk is much smaller than the popular press would have us believe.

  27. I would highlight this portion of that:
    So if what is left of a 500-kt incomer explodes at >20 km up, these 1-kt things don’t really tell us anything whatsoever about city-killers. That is only one data point. Perhaps it is good that they realize that THAT sized meteor is more frequent, but ANY kind of curve (steep, shallow, moderate) can be speculated on from that information, which means basically they’ve learned nothing about city killers.

  28. Folks might note that if the Chelyabinsk object hadn’t come in at such an oblique angle, and instead came down more vertically, it would have penetrated more deeply into the atmosphere before exploding. Had it done so, It brought more than enough violence with it to be a city killer.

  29. Trent –

    Thanks for this, but not exactly for the reason one might expect. I love that you keep finding these things. When I find holes in their presentation/interpretations, don’t think I am critiquing you.

    I went into this – reading the article – expecting to find something fishy. I did.

    The article states,

    2012 VP113’s closest orbit point to the Sun brings it to about 80 times the distance of Earth from the Sun, a measurement referred to as an astronomical unit or AU. For context, the rocky planets and asteroids exist at distances ranging between .39 and 4.2 AU. Gas giants are found between 5 and 30 AU, and the Kuiper belt (composed of thousands of icy objects, including Pluto) ranges from 30 to 50 AU. In our solar system there is a distinct edge at 50 AU. Only Sedna was known to stay significantly beyond this outer boundary at 76 AU for its entire orbit.
    “The search for these distant inner Oort cloud objects beyond Sedna and 2012 VP113 should continue, as they could tell us a lot about how our Solar System formed and evolved,” says Sheppard.”

    Wiki has this to say about the “hypothesized” Oort Cloud:

    “The Oort cloud is thought to occupy a vast space from somewhere between 2,000 and 5,000 AU (0.03 and 0.08 ly) to as far as 50,000 AU (0.79 ly) from the Sun.”

    Wiki on the Kuiper Belt:
    “The Kuiper belt is a region of the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.”

    Okay, now I don’t know about the rest of you, but don’t you think it is much more likely that the object is an outer Kuiper Belt object than to shift the inner edge of the Oort Cloud inward by 1,920 AUs?

    So, this is NOT an Oort cloud object; it is being INTERPRETED by those scientists as an Oort Cloud object. I think it shows how strained the Oort Cloud idea is, that they have to claim something essentially at the orbit of Sedna is imagined to be Oort rather than Kuiper. They never claimed Sedna was an Oort cloud object before. So why is this object at about Sedna’s distance miraculously part of the Oort cloud and not a member of the Kuiper belt? They all KNOW that nothing has been found in the Oort Cloud region, so they find something an inch outside the Kuiper Belt and claim it is Oort. BAD SCIENCE. That is like saying my neighborhood outside Chicago is in Los Angeles or Honk Kong.

    In every one of these papers/articles where they find something new, it seems obligatory that they assert this:

    “[This new discovery] could tell us a lot about how our Solar System formed and evolved.”

    We should take three things away from such assertions:

    1.) They are still floundering about the formation of the solar system.

    2.) They feel they have to crowbar every new thing into the current hypothesis. Instead of perhaps widening the current concept.

    3.) They have to give the public (whose taxes pay for the vast majority of astronomical costs) the idea that progress is made and that the final answer is just around the corner. (“So, please, please, PLEASE give us more funding! We are almost there! We can’t stop now!”)

    “From the amount of sky searched, Sheppard and Trujillo determine that about 900 objects with orbits like Sedna and 2012 VP113 and sizes larger than 1000 km may exist and that the total population of the inner Oort cloud is likely bigger than that of the Kuiper Belt and main asteroid belt.”

    So, rather than just stopping there, they think that two data points is sufficient to extrapolate the number of objects out there near Sedna and 1012 VP113. Wow. Bad science. There is no reason whatsoever to think that the regions which include Sedna and 1012 VP113 are typically populated regions.

    Also, they also assert something about the Oort cloud, after cheating on the very location of the Oort cloud by those 1,920 AUs. (They should also at least point out that the hypothesized “inner Oort cloud” – disc-shaped – is different from the hypothesized “outer Oort cloud” – spherical.)

    …Just bloody pathetic… All of it. We are all dumber now.

  30. Dennis –

    I agree in part about Chelyabinsk and the angle point you make. I was trying to include that without specifically saying it. At the same time, more and more I am convinced that low angles are so much the norm that we should expect essentially all incomers to come in shallow.

