Ancient History

Among the rarest pieces of real estate on planet Earth are meteorite impact sites (around 170 at the last, undisputed count). Roundrock sits inside one of them. This site is a recent discovery, and makes the third confirmed meteorite strike in the great state of Missouri. (“Confirmed” is my word. The science is still being done on this site, but all currently known information about it is best explained by a meteorite strike, and as new evidence has been discovered, it has consistently supported the theory.)

The impact was around 350 million years ago (give or take) when a meteor the size of a football stadium roared down from the sky at 20 miles per second. This part of the continent was under a shallow sea at the time, and the event must have been spectacular.

Roundrock is not within the actual crater, but the shockwave resulting from the impact deformed the bedrock in a 12-mile diameter circle, and Roundrock sits within that.

This impact site is ideal for study because it was shortly covered by sediments (including the sandstone that built many of the early structures raised by the pioneers), so it isn’t greatly weathered. The underground geology of Roundrock that we can see (we only have about 90 feet of topographic drop on our land) is capped by a layer of this sandstone just under a relatively thin layer of soil.

When the meteorite hit (so the current theory goes), water in the impact area was vaporized. The rocks in the ground at the site were churned up to a depth of a couple hundred feet, and then the water came rushing back in. If you’ve seen those photos of milk drops you will remember how the backwash creates a surge into the center of the ring, forming a reverse drop. This is what happened at my impact site, and the churned, mostly liquified rock, was swept into the backwash. The result was a conglomeration of rocks and fossils from various strata at the site that is called breccia (pronounced “bret-sha”), which is one of the very suggestive indicators of a possible meteorite impact. (There are other possible explanations, which have been ruled out in this case.) The contents of the breccia help to determine the impact’s age.

But what interests me most about the breccia is that it is where all of our round rocks have come from. Among the contents of the breccia soup were millions of shards of blue-green shale, which are found at the very core of the round rocks. The mineral-rich waters in the soup then began to adhere to the shale, eventually forming into the lovely spheres that give our forest and this blog their names. There are outcroppings closer to the impact site where round rocks are currently weathering out of the breccia matrix. I can thank the Missouri Department of Transportation for exposing these when they did the roadcuts for the four-lane highway. These outcroppings are peppered with half-exposed round rocks, and they show weathering from when the waves of that ancient sea lapped against them before the whole area was buried.

Roundrock is more than seven miles from the actual impact site, so the question is, how did the round rocks find their way to our woods? There are two probable explanations. The first is that there may have been many places where the breccia surged into place, and our woods was one of those sites. The second is that the rocks may have been deposited there from elsewhere. Massive geological forces would have to have been in play, but that is not impossible, especially given the amount of time available. Also, in recent times (geologically speaking) North American glaciers have shown how easily massive boulders can be moved hundreds of miles from their origin.

There is a third explanation that I would love to be true, but I fear is merely wishful thinking. The impact structure is along the 38th parallel. If you extend this line east across Missouri, you find the two other impact sites in the state. If you continue further, you find another impact site along this line in Tennessee. And if you go to the west, there is one in Kansas. These sites have not been definitively dated yet–and so this is part of the wishful thinking–but perhaps all of these impacts happened at the same time when one large meteor broke into several smaller ones that slammed into the Earth all at once. Roundrock sits inside a semi-circle of topography that might, possibly be yet another impact site–a site within a site. If so, then it could have its own breccia backwash and thus home-grown round rocks.

But that’s the most wishful of wishful thinking. The geologist who has been studying the impact site tells me that the semi-circle is probably no more than a coincidence and not evidence of another impact. Nonetheless, I am happy to have the round rocks and to know the history of their genesis.

46 Responses to “Ancient History”

  1. rachel Says:

    your posts are really long … but it is good to hear what you have to say. you already have some fans!

