University Place  Patrick McLaughlin The Phosphate Crisis in Agriculture  January 16, 2013 UP824   cc >> Welcome, everyone, to Wednesday Nite at 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 sponsors, the Wisconsin Public Television, Wisconsin Alumni Association, and the UW Madison Science Alliance, thanks for coming to Wednesday Nite at the Lab. We do this every Wednesday night, 50 times a year. Tonight, it's my pleasure to introduce to you Patrick McLaughlin. This is probably the third or fourth time Patrick has given a talk here at Wednesday Nite at the Lab. It's a joy to have him back. He's a geologist with the Wisconsin Geological and Natural History Survey which is also part of Cooperative Extension, UW Extension. He is an assistant professor in the Department of Environmental Sciences and an affiliate faculty member through the Department of Geosciences here at UW Madison. 

Patrick received his MS and PhD degree from the University of Cincinnati, where his graduate studies focused on sedimentary architecture of marine rocks in eastern North America. His current research focus is on sedimentary geology of the Paleozoic rocks of Wisconsin and surrounding regions, including sedimentary ore deposits, groundwater transport and contamination, and the context of the fossil record. Tonight we get to talk about something that's near and dear to all of us who like to grow gardens or crops, and that's phosphorus, phosphorus in soil and where are we going to get more phosphorus in soil because not only are we running out of things like petroleum but there's this whole event called peak phosphorus. There's a time in the near future where we think the production of phosphorus out of mines will peak. Where are we going to find more? What are we going to do about that because it's pretty important to maintain the fertilities of our soils, and one of the big deals in that is phosphorus. I'm looking forward to hearing what Patrick has to say about that. Please join me in welcoming Patrick back to Wednesday Nite at the Lab. [APPLAUSE] >> Thank you. Thanks for coming out on a fairly beautiful January evening in Wisconsin. So, as Tom said, I'm going to be speaking to you today about phosphorus and a thing called peak phosphorus and this idea that we're running out of, or the fact that we're running out of phosphorus, at least as we've known it, and oil and gas reserves as well is really a consequence of the continued rapid global expansion of people on the planet. 

We continue to tap and utilize, in some cases increasingly rapidly, more and more of our resources and put stress on natural systems. So, what the charts or what the graphs are showing again is the idea of peak oil. So, on the X axis here we have time from some point in the past, nearing the onset of the Industrial Revolution, to some point in the future. Production here in terms of millions of barrels of oil. And historically seeing a very rapid increase in the production, again associated with the Industrial Revolution, taking us up into the present. And then based on knowledge of proven reserves, seeing some peak very near in the future, and then a rapid, potentially a very rapid decline as the need and as the utilization continues but the supply dwindles. And a lot of folks are cued into that. You've heard of peak oil before, but what you may not have heard of is this idea of peak phosphorus. Again, as Tom said, phosphorus, one of the key nutrients for growing green plants. Also important for just about all living things. 

And it's used very heavily in agriculture, especially since the industrialization of agriculture. We've seen a change in the types or where we source our phosphorus and the rate at which it's used. And, as you can see, the timing here is very similar to that for oil. The timeline is a little bit different, but, basically, from the early 1900s in the Industrial Revolution, especially in the 1950s, and I'll talk about why that rate is so steep there, there's been a very rapid increase in the production of phosphorus with a peak that's in the very near future anticipated. Now, there's some caveats to this, and we're going to get into it because if you get into the literature of peak phosphorus, it's not as clear cut in a lot of people's minds as peak oil. So, in part it has to do with limited knowledge about just what our phosphate reserves are out there. You have vast armies of geologists scouring the globe looking for every last little drop of oil and gas, and then there's me. [LAUGHTER] Studying phosphorus. No, it's not quite that bad, but in a relative sense, there are very few people, there's a lot of question marks out there about just how much phosphorus is out there. How much can we tap into? A recent Nature paper was letters in Nature. 

The author was a financier, and he was saying, hey, scientists, speak up. Phosphorus, this is a big issue. Global climate change, the oil and gas, peak in oil and gas production, and phosphorus. These are three things that are going to transform how we do things on the planet. As human beings and scientists, you need to speak up, and the rebuttal was, pleh, phosphorus. There's half a one-millionth in the crust. There's .5 PPM, parts per million, in the crust. There's tons of phosphorus out there. But you'd have to quarry a lot of rock to concentrate enough of that to make it useful. So, that's a little foreshadowing here. 

