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Sophie Warny - The Many Impacts of Palynology

AAPG Distinguished Lecture Series, 2018-19 Season

AAPG Distinguished Lecture Series, 2018-19 Season

Summary

A Distinguished Lecture talk given by Sophie Warny during 2018-19 AAPG DL Season. Click here for abstract.

Full Transcript

So I'm here to talk to you about palynology and its impact on our society. So I'm really grateful to AAPG and the AAPG Foundation for inviting me.

So I want to speak to you about the various aspects of palynology. But I'm going to start by telling you who we are and what we do.

So my center, CENEX, the Center for Excellence in Palynology at LSU, was started in 1993 by AASP, which is the American Association of Stratigraphic Palynologists. And the society wanted to have a place in the US where palynology would be taught. And so they approached various universities. And LSU got the center. So we are very lucky that they are providing funding for an endowed chair and that we were able to remodel the center.

So we have beautiful office facilities. We have a chemical processing facility. We have library. We have a collection reference where we can use the pollen from various locations in the world to tie into the work we are doing. And then we have a dry lab with five microscopes to train graduate students. So we can train five PhD or master's students at all times.

And then one of our proud possessions that was donated to us by SHELL is the mesozoic dinoflagellate collection. And we've dedicated a mesozoic section on earth essentially. So we are trying our best to create it properly.

So I've just mentioned dinoflagellate, but what do we really study? And what is palynology? So a lot of people don't know that. Palynology means pollen dust. It's dust. So it's the study of dust.

And when you try to understand what that dust is composed of, I like to use a sentence from Alfred Traverse, who was a palynologist who passed away a few years ago. And he used to say, Palynomorph. It's really, "What my net catches is a fish."

So instead of a net, you're using chemical processing. And so we take mud, and we process it with various acid. And at the end, we are getting microfossils, things that are about less than 150 microns and that have an organic wall.

And so when you look at a tree of life picture that I have right here that goes from very basic eukaryote to a plant or animal kingdom, this is where all of the microfossil, depending on morph, can be. And so we have, for instance, dinocysts-- that's one of the plankton-- spore from bryophytes, pteridophyte, gymnosperm, who are producing pollen, angiosperm pollen, fungi, and so forth-- so a lot of diversity. And so we have a lot of different types of microfossils we can use for our research.

And start with the red cross that you can see right here. So for instance, nanoplankton and diatoms are so part of the phytoplankton. But one is siliceous. One has calcareous shell. And so we dissolve them when we are trying to extract their microfossils. So we don't study them.

And then on top, in the animal side of the components, so the zooplankton, you have forams and radiolarians. They are so made out of calcareous or siliceous component. And so we do not study them either, because we dissolve them to get the perimorph out of the section. But everything else that you see in blue are perimorph that you are studying.

And so the really nice thing about working with such a diverse group of microfossils still is that you can really dig a lot of geological sequences, because, through time-- and this is an image of the geological time going from pre-Cambrian to recent in the top of the Cenozoic. You have different types of microfossils that occurred and became extinct.

So if you start on the pink color in the Precambrian, we have the top of the Precambrian, the Neoproterozoic, you have the acritarchs. If you are working on a really old section, you have acritarchs already. You can date this type of section. And then through time, we have all the microfossils.

From the Paleozoic we have the acritarchs are still there, but you have chitinozoan, you have spores. And then vegetation started evolving more and you start having gymnosperm pollen, dinoflagellates appearing in the Mesozoic. And then at the end of the Mesozoic, you have angiosperm pollen. And they dominate the Cenozoic.

So at any geological time since the Neoproterozoic you have one type of palynomorph you can use for biostratigraphy. So that's a very, very successful tool. Other than biostrat, we also do environmental reconstruction. So how do we do that?

Essentially, when we have a rock, we extract the palynomorph. And with that, we are trying to reconstruct what we know about the climate system and how it affects sedimentation, and processes that are dealing with solid earth. So the component we are looking at, for instance, is insulation, so the amount of sun the planet is receiving.

And the insulation is going to influence the type of vegetation we have on the planet. If you are in Alaska, you're going to have different vegetation than in Louisiana, obviously. So the insulation is going to influence that.

By looking at the pollen and spore, we can find out what vegetation we have and reconstruct the paleo insolation. It also affects sea surface temperatures. By that we can look at dinoflagellate cysts, which is also, as you learned, one of the palynomorphs. And they have a very specific range of sea surface temperature and salinity that they like. By studying some of the species, we can reconstruct paleo salinity and paleo sea surface temperature.

And then precipitation. So something we can look at. Precipitation is going to affect your vegetation. It also affecting river discharge and the size of the glaciers. If you don't have any rain, it doesn't matter if it's cold, you're not going to have a glacier.

All of that is tied in. And river discharge, you can see it, for instance, in the freshwater algae that are also palynomorphs. It will affect also the salinity of the ocean.