  2. Roundrock Journal » Blog Archive » Breccia Says:

    […] aquo; Yellow Feathers Breccia In my lengthy Ancient History post below, I mentioned the soupy breccia that formed after the meteor impacted in the ancient ocean 350 million years a […]

  3. Niches :: Some Loose Ends Says:

    […] inside a meteorite impact area, with resulting interesting rock and soil formations. See Ancient History! Tree Trends: Tom Kimmerer indulges us with a whole series of far-ranging interests that […]

  4. Roundrock Journal » Blog Archive » Legalities and Technicalities Says:

    […] an agent who understood what we were after and was able to make two suggestions within the meteor impact site, one of which became our Roundrock. (Note: We did not know that this was a meteor impact […]

  5. Sue Beard Says:

    Hi, I have been studing on my own, and have decided to go with the theory of the 38th parallel. Now if the meteorite that struck Iowa was thought to be very old, But now they have decided that its not that old. And the Iowa meteorite is thought to be the meteor that killed the dinosaurs. So we realize that meteorites could very possibly hit in a group, infact its very logical that a group of meteors or parts of a large one could have hit along the 38th parallel. And along with the one that hit Iowa, killing all the dinos. thanks Susan p.s. field trip july 30th I would like to attend

  6. Susan Beard Says:

    I would like to attend your field trip july 30th. I have been studing the rocks in the osceola-weaubleau area now for approx. 10 years. collecting fossils, and round rocks, and speculating. It was so wonderful when you found the impact site. I knew there was something very special about this area and the fossils. thank you Susan

  7. Administrator Says:

    Susan Beard – Did I say something about a field trip? I don’t know about one. You might try to contact Kevin Evans at the state university in Springfield. He’s the genius behind all of the research and attention this discovery has been receiving.

  8. Roundrock Journal » Blog Archive » Round + Rock Says:

    […] in this photo. Interestingly, the bluff that this cave is in is the outermost edge of the meteor impact structure that Roundrock also sits in. It’s tempting to look out across the lake and ima […]

  9. Larry Ayers Says:

    How fascinating!

  10. Roundrock Journal » Blog Archive » Answers to Yesterday’s Quiz Says:

    […] What grows in Blackberry Corner? If you said Osage Orange trees, I’ll bet you feel stupid right now. It’s shortleaf pine trees that I am having mixed results growing in Blackberry Corner, which was named for the many blackberries that used to grow there. […]

  11. Trenchless Geologist Says:

    It’s fascinating about the round rocks, isn’t it? 38th parallel structures being part of a possible serial impact, or “crater chain”?

    Trenchless Geologist

  12. Roundrock Journal » Blog Archive » Pile o’Rocks Says:

    […] Lately, though, unless it’s a keeper, we just leave them where we find them. Maybe the novelty is wearing off. Or maybe the summer heat and humidity dampen my collecting enthusiasm. […]

  13. Round Rocker Says:

    I have to disagree with the bluegreen shale theory,if that were the case “round rocks” would be found all around the perimeter of the site.I personaly have found rocks of the same composite that are not even close to being round,oblong,one’s with a tail indicating a trailing form was made as the HOT ROCKS fell back to ground,(tear drop)as a rain drop.Some odd shapes with 3, 4 , tit’s poking out in all directions forming a strange looking polygon shape,and most common broken hollow half’s.Bluegreen shale, (yes) in some.Is that how they were all formed I don’t think so.I was not there, and no one was. I think the meteor came in from the South East and scattering hot molten limestone to the North West….Bluegreen shale ?don’t think so……..Round Rocker

  14. Trenchless Geologist Says:

    A couple of clarifications might be in order.

    The blue-green shale pieces are part of the Northview Formation. The original work done by Tom Beveridge on the Weaubleau Structure back in 1951 shows there is actually an area around Weaubleau Creek where the shale simply DOESN’T exist any more. It provides evidence of a hole, punched in the earth, that recorded the impact. The meteorite most surely reached the basement approximately 1200 to 1600 feet below (this was proven to be true by the holes drilled in the structure in 2001, that recovered granite pieces in breccia a mere 200 feet below the surface.

    The round rocks were formed in the beds of limestone after the impact on whatever nucleus existed (many, indeed, WERE shale from the punch hole in the Northview) The rocks consist of post impact chert, and may be asymmetrical, though many are symmetrical.

    A really great summary of what went on can be found at:

    Download Part I of the 2003 Guidebook as a .pdf file. It tells all about it.

    Trenchless Geologist

  15. Pablo Says:

    Thank you, TG!

