It's ironic that everybody thinks that the sciences are actually something that's just cut and dried, doing a lot of math, doing chemistry, things like that.

Not so.

It's the creative aspects that really attracted me to it.

So if I struggle with writing, I'm really good with figures.

And so, I make these beautiful diagrams because I think visually.

And so, when you see patterns that just don't seem to fit with what's around, it's like, what made this?

What could have caused this, right?

[theme music] During the earliest days of our planet, long before the arrival of humans, the Earth was often subjected to large meteor impacts, some of which define the landscape to this day.

Evidence of these impacts has largely been hidden by time, and very few are still visible, but one of them is right here in the Ozarks.

Our guest today is Dr. Kevin Evans, Professor of Geology at Missouri State University, who recently helped discover a visible meteor impact site near the town of Weaubleau, Missouri, which also produced some very unique rock formations that are found nowhere else in the world.

Join us as we talk about how it was discovered and how this ancient meteor impact continues to affect the landscape and the people who live here.

ANNOUNCER: Ozarks Public Television and Missouri State University are proud to present "OzarksWatch Video Magazine," a locally produced program committed to increasing the understanding of the richness and complexity of Ozarks culture.

Visit our website for more information.

Well we're enjoying a beautiful, beautiful Ozarks day.

And so, have a very special guest.

And we have a very special topic, actually.

So before we get started discussing meteors and the Weaubleau structure and all the different things, I want you to kind of talk a little bit about yourself, your background.

Then we'll get into the geology of this area.

This is one of the most beautiful places on Earth, I think.

Actually, in Missouri, it's one of the best, I think.

Kevin Evans is my name.

I'm a Professor of Geology at Missouri State.

I've been there for 20 years now.

Before that, I was with the US Geological Survey for about eight years before that.

Kind of got grandfathered into a very low paying job that I had to leave there at one point.

So in about 2001, I came to Missouri.

Back to Missouri, actually, this was my home.

So I did my undergraduate work at Missouri State, and then went on to University of Kansas for a couple of degrees.

And then went on out to California, so.

And what was your-- kind of your just general research interest and overall-- Well, when I was in grad school, I studied carbonates, mostly.

So limestones were a big thing for me, and comparing rock successions from one place to another, so stratigraphy.

And so, actually it's a career sort of designed for the oil industry, of all things.

And so I didn't really want to work in the oil industry, so I wound up working in the oil industry for the Federal government.

And so I did that for eight years with the US Geological Survey.

So sometimes, projects find me.

And that's kind of what happened here.

I had heard about the Weaubleau Impact Structure from a paper about in 1995, I think it was.

You may recall in 1994, I think it was, there was a Shoemaker Levy 9 comet that broke up when it was going around the sun and then it hit Jupiter.

And so there were 22 pieces of that comet that struck Jupiter.

And so people then said, well, this must have happened on Earth, too, at some point.

There were some structures that ran across Kansas, Missouri and on into Illinois that had been published in 1995.

And they made a list of all of these eight or nine structures.

There's actually like 10 of them that run across here.

They knew about eight of them.

And Weaubleau was among those that they had recognized as like, well, this may be one of serial impact like the Shoemaker Levy 9 comet.

And I thought, you know, nobody's ever shown that these things were actually meteorite impacts.

That's a good idea.

And so I'm going to run with this.

I had just come back to Missouri State University to teach.

And so, as I was teaching, I was working late one night, working in my office.

And one of the skills that I learned with the US Geological Survey was to map with digital elevation models.

And so, I had a Macintosh computer and a little tiny red iMac.

So these sort of unusual sort of computers at the had back at the time.

So one of the things that you could do with these was to be able to stitch the digital elevation models together.

And so as I was doing this-- and looking for the round things because meteorite impacts usually leave around calling card of some sort, right?

And so, I was looking for these things.

And having stitched four of them together, it's like-- and I kept looking closely.

It was like looking for the tree in the woods, you know?

There was so much to look at.

And I said, you know, I'm going to give it up for tonight, and I saved it to my desktop on my computer.

And on my desktop there was a thumbnail image.

And in the thumbnail image, stretching across all four quadrangles, and right in the center of those four quadrangles-- 7 and a half-minute quadrangles-- you can see the round thing.

It took all four of the quadrangles to see the round thing there.

And so, immediately, I opened it back up.

And sure enough, there's this round feature.