If you have more river, like where in Louisiana my lab is, with the Mississippi river, the sea surface salinity by the mouth of the Mississippi is zero essentially. So even though you're in the Gulf of Mexico, a lot of river discharge, means you have freshwater algae there. And so all of that is tied together.

And so by looking at the pollen, the dinos, and things like that, we can really reconstruct the environment very precisely. So where do we do that? Essentially, the planet is your lab.

In the ocean, you're going to have dinoflagellates, you're going to have Acritarchs, chitinozoans. If you're on land, you're going to have the freshwater algae, the pollen, the spores. So there is always one type of palynomorph that you can study. And the red marks are showing projects that we've completed recently or that are ongoing in my lab at the moment.

The outline today, not that I hope you understand better what palynology is, I decided to tailor it after an article I saw in the AAPG Explorer just a few months ago. And the title was, "Finding Oil and Protecting Earth." And this is a major challenge, probably the biggest challenge of our century.

I was trying to give data of things that we are doing in my lab. And we're actually dealing with both. We are dealing with finding oil through biostratigraphy. And then protecting earth. We are doing that both at human scale by doing forensic palynology. But we are also doing it at geological time scale by reconstructing the paleoenvironment.

And so this is how I decided to structure the talk today by giving you examples from these four different sections. The first part of the talk is going to be about palynology and biostratigraphy. Biostratigraphy, it's a very important tool for the industry.

If you Google Veradis basin database-- and I show you an example here in the AAPG database-- biosteering is really adding millions of dollars in savings to any horizontal well. Because it really helps you orient your drilling by knowing in which section you're drilling. And so to find out where you're drilling and how to stay on target, you really need to have a good biostratigraphic scheme. And this is something we do in my lab quite often.

Actually, one of the examples that we've done, it was a project we've done in collaboration with Ecopetrol in Colombia. And this is a project that was one of my former master student's project, Carlos Santos. And Carlos is now with BP in London.

So for that project, the area that was of interest to Ecopetrol was in the Middle Magdalena Basin in Colombia. And there was a new drilling target for Ecopetrol, or at least newer than what they have done in the past. And if you look here, the yellow horizon, where there is a big reservoir. They were much younger. They were in the Cenozoic.

This was most of the focus of the exploration. But they wanted to wrap up the exploration in the Cretaceous. So we got that project, and we decided to work with them on developing that scheme.

So one of the reasons it's such a complicated project and you will need biosteering, is that you have a lot of faults in the region. So you have Cretaceous crusted over Paleocene rocks. It's a big mess of tectonic structure. And you really need to have biosteering to help you.

And so in that case, when you have a lot of tectonic complexity, a lot of unexplored area where you don't have a scheme to start with, and in that region you have a major regional unconformity, it means you're going to have a lot of exploratory risk. So it's really important that you have biostrat to help you in this situation. This is a picture of Carlos at one of the wells that he studied for his project.

Instead of one long section, we were able to get four sections. Not completely continuous but more or less, about 1,000 meter of sediments. And then Carlos studied 80 samples that were selected from these intervals.

So when you get the sample from these cores then you have to extract the palynomorph. And as I mentioned to you in the introduction, we use HF to remove all the sand portion, so all the silicates. We use HEL to remove all the carbonates. And then we concentrate by various means.

So that part of the project was at Ecopetrol. Carlos was able to come at our lab in CENEX at LSU with an 80-sample process. And they look like that, just slides that you're going to study in the microscope.

So we spent a lot of time at the scope describing what he was finding. And this is some examples of his drawings. So he described this species he found. And you can see here some of his drawing of dinoflagellate. And then you go to the database and you try to identify which species you're dealing with.

The diversity of palynomorphs is extremely high, so it's millions of different species. You will need a good reference collection. And in that case, when you're dealing with Colombia, one of the best databases is at the Smithsonian Institution in Panama. The head of that program is Carlos Jaramillo. And so he invited Carlos Santos, my student, there to confirm his identification. So once we had a good idea of what we were dealing with, Carlos went to Panama, finalized his identification, and then we can move to the next step of the project.

So when you're dealing with biostrat, what you're looking for are really three components. So the first one is when is species becoming extinct in your core, essentially? It might not be extinct, but it disappeared from your core. So that's called a last appearance datum.

The other thing you look for is, when is the species appearing in your core? So that's the first appearance datum. And the third one is when is the species really abundant? Is there some environmental factors that are really making your species just loving it and multiplying, and it's called an ACME.

So we look for LAD, FAD, ACME among the species that he discovered in the sample. And the result, Carlos counted 17,410 grains, various palynomorphs of pollens, spores, dinoflagellate, acritarch and other algae by 201 different species. And he used these species to establish a scheme, best biostratigraphic scheme to help with drilling.

That's the raw data after you finish the work at a microscope. And it's impossible to use if you're working on a well. It's too complicated. You really have to be trained to make sense of the diagram. So the next step is to try to tone it down to make it usable on site, And be fast, because you don't have that much time to biosteer.

