- Welcome, everyone, to Wednesday Nite @ the Lab. I'm Tom Zinnen. I work here at the UW- Madison Biotechnology Center. I also work for UW-Extension Cooperative Extension, and on behalf of those folks and our other co-organizers, Wisconsin Public Television, the Wisconsin Alumni Association, and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite @ the Lab. We do this every Wednesday night, 50 times a year. Tonight, it's my pleasure to introduce to you Ken Bradbury. He's the director of the Wisconsin Geological and Natural History Survey. He was born in Richmond, Indiana. He went to-- And went to high school there. Went to Ohio Wesleyan in Delaware, Ohio for a degree in geology. Then he went to Indian University and got a master's degree in geology, and he came here to UW-Madison to get a PhD in hydrogeology. And since 1982, he's been with the Wisconsin Geological and Natural History Survey, and he's been director since 2015. Tonight, he's going to talk to us about Wisconsin's geo heritage. This is in concurrence with this week, which is Earth Science Week all over the world. And I think it's a great thing to think about not only what geology has done for Wisconsin but also geologists, including folks like Increase Lapham, Thomas Chamberlin, who is a geologist and the first scientist who was president of this university, and, of course, Charles Van Hise, who is a geologist and who's, from my point of view, gave the best idea of what the Wisconsin Idea is when he said, "I shall never be content "until the beneficent influence of the university "reaches every family of the state." Rocks are good, geologists are even better.  (audience laughs)  Please join me in welcoming Ken Bradbury back to Wednesday Nite @ the Lab.  [audience applauds] - Well, thank you, Tom, and thanks for inviting me to speak to you. It's a real treat and honor to be inviting to speak to Wednesday Nite @ the Lab. So tonight I wanted to give you a kind of a quick tour around Wisconsin's geology and talk about Wisconsin's geo heritage. How Wisconsin's geology has shaped our past, our present, and our future. And, as Tom said, it is Earth Science Week, all week, and every day is a special day. Today is fossil day. And I'm not sure that's why I was invited.  [audience laughs]   [audience member mumbles a comment]   [audience laughs]  But I can tell you a little story, a personal story. Tom said I grew up in Richmond, Indiana, and I grew up on a farm. And on our farm we had a creek, and that creek had really nice Ordovician fossils of corals and Brachiopods and Pelecypods, which are little shell-shaped creatures. And they were very easy to find, and they were very good fossils. And I used to collect them for Boy Scout projects and 4-H projects and things like that. And they were so easy to find that I thought paleontology was pretty easy stuff, and it actually wasn't until I went to college and I took paleontology in college that the professor brought out these beat up, crummy, decomposed fossils to show us. And I said, "What are these?" And he said, "Well, "this is our best fossil collection "at Ohio Wesleyan University." And I said, "Why, I've got better fossils than this in my backyard."  [audience laughs]  And he said "Where do you live?" And I told him I lived on Elkhorn Creek in Wayne County, Indiana. And he said "Well, that's like the best Ordovician fossils "in the whole North America." And I didn't even know it. So that's how I grew up. I'm not a paleontologist, though. I'm a hydrogeologist. Now, in my talk tonight, I'm going to have a lot of photos and a lot of diagrams, and most of them are from this book called "Roadside Geology of Wisconsin" by Bob Dott and John Attig, who are two retired geologists that are still active in the area. It's an excellent book. We sell it at the State Geological Survey. Or you can buy it on Amazon or probably buy it at the UW Bookstore. But if you're interested in knowing about geology that you can actually see driving around the state, this is a really great resource. So I'm going to talk   And which is many places in Wisconsin. So here's a great shot of the Wisconsin River from Ferry Bluff, taken by one of our colleagues, Eric Carson, who's a geologist at the survey. Heritage, geo heritage, has many values for us, aesthetic art, economic. So here's a woolly mammoth. This is at the Horicon Marsh Visitor's Center. And it shows you the conjunction of geology and history and art, where they've created a woolly mammoth out of iron and steel and rebar and so forth, which I thought was kind of a neat thing. We have a wonderful geologic landscape in Wisconsin. It's a great place to be a geologist. Our landscape, of course, is part of our history and our cultural identity. These are Morgan Falls up by something called St. Peter's Dome that's up in the Northwoods. A neat place to visit.  