    Why? ALL video so far shows low angle. Add to that cross-sectional area of the Earth’s gravity well, compared to the size of target Earth itself. The gravity well is hundreds of times bigger, so we should expect that most objects have to spiral in, not take direct paths down toward the surface. Spiraling in should logically mean lower angle entries.

    Correct me if I am wrong. This all seems to make perfect sense to me, but I might be overlooking something. Your input/feedback/take is appreciated.

  31. Dennis –

    Yes, if the original 500 kt of Chelyabinsk exploded/disintegrated near ground level, it would have been a city killer. But I have to ask those here who know how to calculate it how much steeper the heat curve/ablation rate is when coming more directly through the atmosphere. I know the heat buildup has a steeper gradient if the angle is greater, so that would make ablation occur faster. With that steeper gradient being directly proportional to shrinking the object and the shorter time in the atmosphere being inversely proportional, we have one factor tending toward a larger explosion sooner (higher), while the other tends to have the explosion later (lower). What the results would be is uncertain without calculations.

    This all would go a long way to explaining something to me: How do ANY objects make it to the ground without burning up entirely? The VAST majority do not make it to the ground. What is it exactly that happens that allows the very few meteorites lying on the surface to survive? There probably is a boiler plate explanation for this, but I have not run across it yet. To me it is a matter of once factor overbalancing the other. But how it works exactly I don’t have a clear handle on yet.

  32. Steve G,

    There is a 1950 AU gap between the Kuiper Belt definition and the Oort Cloud Definition.

    That sounds like time for a new theory.

  33. Trent –

    That is my point. But nothing in the paper or article suggested that any new concepts of the two belts was being overtly proposed. They just slipped in the massive shrinkage of the inner Oort Cloud…

    I sometimes wonder if science editors EVER actually read WTF they are covering with their minds alert at all.

  34. Science Daily is reporting the same article —

    “Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast”

    Date: April 9, 2014

    Source:American Geophysical Union

    Picture this: A massive asteroid almost as wide as Rhode Island and about three to five times larger than the rock thought to have wiped out the dinosaurs slams into Earth. The collision punches a crater into the planet’s crust that’s nearly 500 kilometers (about 300 miles) across: greater than the distance from Washington, D.C. to New York City, and up to two and a half times larger in diameter than the hole formed by the dinosaur-killing asteroid

    Article link: http://www.sciencedaily.com/releases/2014/04/140409125851.htm

  35. Interesting, two other article links popped out of that Sci-daily one that will be of interest here:

    1. Tiny ‘spherules’ reveal details about Earth’s asteroid impacts

    Date:April 25, 2012

    Source:Purdue University

    Researchers are learning details about asteroid impacts going back to the Earth’s early history by using a new method for extracting precise information from tiny “spherules” embedded in layers of rock.


    Key ‘graph:

    “Impact craters are the most obvious indication of asteroid impacts, but craters on Earth are quickly obscured or destroyed by surface weathering and tectonic processes,” Johnson said. “However, the spherule layers, if preserved in the geologic record, provide information about an impact even when the source crater cannot be found.”

    2. New evidence ancient asteroid caused global firestorm on Earth

    Date:March 27, 2013

    Source:University of Colorado at Boulder

    A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days indicates the event could have triggered a global firestorm that would have burned every twig, bush and tree on Earth and led to the extinction of 80 percent of all Earth’s species, says a new study.


    Key ‘graphs:

    The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth’s atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared “heat pulse” so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.
    But there was enough infrared radiation from the upper atmosphere that reached Earth’s surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.

  36. All of that is still gradualism’s concocted history of Earth – lots of stuff happening early on, but everything settled down and then nothing has happened anywhere near the time of man. 3.26 billion years ago the Earth was still working out its atmosphere, if I recall… Okay, it was 2.45 billion years ago. So all the stuff about killing off life forms is bogus!

    “The asteroid impact could have wiped out a large percentage of the planet’s lifeforms, vacating niches that the survivors evolved to fill.”

    Huh? With no oxygen, which life forms is the article talking about? Do they ever research beyond their noses? Do they even know what Google is?

    Anyone who knows squat about the formation of the planet knows this stuff.

    (Guys, I don’t go out LOOKING for these contradictions. They just come up and bite me in the butt.)

  37. Hi Steve –

    Google cyanobacteria.

    You may also want to read McSween’s book on meteorites and their parent bodies before moving on to current research on solar system formation.

    Aside from that there is a new podcast series called The Stelle Experience that you may find of use in sorting out your own Stelle experience.

  38. I see no relevance to what happened to cyanobacteria 3.26 billion years ago. If the ones that survived were part of the evolution of life, they were, and if they weren’t they weren’t. It’s not like megafauna died off or anything. Whatever happened back then we can’t change, nor does our thinking that we know something about that long ago change anything that happened. As to a big impactor then, we all expected that to be the case, anyway, didn’t we?