So, we'll move into it. You might be, as Wisconsin folks, you might familiar with the phosphorus issue from kind of the other end. Where does the phosphorus go and how does it mess with natural systems? A lot of study going on on UW campus, the lake center, folks are looking at the effects of phosphorus nitrification and eutrophication of freshwater bodies. Phosphorus in many systems is kind of the limiting nutrient. So introduce some phosphorus and you're going to get some plant growth, and we see that in our lakes. We get these regular algal blooms every spring/early summer as the runoff from fields transports phosphorus into our bodies of water. It doesn't stop there, though. A lot of it bypasses these systems, eventually makes its way into the ocean. The research suggests something like three times pre-industrial levels for the amount of phosphorus entering the ocean place havoc with coastal ecosystems. Coral reefs don't like nutrients. 

They're oligotrophic. They like very low nutrient systems. They like sunlight, and they get all the things they need from their photoautotrophs, the green plants that live within their selves. Add nutrients and then the algae in the surface water goes crazy. So you get these algal blooms. It cuts out the light, smothers the corals, lots of organic matter being decomposed. You get blooms of bacteria. We see that even our lakes here. So you get disease and virus and it's a mess. So there's a real environmental impact and typically, when it goes unchecked, a negative one associated with phosphorus. 

But, of course, it's there and it's running off because it's a kind of keystone element in our industrialized agriculture processes. It is the foundation of what's been called the green revolution. And that is the huge increase in food production we've seen since the 1950s. Really since the industrialization of agriculture. Going from the times they said don't plant those fields, we're trying to keep the economics of food in check, to plant everything, and we're going to go at this from an industrialized scale. And, again, the keystone of that has been phosphorus. So the production of phosphorus had to ramp up in equilibrium with that mechanization of agriculture to make it work. But, because of that, the production of phosphorus as we've known it is changing. Okay? So, let's just move on. Well, let me just point out this graph here. 

So this is from a recent study by Ashley et al kind of showing historic production of phosphorus. So, originally, phosphorus in megatons from 1800 to 2010. Initially, manure. Basically, this is old school recycling. The plants take up phosphorus out of the soil, the animals eat the plants, and then they return the phosphorus to the ground. Spread it on you field and you haven't lost much phosphorus. Of course, some of it's taken up by their bones, so what did they do? They burnt the bones as another source of phosphorus. For a while guano on Pacific and Caribbean islands was mined heavily, pretty much taking those islands right down to sea level in some cases. Human excrete is in there but always kind of a small contribution and looks to remain so. But you see starting in the late 1800s into the the mid-1900s, and then again a big change around 1950 is phosphate rock. 

So this is the dominate source of phosphorus today, mined from phosphate rock or what we geologists call phosphorite. And when I sent this talk title and description over to Tom, we got some feedback, and somebody said, hey, you should look at a paper from 1909 by Charles Van Hise, former president of UW Madison, where he argues for conservation of the soil. Again, so this is 1909, just to put this into perspective. Here was the production of phosphorus at that time, and Van Hise is making the argument for the conservation of the soil. At that time, soil conservation was not really being practiced. Huge amounts of runoff, massive amounts of transport of phosphorus-rich topsoil into the ocean, and the degradation of soils locally. And Van Hise was saying, hey, potassium we can get in a superabundant in potassium chloride, potash, there's huge deposits. If those run out, you can get it out of fine grain, siliciclastics out of shale deposits. It's, in percent level, no problem. There's lot of potassium. 

Nitrogen we know we just rotate our crops, put in some legumes. We can fix nitrogen from the atmosphere which is mostly nitrogen, 78% nitrogen. No problem. The third vital nutrient that you've got to have for plant growth, though, is phosphorus, and it comes from the rocks and it's nonrenewable, it's essential, and we have to conserve our soil because of the loss of that one nutrient: phosphorus. Now, in 1909 they were already mining, in the US, phosphate rock. This little bit here. It's equated to about 2.5 million tons of phosphate mining each year, and a lot of that, at that time, and we'll contrast this in a little bit, at that time was being exported to Europe because they had exhausted their resources there. So early on, we were a major exporter of phosphorus through the mining of phosphate rock. So, to answer the last question,  why should Wisconsin care? Why should everybody care about phosphorus? It's because it's tied directly to out socioeconomic health. Of course, more than 35% of Wisconsin's agricultural land. 

So, if you're growing, you need phosphorus. So if you're a farmer, you're really concerned with the availability of phosphorus and, more importantly, the price of phosphorus because that controls how much your fertilizer costs. Increase the demand or keep the demand steady and decrease the supply of phosphorus, the price of fertilizer goes up, and that gets passed on then to the consumer. And if you look at this plot here, this is just for the last 20 years or so, showing the price of phosphate in US dollars per ton versus the food price index. And you see that they track pretty closely. In 2007-2008, there was a spike in the price of phosphorus. It's debated exactly why. China, a major producer of phosphorus, maybe was holding back on some of the supply. There were other issues. There were some oil and gas issues at the time. 