How do we preserve this geo heritage? Well, we have-- We do it in many ways. We have state, county, and local parks. We have state natural areas. Do you know we have over 600 state natural areas? And the first few of them were all based on geology. Most of them now are based on biological features of some sort, and they're all over the state. And they're probably a little bit underused. I'm throwing a pitch out for that because I'm on the Natural Heritage Council. So we have these natural areas. We have historic sites and markers. We have museums and collections and very fine geology museum here on campus. There's the Weis Museum over there by Oshkosh. Many other geology museums at Milwaukee and so forth. And we have many cultural and custom-- Our culture and customs are linked to geology in many ways. So let's start a little tour around the state. And when I went to put this talk together, I was trying to figure out how to organize it, you know? And most geologists think in linear terms of the past to present or different rock types. And I was having trouble with that, so this is going to be a little more of a hopscotch around the state looking at different things, but there is some organization there. So let's start up here on the dells of the St. Croix River, where we're looking at ancient basalt lava flows that are making up these banks. These banks are basalt lava flows of about a billion years old. And when we think about that, we think let's change this into a mosaic. What's the geo heritage? It's a mosaic of many things. Exploration, science, mining, building, water resources, agriculture, industry, recreation, and tourism. And I don't have time tonight, or I wouldn't have time in a week, to talk about all of these things, so I'm just gonna hit a few of the high points. But to start with, it's important that we think about time, geologic time, and realize that geologic time goes back a long ways. So this is the generally accepted worldwide geologic time scale that goes back to about four and a half billion years. The age of the Earth, more or less. Or 4,400 million years. So that's a lot of years. That's the entire timescale. This is what Wisconsin has. We have the same time, of course, but we don't have all the record of that. We are missing quite a bit. So we have our geologic rocks, or what we call the geologic section, includes Precambrian rocks that are up to three billion years old. We have Paleozoic rocks that are between 400,000--  Or 400 million and five or 600 million years old. And then we're missing a bunch of time or a bunch of rocks up till we get to the Quaternary, which is in the last 100,000 years.  So we're missing very big blocks of time. Why are we missing them? Either rocks weren't deposited here in Wisconsin during those times or, more likely, they were eroded away. In any case, we don't have records of those times. But we do have-- The fascinating thing is we have some of the oldest rocks in the world here, and we have some of the youngest features too, and we have something in between. So it's quite a neat place to be a geologist. So, where are these rocks? Well, these, if we go up to northern Wisconsin, these Precambrian rocks, which are here and up here along Lake Superior, I'm saying they're really, really old. These are billions of years old. Okay? One to three billion years. And then we go to the Cambrian rocks, which are mostly sandstones and some dolomites and limestones that are south-central Wisconsin. And those are only, I'm going to say, only really old. Only 500 million years or so. We can go a little younger to the old rocks, the Ordovician rocks, which are 300 or 400 million years ago. And then what I'm calling our youngest bedrock, which were the Silurian and Devonian rocks over along Lake Michigan here, which are young, youngest if you call 400 million years young. So this is our geologic bedrock, our bedrock section. And I'll talk about the glacial materials in a little while. Just to give you a sense of where those are. Now, I'm very pleased to be the director of the Wisconsin Geological and Natural History Survey because it's Wisconsin geologists, many of whom work for our survey, that discovered or recorded or mapped these rocks. And so what do we do? We are part of the University of Wisconsin-Extension. We do research, inventory, teaching, and science about the rocks, minerals, and waters of Wisconsin. The original survey was a real survey. In other words, a project to survey the rocks and minerals of the state that happened beginning in 1853. And then our organization kind of came and went, and our current organization dates to 1897. But we had, as you can see in these photos, many, many of the famous geologists, some of whom Tom mentioned, were part of the survey from time to time. And the exciting thing about being part of the survey is that we have a huge legacy of exploration in science that we hold for Wisconsin. We have samples, we have mineral samples, rock samples. We have many, many maps and records. And these are the kinds of things we have. Back in 1882 was the first publication of this big tome, "Geology of Wisconsin." And Tom mentioned Thomas Chamberlin, who was a famous geologist. He was the editor of this big volume, which had many authors. He also became one of the first