    Objects flying around the solar system now and in the recent past are relevant, because they can tell us what might happen in the near future. I fail to see that there is any importance to us today about something that happened to the planet 800 million years after it formed. Events that happened then may or may not have had something to do with the very beginning of macroorganisms – so what? None of it will ever be able to be proven to have relevance to us. If it killed off 90% of the microorganisms on Earth, so what? The ones that survived are the ones that were able to take opart in life as we know it, including humans. The ones that died? What difference does it make?

    What happened happened. If it helped sentient life to occur 3.359 billion years later, I’d love to hear someone claim to show the connection(s). No, actually, I wouldn’t want to. Because they will have nothing but suppositions and guesses. It’s not science if that is all they have.

    I think that the article panders to the gradualist meme that all impacts of any size were deep eons ago. Stuff that long ago – who cares?

    Now, if they were doing it with the idea of understanding the beginnings of life, maybe that means something. But that isn’t the angle they took. But even if they did, it would all be supposition on top of the past suppositions, like the lightning bolt in the scummy pond deal (which has been refuted long ago). They had pretty much gotten nowhere in over half a century with that one, and they mostly gave up 20-30 years ago.

  39. Oh, in addition, the cyanobacteia causing oxygen thing was another 800 million years later, so that has no bearing on that impact article. I know we sometimes mush together long ago time periods in our minds, but 800 million years difference is 800 million years. There was no contemporary-ness to the two things. It isn’t like cause and effect could be called up on tying these together.

  40. Hi Steve –

    “I fail to see that there is any importance to us today about something that happened to the planet 800 million years after it formed.”

    Estimating the impact hazard is a sub field of the larger field of accretion studies.

  41. What happened 3.26 billion years ago, very early in the development of the solar system, and when the system was settling down, has nothing to do with the last several million years, much less the Holocene – when humans are here. They are two entirely different eras, with a totally different planet Earth (with almost entirely different life forms) and totally different NEOs.

    Wiki: “By producing oxygen as a gas as a by-product of photosynthesis, cyanobacteria are thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the near-extinction of oxygen-intolerant organisms…

    …They are often called blue-green algae, but some consider that name a misnomer as cyanobacteria are prokaryotic and algae should be eukaryotic…”

    A.) It is not even known for sure that cyanobacteria did what they assert. It is just what some think they did.

    B.) Cyanobacteria were not even bacteria, per se, because bacteria are eukaryotic (actual cellular with a nucleus and mitochondria, etc.), while cyanobacteria were prokaryotic.

    Wiki: “Prokaryotes do not have a membrane bound nucleus, mitochondria, or any other membrane-bound organelles. In other words, all their intracellular water-soluble components (proteins, DNA and metabolites) are located together in the same volume enclosed by the cell membrane, rather than in separate cellular compartments.’

    Wiki: “Eukaryotes… The origin of the eukaryotic cell is considered a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The timing of this series of events is hard to determine; Knoll (2006) suggests they developed approximately 1.6–2.1 billion years ago. Some acritarchs are known from at least 1.65 billion years ago, and the possible alga Grypania has been found as far back as 2.1 billion years ago.'[55]

    Organized living structures have been found in the black shales of the Palaeoproterozoic Francevillian B Formation in Gabon, dated at 2.1 billion years old. Eukaryotic life could have evolved at that time.[56] Fossils that are clearly related to modern groups start appearing an estimated 1.2 billion years ago, in the form of a red alga, though recent work suggests the existence of fossilized filamentous algae in the Vindhya basin dating back perhaps to 1.6 to 1.7 billion years ago.[57]
    Biomarkers suggest that at least stem eukaryotes arose even earlier. The presence of steranes in Australian shales indicates that eukaryotes were present in these rocks dated at 2.7 billion years old.

    All of this was at LEAST 0.5 billion years later – more than 1.0 by most counts. We can’t discuss that time lapse a if it was two weeks earlier. A billion years is 5,000 times longer than the accepted history of modern man. Or 50,000 times as long as since Caesar’s time.

    The life forms that existed at 3.26 Bya were not macroorgamisms whatsoever – no plants, no animals. Just PRE-bacteria – pre-cellular (as we define cellular). There is nothing relevant to present impact risks, to animals and plants. Whatever pre-bacteria (prokaryotes) survived survived. So what? With colonies of quadrillions upon quadrillions, and with much of their activity almost certainly deep underground, a surface impact meant little to nothing about their survival. It hit, they survived, end of story. Did we evolve from them? Almost certainly. How many mutations? Thousands? It is so far in the remote past as to be completely negligible to discussions of risks of impacts today.