But the bottom line is spike in cost of phosphorus immediately resulted in a spike in the price of food globally. This sparked riots in over 30 countries around the world. And in many third world countries this meant the difference between being able to buy food and not having enough money to buy food. So it's a really important issue, and here at home, too, we saw the cost of food go up. So where do we get phosphate from in the US? How much do we have? Is it really running out? Is it all mineable in equal proportion, or does it vary? Well, if you go to the literature and you look, this is what it looks like globally, the picture globally. Phosphates being mined from primarily three different sources. Igneous rocks where phosphate typically is in low proportion, but there are some things called carbonatites and other deposits where you can find phosphorus in relatively high proportion. Although, they tend to be spatially restricted so they're not big deposits. Sedimentary deposits which are layers and typically cover a fair bit of real estate. And then island deposits, and these are the guano deposits that have been heavily mined already. 

In the US, the phosphate rock mining is restricted to about 12 mines is all. So all our phosphate rock that's being mined, remember that plot way back where it shows this huge mountain of phosphate produced is coming from phosphate rocks, it's coming from 12 places in the US. Primarily, Florida, North Carolina area. So, down in here. Tennessee. And then out in the Idaho/Wyoming area and down into Utah. Most of the mining is happening in Florida. This was true in Van Hise's day. Van Hise, in that 1909 paper, said 1909, in 25 years the major deposits of phosphorus in Florida will be mined out. They're still mining. 

Is it good? That's what we set out to see. So I, and I'll go into this in a minute, but I'm going to report shortly in the talk on some work that the Wisconsin Geological Survey is doing in collaboration with the USGS. But that was the big question on a lot of people's minds. If you go into the literature on phosphate, this is what you see. A bunch of question marks. How much is out there? How good is it? Who's got it? Globally, Morocco is referred to as the Saudi Arabia of phosphate. They've got a lot of phosphate. They've got a lot of phosphate. The whole Middle East, not only is most of it wealthy in oil and gas, or at least they were, but also in phosphate. The two aren't related, really, at least in terms of the age of those deposits and the environments in which they formed. 

Lucky coincidence.  So, what I'm going to report on is kind of the beginning of a new US Geological Survey initiative to kind of take a national scale assessment of our phosphorus resources. Are we really facing peak phosphorus? Is the end of phosphate production really looming? If so, what will we do? If it's not, where is the phosphate going to come from? What are those deposits that need to be mined? Let me go back to this for a minute. Right now, again, most of the production is coming out of Florida. The primary company down there is Mosaic, and they have most of the mines, they have most of the beneficiation facilities where they're separating the ore from the waste rock, and the processing plants where they're taking the ore and changing it into a product that can then be combined with other elements to create fertilizer. I think they're IMC Chemical. Anybody familiar with them? They're up here in Wisconsin. One of their local distributors or regional distributors. Florida real estate is part of our lives here in Wisconsin. That's where, until recently, about 90% or greater of US phosphorus was coming from what's from the Florida phosphate district. 

Increasingly, phosphate rock that's being processed in the US is coming from Morocco. So, Mosaic or their partners have holdings in Morocco, barge it to the US to the processing facilities. Morocco and China have multiple processing facilities currently under development so that they can do more of their own processing. So that takes us into kind of the global view. Again, in part, of course, it's resources. There's political implications to this. National security, the US is the leading importer now of phosphate rock in the world. How it's changed since Van Hise's day. We went from the largest exporter to the largest importer in about a century. And global phosphate mining, again, is projected to increase by about 20% in the next few years really, actually, when this data was put out. 

Where's that coming from? If you look at this plot over here from USGS data, most of the production is coming out of China. Pick a resource, any geologic resource and you'll get the same answer. Most of the production is coming out of China right now. Here's Morocco. Again, the Saudi Arabia of phosphate coming in at number two. And depending on the statistics you look at, this varies a little bit, where the US sits in this, how big the numbers are because this is world phosphate rock reserves. So there's a difference between reserves and resources. Reserves are kind of proven. They've gone out, they've done some tests, they've tried to map out the distribution of those phosphate rocks, they've done some analysis to see how enriched they are in phosphorus. So they've tried to calculate how much is there that we could actually mine. 