  16. ROUND ROCKER Says:

    HEY–__ That big hole sounds astronomicaly devastating.Great work by Tom Beveridge,always wounderd if there was a hole,and how one could prove it. Will Part 1 of the 2003 Guidebook tell why these asymmetrical and symmetrical rocks are only found in a very narrow corridor in the North West quadrant,? and not the South East,or any where else. Ever see a round rock float?,,, I have, , not in water,,, in concrete,, 8-inch’s under and slowly back to the top she came,had to remove her, after all these years,, she would not stay down. I guess it’s necleus was an air bubble?,,I don’t know.,,,I’m sure you’ll agree,,you to Pablo,, have found pieces of the post impact chert that are no-way sysmmetrical,asymmetrical,or bsymmetrical,there a blob that has pinnacles with holes through and through.No nucleus in site…..Anyway thanks for your input TG, I’ll read the guide of 2003……..Not trenchless, ROUND ROCKER

  17. ROUND ROCKER Says:

    P S …..You know, my Father taught me the meaning of a word a-long-time ago.It could be all a mere… COINCIDENCE…….diggin a hole, ROUND ROCKER

  18. Trenchless Geologist Says:

    Glad to hear from Round Rocker and Pablo….thank you both. A good discussion is underway. Here’s some more information for you both, and for Roundrock Journal. How does one conclusively prove the existence of a meteorite impact?

    There are quite a few criteria, nearly all of which are met by Weaubleau-Osceola.

    First off, there’s the physical scar of the impact. This includes the crater rim, the impact breccia which has filled it, and the fallback breccia which thins with distance from the crater.

    Next, you should have the presence of minerals (in the case of W-O, this is quartz) which have PDFs, or planar deformational features. Quartz grains normall split with the fracture surface of bottle glass (called conchoidal fracture by the geologist). Instead of this fracture surface, meteorite impact minerals (those that experienced the shock of the impact) have cleavage planes. Quartz is a great index mineral because it DOESN’T HAVE normal cleavage planes. Thus, the quartz grains at W-O are said to be ‘shock quartz’. It normally takes a microscope and a lot of patience to find these, but they’ve been found here.

    The presence of a geophysical gravitational low, taken in conjunction with the first two criteria, also indicates the probabllity of meteorite impact. You need to have a gravitimeter, a geophyiciist with a PhD, and relatively little background gravitational anomaly to figure this out.

    A geochemical signature of platinum-group elements is also something that impact scientists look for. Platinum group elements also includes iridium, which was responsible for finding the large meteorite impact (now generally accepted among scientists) that killed off the dinosaurs at Chixculub, in the Yucatan penninsula of Mexico.

    The only thing not present at W-O, and the one thing that Dr. Evans and the rest of the scientists involved with the search are looking for, are shatter cones. These are conical structures caused by the shock wave of the impact moving through solid rock. They are present at the other 38th parallel structures at Decaturville and Crooked Creek. Where are they at Weaubleau-Osceola?

    Kind Regards,

    Trenchless Geologist

  19. ROUND ROCKER Says:

    Anybody: Anywhere: On Earth, know of anyother impact site that has similar post impact chert formed like Osceola has? Anywhere?……much to HOT to look here………red faced… ROUND ROCKER

  20. Rock n Roller Says:

    What happen here? I have visted this site several times and thought no one was talking.All of a sudden there’s a conversation going on and now nothing. “Trenchless Geologist” I dont know about ROUND ROCKER but I went to your site on the 2003 guide book GREAT STUFF thanks for that information. But lets get back to the subject, I would also like to know if theres anymore Impact Sites in the midwest with round rocks ..not red faced Rock n Roller

  21. Trenchless Geologist Says:

    Rock n Roller:

    Thanks! Glad to see that the guidebook link was appreciated. Speaking of OTHER impact sites with round rocks like at Weaubleau-Osceola – – – – there are none, to my knowledge. I’ve been to both the Decaturville and Crooked Creek impact sites in Missouri – no round rocks. In this, the Weaubleau impact site is unique.

    There is DEFINTELY a whole lot of special people and phenomena in Round Rock Country. After finding this site, I thought I’d contribute to the developing forum, being:

    1) A Missourian
    2) A Geologist
    3) a meteorite impact scientist.