  42. Hi Steve –

    “I fail to see that there is any importance to us today about something that happened to the planet 800 million years after it formed.”

    Once again, estimating the impact hazard requires a pretty good grounding in accretion studies.

  43. If by accretion is meant the agglomerization of larger bodies from smaller, none of that even remotely addresses how the supposed stones formed in deep space before they agglomerated together. Read on strengthless bodies. There is not enough gravity force to do more than have the two bodies lightly kissed up against each other. Those researching strengthless bodies realize this reality. I have been looking high and low for explanations on what source of high pressure (and temperatures) existed that could have compressed such solids at ANY size. Look at my numerous comments on the Allene meteorite and the materials found in it – including olivine and peridotite, which can only form at millions of PSI and VERY high temps, both. Impacts don’t explain any of it, because impacts are destructive, not constructive – they blow more ejecta out than are added by the collision. Collisions should cause pulverization if anything. THIS is how it happens in the present, so uniformitarians cannot dream up some special magical impact conditions that only existed in the past. “The present is the clue to the past.”

    Their entire accretion concept is a house of cards that has no basis in physics and metallurgy and geology. On a scale of 1 to 10, with 10 convincing me thoroughly, I rate them and this idea at a 0.23.

  44. Trent, thanks for the link. I am following it and look forward to the press conference on the 22nd. I will get something up beforehand so Googlers that day will find the Tusk.

  45. The universe recycles everything, even the guts of exploded stars, and the broken remains of supernova-blasted planets. “Accretion” is only one side of a cosmic cycle, it’s opposite is “Dispersion” Remember, 100% of the material in a new star, and it’s surrounding planetary accretion disk, consists of the debris of previously exploded stars, and the remains of any unfortunate planets that were blown away by the explosions of the stars they were orbiting.
    I don’t see any reason to assume that all of the shrapnel from the destruction of those planetary systems must be stuff so pulverized that only molecular sized dust particles remain to be cast outwards in the debris of a supernova. Depending on the distance from the actual exploding star I’d imagine that fragments of the broken, cores of a star’s outer planets might survive in rather large chunks, melted by the heat but otherwise intact. Only to fall into the accretion disk of a new born solar system.

  46. Dennis –

    Interesting take you have on all of that, stuff I myself had not considered yet. Nice food for thought. Totally worth keeping in mind!

  47. agimarc –

    As usual, you find some good stuff.

    However, the article makes some assumptions – in line with current accretion concepts – that are only that, concepts. But even the author writes:

    “The object is not expected to grow any larger, and may even be falling apart.”

    They apparently had not noticed this arc before. It being on the edge of Ring A, it seems conceivable that it is the defining object of the outer edge of Ring A, sweeping material to it. As I understand their thinking on the gaps between rings, that is what they hypothesize is happening there. Someone correct me if I am wrong. It seems only consistent that an object would also define the outer edge of Ring A.

    At the same time, it is quite apparent that they DO assume that this object has been building from zero diameter. Astronomer Tom van Flandern’s exploding planet would also account for an object being there, as well as all the matter in all the rings – in a different hypothesis altogether. In that case, it would be much more like what Dennis is talking about above – large chunks that get caught up in an “accretion” ring around a major body. And in that case, the body is attracting material – but not necessarily forming into a solid body. If I am right, the material simply lies lightly on the surface of the chunk, and the chunk came from the exploded planet. (Which is what propose along with van Flandern is the real source of asteroids and comets – and even the Kuiper Belt objects. I don’t include the Oort cloud, because van Flandern’s concept makes the Oort cloud unnecessary as a source for comets.) BTW, I call it van Flandern’s because he seems to have put the most thought into it; it was first proposed back in the 1700s by others when asteroids began to be detected.

  48. Steve; I’ve just returned from a week away from everything but horses. Took the wife with and found out we still like each other. I was reading on the tusk trying to get back up to speed and read yours and Trent’s conversations about accreation and their mechanics. One thought to throw in the mix: If there is strata of debris circling various objects, Planets, suns, semi large bodies they are somewhat orginized through speed and weight seperations then something comes through their zone and disrupts their stratafication, could this provide an eddy effect causing some of the debris to be swirled into the object or other pieces of the debris soup? Also if the obeject is moving in the same direction as the whole group but at a greater speed could this cause other debris to be dragged along or impacted and incorporated into the initial object until sufficent density is accumulated to form some sort of gravity?