Versus resources which is just kind of like, yeah, some geologist said that there's this much out there, but we don't really know. So you'll hear those two terms kind of conflated a lot, reserves and resources. So, again, one of the questions we wanted to test was, is this accurate? Are the reserves in the US really this small? This is largely based on where the production is now, and that's Florida and Idaho, primarily. So, we're producing phosphorus, is any of it being recycled? Well, depends on your definition of recycling. Are they trying to catch the phosphorus as it runs off the land and reapply it to the fields? Typically not. Although, there is again the application of manure which is a type of recycling of phosphorus. Government stockpile at this current time: zero. There's no surplus. There's no stockpile. So, again, China decides, hey, we think we need to hold on to our phosphorus right now, we're having a big agricultural boom here, we want to make sure we have enough. 

Okay, what are all those agricultural producers going to do in the US who are now relying on Chinese phosphorus or Moroccan phosphorus? So, understandably, the government's concerned about this. And, again, just another graph showing some other numbers that, again, this is production so this upper graph is reserves. How much potentially is out there, somewhat proven. Down here is production. How much is actually being mined right now.  And so here, you can see right now, China's way up there. Morocco and the US are about even, but, again, Morocco has huge reserves that are relatively untapped still. And, again, they're somewhat dependent on their processing facilities coming online. And right now, again, mostly it's being barged over to the US. So, why did I get involved? I hate to admit this in a room full of Minnesotans, but I'm from Illinois. 

[LAUGHTER] I'm from Illinois. I'm up here in Wisconsin. The one thing I share with Wisconsin natives is I come from mostly an agricultural state. Illinois, probably more than any other state in terms of ground covered by corn and soybeans, is dependent on phosphorus. My graduate studies, I focused a lot on, as Tom said, the stratigraphic architecture of marine rocks. What does that mean? It means how are they stacked up? Where do they come from? What were the environments that they represent? In part, I was really interested in what they call chemical sedimentary rocks. Rocks that kind of precipitate out of sea water. They're kind of capturing, in part, what the composition of sea water was at that time. You can learn a lot about changes in ocean composition through time by looking at those rocks. And I've created some plots where I tried to capture all the different types of chemical sedimentary rocks and the kind of environments in which they are found and the estimates on the duration over which they formed. 

And you can see this giant balloon here is phosphorite. So that's rock phosphate. It was a major interest of mine. As I come to the Wisconsin Survey more and more, I got interested in trying to bridge, the last talk I gave at Wednesday Nite at the Lab, trying to bridge generating the climate and oceanographic records from deep time, from rocks hundreds of millions of years old, many of them right here in Wisconsin, to trying to understand how the ocean climate system changed through time, it's interactions with life on Earth, and how there were feedbacks between the rocks and forming rocks. It basically boils down to the cycling of carbon, phosphorus, and iron to control a lot of those dynamics. So, I had a collaborator on some other projects at the USGS, and he said, hey, this is an important issue, why don't we pick this up. Great for us and great for me. We have some phosphate deposits right here in Wisconsin that stretch over into Iowa. And opportunity to look at our phosphate here, try and understand how it fits into the national picture in terms of our phosphate reserves. An opportunity to take really sound fundamental geological techniques, mapping, lithological, sedimentological, work, stratigraphy, the study of the layering of rocks, and combine it with some really cutting-edge, highly technical analytical infrastructure that the USGS has in their Minerals Resource team over in Denver. 

So, the goals of the contract that we won with the USGS, two-year contract. First was to compile everything that's been written about these deposits in the US. Make sure that we know the full breadth of these things. How many are there? Where are they? What do people know? The second goal, and that's where I came in because I'm a field geologist, was get out there and actually sample these materials. So, call colleagues down at the Florida Geological Survey. Hey, do you have materials in this stuff? I know they're out there strip mining this stuff. You have cores, drill cores through it where you've actually brought up the material in your repository? Again, Florida has really been the main producer. So that was critical. They're still the primary producer. The other was to contact folks out in Idaho, Wyoming, to go out and look at materials from that phosphate district, which are much older. 

So, the phosphate-bearing rocks, or, really, sediments, of Florida are only about five million years old. Now, there are some other phosphate deposits kind of sitting underneath those that stretch back to 10-15 million years ago. Blink of an eye for somebody like me. I deal in hundreds of millions of years. It's always kind of a trip talking to geologists. We love to just throw around huge numbers of geologic time. The key is that those Florida deposits, especially the ones they're really mining, and I'll show you some pictures, it's not rock. It's basically sediment, and that's the key to the economics of the Florida deposits. You don't have to go bust up a bunch of rock. You don't have to use explosives and huge loaders and dump trucks and crushers, which is the typical operation for, say, crushing stone. 