And it's like I found it on a computer first.

And it's, like, so this is the Weaubleau Structure.

It had been called the Weaubleau Structure since the 1940s.

And so in the 1940s, there was a guy named Thomas Beveridge.

He later became the state geologist of Missouri.

And he recognized this area as being very unusual.

And he mapped one quadrangle to the east of here and noted that there's some unusual geology going on here.

I don't quite understand it.

And he thought it was maybe thrusting over a dome.

And so, thrusting being a sort of a mountain-building process that's not typical in this part of Missouri.

We usually get flat lying rock, one rock on top of another, essentially.

So here we have this round feature.

And I thought, I'm going to show this to some of my colleagues.

Ken Thompson was across the hallway from me, and so I took the image over to him and he didn't say anything.

He just looked at it and just started shaking his head.

And I kind of knew I was on to something at that point.

Nobody had ever seen the round thing here before.

And yet they'd already interpreted it as a meteorite impact, just from other people publishing things like Tom Beveridge's work.

Interrupt you real quick.

How long is the structure-- how long has it been known that there's something there, but they didn't really know all the detail and everything?

1940-- 1940s, I guess you could say.

1949 is when Tom Beveridge finished his doctoral dissertation on this area.

He didn't know it was a meteorite impact structure at the time, of course.

He worked out of-- he was working on his PhD out of the University of Iowa.

And so a guy who was working at the same time, his name was Hendrix, and Hendrix was studying another impact structure in Missouri that we recognized as an impact.

And he actually interpreted it as an impact structure at Crooked Creek, which is a little bit south of Steelville.

And so Hendrix made that interpretation, but Beveridge didn't make that interpretation.

He was looking for something else, I guess.

He was looking-- yeah.

He said, you know, sometimes you can't see something unless you can think that may be what it is, right?

And so when I was looking for this, I was, like, there may be an impact here.

And so one of the things that I looked at is I got to see the round thing for the first time.

And I showed it to my colleagues.

It's like, I don't know what that is.

So the very next day was a Saturday and I drove up here in the snow.

And I saw some of the outcrops that are along Highway 13.

And we're about maybe five miles north of Collins, and maybe about eight miles south of Osceola.

And along the highway there there's a breccia.

And so I stop and collect some of the rocks from this breccia and took them back with me.

And it's, like, this is kind of another calling card for a meteorite impact.

It's still not proof, however, right?

So we have the round thing.

When you really look at these round things, they're really kind of cool, right?

So Decaturville has one, that's a little bit north of Lebanon.

The little town of Decaturville is actually in the impact structure there.

It's a little bit south of Camden.

And so, Camdenton in Camden County, it's right on the county line there.

And so Decaturville is one, Crooked Creek is one, and then Weaubleau had been interpreted as one in the 1990s here, as a cereal impact.

So the question's still out there.

Are these serial impacts?

Because there's three of them that we recognize today as being meteorite impacts.

So what did it take to show that this was a meteorite impact?

Let me interrupt you a little bit.

A serial impact, what is that, where the meteor breaks up and there's several pieces of it that go?

That's right.

So one after another in a row, perhaps, right?

So the idea, anyway, is that they would have come in.

And so there's some structures in Kansas, a little bit to the west of here, that-- there's one called Rose Dome.

And right next to Rose Dome is Silver City Dome.

Well, Silver City Dome has igneous rocks in it, so it's not the same thing.

And so, the igneous rocks had intruded below and left the rocks around there kind of domed up.

And so, Silver City dome right next to Rose Dome, it's the same sort of feature, igneous features.

The next 1 over is Weaubleau here.

If you go a little bit farther to the east, it's Decaturville.

And then a little bit farther from that, it's Crooked Creek.

And a little bit farther from that, there's one called Furnace Creek.

And Furnace Creek is another one of these unusual features that has igneous rocks in it.

It's not an impact.

It's got basalt in it, actually.

And then you go a little bit farther to the east, there's an area called Avon.

And so, Avon, really massive round sort of features.

I started mapping all these things and thought, where are they all at?

Where are the round features associated with this string?

And you find out that some of them are just-- happen to be aligned.

And so in Avon's structure, it's another igneous feature.

If you go to southern Illinois, there's a place called Hicks Dome there.

And Hicks Dome is another classic, onion-style dome feature, right?

So you can peel the layers back.

So the oldest layers are in the middle, essentially.