  49. Steve – you’ve got me on a search to find supportive observations for accretion, which is fun and moderately challenging / interesting. The outer solar system is a pretty wild place. I suspect that we will see processes in the ring systems that may point in that direction. Ran across something a few years ago that described a pair of shepherd moons covered in a thick blanket of ring material, implying accretive growth. Unable to find it again. Will post when and if I find it. Also need to look further into Miranda.

    On a related topic, looks like the B612 Foundation has their hands on data that may double to triple the currently agreed upon flux of bodies from the sky. Announcement scheduled for April 22. Cheers –


  50. Jim –

    You scenarios are probably more or less correct about accretion, s I’ve read in various places. And they do make sense logically. (but don’t let either sway you completely – it is empirical that trumps all – and sometimes it DOES, making logic and reason look pretty bad sometimes.)

  51. agimarc –

    I laughed when I read the “covered in a thick blanket” point you made. I do NOT doubt thick blankets. I mean volcanic ASH can often be a thick blanket. But if you dig down into ash, all you get is ash. (Someone correct me on that if I am wrong, but I don’t think so.) And that is under the gravitational pull of a massive planet like Earth. Now deposit that ash onto a small asteroid. When heavier sediments or lava are laid over the ash there can be sufficient compression to solidify ash, but normally not ash over ash. At what point does the blanket solidify? And under what conditions?

    I simply argue that the conditions do not exist in deep space under microgravity conditions on asteroids – even 100 km ones. it is STILL microgravity.

    DO have at it! I’d love to have someone bring in lots of things I haven’t found yet.

    If you haven’t noted my comments on Itukawa, google it and look at the thin blanket of debris.

    I mean, it is like pointing at windblown dirt in the back of a dead end alley and then expecting it all to harden into granitic rock or near diamonds. I do NOT see that happening to that debris. It will sit there till hell freezes over and still be a blanket of loose dust or rocks sitting perkily on the surface. I assert that NO congealing or agglomeration into other more complex materials will happen.

  52. Steve –

    I thought we reached an impasse with Itokawa – you describing it as one or two solid pieces with a regolith cover and me adopting the rubble pile description. Figured that particular horse was way past dead.


    There are two Saturn shepherd moons Atlas and Pan that appear to be accreting ring material. As the moons are much larger than the rings are thick, what you end up with is a ridge 2-3 km high around the moon centered on the ring plane. Interestingly enough, not a lot of other shepherd moons appear to be doing this.


    Finally, you have the Uranian moon Miranda that looks like it was disrupted and then re-accreted into a spherical object. Current argument is between the tidal disruption vs an impact-related event. Problem with tidal is that we already know what happens with tidal forces on moons with Saturn’s Enceladus, Jupiter’s 4 Galilean moons, none of which show the layering that Miranda does. Cheers –


  53. Steve –

    Interesting you ask about how accreted ices (or anything else) will solidify. Ever hear of sintering – the mechanical heating of ices / dust?

    In the cold country, you see it most often with avalanches, which flow like liquid, yet set up like concrete once stopped due to the partial melting of ice crystals. Someone trapped in an avalanche is immobilized when the flow stops, unable to dig out. You get the same effect with a snow plow / snow blower.

    We also get snow dumps, where road snow is dumped after the streets are cleared. They slowly melt over the summer. While melting, they also turn black and form a crust as the water content sublimates out / melts. Same thing should happen to a high percentage ice content comet / asteroid.

    Finally, impacts deliver energy in the form of heat to bodies. Low speed impacts stay intact. High speed ones don’t unless one of the bodies is pretty big. I think an accretion history starts with slow speed accretion as like the Saturnian rings, everything is pretty close together and moving relatively parallel. Over time, as the various bodies grow, the relative velocities of the impacts also grow. Yeah, I know I’ve just introduced another constraint. But it is a constraint we see at Saturn and perhaps with Miranda. Cheers –

  54. Actually, agimarc, I can see ice solidifying in probably more than one possible way, but not “anything else”. Water’s freezing point and its nature – that it doesn’t really need much pressure at all to solidify – makes its solidifying a simple event. It is the ones that also need ULTRA HIGH PRESSURE that I have a problem with.

  55. agimarc –

    Also, about Itukawa, neither yours nor mine explain how the large main body is solid.

  56. Steve,

    So I was in Washington DC for vacation, and spent a great deal of time the geology section of the natural history museum. They have a fantastic display of meterorites that have been sectioned.

     I was in that display for several hrs., what I noticed is that many displayed the very very fine grain structure that is indicative of the accretion model, but there were several that had a very different structure, they huge “grown” crystals of near gem quality peridot. It is visibly obvious that these crystals grew out of solution. 