It's sediment. You just strip it off. You just go out with a big drag line and you strip it off and it's really economical and you can, just by using giant sieves, just giant shakers with screens, you can concentrate the phosphate to really nice, economic levels. So that beneficiation process of separating the waste from the ore. We also went out and looked at the secondary deposits. Let me back up, yeah, to this. So, there was a USGS study back in 2002. Primarily, it was a literature study where they've said we've kind of scoured the literature, at least to their satisfaction, and we found this five, six, seven, eight primary phosphate deposits. They've either been mined in the past, people have talked about mining, they're at concentrations that are high enough that they could be mined. So, again, that was the Hawthorne group in Florida, which are these very young sediments and sedimentary rocks, mostly carbonates. 

So, CaCO3, calcium carbonate. Mostly the shells of marine organisms. The Phosphoria Formation. You know it's got phosphate, right? With a name like Phosphoria. That is Permian aged. So it's about 260 million years old, let's say. The Monterey Formation, interestingly, just about the same size as the, sorry, just about the same age as the Hawthorne group in Florida. Closer to home, the Maquoketa group. Now we're getting into really old rocks. These are rocks that are about 440 million years old. 

The Maquoketa group, that's what's pictured here. All these little circular things are phosphate granules and pebbles. And even some worked on how these things formed from looking at the local rocks by our colleagues over in Iowa. Similar aged deposits, Ordovician, again, about 44-50 years old, down in Tennessee. These things have been mined, especially in big sink holes where you've dissolved away the limestone rock and left a residuum. The residuum was typically, in those rocks, highly enriched in phosphate. And then, getting really old, 1.8-billion-year-old rocks of the Ironwood formation and associated in northern Wisconsin. Now, if you listen to the news, and especially the governor, there's a lot of interest in those rocks. This is the Gogebic Range in northern Wisconsin. Not only is it full of iron, to differing extents, but also there is some phosphate in those rocks and in their lateral equivalents and rocks that sit on top of them up into the upper peninsula of Michigan. 

So, a fantastic opportunity to take a look at a broad swath of rocks from five million to 1.8 billion years old across the country. And to finally, then, kind of test the models about how these phosphate enriched rocks formed. These are all marine rocks. Okay? So we're specifically looking at phosphate or phosphorus-rich sedimentary rocks that formed in marine environments. So, again, we're doing this work as contract work in collaboration with the US Geologic Survey, in particular the Minerals Resource team. They have the cutting-edge, state of the art analytical facilities and fantastic for this type of world and world-class scientists to collaborate. So it's a fantastic opportunity. Why did they pick us? In addition to my experience, we have these known deposits in the region, these phosphate-rich rocks of southwestern Wisconsin and into the Dubuque area around Iowa. A little self-promotion here, the Wisconsin Geological and Natural History Survey is kind of, not only are we geologists and hydrogeologists that work throughout this state and kind of keepers of knowledge about the geology of the state, but also we're keeper of rock samples from around the state. So we have a facility out in Mount Horeb that is kind of a rock library from around the state. 

We have about 600,000 linear feet of drill core. So these rock cylinders that are drilled out of the ground that either we've taken and sampled ourselves or that were donated to us from private industry or other state agencies like DNR. And we have the ability to strategically sample that as we have our own drill rig where we can say, hey, there's a need to collect samples over here, there's not existing samples, we can go collect those samples. All that was critical to being able to actually carry out the work of this contract, and the work is on-going. We're just into the second year of the two-year project. So, a little bit more here to wrap up. Just about, specifically, what these places look like, what the rocks and the sediments look like, what's kind of going on in these different mining sectors, and a bit of wrap-up. So, Florida. The Florida phosphate district is primarily restricted to the area just east of Tampa. So, these rocks, the primary deposit is called the Bone Valley Member, and it's called the Bone Valley Member because the premiere deposits of Miocene/Pliocene age, again about five million years old, were truly bone deposits. 

These were channel fills that were full of the bones of vertebrates, vertebrate animals, mostly mammals, from about five million years ago when sea level was low, channels cut their way through. The animals were concentrated in places, their bones were anyhow. Swept off the landscape, concentrated in fluvial channels, in river deposits, and then, at least the theory goes, enriched in phosphate. Of course, bone is appetite. It's phosphate-rich mineral. And then when the seas came up and the sea water chemistry was such that it contained a lot of phosphorus, that bone nucleated even more phosphate. Again, Van Hise was, in part, right. Mostly those deposits are gone. What you see down there now is that they're reworking some of the old tailings. In some cases, they are going after lower quality deposits. 

Here, you see a huge drag line. So this is, basically, a humongous giant crane. If you've even been to central Illinois, you've see the giant holes these things can make. It's the same kind of thing they use a lot in strip mining for coal. Basically, it's just what it sounds like. It's a giant bucket that they drag, using a line, across the landscape. We were told by some of the old timers down there, yeah, you know, I used to be a geologist in one of these pits and we'd walk out with a can of fluorescent spray paint. You walk along and you spray underneath the horizon that they need to strip off. Then they come, strip that, and, again, mechanically separate it. Turns out that there's only typically about 3% phosphate in these rocks. 

