Documenting Past Climate Change

Abstract

To eliminate the variability inherent in the weather, ‘Climate’ is taken to be a 30-year average of temperature, precipitation and other factors. As the old saying goes, ‘The climate is what you expect; the weather is what you get.’ Earth’s climate has varied between two major states, ‘greenhouse,’ where there is no ice in the polar regions and equator–pole temperature gradients are small, and ‘icehouse,’ where the polar regions are covered by ice and the latitudinal temperature gradient is large. During the icehouse state, the climate oscillates between glacials when the polar ice expands down to the mid-latitudes, and interglacials when it is restricted to high latitudes. The last change from greenhouse to icehouse occurred about 35 million years ago. For the past 800,000 years, glacials have lasted about 80,000 years, followed by a deglaciation lasting 10,000 years and an interglacial lasting 10,000 years. Determination of changing geologic process rates has become possible through the development of more sophisticated techniques involving potassium–argon dating, reversals of Earth’s magnetic field, fission track dating, astronomical dating, and tritium, carbon-14, and beryllium-10 dating techniques. Human activities have greatly accelerated the rates of geologic change. The climate of the past 6,000 years, during which civilization has developed, is the longest period of stability in the past few million years.

Intermezzo V. A Postdoctoral Year in Switzerland—and Europe: Part I

While working on my Ph.D. I gave serious thought about what I wanted to do next. As one of the measures taken to develop science in the United States after the launching of Sputnik in 1957, the National Science Foundation had announced a program of awards for Postdoctoral study. I was tempted to see if I could squeeze in one more year of learning before entering the teaching profession. I asked Hans Thalmann what he thought I should do. He suggested that if it were possible, it would be good for me to continue my studies in micropaleontology at an institute where many micropaleontologist had received their training—the tiny Geological-Paleontological Institute of the University of Basel in Switzerland. There were only two regular faculty members, Louis Vonderschmitt, geologist, and Manfred Reichel, micropaleontologist. Reichel’s personal specialty was the study of ‘larger foraminifera’. These fossils, abundant in Late Paleozoic, Cretaceous and Early Tertiary marine strata range up to several centimeters across.

In the meantime, I had been contacted by George White at the University of Illinois. He wanted me to apply for a position there. I wrote him that I might want to have a year of postdoctoral study if I could manage it. He thought that would be a good idea, but wanted me to apply anyway. I sent in applications to the University of Illinois and to the National Science Foundation. I received an offer from the University of Illinois and a postdoctoral award from the NSF at the same time. I called George White about my dilemma, and he said the matter was settled at Illinois. They wanted me, and could wait a year for me to come. I tell this because this is the way things were done in those days. Lyndon Johnson, as leader of the US Senate saw to it that science was taking a massive upswing in the US. Academic positions became available as well a funding for research.

Two friends who attended our informal micropaleontology seminars at Stanford were Al Loeblich and his wife Helen Tappan. They had just published a major monograph on the planktonic foraminifera, which was immensely helpful to me in my research. Al worked for Chevron. When he found out I would be spending a year in Basel, he approached me with a proposition. He was very interested in obtaining sample material from the sites in Europe where planktonic foram species had first been described, known in the profession as ‘type material’. Chevron would pay me $25 per sample; the samples had to be at least 1 kg. It turned out that there were more than a hundred localities involved, so it was a significant sum of money at the time. The possibility of having funds to travel around and see so much geology sounded great, but I needed approval from the National Science Foundation. To my great joy, they approved of the arrangement, but with one proviso: I had to spend all of the money on travel expenses, every last cent had to be for expenses.

My father retired in 1959 as his company was sold to a larger insurance firm. He was in is early 60s and they had set him up with what at the time seemed a nice retirement plan. However, he remarked at the time that the executives at the new company had salaries that were almost double his. In his day, the executives worked to earn money for the stockholders; he feared that we were entering an era when executives would work for their own, not the stockholder’s benefit, Only recently have I come to realize what great insight he had into economics.

Dad decided to make his first trip to Europe, with me as his guide in the summer of 1959. We were going first class. We flew from Dallas to New York on one of the new American Airlines jets, they had been operating only six months. In New York we boarded the French Liner Liberté and sailed for France. My experiences in crossing the Atlantic had been on a freighter in 1953, and then in tourist class on the Italia in 1955 and Mauretania in 1956. I had bought a tuxedo, required for dinner, before leaving Palo Alto. Dad was immensely proud that I spoke some French, and I was in charge of negotiating the wine list.