So the first thing he did was to take all of his data, and instead of distributing them by abundances, what he did is to distribute them by last appearance datum. So when are they disappearing in the well? And you can see that green line that's going down, it's each species disappearing from the diagram. So a lot of them are disappearing in the yellow interval, light yellow, and then darker yellow.

And the reason we organize them by last appearance datum is because when you are drilling and your drill bit goes down, you have some contamination, and even if it's minimum, of what's on top to what's under. But if the species is not there because it disappeared from the well, you're not going to contaminate it. So your last appearance datum is the thing that you know for sure is the last time it appeared. You won't have contamination problems. So to avoid caving, organizing by last appearance datum is really the way to go.

So once that is done, you have to make it a little bit easier too for the people on the well. One thing we try to do is to divide the area in smaller portions. So in that case, he divided into three portions. And these three portions, then he selected the key important events in each of them.

So these are the three portions, the three divisions he made. And for each of them, he selected a few events happening, whether it's in ACME, a first appearance datum, and so forth, or the range. So you can see these vertical lines that are just interrupted on top and bottom. These are the ranges, a time when a species appear and disappear within the core.

So that makes it very easy. You don't have to deal with all the data you just view what's important. And to make it even easier, he added pictures. So that really anybody on the well with a minimum knowledge of palynology can use that.

So this is the part that's very practical, you can really use. It took 2 and 1/2 years of work for Carlos to come up with that scheme. So you can see why-- palynology, one of the drawdowns is that it's a very slow process, takes a lot of time and patience at the microscope. My students need to know that when they come to my lab they're going to need a lot of patience and a lot of alone time at the scope. But that's part of the job.

One of the things we can do with the data once you have your biostratigraphic scheme we can move into something that's called sequence stratigraphy. The way sequence strat works, it's looking at sequences related to sea level. And the way our data can be integrated with sequence stratigraphy is by looking at a type of environment where you find these different data.

So for instance, if you look at the diagram on top, you can see first an image of pollen, then of spore, then some dinoflagellate. So the pollen can be in all kinds of environments, but the spores, then they need their humidity to reproduce. So it's usually in more coastal or in swamps, but it like the wet environment. Then you have the literal type dino and then the offshore dino.

And so when you look at the diagram, it essentially shows you something that goes from inland to offshore. And so you can tie your data from this diagram, your pollen, your spores, your dinoflagellate record and tie into a sequence strat model by-- your maximum threading surface, for instance, is going to be when you have your pick of dinoflagellates, and so forth. What you do then, you can tie your distribution of these various groups from inland to offshore to sea level curve, like the Haq et al. curve, and allow you to more precisely date your sequences.

So we've done that in many other sites. For instance, we were just last week in the Permian Basin. And that's a project we are doing in collaboration with Art Donovan at Texas A&M. Art and his group at Texas A&M are doing all sorts of unconventional reservoirs outcrop characterization.

But our portion is to do the palynology. And so we were just in the Permian Basin with 15 grad students from LSU. So that's one of our new targets we are developing right now.

And then the other one we're working on right now, it's to develop better paleogene biostratigraphy for the Gulf of Mexico. And to do that, we are currently looking at three wells. So if you look at the picture of the Gulf of Mexico, you have the big pink reddish circuit on the bottom. It's the site of the Chicxulub crater.

Most of you must know what Chicxulub crater is. But if not, that's the impact crater left at the end of the Cretaceous. That's the meteorite that wiped out the dinosaurs. It's probably one of the most famous geological events.

That core was acquired by IODP and various groups. Sean Gulick at UT was one of the PIs. And we got very lucky to have the contract to analyze the palynomorph from that very iconic core.

So we are doing that core. And then we have two wells in the northern part of the Gulf of Mexico that we got from Shell. And we are developing that biostratigraphic scheme for these two cores.

So the next section I want to talk to you about is starting about protecting earth's focus of the talk. And the first one, it's a very human scale. It's how we can use forensic palynology to deal with modern crimes, and so forth. I first have to thank Dr. Vaughn Bryant, who is at Texas A&M. And he's really the father of forensic palynology in the US.

Thanks to him, two of our former students are now actively working for Homeland Security using forensic palynology. That would not have happened without him speaking about palynology and how we can impact forensics. So a few years, Vaughn invited me to an intelligence meeting in DC. They had invited about five or six palynologists. And they wanted to discuss how really we can use forensic palynology for geolocation, which means, can we use pollen from an object, a person, drugs, artifacts, whatever to geolocate their provenance?

One of the things that we discussed at that meeting is that, so first, it's not that simple. You have about a little bit less than half a million pollen grains, pollen species on earth today. That's not speaking about a geological time. This is modern species distribution. So an amazing distribution complexity.

And then we don't always have the right reference collection from the area that we are interested in. So finding these assemblages from the target area, what's called a pollen print, it's very difficult. And it takes people who are well-trained in palynology to do so. And it's not that many of us because very few people know about palynology.