That doesn't even qualify as phosphorite which is greater than 12%. But, because it's mostly sediment still and not lithified into hard rock, you don't have to crush it. You can just strip it off. Again, mechanically separate the ore from the waste, and now you've got a product that's 30% or greater in phosphate. So, it's very economical in that way. One of the largest industries in Florida, besides tourism, you've got phosphate mining. And Florida is really dependent on it, and so they're not happy to see it fail. The problem, primarily, and one that Van Hise never envisioned, is that the sprawl from Tampa is developing the land over the top of the phosphate deposits. So, it's not that they've mined away all the phosphate, it's they can't get to it. And in some cases, the folks down at the Florida Geological Survey were telling us about incidences where word got out that Mosaic was buying a $250,000 home to bulldoze it so they could strip the land it was sitting on if they had some kind of information that there was an especially enriched deposit underneath. 

So the issue really with the Florida phosphate market, in part, is one of development. It's political. It's weighing the influence of the developers versus the phosphate industry. However, again, it also boils down to the availability of the phosphate in those unconsolidated sediments. So the stuff that isn't rock. There's a lot more phosphate underneath it, but it's in rock. So, if they're going to continue mine down there, which they have this huge industry set up, everything's in place, the infrastructure is all there which makes it very economical, they're going to have to start crushing rock. I could tell you, we sample the heck out of that stuff, and it's not that hard. You didn't have to hit it very hard with a hammer to get it to explode. So, anyhow, that's the situation in Florida. 

So, part of the peak of peak phosphorus, this is kind of the crux of the thing, and you'll hear more about this in the next slides, but it's especially pertinent because so much of our phosphorus, so much of that peak is dependent on Florida. It's really about the availability of phosphorus in those sediments. So, peak phosphorus is really a peak of easily available phosphorus. Phosphorus as we've known it. Cheap, readily available. It's cheap because it's easily separated, easily processed and concentrated. If you're going to start busting up rock or dissolving rock, now it's a lot more expense involved. And there may be other stuff in there that you then have to deal with as well, especially if you're dissolving it, then maybe you're dissolving some of what was typically separated out as waste, and then you have to take more steps to concentrate it. So, it's an issue of economics. The peak is about economics. 

Phosphorus as we know it is peaking. There is more phosphate out there, there is more phosphorus, but it's not as cheap. And that's an issue. That's a real issue. Rocks of the same age, different part of the continent, over in coastal California. Sorry, I'm still in Florida. I'm jumping the gun. I wanted to talk just briefly about where we sampled. This goes back to the idea that not only do we want to understand the system of where the phosphate deposits are, but we want to understand the system that created these phosphate-rich deposits because that allows us then to prospect much more effectively for where other deposits might be where we just don't have any data. So we took a whole series, thousands of samples from cores that the Florida Survey holds in their repository. 

They also, most of geological surveys in the country are kind of keepers of samples as well as keepers of data. We did a transect from the phosphate district, which is up in here. Again, here's Tampa. Tampa is sprawling out this way. Here's the phosphate district. Transect from the phosphate district down into the southern area, kind of down toward Sanibel Island. I didn't get to go to Sanibel Island. I got to say it was a real disappointment about the trip to Florida. Mostly we were up in Tallahassee landlocked, the state capital. But we got to look at rocks that come from underneath near Sanibel Island. 

And we did that because there's a major change in the thickness and quality of the sediments and the phosphate as you go along there. So there was a major change originally in the kind of depositional conditions along that area, and that's really going to help us evaluate the oceanic conditions. Was it dependent on the depth of the sediment, the sea floor? Some folks have suggested that it has to do with you can concentrate phosphate in marine systems through wave action and what they call winnowing, removing of finer grain material and leaving more dense material behind. So this is going to allow us to get a handle on sedimentation rate, water depth, the age of the deposits, a whole series of things through using several techniques, including looking at some isotopes of carbon and sedimentology and geochemistry on the phosphate. Now we move to California. So, about the same age, deposits over in California also contain lots of phosphate. Actually, I'll cue you in, rocks of this age all over the world contain high concentrations of phosphate. It's been called the Monterey hypothesis for the Monterey Formation of California. This rock is anywhere from, like, 27% to 64% phosphate. It's incredible. 

This black kind of mud that kind of holds together. Again, it's very young. These sediments, unlike those of Florida, Florida they were deposited in shallow, if not terrestrial, settings. So the terrestrial ones have the vertebrate bones. We were looking at sediments that contain manatee bones. So very shallow, near shore. Dugong, which is a type of manatee relation. Lots of clams and stuff like that. So, shallow, near shore sediments. Contrast that with the Monterey Formation. 