presidents of the University of Wisconsin. But here he is from the front part of this. He's talking about having the honor of submitting volume one of the final report of the  Geological Survey of Wisconsin. Of course it wasn't really the final report because here we still are over a hundred years later. But it was a really interesting time. And these guys were, you know, they were real adventurers And I wanted to just read a little bit out of that book talking about what they went through in mapping the Flambeau River, which is up in northern Wisconsin. And part one of the things that happened during that mapping is one of the geologists, a guy named Moses Strong, was killed, drowned in the Flambeau River during this work. But some of the things they talked about in their report, they say "The large amount of holy uninhabited territory "had to be traversed. "Unfavorable weather. "Low water in the streams made it necessary "to drag or carry the canoes over considerable distances. "The inaccuracy or incompleteness of the government survey "throughout much of the region all conspired "to make anything like complete work impossible. "On the night of November 5th, "the river closed with ice. "This necessitated the abandoning of the canoe, "packing of specimens, provisions, and camp equipage, "rendering it desirable to avoid all travel "not absolutely necessary to the work before us." So these guys were, y  And then, of course, if you're in that area, who wouldn't go to Devil's Lake? So here we are at Devil's Lake State Park. And this has a lot of cultural significance as well as geological significance because we know now that it's the most popular state park in the state, but historically it was always popular. In fact, there used to be several hotels on the banks of Devil's Lake. The railroad there used to run from Chicago, and people would ride up from Chicago to spend their vacation at Devil's Lake. There were steamboats on the lake and so forth. And I'm told that on this particular boat that Abraham Lincoln's wife and Ulysses Grant took a ride one time. So there's a great history of culture at Devil's Lake State Park, but there's fantastic geology too. So if we look at these, at these quartzite cliffs that form the nice talus slope and the bluffs there, that's the same rock that we just saw over at Parfrey's Glen and at Ableman's Gorge. If we climb up there to a place called Elephant Rock, which is along what's called the East Bluff Trail, we can see these relationships again, where we have the Precambrian quartzite at the bottom, we have Cambrian sandstone at the top, and in between you can see quartzite boulders that have been incorporated into that sandstone. This is just a wonderful place to understand the cycles of erosion and deposition that happened in geology.  And as long as you're up there, of course turn around and take in the view because it's a wonderful place, and this is how it looked last Friday. The trees are probably a little bit better now. So those are the really, really old rocks. And now let's talk a little bit about the Cambrian rocks. And these are also really old, but they're 500 million years younger than those Precambrian rocks. So this is-- And most of these rocks are sandstone. And so sandstone is just rock that's made up of the kind of sand you might find on a beach. Here's an outcrop of typical Cambrian sandstone, and you can see the cross-bedding there. So we know that this was deposited in some sort of fluvial or wind-blown environment. In the upper right there, you see a microscope photo of the sand grains. This is from a sample right here under us in Madison. And you can see how those grains are rounded. They're sorted, which means they're all about the same diameter, and they're almost entirely quartz. They look like little pieces of glass. And that's really a-- That shows you a very mature sandstone, meaning it's been sorted and blown around for a long time before it was deposited. That sandstone, that Cambrian sandstone, covers much of the bedrock, is part of the bedrock in much of southern Wisconsin. Here's a great bluff of Wonewoc, the Wonewoc formation near La Crosse, off of Highway 14 if you're driving into La Crosse.  These were formed in a shallow, probably beach or dune environment. So here you can see, you know, as the shorelines came and went, the sand was deposited along the shore. It was probably rearranged by some sand dunes. There could have been some submarine cross-bedding. There are some marine shells and burrows in some of this sand. It's a very widespread formation. In fact, Wisconsin is really a pretty sandy place. And there's fantastic places, if you go down to southwest Wisconsin in the driftless area, you can see great outcrops like this, it's at the town of Rockbridge in a little town park. The cool thing here is there's a tunnel right through the bluff, so you can walk from one side to the other right through the sandstone here and come out the other side. Kind of a neat place to go. There are these towers of sandstone that you've see if you've driven