One of the things that's super important is collection. And so when you deal with a museum collection, you inherit essentially hundreds of years of people doing field research, and in countries where we actually cannot go anymore because of wars, or they're inaccessible today because of various reasons. So these museum collections as resources that we could never get back if they are lost. And they are extremely important to create the pollen print that we need.

A few years ago, a few museums were targeted for foreclosure for major reduction because of budget cutting. And one of the reasons I think people don't always understand the value of museums, they think its places where old stuff is stored. But in our case, I wrote that article in the journal Science to show that we were working on that project and we needed samples from a specific location.

And in our collection at the Museum of Natural Science at LSU, we had a little less than 5,000 samples from this location. So if that museum would close, these would be lost. Preserving museums is extremely important for many reasons.

One of the projects I'll show you just briefly, some of the thing we've done, was to try to see if we could geolocate the provenance of drugs from various arrests and see where they could come from. So when you do that, one of the things you have to do first, you extract the pollen from the drugs, which this is not the part that we've done. That's a part of something by the authority.

Our portion was to try to develop a pollen print map of things that they could compare to. And so for that, collection was super important. So in that case, when we looked at the target area from the possible location, we didn't have geological samples from that region.

But when I came back at LSU after that meeting, and we were discussing that topic at our curators meeting, it came to me that the person in front of me had spent 40 years in that country collecting mammals. And pollen on you all the time, so you're covered. If I vacuum you right now I'm going to find tons of pollen. And so we figured that maybe we can vacuum the mammals and get a pollen print from these mammals, and use that to create a map.

So we submitted a patent for that. And then we tried it. This is our Museum of Natural Science on the LSU campus.

And this is my former colleague. You can see, he's now retired. Mark Hafner, who collected mammals for 40 years, or so. And then Shannon Ferguson, the student who helped us with the project.

This is the one tool we used the most. It's called a forensic vacuum. You have to be extremely clean, so you need to use gloves. We wiped all the surfaces clean between each different samples. And I should note that, every mammal that is collected have been stored in airtight containers since they've been collected. So there is no contamination, or at least very minimal contamination.

And this is an example of us vacuuming a little mouse, and rats, and so forth. And you can see in the filter, it was quite successful. A lot of them had dirt from the country where they were collected. Some more of our vacuuming a little mouse.

And so at the end, we had various samples from various locations. So at each location we tried to vacuum a diversity of animals to increase our chances of having enough pollen. So that's what we ended up with.

And then you have to extract the palynomorph just like you do for biostratigraphy. So you use acid, and so forth. At the end, we ended up with some residue from each location. And you can see, I think on number 15, the little black dust on the bottom of the tube. This is the pollen after you process the sample.

So then you take that and you make a slide. And you analyze it just like you would a geological sample. So we've done that for that project, and find that it actually works well.

This little mouse, and rats, and squirrels have tons of different pollen from different locations. And so now we are starting to build this pollen print from that country. And that can be used in the future.

One of the interesting parts of that is that Shannon, my student who is doing a PhD on the Gulf of Mexico yields, completely different topic, ended up being invited for two internships with Homeland Security. And at one of her internships, she was actually offered a job after a very sad case. Right after she arrived, she was just supposed to do a CM picture.

A child had been murdered. And she got to vacuum the blanket and some of the clothing from the child. And thanks to the pollen print from this clothing, her and her boss at DHS we're able to narrow the location of where the victim was. So they were able to crack their case thanks to that. Now she's a full time employee at DHS, and one of two forensic palynologists.

And the last section I want to talk to you about is how we can use palynology for paleoenvironmental reconstruction. And so that's a big component of what we do in my lab at LSU. I will talk to you about an example from two locations, one in the Gulf of Mexico and the other one in Antarctica.

The first one that's a big project we had in collaboration with Dr. John Anderson at Rice University, and one of his students, Alex Simms, who is now a professor in California. And the topic of the entire project was to try to understand the influence of climate and eustasy on sediment yields. So very important factors to know how the yield is affected by environmental factors.

John Anderson at Rice has had many, many graduate students working on any area of the Gulf of Mexico off the Texas coast. He has cores from many of these locations. And for Shannon's project, we focused on three friend bases.

And today I won't have a lot of time to present everything, but I'll focus on Corpus Christi Bay. So for that Bay, we looked at one core. That's a core that you can see there. It's CCB02-01. And that's a core that's in the back of the Bay.

So you can see in the front of the Bay, there is Mustang Island. That's a barrier island that's actually protecting the Bay from invasion of salinity from the Gulf of Mexico. So you can see, it's a very effective salinity barrier between the Gulf of Mexico, normal marine salinity, and the Bay.

So that core, if you look where Mustang Island is marked in purple, there's a barrier island. And then if you look towards the other side, towards landward, that's where the land is. The blue is marking the Bay area.