We still didn't have the proof for an impact, however.

And so, that took one of my colleagues at Missouri State.

His name is Chuck Rovey.

And so Chuck, bless his heart, he says, let's go and let's start looking for these things.

So we actually had a short symposium at Missouri State, led by a guy from the national-- I think it was the Smithsonian.

His name is Bevan French.

He was an impact guy.

And he taught us how to look for things they call shocked quartz.

And so we found shocked quartz here.

And that's what was really the best calling card we could look for.

There's two things that really stand out for meteorite impact structures, and that's you can either see shatter cones-- shatter cones are essentially high pressure sort of features, where if you expose rocks to shock pressures, essentially what they do is they form these sort of striations that all point to a center point.

And so, they just kind of radiate away from that.

And so we've seen these at Crooked Creek before.

They'd been described from Decaturville as well.

We have yet to find them here, but we do have the shocked quartz, and so we have shocked quartz from all three of the impact structures in Missouri.

We have shatter cones from two of the impact structures.

And so the shock quartz is pretty interesting.

It's a story where the littlest, tiniest grain of rock is enough to show and make an argument-- if you have enough of them-- that this thing was actually exposed to shock pressures.

You may be familiar with one of the characteristics of a mineral called quartz.

Quartz is a lot like glass.

And in fact, you melt quartz to form glass, right?

So quartz will break with what they call conchoidal fracture.

Native Americans knew this from the earliest phases of their occupation of this continent.

They could do flaking scars to make projectile points.

And so projectile points rely on that sort of conchoidal fracture to make sharp points.

And so that's usually what quartz does.

But if you expose it to enough, if you have a big enough hammer and expose it to shock pressures, quartz will actually break along where its crystalline boundaries are.

And the crystalline boundaries actually shift, and they make solid state glass.

It's called diaplectic glass.

It's a little bit in the weeds here, but that's one of the things that's pretty interesting.

And so shocked quartz is a whole series of lines spaced at about 10 microns across, 10 thousandths of a millimeter, and you have these sort of linear features.

And they all line up.

And you get multiple directions, in fact, with shocked quartz in impact structures very commonly.

And so we have the shocked quartz here.

We have yet to find the impact-- the shatter cones that are here.

We think that they're here.

The interesting thing is, of course, OK.

So you find the round thing, you zoom in on it, and actually, it's two round things here.

So we have a big round thing, which is about 12 miles across, and then there's a smaller round thing that's about five miles across.

And that's what we call the main impact area today.

They're offset from one another.

So in the southwestern corner of this larger 12-mile across ring-- and we're actually right at the northwestern corner of that ring sitting right here.

this ring is 12 miles across from top to bottom, east to west.

There's a smaller ring inside of that that's five miles across.

And that's the main impact area.

And that's the area that's full of this impact breccia that has all the shocked quartz in it.

So we're pretty sure we've learned a few things about this over the last 15 years, 16, 17 years since this thing was-- since I first found the round thing.

That that main impact area is-- the meteorite had to come from what today is the southwest.

And so it hit and it pushed everything out, essentially.

So that's what our tectonic RAM is.

So we have the two round features, one 12 miles across, one five miles across.

And so are they related to one another?

Well, inside of this, the geology is that we get a whole series of folds and thrust faults on the outside of this rim.

In fact, there's a quarry that's a mile and a half outside of that main impact area, so just a mile and a half to the northeast of that five mile across area.

In that quarry, it looks like a nuclear bomb went off, right?

It's like all the rocks are not-- they're not layered at all, in fact, so they were at odd angles.

Their folds-- JIM BAKER: Just mashed?

KEVIN EVANS: They're just a mash.

And so in geology, we call that a melange.

It's something that was just totally mixed up.

You get that sort of thing in tectonic rim, tectonic features.

Sometimes, like in California, you'll find a melange there.

That's all from tectonicism.

This melange was all from that meteorite that struck that was five miles across.

The thing came in, it penetrated into the rocks.

If you can imagine something going 20 times faster than a speeding bullet, and it stops within 3,000 feet inside of the Earth.

All of that energy went into that impactor, and it sent shockwaves through the impactor.

It sent shockwaves through all the surrounding rocks.

We call them target rocks.

And then it vaporizes like an explosion, so the whole thing exploded then.

And when it did that, it pushed all the rocks out.