    I’m not Kevin Evans, and I choose to remain anonymous. BUT, if I can add to the discussion here, I’d be glad to help in anyway possible.

    Until next time,

    Trenchless Geologist

  22. ROUND ROCKER Says:

    OKAY__okay:__Mabe it came in from the Southwest…YES.. Rock n Roller.. I have been to the site,and yes I have read the guide,and yes it’s probable I got my idea from a misquote.And no I did’nt get it from CNN,I got the idea from a friend…Sounded super to me…BUT.. and that’s a BIG BUT,some of this so-called chert I have found, looks to me, to have been molded.With no nucleus,some with the nucleus, thats a hole through and through??/…”PUZZLING”…Some of this stuff has’t to be from the HOT BLAST,thats just a given…But HEY , thanks for getting an answer to my last question….Very interesting…Not to shure they should’nt call it pre-impact chert…And to your last question Mr. or Miss……. Trenchless Geologist…I think Mr. cant be shure, been wrong before…I think Mr. Evans needs to drill deeper…..I don’t know…..I do know my well is only 280 feet, and it cost a bunch …….w/out face ROUND ROCKER

  23. Rock n Roller Says:

    No problem ROUND ROCKER, I was interested in that question myself.Mabe you should have been more specific on who you asked.As for drilling deeper, 800 feet sounds pretty deep to me. I’m not shure, I’m not a geologist, I just like round rocks or “Weaubleau Eggs”.Find all this fascinating.Now everytime I drive through a highway cut out, I find myself slowing down to look at the stratis lines for signs of something.I also have found some strange shapes in my searching.One rock is shaped like a heart, thinking of sending it to my EX, HEART OF STONE.
    Later…Rock n Roller

  24. ROUND ROCKER Says:

    HEART OF STONE: Sounds like that did’nt go well,speaking of hearts I think my heart is out of this social internet intercourse….However it’s been educational.Thanks to – Trenchless Geologist -Like my Grandfather use to say “knowledge is no burden to carry”…Good hunting.. Rock n Roller… you to TG,,,,,,,Thanks ROUND ROCKER

  25. maxine Says:

    We just found a small piece of meteorite over the week end on the lawn. July 06

  26. jim holcomb Says:

    found a round rock at a construction sight in manchester tenn where they were bringing in shot rock to bring the sight up to the desired grade. the rock looks very similar to weaubleau rocks i have seen on the internet but smoother. any reason for these to be around this area or maybe its just a 4″ round river rock, curious jim

  27. walter zeitschel Says:

    hello friends, i write you from germany and my english is very poor.
    i am interested to buy or exchange osceola round rock balls from the osceola impactsite. can you help me ? with impatience i wait for your answer. thankyou in advance.

    best regards yours walter from germany

  28. walter zeitschel Says:

    have you received my mail ?

  29. Pablo Says:

    Walter Zeitschel – No, I have not received your mail. Could you send it again?

  30. susan beard Says:

    Hi Walter Zeitschel, get a hold of me if you want some weaubleau-osceola round rocks, or weaubleau eggs. I have a few. I have been picking up a few fossils, and rounds, now for about 10 years.

  31. susan Says:

    Now if the meteorites hit and killed the dinosuars, could the round rocks be dinosaur eggs?

  32. Walter Jeffries Says:

    Very neat! I have emailed this page’s link to my sons to read. Thanks for writing about this! I love reading your research posts like this one.

    I don’t think we have anything naturally occurring like this at our place, aside from three round rocks mailed to me by a friend. I don’t even find fossils in all the digging I’ve done. I think that is because our rock is igneous (sp?) so everythings churned and melted.

    What we do find occasionally are polished rocks, generally green, that were probably deposited on our mountain top by the glaciers. However, they are far from Round Rock(s). 🙂

  33. Johnny F. Tonko Says:

    Hello Everyone:

    I’m interested in knowing more information on the specimens of “chert” that is mentioned in this Journal. Further information on my research findings related to the 38th Parallel Structures can be found on my website by using the “Crater Research” tab at


    Data collected during impacts from the comet Shoemaker-Levy 9 into Jupiter prompted further research into an established crater chain on Earth. That effort now supports an extension to the 38th parallel structures. The alignment from Alamo (Tempiute) to Hicks Dome, first identified by Johnny F. Tonko, supports an extension of the serial impact structure set. The original series of depressions and deformation structures was approximately 700 kilometers following the 38th Parallel through Kansas, Missouri and Illinois. The Tonko Lineament extension more than triples the previous length to a total distance of 2367 kilometers, through Colorado, Utah and into Nevada.