through central Wisconsin. This is called Rabbit Rock near Adams Friendship. But there is Roche-a-Cri and there's Friendship Mound. There's many of these sandstone outliers. And these were places where the sandstone was just a little more resistant to erosion. And so as the sandstone, which completely cover the area, eroded away, these towers were left. And, actually, I'll talk about Lake Wisconsin in a few minutes. These stood up as islands in Lake Wisconsin, in Glacial Lake Wisconsin. Now, when we start talking about sand, we can't avoid the topic of frac sand mining, which has been a very important new industry for Wisconsin. It's a bit controversial, certainly. But it's-- We have it because we have such a large area of sandstone, and all these little red boxes are places where there are frac sand mines. Now, to be clear, we don't do any fracking in Wisconsin. Sometimes there's a misnomer that we do that. We don't do that. Fracking is done in other places, but the sand that they use is mined here and is shipped out of the state to mostly western states where they do the fracking. And it takes a lot of sand. It takes trainloads of sand for a single well. It's amazing how much sand is used. And Wisconsin has the best sand because we have this quartz sand that's got the right hardness, the right diameter, the right sorting and so forth. So it's an important industry. But that let's me transition to talking about mining in Wisconsin. This is a modern mining industry, but Wisconsin has a great history of mining. In fact, if you look at our state flag or our state seal, there's a miner on there. That miner was probably a lead miner because our first mining was really lead mining. And this is a vein of galena, which is an ore of lead that you can see now down near Platteville. And early lead mining was an important cultural feature of Wisconsin. The Native Americans, of course, found some of these lead ores at the surface, and they found they could make-- They're pretty malleable. They could melt them easily, and they could make trinkets or even utensils or tools out of them. Later on, the first settlers started mining, and they dug shallow mines that were called badger holes, and that's one of the reasons we're called the Badger State because the shallow mines were called badger holes. And if you go down to southwest Wisconsin now, you can still see some of these diggings. And, of course, as mining became more sophisticated, they started to go underground, like this, and they mined not only lead but zinc as well. And there was quite a mining industry in southwest Wisconsin for lead and zinc. And that had a lot of cultural significance too because the tin miners from Cornwall, England migrated and settled in southwest Wisconsin to work on the lead deposits because they had a mining culture. And now you can go to Mineral Point and there's Shake Rag Alley, and there's a lot of mining culture, and gift shops too, left over from that time.  During the-- You know, in the late 1800s and early to mid-1900s, the mining was done on a pretty big industrial scale. This is the Calumet and Hecla Mine at Shullsburg, underground mining. It's interesting to note that most of the bullets from the Civil War, I'm told, came from lead mined in southwest Wisconsin. So this was a big industry, but it wasn't our only mining industry because we also have done a lot of iron mining. And so we had a number of mining districts around the state. The southwest lead district was down here, but the iron mining, or the ferrous mining, occurred around Baraboo, occurred over in Mayville, Black River Falls, and then a lot up in the Gogebic Range up in northern Wisconsin. And what they were mining for most of those mines was taconite ore, which is a iron ore that's very heavy, very old, again Precambrian rocks.  There's an interesting history there too. I don't know how many of you remember the Jackson County iron mine, which was up near Black River Falls. It was an open pit mine that closed in the mid-1970s. It was a very big mine that was over 300 feet deep. And it closed not because they ran out of ore but because the economics didn't work out anymore. That was reclaimed, and now it's a county park called Lake Wazee County Park. It's one of the deepest lakes in Wisconsin, again being over 300 feet deep and it's a mecca for scuba divers because the water is so nice and clear. Another interesting note, this is in a very flat area of Wisconsin and now there are hills around. The hills are the old mine spoil that they left there and revegetated. So that's an interesting place to visit if you're up around Black River Falls. Our probably most famous mining is from the north from the Gogebic Range, from the Hurley and then Ironwood, Bessemer area, just on the Michigan border, where iron ore was discovered. And these were mostly underground, deep underground shaft mines. And, in fact, at the time, in the early part of last century, they were some of the deepest mines in the world.  These went down a couple of thousand feet. The air was hot down there. Water was warm that came in.  