So you can see, John Anderson and his group took several cores. That's these vertical lines in the Bay. And we decided, we studied one of them that's marked right there by an arrow. And all the numbers that you see down the core, are dates. John and Alex, during Alex's PhD, dated the core very precisely.

So in that case, when we came, we didn't have to do biostratigraphy. The core was very well dated. We can focus on the environmental reconstruction. Do we see any climatic changes in the core, changes in insolation, in river discharge? The things we were discussing in the beginning of the lecture.

So this is some of the diagram created by Shannon. There is not that much diversity in types of plants that she found. But really, we could find an interesting signal nevertheless. So when you took these data and create some correspondence analysis, you do some statistical analysis on the data that she found.

Something very interesting appears. So you can see four clusters, from a red, you see a light purple, darker purple, and a green. What it shows you is that from going to the bottom of the core at about 10,000 years till the top of the core at about 1.6 thousand years, you have four zones of different vegetation, which means climate changed through that interval. And it went from more dry, when you have more grasses, to more humid, where you have more trees.

This was interesting. We didn't know much about that region before. Shannon published the result of the change in vegetation in that region in GeoBytes.

But then one thing was really puzzling us. It's that little purple area that you see it right here. At that time, we looked in the pollen record and we couldn't see anything going on. So definitely, not a vegetation change. But still, there was something in that interval that was translated into the statistical analysis.

And when we started looking at the dinoflagellate record from the same sample, we understood what was going on. At that same area, that little peak, you have fivefold increase in dinoflagellate. Which means that the dinos, for most of the core, are not really there. You had a few species who are usually tolerant of low salinity, more like 20, and so forth. But during that one time interval, you start having a fivefold increase, great abundance of dino.

And most of the dino is called polysphaeridium zoharyi, which is a dino that really favors full sea surface salinity, more like 35. And again, the Bay today, the average salinity is about 22. So that means that for that time interval, it's not so much the vegetation that was changing or the climate, you had something going on on the marine side of things that completely changed the salinity of your environment.

And so we did some reconstruction. And if you look at the bottom of the blue and green diagram, you can see a reconstruction of what Mustang Island was likely like 10,000 years ago. And then on top, is what it must have looked like during the dinoflagellate increase.

And so from our reconstruction, we think that either Mustang Island was overtopped or breach. So something major happened that the salinity was pretty much equivalent to what you find in the Gulf of Mexico. No more salinity barrier, no more barrier island, or at least it was extremely reduced.

Alex Simms, who did his PhD on the topic before we did the palynology, had found out that you likely had a 15-kilometer retreat of the bay-head delta inland at that same time. 15 kilometers, that's a massive inland retreat. So massive flooding at that time. All the oyster reefs either died off or had to migrate inland as well. So major environmental changes.

This is a figure from Anderson, et al. In 2010. And that's a curve of sea level rise for the last 10,000 years. And you can see, sea level rise was happening very fast 10,000 years ago. Then it starts slowing down.

And these other colored lines under the diagram is showing you the barrier island along the Texas coast. So you can see, the dashed line shows that they were not very stable. But the full line means they were very stable and they were able to keep up with sea level rise.

What we were thinking before our studies, that the barrier island near Corpus Christi was very stable for the last 10,000 years, and it was able to keep up with sea level rise. But then our new data shows that definitely there is a gap there. And we think that during that short time interval, the island was not able to keep up with sea level rise.

So something pretty major happened at that time. And we think that what happened that's major, and it coincides with that the data that we are finding-- is on that paper, and there are many others on the topic-- were the massive ice sheet melting in the Northern Hemisphere was accumulating a major lake in the back of the ice sheet. And at some point, that broke off. And that massive lake just got distributed into the Atlantic Ocean.

So that's called Lake Aggassiz mass wasting. And it's coinciding with the event that we are seeing there. So that raised about 2-, 2.1-meter sea level rise in Europe, and about 2.4 meters on the Gulf of Mexico.

So it's not huge. It's 0.4 meter. But it's definitely sufficient to damage the stability of the barrier island.

This event, we published it in The Holocene. And one thing that we are really concerned about is that it's really showing you that barrier island can keep up with small gradual changes. And what we really should be concerned about is these very tragic, large scale events.

So again, that's a great type of study to show you analogues. So now here for what might happen with future scenario of accelerated sea level rise. So we have studied a lot of work recently on reconstructing past climate and environments from the Antarctic.

One of the reasons we are doing that is to try to understand what are the triggering mechanisms that really made these climatic changes happen in the past, and see what's going on. Is it tectonic, climatic, and so forth. It's of great concern to the scientific community because there is so much water that is currently in the ice sheets.

So you have about seven meters of sea level equivalent that's stored in the Northern Hemisphere. And then we have about three to five meters of sea level equivalent that's in the West Antarctic ice sheet. And about 53 meters of sea level equivalent that's in the East Antarctic ice sheet. So a lot of water that can potentially affect our coastline.

We are not at all saying that you're going to have 53 meters of melt anytime soon. But just a little bit of melting can really impact us a lot. And we are seeing some melting right now. So this is real data, not historical reconstruction.

