Incoming: The Chicxulub Impactor, Part 2 ― Evidence By Stephanie Osborn

Incoming: The Chicxulub Impactor, Part 2 ― Evidence

By Stephanie Osborn

Why would anyone even think about an asteroid impact? Let alone killing the dinos?

Well, it turns out that there’s really quite a bit of evidence to indicate exactly that.

Remember that series of arcs that Glen Penfield and Antonio Camargo-Zanoguera found in the gravity and magnetic analysis on and around the Yucatan Peninsula? Well, it’s definitely there, and it forms at least one complete and nigh-perfect circle. SO circular that it almost doesn’t look natural. So circular that that was one of the facts in opposition to the possibility that it was a volcanic structure. It’s right on the Yucatan coast, half-onshore and half-offshore. The circle’s center is a scant couple of miles offshore from a little barrier-island town called Chicxulub Puerto.

More, that same onshore semicircle is fairly filled with cenotes―vertical sinkholes down into what are usually water-filled caves. But the cenotes occur ONLY ALONG or OUTSIDE the semicircle; there are only a scant handful within it. There is also a broken outer semicircle of cenotes which parallels the main semicircle. All of these structures are likely to be due to the shock wave passage from impact.

As for the boundary layer clay, ONLY the clay shows high abundances of iridium; it is scarcely found above or below the boundary. And it’s fairly uniform in its abundances around the planet.

In addition, within the anomaly ring are found vast quantities of material showing evidence of a sudden shock, high temperatures, high pressures, or all of the above. These materials include:

    • Volcanic breccias―broken rock fragments cemented together by melted rock.
    • Shock-metamorphic material―material distorted and chemically changed by the high temperatures and pressures generated by the shock wave.
volcanic breccias
Suevite, a type of impact breccia welded by melt. Note the largest fragments are 9” across. Photographer unknown; source Wikipedia.



  • Shatter cones―three-dimensional, branched, fan-shaped fractures in rock caused by high pressure.


  • Shocked quartz―quartz whose crystalline structure has been deformed as a result of extreme pressure.
    shocked quartz
  • Brazil twinning―“Conjoined-twin” quartz crystals, where two crystals share part of the crystalline lattice.
  • Tektites―impact glass, a kind of obsidian produced by the melting of the impactor and crater material, and then ejected. It rapidly cools in atmosphere, forming glass particles, usually in aerodynamic shapes such as teardrops.
  • Osmium―like the iridium, the osmium isotopic ratios in the clay layer have cosmic abundances.
  • High concentrations of soot at the boundary layer.

All this was found roughly in the first decade after the Alvarez paper.

BUT WAIT! THERE’S MORE! as the commercials say.

Also found in the boundary layer:

  • Shocked zircon crystals, deficient in lead (likely from being vaporized in the impact.
  • High concentrations of tiny diamonds.
  • C60, aka Buckminsterfullerene, was mixed in with the soot at several sites.

Meanwhile, in the core samples from the crater, scientists have found:

  • Pink granite, of a type normally found deep in the crust.

What they did NOT find in the core samples:

  • Gypsum. Since it’s a sulfate mineral, it was probably vaporized and ejected into the atmosphere.

So when you start to analyze all the clues, it boils down to several descriptors. Whatever happened, happened suddenly, generated extremely high temperatures and pressures, and carried cosmic isotopic abundances of elements that otherwise tend to be rare on Earth.

And that all points to an impact.

Next up: the impactor.


For more details, check out INCOMING! The Chicxulub Impactor by Stephanie Osborn on Kindle and Nook.



Tourist Trap (Division One Book 11) NOW AVAILABLE FOR PRE-ORDER


After months of “playing target,” the heads of the Alpha Line special forces department, Alpha One—Agents Echo and Omega—finally take a very special vacation on Tiniken, the “Eden planet,” for some much-needed R&R. The pair kick back, relax, and play tourist, exploring this lovely alien world together.

But when they unwittingly cross paths with a Cortian slave ring and the Cortians recognize Echo as “Cortian Enemy Number One,” he becomes their next target, and “Eden” displays a seamier side. Can Omega and the rest of Alpha Line find Echo before he is sold as a slave… or worse?