I'm told they had horses and mules that they used for pulling the mine carts around that lived underground. It was a huge operation. So now if you go to Hurley, you can see things, like this is a core sample from the Hurley mine shaft that's about five feet in diameter. And it came from a couple thousand feet below the surface. And this was a bid deal. You can look at the-- Here's an article from the 1886 Chicago Tribune. I know that you can't see all this, but it says "Wisconsin bonanza, "newly discovered iron region near Hurley. "The wilderness of a year ago has vanished, "and in its place there are flourishing cities and theaters, "banks, saloons, and electric lights. "And it will bring its owners money and some frauds." So there was a bit of controversy about mining even back then. Another kind of mining that has flourished in Wisconsin is our dimension stone, dolomite and limestone quarries. These are mostly in eastern Wisconsin. And here's a couple old historic photos of miners at these old dolomite quarries. 

 Some of that dolomite was used to make cement by burning it in kilns. And so there are few historic lime kilns around where they would take the dolomite or limestone, grind it up, and burn it, and that changes it into a material they can make cement out of. So here is a park at Grafton, Wisconsin where these old lime kilns are. And you can go up to Door County or up the Door Peninsula and find other old historic kilns. But this gives me a chance to transition to talk about eastern Wisconsin and the Niagara Escarpment. And, again, so here's a map of eastern Wisconsin. Again, we see many little red triangles, each of which is an interesting geological spot. Again, worth a visit. So the Niagara Escarpment is this dolomite formation of Silurian age. We call it, generally, the Niagara dolomite or the Niagara Escarpment that goes up to the Door Peninsula and forms that peninsula and actually wraps around the Michigan basin to form Niagara Falls. If you've ever been to Niagara Falls, you're looking at the same rocks that you are in the Door Peninsula. And the way, why that forms is that we, you can see on the right of this slide, the eastern part of the state, the rocks are dipping down toward Lake Michigan. The Niagara formation, the Silurian rocks are a little bit more resistant, and so when they erode, they form this escarpment on the western side. And then this is called the dip slope that goes to the east And what we get from that are these high cliffs that you see in Door County. This is near Fish Creek off of Peninsula State Park, actually near Ephraim in Door County. See these high cliffs of Silurian aged dolomite. And if you go to the other side of the county, the Lake Michigan side, you see lower cliffs. This is Cave Point County Park in Door County. Both fantastic places to visit, by the way. But this is why the cliffs on the eastern side are lower because the dip of the rocks is from west to east. And where do these rocks come from? Well these rocks, these are dolomites and limestones that are made up of the tiny bodies of millions and billions of little sea creatures that flourished in a shallow tropical sea. And much of it was a reef environment, like we might find in the Bahamas or off of Florida today. And so when we look at those rocks, we often find fossils. So the Silurian Sea may have looked something like this. A shallow, warm kind of tropical sea with all these different creatures that lived back in Silurian time 400 million years ago. We know those are there because today we can find fossils. We find, these are brachiopods. These are the same kind of things I used to find when I was a kid in Indiana. Although we didn't find any trilobites there. And mine were better sometimes. But we find brachiopods. These are corals. This is a trilobite. This is our state fossil, by the way. And these are stromatoporoids. They're a very primitive kind of animal.  These can be found in these rocks. I mentioned quarrying. So now if you go to Potawatomi State Park, which is just south of Sturgeon Bay, and climb up on the lookout tower and look across the bay, you can see this big quarry, and it's actually called the Big Quarry. This was an historic quarry that's now a county park where they quarried these big blocks of dolomite, and they would load them onto ships that would come into the harbor here. And those would be shipped down to Chicago, shipped to the cities in the south, shipped all over the Great Lakes because this rock was such a good building stone. And it could be crushed and used for roads and many things. So this was a huge industry in Door County and other places up along, up and down the coast where transportation was easy because you had shipping and the rock was plentiful. And so now that's been turned into a park. And by the way, they still, not so much in Door County, but other quarries in eastern Wisconsin are still producing a lot of this dimension stone that's getting shipped all over the United States. I was in a quarry near Chilton a year or two ago, and they were taking big blocks. They were getting shipped to Houston, Texas, of all things to be used as breakwaters. So, you know, pretty expensive thing to do.  