This is data showing that there is currently oceanic warming around Antarctica. Some areas are getting colder, some weird effects of current. But most of Antarctica is getting warmer.

And then you have also atmospheric warming. Most of it is happening on top of the West Antarctic ice sheet. So this is the most fragile one. When you hear about problems in Antarctica, it's often coming from that region.

When you combine both oceanic and atmospheric warming, you're going to have ice loss. So there are some various data. But NASA did a really good compilation of ice loss in the last 10 years.

And there's a movie online. I put the link here. And it shows you the cumulative mass that's been melting since about 2006, or so. And so you can see in black is the most melted area. And then in orange is a trouble area. And the little orange area to the east, I'll mention, I'll show you some data from that region.

So why do we care? We are not speaking about 53 meters, but even one meter of sea level rise would really change our way of life. So for instance, this is Louisiana with one feet of sea level rise.

And you can see with that, New Orleans would be an island. A lot of the coastal beaches in Florida that we love would be also underwater. Obviously, we care about that.

And it's not just a sea level rise issue. As you're warming sea surface temperature, you're also increasing evaporation. There are more and more storms, you're fueling hurricanes, you have more rain events.

And this is a picture of my daughter when we got stuck at our house two summers ago because we just had a really long rain event. It was not even a hurricane. And Baton Rouge got flooded.

And we had millions of dollars in insurance costs for the entire city. And the same happened in Houston last year, and in North Carolina this year. So these are the type of things, if it keeps happening, we're going to see more and more happening.

It's not just us. It's the oil infrastructure and the jobs. Because for instance, in Louisiana, on the Gulf Coast, we have so much of the oil infrastructure for the refineries and the operation for the drilling offshore. And all of these are a threat with the sea level rise. And the major hurricane coming and hitting the coast. So that's really something that we are all concerned with.

When people are asking me about what I think about climate change, and is it really happening? What can we expect? The more you know about it, the more you realize this is not a simple answer. And the only way to answer the question is by using a climate model.

So there are a few groups. One of the best climate modelers in the US right now are Rob DeConto and Dave Pollard. They are in Massachusetts. And this is one example of a diagram that Rob loaned me for a talk I gave a few years ago. So that's not his latest slide. But it shows you some example of all the components that are affecting the climate.

And when you see that, it's very easy to understand that you cannot do simple prediction without having this massive model making calculations for you. You have to take not only atmospheric current, oceanic current, tectonics, insulation, Milankovitch cycles, the cover, whether it's CI, so vegetation. So all of these are affecting one another and affecting your climate prediction.

Again, with that climate model, it's not an easy answer. And thankfully, we have some excellent modelers in the US right now. So when I tried to work with modelers and provide data on what happened in the past, what we really need to do is to get samples from Antarctica and try to characterize how fast the ice sheet advanced and retreated in the past. And really understand what's triggering these advances and retreats. And to do that, we are looking at the vegetation.

So the vegetation when the ice is not there, it's very lush and you have a lot of it. And as the ice advances, you start losing your vegetation. So we see that in the pollen record.

I've been trying to get my hand on every possible sample that I can from Antarctica, which it's always a lot of competition. Everybody's applying for these samples. And so you have to make the case that you're not going to mess up, and you can take good care of your sample.

So I've been looking at samples from different sites so far. One of the things that I want to show you is five locations that we studied. And I won't be able to go into details with all of them.

But we looked at a section at the lowest possible latitude at the Antarctic Peninsula. It's with the program called ShalDril. We looked at some samples from the Siple Coast, thanks to a big program called Wizard, that drilled under the ice sheet into a lake, a subglacial lake.

We also were part of the Andrill Project, where the drilling was from a moving ice sheet. It was an amazing engineering success. Then some samples collected by hand in the Dry Valleys. So not a drill. And then finally, the Sabrina Coast is one of the last projects we've done.

So it's not always easy to look at the sample on the transect, so I'm going to show you where the samples are located on you on a regular geographic map. This is Shaldril. And you can see, this is at the lowest latitude. It's the warmest site. It's closer to Tierra del Fuego.

The Siple Coast. The Ross Sea with Andrill. The Dry Valley in the mountains. And the Sabrina Coast. So you can see, there are a lot of places in the Antarctic I haven't studied yet. But these are the five big sites that we were able to have.

If you look at the geological time scale now of how these samples are split, you have some samples here in the Paleocene, Eocene, some in the Eocene, some in the Oligocene. We have a very long section, Andrill in the Miocene, which is a continuous section 10 million years. And that's because we worked with a lot of different countries. And then these little time intervals area from these mountains from the Dry Valley. And finally, some Plio-Pleistocene samples.

I'll start with the first project. The peninsula, that's the one that was done by John Anderson at Rice. He started that project to allow scientists to be able to drill close to the continent. And big drilling cannot go there, but his idea was to put drilling rigs on a boat, and so being able to drill closer to the continent. And so that was called shallow drilling, Shaldril.