It pushed them to the northeast, it pushed them to the east, it pushed them to the northwest.

So we get different kinds of expressions-- But the impact area stayed intact?

KEVIN EVANS: Pretty much, yeah.

And then it blew everything out to create the second-- KEVIN EVANS: Yeah.

I was trying to visualize how that would-- So ironically, one of the unusual features that we see in this area, there's a whole-- you can't see it on camera right now.

But just below us, there's 120-foot bluff.

On that 120-foot bluff is exposed limestones.

Those limestones have all sorts of thrust faults where you can see the rocks have been kind of scooped and pushed, essentially.

And then there are broken folds, if I could illustrate here.

One of the folds is like this, where the layer has been folded up on itself like this and then broken right here.

And then all the material that fills in, it just mixes everything around below it and fills in.

So we have one that we call Knuckles.

There's another one that looks like a shepherd's crook, where it's been bent the other way.

So this whole cliff side here is this record of that collision that occurred three miles away over here.

So it was a massive explosion that left that behind.

The quarry, which is not available to us anymore-- the landowner had passed away recently here, Mr. Brownlee.

But hopefully at some time, we'll be able to get back in there with a drone and be able to film with that again.

It's like something just blew up inside of that area.

So that's a mile-and-a-half outside.

We're about three miles here outside of the main impact area.

Inside the impact area itself, it's a bowl-shaped sort of feature.

And as deep as we've been able to drill, which is only 320 feet.

That's the deepest core that we have.

We have about 12 cores from this thing, and it's breccia all the way down.

It's like, OK, so you wonder what breccia is, right?

Breccia is the name of a rock.

I was just getting ready to ask.

Well, it's like nature's concrete.

And so if you can imagine concrete, you get aggregate, right?

So aggregate is made out of, in this case, pieces of limestone, pieces of dolomite, pieces of silt stone, pieces of chert, and pieces of-- well, pretty much everything, even granite.

And so, well, there's no granite exposed around here.

In fact, so when this thing came in, it went deep enough to where it could hit granite.

Which, from nearby wells, we know that's about 1,800 feet deep here.

It went all the way down to the granite basement here and punctured it, and then brought it back up.

So when these things-- when they occur, they explode in.

They explode downward.

They push things outward.

They blow up like a giant splash.

And like a milk drop in a saucer-- and you've probably seen photography where it shows the milk drop hitting and then it pops back up like this.

Well, that's another one of the calling cards from a meteorite, is that you get what they call a central uplift.

The central uplift is where all the material rebounds back upward like this.

And it could have been-- if we'd have been sitting here, we'd have been long gone.

But only three miles away that way, if you can imagine, about a mile up in the air there's this giant splash of material that is breccia.

The whole thing collapses back down mixing the granite, mixing the pieces of every kind of rock you can imagine from here all the way down to the granite, and turning it into concrete, essentially.

So from a geological perspective, normally, you have kind of the rocks and the formations are laid out in certain patterns?

KEVIN EVANS: Yes.

And so when they get all mashed up, you say, oh, OK.

This is interesting.

Something happened, right?

Breccias always tell a story yeah.

A couple of things I was going to ask you about, the Weaubleau Eggs, because just the name just is attractive.

So what's with the Weaubleau Eggs?

Well, inside of that impact breccia that is in that five mile across area, it actually extends a little bit beyond that.

Just kind of lapping out like icing over the top of the cake.

These round rocks-- and there's some features around here you'll see.

The round rocks themselves actually are made out of chert.

And they're inside of that impact breccia.

And the unusual thing is when we first started seeing these things, what are these things, you know?

And the first idea is, of course, these things were like droplets essentially coming out.

But they're not.

They're not, actually.

And so what they are, they're are tiny pieces-- very commonly, anyway-- mostly of silt stone.

And the only salt stone around here is a Mississippian Age rock.

It's called the Northview Formation.

If you're in Springfield, it's the sort of material that they put the sanitary landfill into because it's made out of clays.

And silt is a little bit coarser grain material than clay.

These silt stone clasts make up the core of these round rocks.

And so, silt stone is a little different from all the carbonates because it's got silica in it, right?

And so, oftentimes, if you're going to form a silica, and a lot like chert forms in natural settings, it forms a lot like petrified wood, where molecule by molecule it just keeps growing outward.

And the most common shape, of course, is for something to grow outward and into a round shape.

And so these things actually are a product that we call them diagenetic.