Deposited at maybe 3,000 feet depth. Offshore. Deep, deep marine conditions. Pacific plate is rotating in kind of a counterclockwise direction relative to the North American plate, and that rotation, San Andreas Fault, that's what that's all about. In the Miocene, that was creating these basins offshore. Actually, go to Google Earth, do kind of a low-angle look at offshore Los Angeles, which is down here, and you'll see these deep areas of the sea floor. These are pull apart basins where the oceanic crust is kind of pulling apart as it rotates and creates lots of faults. And those areas kind of subside and create lows. And, relative to that, the area in between receive some pressure, compression, and rise up and create highs. And so you have these bowl shaped areas where you have deeper water and sediment kind of traps them there. 

That's the idea for the Monterey Formation. Very high organic carbon content. So these are really black muds. Lots of organic matter in there and lots of phosphate. We studied a series of outcrops, and this was, well, it was wintertime in California, so it was kind of cool and misty. From Santa Cruz all the way down to Naples Beach just near Santa Barbara. And, again, this is still a tectonically active area, so these had been uplifted from thousands of feet offshore. I'm just going to share with you a perspective really quick about these deposits. So, here they are. These rocks, excuse me, I'm stepping out of the light, these rocks up here in this image are dipping at about 60 to 90 degrees. 

So, these sediments have gone from about 3,000 feet below sea level to above sea level and tilted kind of on end. This is what they look like when you get up close to them. So their weathered appearance is this kind of whitish, but when you get up next to them, you can see they're very dark in color, that's due to the high organic content, and the phosphate is actually in these kind of yellowish nodules. It's an incredibly cool place to go because it's really an entire petroleum system you can see right on the shoreline. So these rocks, these high organic carbon rocks are the source rocks for oil. The Monterey Formation is one of the major oil producers, or the major oil producer, in California. So you have all this organic matter, it matures under pressure and temperature, and it migrates. The migration pathways, in part, are in the rocks themselves. So if you look at the Monterey Formation, you see all these fractures in places, kind of clusters of fractures, and there's tar bitumen coming out of those. That's the petroleum. 

And if you stand on the shoreline, you look offshore, you see oil platforms just offshore of where you are, where these rocks, dipping at 60 and 90 degrees, plunge down and those oil platforms are sourcing oil out of those rocks. So it's fantastic. You can stand there, you can see the entire petroleum system. Oil industry loves it. That's where they take people to train them about how that all works. Looking at some of the older rocks. So these are those rocks that are 260-275 million years old. This is the Phosphoria Formation. The western phosphate field shown here in some US Geological Survey data. Primarily, the western phosphate mining district is all right here in southwestern Idaho. 

There's stuff in Montana and over into Wyoming. It's pretty minimal. There is a nice, big mining operation down near Vernal, Utah, but, primarily, it's in southwestern Idaho. This is a little bit more like the Monterey Formation. It wasn't necessarily deposited under really deep conditions, again, this submarine environment, but it is very high in organic carbon. So, they're in a black shale succession. So the rocks are very plating, fine grained, and there are phosphates, maybe about a meter thick phosphate rock deposits associated with these black shales. And they're a little thin phosphate horizons up in the black shales. And we've done some study on these, and USGS has some cores. This is just a nice Google Earth image from looking north towards Thermopolis, Wyoming. 

And here you can actually kind of see a window into the Phosphoria Formation, which is these dark sedimentary rocks here, the sedimentary rock is, in part, the weathered material, with younger red beds sitting on top. Red beds being mostly terrestrial sediments that the iron's been all oxidized. So these are red rocks, sandstones and finer grained siliciclastics sitting on top of these very dark phosphate-bearing rocks of Permian age. The thing about Phosphoria, it contains really high levels of selenium. So this is a toxin under elevated conditions. So they're having some major environmental issues out in Idaho associated with the acid mine drainage from these mining areas where selenium is entering the freshwater supplies and killing off all kinds of fish and trout streams and things like that. Not too foreign from some of the issues we encountered every once in a while in parts of our state. Closer to home, the Maquoketa group. This is Ordovician. This is, again, about 450-440 million years old. 

So, getting back there a little ways now. Anywhere from about 12% to 42% phosphate. It's rock. Phosphate is hard stuff. Again, it's kind of like, it's a little bit more like Phosphoria than anything else that I've mentioned so far in that it's associated with black shales. These black shales do not contain elevated levels of selenium, though. You can see these rocks. You go down to, there's a little hamlet called Graf just west of Dubuque, and it's a favorite fossil collecting site, especially the UW Madison students go there, folks from all over the region, especially intro geology courses, paleontology courses go there. Cephalopods, in the millions. Cephalopods are straight-shelled marine organisms related to squid, especially abundant in parts of the Paleozoic. 