     So I now see where you are coming from in your thoughts on the pure accretion model. 

     The only way these very large crystals can form is out solution, in this case magma.


  57. Cevin –

    Be a little bit careful with your conclusions based on other crystals. While peridot, the gem (perfect enough for gems), have water involved with their formation, they are formed in ultra-high pressure and extreme temperature, out of peridot . .

    Formation of Peridot

    Peridot (or olivine, as the mineralogist calls it) is a mineral that is very common in nature, particularly in basic igneous rocks (i.e., those low in silica content). It is so common that a major igneous rock type is called peridotite. However, gem peridot is very rare.

    Since diamond-bearing kimberlite is a type of peridotite, peridot, as might to be expected; is an important constituent of the peridot has altered to serpentine, peridot is an important constituent of kimberlite in the lower reaches of the mines. However, it does not occur in large enough fragments to be of interest as gemstones.

    In some areas of the world, rocks made up almost entirely of peridot are found. Most of the major chromium deposits in the world occur with the mineral chromite disseminated in a rock called dunite. Although the grains of peridot in dunite are transparent and of a lovely color, they are too small to be of interest as gemstones. Only very rarely do igneous rocks in which peridot occurs have peridot crystals of a size and perfection to be of interest to the gemologist. Since olivine is one of the earliest minerals to crystallize from an igneous melt, it often occurs as fairly large crystals in a minutely crystalline groundmass; however, it is usually too badly fractured to provide gem crystals. Thus, despite the wide distribution of this rock, it is exceedingly rare when the major constituent is found in gem quality. In addition, where it is formed in gem quality crystals, its tendency to alter rapidly to serpentine reduces further the chances of finding crystals of gem quality.

    The two situations in which gem quality crystals seem to occur are in cavities in an extrusive igneous rock and in contact metamorphism of sedimentary rocks containing magnesia and silica, such as impure limestone or dolomite.

    Recent studies by Professor Richard Jahns, Ph.D., indicates that large gem quality crystals are unlikely to occur in magma that cooled under ordinary conditions at depth. He has demonstrated that an essential condition to the formation of large crystals of excellent quality, structurally, is for the melt to reach a condition of water or other fluid saturation. Such a condition could occur quickly, if the magma moved toward the surface with an accompanying reduction in pressure. With a highly volatile liquid or gaseous phase, large, fine crystals may grow at very rapid rates (in a matter of weeks or months). Of academic interest only is the fact that peridot is sometimes found in meteorites. The grains are always very small and never of gem quality.


    So, all of this discussion is about Peridotite, peridot’s parent and inclusive material. When you saw peridot crystal in those meteorites, be aware of the peridotite, too. It is a form of olivine, and both are closely related to kimberlite, the rock that diamonds are found in. And I think we all are aware that diamonds are formed by ultra-high pressure and extreme temperature. So you are discussing the first cousins to diamonds, at least in the rocks they are both found in. THAT was my first real clue.

    How small were the peridot crystals you saw? Would you agree that they were “very small and never of gem quality”?

    This, too, from EHow.com, though I am not sure how reliable that site is, in general:

    From Olivine to Peridot
    When olivine crystallizes, it turns into the gemstone form we know as the peridot. This process involves long periods of high temperature and pressure within the rocks in which the mineral is found, and occurs on geological time-scales–sometimes millions of years.

    Olivine has a very high melting point, which explains why it’s mainly found in places like volcanic rock and the mantle of the earth (where pressure and heat are abundant). In these deep, hot places, the gem we know as the peridot is slowly formed.


    And this:

    Most gemstones of mineral origin are formed in the earth’s crust. But there are two exceptions; both peridot and diamond are formed much deeper in the earth, in the region referred to as the mantle. Peridot crystals form in magma from the upper mantle (20 to 55 miles deep), and are brought to the surface by tectonic or volcanic activity where they are found in extrusive igneous rock. Diamonds were formed much deeper in the mantle (around 100 – 150 miles below the surface), at extreme temperatures and pressures.


    THIS is why I see olivine and peridotite in meteorites and MUST reject the accretion theory, at least as it has to do with asteroids (which are what meteroids are in space) and meteorites (after the meteroids hit the Earth’s surface). It only forms at ultra-high pressures (about 4 million psi, as I recall), and also needed is high TEMPS.

    If someone can explain to me where the high temps and pressure come from, out in deep space, I am all ears. For the moment I reject out of hand that impacts did it, because – as I’ve argued, too – impacts are destructive, not creative. Impacts on asteroids and comets (we’ve seen it on both) gouge out craters, and the debris returns as regolith – dusty debris covering the surface of asteroids and comets.