We did the palynology for that section. And we were able to record about five different intervals from the Eocene till the Plio-Pleistocene. And I'm not going to go into a lot of the details here. But if you look at the diagram, the last column shows you the type of vegetation that we found, and also how it decreases slowly through time.

As the ice advances, you have more and more erosion. And so the vegetation in place is disappearing. And you get stuff from Permian and very old vegetation coming to be mixed. And so all the whitespace had a reworking on this side. But the one thing that's really important as a take home message, is that the vegetation disappeared 12.8 million years. And I want you to remember that, 12.8.

The second site from Antarctica I want to share with you is from the Ross Sea. In the Ross Sea we were very lucky to be part of an international drilling operation called Andrill, where countries from Europe, countries such as America and Australia were partnering to do that massive drilling in Antarctica. So we got over 1,000 meters of sediments with 98% recovery, which is an amazing engineering prize. It's very seldomly achieved. And doing that in Antarctica was almost unheard of.

One of the main results we found is that when we started drilling-- and we knew we were going to hit Miocene, at least we hoped so. And we really didn't know if vegetation was still there in the Miocene. So just getting vegetation was a big excitement for us, when we started getting the first pollen and spore from the core. And really being able to realize that you still had vegetation at that time, even though we know the ice sheet was already there. You had pockets of places where vegetation survived.

But looking at the dinoflagellate and the freshwater algae, all the samples were barren. And so it was barren, barren, barren. So I spent weeks looking at samples with nothing, no dinoflagellate, no freshwater algae. Which means that the ocean was too cold, too much ice for having any dinoflagellate. And no fresh water, no ponds, no rivers in the Antarctic at that time because you didn't have any freshwater algae.

And then one day, I put that one sample at about 310 meters in the core. I will always remember because it was full of dinoflagellate. And at first, I thought I had contamination from another site.

So I reprocessed the sample. Asked my colleagues in New Zealand to send me some of their sample from the core to double-check. And we got all excited because it was full of dinoflagellate and freshwater algae.

So we knew we hit an interval that was very, very special. And because we were dealing with so many scientists on that project, we were about 100 scientists, we were able to date the interval where the dinos were coming back, and the freshwater algae were there very precisely. And you can see the time interval right there in orange and in green.

And this time interval corresponds to the peak condition of the Mid-Miocene Climatic Optimum, which is a time when we knew the Miocene was warmer. We did not think it would have impacted the Antarctic ice sheet so much that you had melting, with freshwater algae coming back, dinos being able to migrate back from closer to New Zealand to the Antarctic. So that was very exciting and interesting.

When we published this result, about five days later, I got a phone call from somebody called Sarah Feakins at the University of Southern California in Los Angeles. And Sarah and I didn't know each other, but she explained to me that she studies hydrogen isotopes. And she gets them from leaf waxes. That's a proxy for paleoprecipitation.

When she told me that, I looked at her record. And she looked like a fantastic scientist. So I sent her some of my sample. And she did an hydrogen isotope on our sample.

And what the data is giving us is some record of paleoprecipitation. If you look at the Antarctic map of modern data today, it shows you that when you have values of about minus 50, minus 80, it's not very depleted. You have quite a bit of precipitation.

And when it's very blue, dark blue, purple, like you have on the bottom of the scheme, you're in very dry places. And the area where we were working in the Ross Sea, right now is used as an analog by NASA as one of the driest places on earth. So they are using that to study other planets. That's how dry that area is.

You were at delta D data of minus 400 today. And during the time interval where to pollen are coming back, we have minus 50, minus 80. Which means it's not only getting warmer, you're getting a lot of rain at that time.

So what that study showed us is that it completely changed the hydrological cycle around Antarctica during the Mid-Miocene Climatic Optimum. And that's one example to show you that the climate system is so complex. You have this feedback mechanism. And it's not just warmer, it's getting more rain.

And then it can accentuate fast ice sheets melting. It's like if you put ice cube in a cup of water, the ice is going to melt way faster than if you leave it on your table. All of that is having influence on one another.

The third portion I want to discuss in Antarctica is a project we've done very recently with Sean Gulick at UT, Amelia Shevenell at the University of Southern Florida, and Amy Leventer at Colgate University. And then Amy and I shared a student, Katie Smith, who did some of the thesis at LSU and some at FSU. So when you look at this map of Antarctica, if you remember from the beginning of the lecture, I told you that most of the melting is happening on the West Antarctic ice sheet, where you see the black colors on the little diagram on top.

But there are some areas in orange on the East Antarctic side. And one of the reason is that, that ice sheet is marine base, which means it's in contact with the water, it can melt faster. And that's one of the areas that we are worried about right now.

We went there at Easter. Sean Gulick and some of the colleagues went there and did some seismic studies there. This is a seismic profile that Sean Gulick published in a recent study. And it shows you different packages. So MS-I, MS-II, and MS-III.