As long as you're in Potawatomi State Park, you got to take a look around and enjoy the fall weather. But while you're there, you'll notice the eastern terminus of the Ice Age Scenic Trail. And so now I'm going to transition to talk a little bit about our Ice Age geology. So the Ice Age Scenic Trail is a hiking trail that starts up here at Potawatomi State Park, wraps around the glacial boundary, and ends up at Interstate Park, which was my first slide. So this is the glacial boundary of Wisconsin. And many of you have probably seen a diagram like this. It shows you what the Laurentide Ice Sheet did between 100,000 and about 10,000 years ago. One of the things it did is it damned up Glacial Lake Wisconsin, and it didn't get down to the driftless area down here, which is why we have a different topography down there. But when you see pictures like this, and this is what you often see in textbooks, you kind of get the idea that that's what it looked like, and the ice was either here or it wasn't here. And it was either here or it was gone, and you don't really get the dynamics of this system. So our survey has recently done something to help educate people better about what actually happened. And so this is a little video that was made by our State Geological Survey. The authors are Dave Michelson and John Attig again, two retired geologists that are still active. And so what they've done here is put together a series of maps in kind of a time sequence. And so what you're going to see here, and it takes about a minute or less to run through this, is on the left a map of Wisconsin with ice coming and going and on the right here you're going to see how many years ago it was. And it goes kind of quickly, and I might even show it twice. But as you watch it, keep in mind where the ice was, and look at these lakes that are damned up in front of the ice. And here's Lake Michigan down here and Lake Superior. And just see how that happened. So let's just watch this and get a sense of the dynamics of the Pleistocene, the Quaternary here. You can see how it wasn't all one thing, and it didn't happen all at once. It happened in a number of pulses over different times. And over tens of thousands of years.  And I think this gives you a sense that the ice was not stagnant. It was moving around. It was retreating during warm periods and almost going away and then coming back. And the time, sometimes things happened fast, sometimes rather slowly.  What I'm going to do, I'm going to show part of that again just to give you a-- And I'm going to stop and I'm going to point out a couple of things in case you missed it. Come on. Because one of the things, I think it's interesting to look at these glacial lakes. And you know that the land, in central Wisconsin we have a big sand plain, and that is Glacial Lake Wisconsin, which was damned when the ice hit the edge of the Baraboo hills right there. Now we have a lake. And suddenly it's going to drain. And when that lake drained, what happened? It drains when this ice leaves it right there, and what happened then? It carved the Wisconsin Dells. That's where the Wisconsin Dells formed from the drainage of that lake and the erosion of all that water going down the Wisconsin River at that time. And then there was another lake that formed east of there that was Glacial Lake Oshkosh. And that's why, if you go over toward Oshkosh or Outagamie County, you have a lot of low, flat-lying, clay material there. How do we know about the glaciers? Well, we see features like this. These are glacial scratches on some of that soft dolomite. And so we geologists can look at these and tell which direction the ice came from. And that gives me a chance to talk about some of the great glacial features we have here over in the kettle moraine, over near West Bend, Washington County, and Waukesha and parts of Milwaukee County, where we have world class glacial topography. These are drumlins, sculpted features on the landscape from the ice sheet passing over that's rearranged the topography and kind of sculpted it. Here it is in summer. Here's a drumlin field in the winter. And these are world class. Pictures of Wisconsin drumlins are in textbooks all over the world because this is world class. And you can get a sense for this, of the dynamics of the ice moving over there. And, of course, as the ice retreated, it left behind deposits. And these are-- This is a diagram of how the Interlobate Kettle Moraine formed as a lobe of ice came from Lake Michigan and a lobe came from Green Bay, and where they met, they left a plain of collapsed outwash. Meaning there was ice in there that melted and left this collapsed topography and left a lot of other features. And that's what we call the kettle moraine now. Another great place to visit, and what you see here is this sinuous hill is an esker. This was a river that flowed on top of the glacier. When the glacier melted, all the sand and gravel fell down, collapsed, and formed this long, narrow, circuitous hill.  