    In addition, a previously unrecognized impact crater, the Gunnison Crater, fits well into this alignment. The Gunnison Crater impact structure is 8.4 kilometers in diameter and is near the city of Gunnison, Colorado at LAT 38.48188 LON -106.98386. Gunnison Crater, first identified and confirmed the author, supports hypervelocity impact origins by evidence of tektite and impact breccias recovered from the structure.

    Precambrian granitic rocks of the 1700 M. Y. age group are prominent in the crater rim remnants and crater basement. Fragments of suspected early Pennsylvanian rock can be found in the breccias. Preliminary age estimation is 320 M.Y. for the Gunnison Crater. This preliminary dating fits within the age constraints bracketed by the Silurian and Pennsylvanian ages of other proven, probable and suspected craters along the lineament. Given erosion of the crater, the age and inclusion into the lineament is plausible.

    Copyright © 2006 by Johnny F. Tonko
    All Rights Reserved

  34. sue beard Says:

    I love this round rock site. very interesting. I can see where you can see these round rocks as concretions, for some of them probably are. BUT, it is obvious to me, that all of them are not concretions. There has been a conglomeration occuring around the rounds, which is logical. Because of there age. But if we look past the conglomeration that has formed around the round rocks. (Say 1 inch for an example.) We are looking at the original round rock. What is it now? Possibilities can be many. What exsited millions of years ago when these precious rounds were formed? We can learn alot about the earths history from these round rocks, using an open mind. Throw the old books out, and use are new techknowledgy.

  35. Amina Wyrick Says:

    I live in Kansas City, MO and we have a perfectly round rock in our back yard about the size of a bacchi ball or a bit bigger. The round rock is very heavy and is not man made. The outside finish looks to be a sandstone color. Could this be a round rock, dinosaur egg?

  36. pablo Says:

    Don’t think it’s a dinosaur egg. I think it’s probably a concretion, which is a naturally occurring round stone. Not common, but not impossible.

  37. Kansan Says:

    Everyone please take note. There is No confirmed impact site along the 38th parallel in Kansas. Nor are there Any geological indicators of such an impact at ‘Rose Dome’! So, if you are studying impact sites or considering the ‘crater chain theory’ you should be aware of this.


    a Kansan

  38. austin Says:

    who ever reads this has way to much time on there hands

  39. sue beard Says:

    Amina, you said you found a round rock in your yard. People from kansas city has come to osceola for years, and have carried many rounds back to the city. It is very likely your round came from osceola. I don’t see why it couldn’t be a dinosaur egg. One of these days, we’ll know for sure. I have found several round rocks in one general area, and they were close to be the same sizes. Suggesting a nest of several eggs close to the same size. coincidence that they were all same size? I don’t think so.

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  42. Ken Greene Says:

    I have maybe 20 round rocks. Large and small. All found in the Branson Mo. area on construction sites. I could provide pictures if any interest

  43. Ken Greene Says:

    I might add that it is 109 miles to Osceola Mo.

  44. Paula Says:

    I found a small balling ball size Weaubleau Egg in backyard. I live in Grandview missouri.
    It even has what lots like iron deposits in it.
    Has there been any other rocks found in my area

  45. Paula Says:

    I found the rock buried in my backyard in the ground only a little of the top was showing. I have lived in this house for about 20 years

  46. Elizabeth Lonsdorf Says:

    Last year I was messing around with a friend’s metal detector out in a wooded area by her house. The metal detector picked up something under the dirt, which I thought would have been an old coin, but to my surprise, 6 small round rocks burried in a shallow hole. The small rocks remind me of large bird eggs, except they all have a little hole on one end, as if they were plucked off of a stem. The rock’s strongly resemble the round rock’s found in Missouri. The crazy thing is, I dug my rock’s up in Canyon Lake, Texas. Thirty miles north of San Antonio.

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