Dad had an old friend, Larry Green, who had become very wealthy and now lived in tax-free Liechtenstein. Larry had made and lost several fortunes. His latest one had come about when he sold the French automobile company Renault on the idea of selling their cars in the US. Larry set up dealerships, and received a commission from every car sold. He had arranged accommodations for us in Paris, at a small hotel, the Raphäel, on the Avenue Klèbèr, just a block from L’Etoile with the Arc de Triomphe. We were greeted like old friends, M. Green was well known to the staff. We had a suite that Larry apparently kept reserved, in case he should want to visit Paris. Those were the most luxurious accommodations I have ever had in Europe (or the US for that matter). My father was impressed, and even a bit taken aback. A few days later we were to pick up a car at the Renault factory, but first we had a tour led by one of the executives. Even in 1959, the production line was robotized; the chief role of humans was to try to find bad welds and other imperfections, using hammers and chisels if necessary. It seemed way ahead of automobile production in the US.

After a week we left Paris and headed for Basel, where I dropped off a suitcase of winter clothing for storage at the Institute. All of the faculty and students were away on a field trip. We went on to Zürich were I showed dad my old haunts. Then to Liechtenstein and Larry’s chalet. Liechtenstein is a small country, about 160 km² (62  sq mi) on the east side of the Upper Rhine valley between Switzerland and Austria. It is a constitutional monarchy governed by a Prince, who lives in a castle high on the mountainside. Larry’s chalet was located about half way up to the castle and had a magnificent view over the town of Vaduz and the broad Rhine valley. In spite of its small size, Liechtenstein is an economic powerhouse. Many of the world’s largest corporations have their home office there. The offices are actually mailboxes in a small office building in Vaduz.

From Vaduz we headed for the Alps, with our first overnight in Lucern. There disaster struck. My father slipped in the shower and broke his leg. We got it set and put in a cast, and continued our trip, but not through the Alps, since he could hardly walk, but to Vienna, then Venice, then across northern Italy to Provence in the south of France. In Monaco we met Larry Green again. He had a yacht docked next to the harbor entrance. After that my father took the train back to Paris and flew back to the US. Later he said that his greatest mistake was to continue on with our trip rather than immediately flying back to the US, and to come back to Europe later while I was still there.

From Provence I drove back to Basel, where my Postdoctoral year was to begin September 1. I went to the Institute to get my suitcase and learned that only a few days before, Professor Reichel had a heart attack and was in the hospital for an indefinite stay. Professor Vonderschmitt was very kind and introduced me to an Adjunct Professor, Hans Schaub, who worked on a special group of larger foraminifera, the nummulites. The word ‘Nummulite’ stands for ‘coin stone,’ and these fossil forams are the size and shape of coins, but one species, found in the rock used to build the Great Pyramids in Egypt, reaches the size of a dinner plate.

Hans Schaub had worked on them for 20 years, carefully collecting them from layers of sediment in a deposit called the Schlierenflysch just inside the northern edge of the Alps a short distance south of the Lake of Lucern. At that time, ‘flysch’ (pronounced fleesh) was a bit of a mystery. It was a sediment formed as the Alps were being deformed in the early Tertiary and shoved onto what was then the southern margin of the European continent. The Schlierenflysch is a sequence of alternating sands and shale. We now know that the sands represent periodic submarine landslides down the slopes in front of the rising Alps while the shales are deposits formed by settling of particles through the water column during the normal process of sediment accumulation. The sands represent deposits that formed in hours, the shales deposits that formed over1,000s of years.

Everyone said that there were no more nummulite fossils to be found in the Schlierenflysch, Hans had taken them all. He had just recently put together a history of their evolution. He showed me his collection of samples and specimens. The nummulite fossils were in the sands, and the shales seemed to be devoid of fossils. Hans thought that maybe there could be planktonic foraminifera in the shales that had gone unnoticed.

Now a brief digression: while I was in my last year at Stanford, we had a brief visit from Milton Bramlette, an older geologist who had been with the US Geological Survey but was then at the Scripps Institution of Oceanography. He had gotten interested in extremely small fossils, ‘nannofossils’ that could only be seen with a high powered microscope. They were mostly a few microns (1 μ = 1,000th millimeter) across. Some were elliptical ‘coccoliths’, similar to the plates of Emiliania huxleyi you saw in Fig. 1.3. Others, ‘discoasters,’ looked like miniature stars. He showed us how to extract them from shale by scraping off a bit with a knife and making a slurry in water.