66 thoughts on “Incoming: The Chicxulub Impactor, Part 2 ― Evidence By Stephanie Osborn

          1. I got a catalogue with yard velociraptors in it today… No, I’m not getting them. The yard carp, however, might be fun. Especially to go with the shark fin already cruising in the flower bed.

      1. Pretty much anything I’d say has already been said. If the core were extant underground, I think the magnetic and Bouguer anomaly plots would show a masscon there, and they don’t. Ergo there’s probably not much left; it vaporized and/or melted and mixed into the ejecta. The sheer quantity of offworld-abundance rare earths like iridium and osmium that is found in the worldwide boundary clay layer is evidence that it got pretty thoroughly spread around.

        And no, the evidence indicates that this was a stony asteroid, not a nickel/iron one. So no forging possible, even if the core did survive.

        1. Ah, but as a stony asteroid, we could have a massive piece of glass that we could chip into a dagger.
          Or we could collect a heck of a lot of tektites and melt them together to make a glass dagger that way.

    1. Probably very little was left. IIRC, the Chicxulub was probably a rocky body, not an iron-nickle one, or we’d see a lot more metals in the K-T layer. And most of it probably vaporized. What didn’t may be too far down to drill to. And I don’t recall any seismic studies showing a body or bodies in the center with differing density. But Stephanie probably has access to sources I don’t.

      1. If it was deep enough, it could have gotten drawn down and remelted, depending on the location.

        Vaporized material could make for an interesting scenario, if it is toxic, and the bigger creatures on the planet don’t have the metabolic pathways to excrete it at those concentrations.

        1. I’ve a vague recollection of someone saying it probably broke up small enough at impact to have dispersed (ie nuggets sized at best scattered about) and maybe one theory where it made the mantle trip, either directly or via fissures from impact. No clue as to how valid, or if I am even remembering it right.

    2. If there’s anything left, it’s 20 KM underground. Far too deep for mining.

      Which, inevitably, reminds me of a movie far, far worse than ‘Armageddon’ — ‘The Core’. If you know anything AT ALL about geology that movie will make your brain hurt. You’ll want to strangle the producers and the scriptwriter just to prevent them from inflicting that much stupid on the world ever again.
      “No capes!” — Edna Mode

      1. “The Core” was one of the better horrible movies for the Geology Department’s Bad Movie nights. The unobtanium was a nice touch. 😛

        1. From what’s written in the two posts above,The Core sounds like a Roger Corman product. So, I go look it up and low and behold, it came out of Paramount.

          Probably would have been better if Corman had done it.

      2. I stay away from all those kinds of movies. In general, most moviegoers don’t like it when I throw bricks at the screen, and my husband kindly got us a very nice flat-screen TV a bit back, and I prefer to keep it functional as well…

        1. We had unbuttered popcorn for tossing, and the good stuff for eating. Adult libations were reserved until after the screening, when the faculty and grad students retired to Ye unOfficial Watering Hole.

        2. These days, they won’t let you take bricks into the theater anyway.

          Is that because of you?

  1. AIUI, the Chicxulub evidence is clear proof of a major impact.

    What it does not prove is that the impact caused the K-T extinctions.

    The fossil record does indicate that – up to a point. IIRC, there are signs of decline in some fossil species below that clay layer, and signs of persistence of some fossil species above the clay layer. IOW, the extinctions may have taken place over hundreds or even thousands of years. Still an eyeblink in geological terms, but not the instant event that the impact could have caused.

    It is further argued that there was another event at that time with comparable (and longer-lasting) effect on global climate: the massive volcanic eruptions that produced the Deccan Traps, basalt formations covering most of central India.

    OTOH, there are also suggestions that the Deccan Traps eruptions were started or accelerated by shockwaves from Chicxulub. So we go full circle, perhaps?

    1. Probably a one-two punch. Maybe some of the dinos made it through the initial impact, only to succumb to the Deccan eruptions; or vice versa depending on the sequence.

      Such an event happening today would probably result in another human genetic bottlenecking.