How did it form?

It formed across-- the formation of this thing is within the rock itself.

And so it was actually a diagenetic rock.

They're going to go around to do a little bit of shooting and some of the scenery-- scenes and stuff.

So what are what are some of the key features that you identify in this area?

You've already identified a lot, but there were other key features?

KEVIN EVANS: The really cool ones in my opinion, they're some unusual features as well.

The round rocks are really pretty cool.

Any time you find a round rock, you're relatively-- if you find a round rock that has-- OK, everybody contacts me.

And it's like, I found round rocks in Tennessee, or I found round rocks in Mississippi.

There are other processes that can form round rocks.

They don't always have to be impact structures.

But the ones around here, we find them associated with that impact breccia.

So the impact breccia is cool.

The round rocks are cool.

The folds and the faults are amazing around here.

So the ones just along the cliffs, I bought a boat just to be able to study these things.

I have a hand drill so we can go in and test.

Was it actually lithified sediment, was one of the key questions we want to answer here.

Because this thing hit when this was shallow seas here.

So it sounds like you still have a fairly live research interest, a lot of stuff to-- The research is going to go on forever here, let me put it that way.

Long after I'm gone, people will still be studying this feature.

Before we end the show, which is going way too fast for me.

But before we ended, I wanted to kind of pick your brain a little bit about the process you use.

I'm always interested-- I was telling you earlier about I'm interested in artists and scientists.

Because scientists are considered to be just you look at something, you observe and all that.

But scientists have critical thinking skills and imagination.

They have to have that as well.

So what's the process that-- when you went through and did all this stuff, what's the process that you generally go through as you're trying to find out something new, or prove something?

It's ironic that everybody he thinks that the sciences are actually something that's just cut and dried, doing a lot of math, doing chemistry, things like that.

Not so.

It's the creative aspects that really attracted me to it.

So if I struggle with writing, I'm really good with figures.

And so I make these beautiful diagrams, because I think visually.

And so when you see patterns that just don't seem to fit with what's around, it's like, what made this?

What could have caused this, right?

And if you already have an inkling of what you're looking for-- which I did when I was like, what are the round things that are associated with these serial impacts, right?

The serial impact in itself is another story, right?

So the creativity is just something that naturally came to me.

You can't teach somebody creativity, they say.

You're born with it or you don't-- you either have it or you don't.

But at the same time, it's like it's a critical skill for a scientist to be able to have that creative spark, you know?

You have to think.

It's like, where did this come from?

You have to have a lot of curiosity, I guess, too, right?

Curiosity is a huge thing.

Intellectual curiosity is big.

So to kind of bring it back full circle with these things that were found and published on 1995.

Are these serial impacts?

We have three of them in Missouri that are pretty well-documented.

This is pretty well-documented.

Decaturville, Crooked Creek.

And they're all lined up.

If you drew a straight line in between those three alone, you would find that the middle one in between is only a quarter of a mile away from the center of the center of it.

And it has a central uplift.

Crooked Creek has a central uplift.

This one has a central uplift, but it's buried deeply below.

This one's like the one that it hit and is perfectly preserved still.

If we were able to drill this, we'd have to be able to drill 2,000 feet to get to the bottom of the crater.

So just real quickly, so the theory really is focusing on the serial impact.

That's the theory, that the serial impact did, in fact, occur.

The best evidence we have it says that these are not the same age, however.

So if you may have had one or two that were like Decaturville and Crooked Creek, maybe a binary impact.

And those things have been recognized elsewhere before.

But we're pretty sure it wasn't three of them breaking up.

And if there were three of them that broke up, we would have had to have broken up around the moon, essentially.

Which is really pretty close.

Well, we're out of time.

And I really appreciate your explaining all this.

And I think I'm going to have to sign up for a geology course in my future here.

So that was very interesting.

Thank you very much for sharing all your expertise with us.

Yeah.

It's a lot of fun.

It's like it found me.

I didn't find it.

Thank you.

We'll be back in a moment.

ANNOUNCER: Ozarks Public Television and Missouri State University are proud to present "OzarksWatch Video Magazine," a locally-produced program committed to increasing the understanding of the richness and complexity of Ozarks culture.

Visit our website for more information.

I'd like to thank our guest, Dr. Kevin Evans, for talking with us today.

And we'll see you again next time on "OzarksWatch Video Magazine."

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