    I say “for the moment” because there MAY be some way what we find as meteorites are remnants of impacts, if the meteorite represents the core of a body which – as it passes through the atmosphere – ablates the outer shell of a body, leaving only the core intact (which hypothetically might have been pressurized by impact and made stronger). This scenario doesn’t exactly explain the high temps, though.

    At the moment, peridots and peridotite and olivine are understood to have been made at depth, near the mantle, or atthe LEAST in the aesthenosphere, more than 80 km deep.

    So, in my mind, it is up to the astronomers to explain the existence of peridot/peridotite in the meteorites. To me, this amounts to an extraordinary claim, that this material, along with olivine, can possibly have accreted without the existence of great pressure and great temperature.

    And now, with the mention of liquid WATER involved, NOW how do they explain it?

  58. Steve,
    I think I was unclear, by precipitation out of solution, I was referring to magma, which is a liquid solution of metals and non metals, ie iron silicon and oxygen.
    These near gem quality crystals are very very large. I took photos that I would post if I could.
    The sectioned meteorite was approx. 18″ across the section face and the crystals that were exposed several inches across and displayed a regular polyhedral cross section.
    Like you said, these types of crystals require heat, pressure and time to form.
    So I can totally see where you are coming from, these types of crystal had to have formed whithin a planetary object.
    So, my question is now, how did the deep crust materials end up in interplanetary space?

  59. Steve ,
    I have to admit , in my haste to reply, i didn’t thoroughly read your reply.
    So water is required to form these types of crystals.
    With some of the olivine based meteorites, it’s obvious that they were formed by accretion, grain size is almost microscopic and evenly dispersed.

  60. Cevin Q: “So I can totally see where you are coming from, these types of crystal had to have formed within a planetary object.
    So, my question is now, how did the deep crust materials end up in interplanetary space?

    THANK YOU. For understanding the point I had been making. That is IT, in a nutshell.

    As to them having to form inside a planet, I actually posted a link somewhere in the comments to a paper that discussed the Allende meteorite, which was even bigger than your VERY nice sized 18″ baby. And in that paper, the authors actually arrived at how big/small a body had to be in order to allow olivine (or peridotite? I can’t recall now) to form. That size was 3000 km in radius. But they can NOT form in the planetary core – there has to be other materials UNDER THEM, putting them the right distance from the surface, but also where there is heat from the core..

    So, we have these facts:

    1. Peridotite and/or olivine can form only from the pressure at depth within a planetary body of a minimum 6000 km diameter. (The Moon is only 3475 km in diameter, so if those authors are correct, it would not be possible for the Moon to have peridotite, olivine, and probably no diamonds, either.)

    2. Peridotite and olivine are found in asteroids/meteorites (and perhaps in comets, too***).

    3. Having been created deep underground of a large body, peridotite and olivine somehow were removed from there.

    4. Having been somehow removed from deep underground of a planetary body, some peridotite somehow ended up instead inside of and integrally part of an asteroid in space which ended up crashing to Earth.

    Not many mechanisms come to mind, do they?… But we all know the obvious one.

    *** Based on the one NASA paper from the 1960s that I lost track of and that talked about 47% of all asteroids have at least one characteristic of comets. From other reading, I’ve seen more of this kind of mention, and I tentatively take that to mean that there is a lot of overlap between comets and asteroids. Time will tell.

  61. Cevin Q: “With some of the olivine based meteorites, it’s obvious that they were formed by accretion, grain size is almost microscopic and evenly dispersed.

    I don’t understand why grain size would be important.

    What is your thinking there? Accretion is only small grains? Impacts would pulverize?

    The latter is another point I’ve been making, so that would explain the small grains.

    But HOW do you get the grains to form into a solid rock? At least some of these meteorites look for all the world like metamorphic rocks (like granite). But metamorphic rocks are also formed by high pressure and high temperature!

    You can take as many grains as you want to and accrete them via mutual gravity, and they will never fuse together like the Allende meteorite is fused. The grains will just lie there, in a “rubble pile” (not my term), as a strengthless body. The slightest jostle on an asteroid or comet will send dust dispersing out into space. As I’ve pointed out, dust on the surface of even the Earth just sits there, being moved about on the surface by wind and rain. But not being fused.

    Somebody in this hypothesis is CONfused.

    Seriously, all of this is basic materials science – and that is based essentially on basic physics and chemistry and geology.