Today their modern relative is the nautilus, who lives in the deep sea. Fantastic for fossil collecting, but also, potentially, an economic deposit of this kind of fits in that realm of secondary deposits. In part, some uncertainty as to the distribution of this deposit, and also it's under farmland, largely. And it was always said, well, who's going to tear up a bunch of farmland just to get some phosphate? But you know, times change. There's been some mapping done. So there's some fairly nice and advanced maps about this deposit and its distribution, at least locally, in eastern Iowa. We've been doing quite a bit of work on this interval. In eastern Wisconsin we've been, for the five and a half years and then some that I've been with the survey, we've been doing a lot of mapping in eastern Wisconsin, geologic mapping to support a whole variety of things as part of a US Geological Survey program called STATEMAP. And that's given us incredible insights into the subsurface geology of eastern Wisconsin up on the Niagara escarpment. Primarily, we've been looking, mapping at least, in Sheboygan and Manitowoc County, but we've been studying the rocks to the north and the south. 

It's allowed us to create some pretty nice, highly detailed views of what the subsurface looks like. So this is a cross-section of the subsurface. This vertical is thickness. There's a bar for 25 feet, and there's 25 miles there. And, again, this is basically a cross-section from Milwaukee up to Door County. And some of the phosphate deposits are present in this interval. Actually, there are multiple horizons. But this is pretty far underneath the surface. They come to the surface over near Dubuque. There are other horizons too, like the Neenah ironstone used to be mined for paint pigment in eastern Wisconsin. 

Actually turns out to have about 6% phosphate in it. Probably not something you want to go mine for phosphate, and yet more enriched than what we have down in Florida in terms of just total phosphate per rock volume. So we've done a lot of sampling through this interval, and it's giving us a lot of great information about Wisconsin rocks and a potential local economic source of phosphate. We spent some time down in Tennessee also. Again, rocks about the same age. Lots of phosphate, lots of beautiful outcrops to study down there. And, finally, we've been spending increasing amounts of time looking at rocks from the northern part of the state up into the UP. Again, these rocks are very old. These are 1.8-billion-year-old rocks. Again, associated with the black shales. 

There's kind of a theme, at least in some intervals. The Ordovician rocks of Nashville, sorry the Ordovician rocks of Nashville area and the rocks and sediments of Florida, Hawthorne group, are similar in that they are mostly carbonate with phosphate in it. The rest of these deposits, from the Monterey Formation to the Phosphoria to the Ordovician of Wisconsin to these 1.8-billion-year-old rocks in the northern part of the state, they're all similar in that they're associated with black shales. So there's basically two types. There's one that's in carbonates, and there's one that's in black shales. The carbonates, not so concentrated, but most of the waste rock is inert. The black shales, more concentrated, but lots of nasty stuff in there. So, again, economically, there are tradeoffs there. That's what some of the stuff from the north looks like. These are all sulfides. 

That's pretty nasty stuff. It oxidizes readily. Puts all kinds of arsenic and sulfur and things like that into the water that you don't want to deal with. So, conclusions. Are we at peak phosphorus? Just about. But, again, that is phosphorus as we've known it. So, cheap, readily available phosphorus primarily from Florida. Okay? Total rock phosphorus? There's more but there are issues associated with it. Greater cost of extraction. More potential environmental issues to deal with. 

Bottom line, you don't provide phosphorus, people around the world start to starve. We stacked the deck here. We've created all this food. The population has expanded. Now what? We've got to have phosphorus to keep going or we have to change the way we do things. This is a scenario put forward for Cordell et al. So, this is phosphate rock as historically produced, looking forward toward a peak phosphate of phosphate rock as we know it, and it's decline. If we don't come in with other sources of phosphate rock, this is the scenario. Well, more manure, maybe change the way you do things. So they say, they provide different scenarios. 

They say business as usual. This is the amount of phosphate or phosphorus that you need to support the global population. Change the way you do things. Eat less meat. More food chain efficiency, more agricultural efficiency, and potentially you can bring that volume down to a sustainable level. And we can talk in the question session about where you think it's going to go, but we tend to do things business as usual. Right? So my guess is they're going to ramp up phosphate mining in these other deposits. But, again, that's to be seen. We've collected a ton of samples during this project so far. Again, we're only starting year two. 

A lot is still in analysis, and we'll keep you posted on the progress. Thank you for your attention. [APPLAUSE]