I wanna switch now and talk about water a little bit because we have a great heritage of water. Wisconsin has abundant-- Well, you know, we're a water-rich state, and that had a lot to do with settlement, why people wanted to live here. Availability of water was critical to development and settlement, agriculture and industry. And remember that all water, particularly groundwater, which is my expertise, is part of the water cycle, and it all starts as rain or snow on the landscape. Much of it runs off and becomes surface water and goes into lakes, streams, or wetlands. Some of it recharges and becomes part of the groundwater system. We have great aquifers here. An aquifer is just a geologic unit that can transmit or hold or store useful quantities of water. Groundwater flow can go short distances, just from the infiltration to this lake, or it can go very long distances and discharge into a river, like the Wisconsin River or Lake Michigan. And groundwater sustains our lakes, springs and wetlands. This is the Mink River estuary up at the tip of Door County. Another great place to visit. It's there because of Lake Michigan, but these are springs in the estuary that are there because of groundwater. Groundwater flows through aquifers, and the geology I've been talking about forms these aquifers. And so in the northern part of the state we have these Precambrian rocks that are things like granites and rhyolites and quartzites and you can see some of those rocks if you go to the dells of the Eau Claire River. Those are rhyolites there. The sandstone aquifer that I mentioned, the sandstones that occur in southern Wisconsin form a great sandstone aquifer. And you can see those sandstones if you go to the Dells and go on the boat trip. Those are some of the sandstones, Cambrian sandstones you can see there. And then we have the dolomite aquifer that you can see in outcrops over in eastern Wisconsin. All these are really good aquifers that supply cities, villages, industries. I like to show people this slide to give you a sense of relative depths. So this is to give you a sense of where these aquifers are beneath our feet. So this is a view of Milwaukee taken from the lake, if you're out on a boat in Lake Michigan, with the geology pretty much to scale. This is to scale. So the tallest buildings in Milwaukee are about 600 feet high. And the typical domestic well in Wisconsin, like a well I have in my house south of Madison here, is between 100 and 300 feet deep, or about half as deep as the tallest building in Milwaukee. Many of the municipal wells, like the wells we have here in Madison where we get the municipal water supply, are between 200 and 800 or perhaps 1,000 feet deep, and they're reaching down to this sandstone aquifer where it occurs. However, the deepest wells in the state, which are mostly over in eastern Wisconsin near Milwaukee and Waukesha, get down to over 2,000 feet deep. Think of that compared to the tallest building in Milwaukee next time you're there. We're looking at something that's three, three or possibly four times as deep as that building is tall. And some of these wells are a hundred years old. So imagine the effort that went into drilling them a hundred years ago, and the public infrastructure value that they have now. I think it's just an interesting thing to consider that these are hidden infrastructures that are really important to us. I mentioned I've been talking about bedrock aquifers, but we also have, because of the glaciers, we have this sand and gravel aquifer over parts of the state, much of the state, that composes a shallow aquifer. And much of it is along river valleys. Up north I've shown all this is sand and gravel, but some of it yields better or more water than other places. Here's an example of how that sand and gravel looks near West Bend. But that sand and gravel, which was formed, for example, in Glacial Lake Oshkosh, forms a great shallow aquifer that's in the central sand plains that supports our potato and vegetable industry, and supports a lot of irrigation. And so it's  Groundwater discharge has been a really culturally important thing in Wisconsin. And, historically, we had a lot of artesian or flowing wells that flow under natural artesian pressure. This was one in Door County that I took a photo of a number of years ago. These were often the places, reasons people located homes or houses or villages in certain places.  This is an interesting picture of a flowing well in De Pere in 1890. And you can see the water here is flowing up at this level. It's flowing like 30 feet in the air in downtown De Pere. You can see the guy in his raincoat standing below and all the people excited. This is like one of those oil well gushers you see in Texas. But the artesian head or the artesian pressure historically was way above the land surface in eastern Wisconsin. Since we've developed and started drilling wells and pumping water, that artesian head has diminished, and the wells don't flow there anymore. But, historically, that was a pretty big deal. Imagine just drilling a well and then the water just flows under its own pressure. You don't even need a pump.  