MS-I is indicative of time before the ice sheet advance. Then you have that blue horizon, where it's written, "First grounded ice." It's when the first time you have ice sheet advancing on Antarctica. And that MS-II package was really worrying us because we could see in the size meter that it's a very unstable ice sheet, with a lot of advances and retreats. And then once you're at MS-III, it's very solid, very stable ice sheets.

And so that was our job with Katie, my student, who is now a curator at IODP in Texas. We did the biostratigraphy for the core. And these are some of the new species she found.

That makes the project very hard, because when you're dealing with new species it's exciting. We got the cover of Nature thanks to that. But it's also very hard to do any dating because they are new species.

So thankfully, we had enough species that we knew in the core to date the glacial advance. We think that it advanced for the first time there, either late Eocene or early Oligocene. So the main take home message from that part of the study is that, during that first inception of ice sheet, probably in the Oligocene, Miocene, you had a lot of instability. That part of the ice sheet in Antarctica is less stable than we first expected.

And the final portion of the work in Antarctica I want to share with you, is some work we've done in the Dry Valley. So in the Dry Valley, it's very different than the other projects because it's not a result of coring in Antarctica. It's old-fashioned fieldwork, where Dave Marchant from Boston University and his group of students went to the Dry Valley for 30, 40 years and collected samples.

He trusted us with all his samples. Sent us two extracts to palynolomorph. And we spent about three years working on that project.

So when we looked at the samples, you can see these are in the Transantarctic Mountains. So these are samples that were taken at the outcrop, not using core. Most of them ended up being barren. And it's not very surprising, because a lot of them are Plio-Pleistocene. And it fit what we had seen in many, many other sites in Antarctica.

But there were two sites where we were very excited to find vegetation. And one of them is in the Victoria Valley. Pretty much the same exact type of vegetation that we found with the Andrill project. Tundra vegetation, probably Mid-Miocene. Very, very similar, confirming what we had found with Andrill.

And the other site is in the Beacon Valley. And I put a question mark with 13.6. That's the best date we have so far. But it's not confirmed, so we would need to do more work on that.

But what's interesting at that site is that by then, the only vegetation that you have are grasses, moss, and some colobanthus, which is a plant that can survive in Antarctica today. So very, very primitive, very rare vegetation. It's definitely showing the last surviving plants that could be found in Antarctica. And we think it's 13.6. But to be certain we're going to use that date, 13.85, from the paper by Lewis et al. That was written on the location very close to that site, and where they find the last vegetation at that date.

So other than these sample, we looked at hundreds of samples that were not seen on the map, but from various piston cores taken all around Antarctica. And all of these Plio-Pleistocene samples are always barren, and at least all the ones we've looked at so far.

So to conclude with Antarctica, one thing I would like you guys to take home is our data is really showing us how vegetation changed since the ice sheet advance. And how the vegetation slowly disappeared, and what type of species survived. And when they really just couldn't keep up with the ice sheet advance.

And so again, we have 13.6 for the Ross Sea and 12.8 for the peninsula. Remember, the peninsula is in a warmer part of Antarctica, closer to Tierra del Fuego. So when you look at these dates, and you see something like that, that's a recent study by some British group where these biologists are studying vegetation there. And they really can see an increase in the last 50 years of vegetation in Antarctica. Mosses are coming back, and in quite a dramatic fashion.

So if you don't know about the geological history of the plant evolution in Antarctica, it might not seem very scary. But when you know that the last time you have vegetation in Antarctica, or at least that we see in our record is 13.6 million years ago, that puts things into a geological perspective. And on this diagram, is a little complicated with probably too much text, but that's a curve of the CO2. And again, CO2 is not the only factor changing the climate.

We saw in the climate model, it's one of the components. But it's a very important one. CO2 was very high in the Paleocene. It was even higher before in the Cretaceous, and then started going down by natural processes through a time like weathering and things like that.

And then it became quite stable between 500 and 700 for a long time in the Oligocene and the Miocene. During that time, that's when we start having these ice sheets advance in Antarctica. And our vegetation disappeared at 12.8 and 13.6.

So that's when the CO2 is going under 500. So 500 for us is a very important benchmark for when vegetation could recolonize Antarctica in massive way to do routine Palynological record. So 500 is not that far from today.

We are at 405. And we are increasing about 2 PPM per year. At least we have done that for the past 20 years or so. So we are about 50 years from being at 500. So that's why there is a lot of concern-- one of the reasons there is a lot of concern in the scientific community.

So to come back and finalize the talk. First again, I really want to thank AAPG and the AAPG Foundation for giving me the chance to share my research. And I'm really glad they put that ad.

It's definitely one of the biggest societal challenges of our century. Not an easy one. And I know a lot of the companies, the major oil industry are working towards finding solutions. So we should do our part too. Thank you.

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Distinguished Lecturer

Sophie

Sophie Warny

Associate Professor/AASP Chair in Palynology

Louisiana State University

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