  62. Steve,
    Do remember that silicon carbides and olivine have been shown to be present in the atmospheres of very young stars, stars young enough to not have developed solid planets yet.
    Grain size comes into play because when the individual crystals are small enough they will stick to each other. And not just stick to each other in an adhesive sort of way, they will actually share electrons and essentially become one crystal, and they will acquire more micro crystals. Two unrelated but analogous processes illustrate this. One being the act of “wringing” two finely ground surfaces together. It used to a be used as an Ooh and Ahh teaching moment in beginning machinist apprentice programs.
    Two gauge blocks, they have to have pristine surfaces with no scratches, are put face to face and twisted or “wrung”. The surfaces are so smooth that the wringing the two surfaces to share electrons. When two blocks are properly wrung, almost no amount prying will separate the surfaces, they have to be unwrung.
    The other is represented by galvanic corrosion of two dissimilar materials places in close proximity, such as iron based and aluminum based alloys, or with similar sticky or gummy materials, such as 300 series stainless steels.
    My first experiencence with it was a bicycle mechanic, when I was young. In the early days of non anodized Al parts, handlebar stems would fuse to steel steering tubes over time, even when coated with grease or oil.
    The example I have to deal with all the time is a stainless fastener threaded into an aluminum member.
    If anti seize compounds aren’t used the screw will become welded to the hole.
    The other is two very closely spaced 304/316 parts can seize upon assembly. I’ve had two parts seize upon hand fitting of the parts, not press fits but very close tolerance slip fits will roll up a gall by simply slinding them together

  63. Cevin Q –

    The silicone carbide and olivine in young star atmospheres – something new to me. If you could point me to something on that, I’d appreciate it. I can google it, but I’d like to see what you have on it.

    The rest of your discussion is interesting, and I typed in several responses, based on my 40 years of industrial design with stainless steels and aluminum, but I decided that that is a bit off-topic. If you want to discuss it by email, I can do that.

    As to the basic discussion here, of materials forming into larger materials, I’d have to say that unless the pressures are provided, such crystalline binding simply by proximity/contact is far from adequate to create peridotite or olivine mineral – the parent materials from which the peridot crystals can ONLY OCCASIONALLY be made. Everything I find on these materials talks about MILLIONS of PSI. Touching – even intimately touching or under SOME unit stress – is not enough, from what I keep finding. The entire environment that the two minerals are within is necessary – and this idea fulfills neither the high pressure requirements nor the high temperatures needed. Under no circumstances do these materials form at lesser pressures and lesser burial depths than below the lithosphere and above the core of a planet. Adding in that other requirement – super-high temperatures – I’d argue that what you are bringing into this is not related – though it is interesting. There is no possible substitute for either the temps or the pressures. You need both – and LOTS of both.

    BUT: Bringing the other possibilities into the discussion is PROPER, even if in the end it doesn’t suffice. ALL possibilities should be brought into the discussion. I don’t mean to dismiss these points out of hand. It is just that the pressures and temperatures trump other and lesser candidates.

    The mention of some liquid water being necessary in the one paper for peridot gems to form is yet a third requirement. Such liquid water within the body of a comet or asteroid in outer space – accompanied simultaneously by high temps and high pressures – this seems impossible. What is had out there is ultra-low pressures and ultra-low temps. SOME temperature rise on the side facing the Sun? At certain AU, yes, but not out in the asteroid belt (for example).

    Wiki says: “When sunlight hits the moon’s surface, the temperature can reach 253 degrees F (123 C).” Since the Moon is at 1.0 AU, we can safely say that the surface temps on a Near Earth Asteroid is going to be somewhere near 253°F. Space.com says, “The average temperature of the surface of a typical asteroid is minus 100 degrees F (minus 73 degrees C).” As you can see, these are much too cold. +253°F or -100°F are nothing like the 1300°C to 1600°C (2370°F to 2910°F) given for the asthenosphere where peridotite and olivine are found.

    If these specific solid rocks found in meteorites cannot have formed in space, it is incumbent on us to ask where they COULD have formed, based on the physics, the crystallography, the chemistry and the forces necessary for those specific materials to form. If many of our attempts to explain this don’t succeed, at least we can begin to narrow down the possibilities.

  64. Mr. Thompson; I would like to thank you for the excellent compilation of reading material. This will be extremely helpful to a lot people here at the Tusk.

  65. Trawling this site for whatever is found interesting, I happened on this thread. The subject matter is very interesting, and the length of the list of material is impressive.

    I looked for Dodwell under ‘D’. It is there. I feel sure I have vindicated the gentleman. He was dead right.

    The piece on Arthur Custance makes interesting reading. If I got the gist of it right he complained of absence of geological evidence (WIT corrects but says in the distant past. Evidence shows it was not so distant, between 5000 to 2000 bce, and repeatedly). There is evidence, once it is noticed, — and we overcome the shock, and the denial, of it.

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