And that leads me to talk a little bit about springs. We have over 10,000 mapped springs in Wisconsin. And we're studying them now. We're trying to map them more. I'll talk about that in a minute. They've historically been really important as for settlement, for locating villages and industries, and also as an industry of bottled water. So here's bottled water being consumed at the Bethesda Spring in Waukesha County. Waukesha, in fact, was called the Spring City. That's its nickname because it had so many springs. It was known as the Saratoga of the Midwest after Saratoga Springs, New York, which is famous for its springs. People traveled from all over the Midwest to come to Waukesha to drink the water or bathe in the water. Unfortunately a lot of those springs are no longer there. They've been destroyed or drained or built over, which is unfortunate. We have a rich history there.  Our relationships with Illinois has not always been great. Prior to the 1893 Chicago World's Fair, there was a scheme to pipe water from Waukesha down to Chicago to serve the World's Fair. And there was almost a riot because it was opposed by people in Waukesha County. And in fact here's a political cartoon showing the Chicago-- It says "Waukesha frightening away the Chicago hog." And Chicago is represented as a hog trying to drink out of the Waukesha spring. And I guess these are all local politicians trying to shoot it or beat it up or hold it back. And things never changed because during that time there was actually a protest train that came to Madison. You can see it says "No pipeline." If you can't read it, the caption of this, this was in 1893, the caption says, "Special Waukesha train to Madison "to fight granting a franchise "to pipe the Hygeia Spring water to Chicago." So things, political protest in Madison is nothing new, apparently. Nor are schemes to pipe things different places. Here's an interesting photo that I really like. This is what we call the Big Spring at Donald Park right here in Dane County over by the town of Mount Vernon. Historical photo where the town turned out with a brass band, everybody in their Sunday best. I think there's even a choir over here, to assemble around the spring for a town picture. And that, you can still go there now. There's no brass band today, but it's a wonderful place to visit. There's a little park there called Donald Park, and there's a nice hiking trail. It's a great place to visit. It's one of the biggest springs in Dane County. And we are doing a statewide spring survey now, and I thought I'd kind of wind up with this little video just showing you some nice artesian flow in a spring. Now this happens to be in Cadiz Springs in Green County. The person that took this picture is named Grace Graham. She's one of our employees at the Survey. And this leads me to talk about what our Survey does. One of the things we're doing right now is a survey of all the springs in the state because that hasn't been done for almost 50 or 60 years. 

 So, what are the other things we do at the survey? Well, we do lots of things. I know you can't read all this, but we work on geologic studies. Last year we had projects in all 72 counties, which is pretty good for a staff of about 25. We collected over 2,000 feet of rock quarry with our drill rig. We looked at over 153 groundwater monitoring wells. We maintained a core repository of-- It's got over 600,000 feet of rock core out at a facility we have in Mount Horeb. We have thin sections of rock. We have water well cuttings. We do many projects, like we're working on the St. Croix Waterway. We're working in the driftless area. We're working on many Wisconsin counties. We have all these pages of field notes, thin sections. People download publications. We had over 24,000 publications downloaded from our website last year. We had over 14,000 educational contacts. We're on Facebook and Twitter thanks to Carol McCartney over there. We do groundwater models. We study different parts of the state. We study water quality. We study geologic history. It's an exciting place to work, and I'm so proud of our staff. If you want to know more about us, take a look at our website. Here's the address. One of the things you can do if you go there, is you can search for publications about Wisconsin. You can search by area of the state, you can search by topic, you can search by author or type of publication. So there's a lot of information there that changes all the time. So to wind up my talk, geology has had profound influences on our culture, our past, present, and our future. Wisconsin's a great place to study geology, and it's a great place to be a geologist. So I would like to urge all of you to take advantage of the opportunities that we have here to appreciate our geo heritage and get out and look at some of these features. So, thank you very much.  [audience applauds]    I'm Tom Zinnen.