    2. No. In fact, there were at least 3-4 prior eruptions of the Deccan Traps before the impact. Complete with extant fossils. Because the KT-boundary clay layer occurs in the third intertrappean layer, not prior to the trappean layers. Therefore it was already in eruption PRIOR TO the impact and could not have been CAUSED BY the impact.

      As to the rest, that’ll be discussed in a later installment of this blog series.

  2. Didn’t the dinosaurs all died off from smoking cigarettes? Learned the from ‘The Far Side’.

    Seriously though, love these lessons you grace us with.

    1. Yup. The Tunguska Event is what happens when you send several thousand tons of Lucky Strikes backwards in time several million years.

      LSMFT “Be Happy – Go Lucky!”

      1. Back when I smoked, I smoked Lucky Strikes. You might have something in the idea that they got sent backwards in time. By the time I quit, I had a heck of a time FINDING any Lucky Strikes (part of why I quit… too much work). All those cigs had to go somewhere!

        1. A book on the history of tobacco in the USA claimed that when the 1950’s studies came out and filters became a big deal (though the very first filter was “blue” asbestos – which actually made cigarettes MORE dangerous), the new filtered brands took over bigtime and the old unfiltered suffered if they didn’t add a filter right fast. Thus, supposedly, Lucky Strike that was a market leader, lost quickly to Marlboro & co.

          A few years ago I saw a convenience store manager looking through a tobacco company catalog and started chatting some. Supposedly it is (was?) still possible to get “old” brands (Luckies, Chesterfield, etc.) but they need to be asked for by the manager specifically as they are not the Big Sellers (Marlboro, Camel, Pall Mall, etc.) Really, I was surprised to see Parliaments at a Walgreens sometime this past Summer. I’ve no use for cigarettes, but I find the subject fascinating, somehow.

          1. Sadly, I see the fascination… not quite up there with mechanical pencils, but close!

            OTOH, I actually have a use for mechanical pencils.

      2. Could have been worse. Could have sent back some of those nasty Russian unfiltered things. Talk about a mass extinction!

    1. Breccia as a geological term has been in existence for quite some little time. It’s Germanic in origin, routed through Italian, and in use since at least 1800, according to the online Oxford dictionary. The Italians used it as a reference to ‘gravel,’ which makes sense when you realize what the geological rock really is, and the Germanic root pertains to the verb ‘to break.’

      1. And that adds even more layers of awesome– to a freaking throw-away joke so that the troll gangster had a group.

        When I looked it up way back when, it was something like “rock made out of a bunch of smaller rocks,” which worked.

      1. One of my favorite things about my engineer-trained husband watching history lectures with me is seeing him catch things in Discworld that l caught years ago.

      1. At least he died, rather than was snuffed out in fear.

        Dude had bravery. I don’t know if he recognized that he put it into Vimes, but that’s the best shorthand I can think of– the kind of bravery that keeps going until it ends up on the opposite conclusion, because that’s where the ‘go and check’ lead him.

        The idea of that being defeated in the final hour, surrendered in terror, is …obscene, fits best.

        Instead, he fought to the end. He kept that courage.

  3. I’ll be leaving in a few hours for Hallowcon in Dalton, GA, so I’ll be out of pocket for a few days, guys. (I quit even trying to get online during a con; I stay so busy that 99% of the time I didn’t even boot the computer. I sometimes look up something on my phone for a panel discussion, but that’s about the extent of it.) If you have further questions, feel free to post ’em here and I’ll see what I can do when I get back. Or you can wait until next Th and the next installment; I’ll be free all weekend then.

    1. The only way that makes sense to me is ‘Chick-zoo-loob’

      Who used to live in that area? Could be from Toltec.

        1. FYI Yucatec Maya is the original language from which the place name derives. The crater/impactor is named after a little village on a barrier island on the coast of the peninsula, Chicxulub Puerto, or something like that. I’ve not really been able to find out a lot about it, but I’d expect it’s a fishing village from of old.

          And I just lucked onto this:

          It seems the name means “devil flea” or the like in Yucatec Maya. I think maybe I don’t want to visit there to find out more…

  4. I’m a northern Yankee with too many accents mushed together. My wife says I speak French like I was a New Yorker in Boston talking with a mouthful of pebbles. I tend to pronounce Chicxulub as Chicks Zul Lub.

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