The evening after Hans Schaub showed me his sample collection. I took a stereoscopic binocular microscope to look at pieces of the shale as he had suggested. If there were planktonic forams in the shale, some fragments should have been visible on the surface. But there seemed to be nothing there. I decided to try scraping off bits, making the slurry, and looking at it through a high powered microscope.

One of the meanings of the word ‘epiphany’ is ‘a moment of great or sudden revelation’. I don’t remember the exact date, but it was about 6 p.m., and everyone had left the Institute. When I looked through the microscope, I saw myriads of nannofossils. I took another sample, from higher in the stratigraphic section. It too had lots of nannofossils, but they were different. I forgot all about getting dinner and worked through the night. By morning I had looked at many samples, each one different from the others. When Hans came in the next morning, I told him that his shale samples were full of nonfossils. Furthermore, I told him that if he gave me an unknown sample, I could probably tell him where it came from in the stratigraphic section. Hans was dumbfounded. He started giving me unknowns, and indeed I could tell him which layer it was. Louis Vonderschmitt came in and joined the party. This could be a major key to unraveling the history of deformation and uplift of the Alps. In one night I had made as much progress in deciphering the stratigraphy of the Schlierenflysch as Hans had made in 20 years

Early in the fall I made a few collecting trips in Switzerland, now not just for planktonic foramifera, but for nannofossils as well. Shipments were sent off to Al Loeblich at Chevron, and the fund for travel expenses began to grow.

Later, toward the end of October, Hans Schaub and I headed off to France and northern Spain to collect samples from a number of localities.

Our first stop was in Paris, to discover what was in the collections of the Musee d’Histoire Naturelle. Hans wanted to see the nummulites, and we were shown into a large room filled with storage cabinets. Each cabinate had many drawers with cardboard trays containing the fossils and a label telling what they were, and where they had come from. Hans was excitedly going though the drawers, making notes on what they contained. Then he opened one drawer, and it dropped out, spilling everything onto the floor. Fortunately he knew these fossils so well he was able, in a few hours, to get them all back into their correct trays. There was a note left over. It read something like ‘On December 12, 1858, I opened this drawer, and it fell out of the case, spilling all the contents onto the floor. I have put everything back into the proper trays as best I can. I will ask the staff to have the drawer fixed—D’Archiac’ ‘D’Archiac’ was Étienne Jules Adolphe Desmier de Saint-Simon, Vicomte d’Archiac (1802–1868). Hans roared with laughter on reading it. No one had looked in that drawer for a century, and the staff had not gotten around to repairing it. Hans left his own note in the drawer, presumably for someone in the 21st century.

Paris lies in the middle of a geological basin, with Tertiary rocks underlying the city, and a ring of Cretaceous chalk surrounding it, and encircled by Early Cretaceous and Jurassic rocks further out, This was the region that had formed the basis for Baron Cuvier’s idea of catastrophes and successive creations. Through his study of nummulites Hans Schaub had been able to show that the Tertiary deposits of the Paris Basin, that had been the crux of Cuvier’s ideas, represented only moments of geologic time. Indeed, the time intervals represented by the Tertiary deposits were so short that no evolution was evident in them, just as Cuvier had described. Through his studies elsewhere Hans had been able to demonstrate that most of geologic time was represented by the bedding plane surfaces separating the rock units.

Our first area of interest for sample collecting was in the Loire Valley and near the city of Le Mans. Then we headed south to the Bordeaux region. North of Bordeaux the rocks dip down to the south into what geologists call the Aquitaine Basin. After examining some sites along the edge of the Gironde Estuary, we headed to two famous places south of Bordeaux.

The first was the type section of the Burdigalian Stage. The physical units of the geologic column presented in Chap. 3 are Systems; the age of each System is a Period. Each System is divided into smaller units, called Stages. Their time equivalents are 'Ages'. Each stage has a reference section on which it was based, designated the ‘type section’. The type section of the Burdigalian Stage (Lower Miocene) is in the forest behind an elegant home, known as Le Coquillat in the village of Léognan. We asked the owner of the home for permission to visit the exposure, and he was delighted to meet us and to show us the way. The locality is a pit in the forest, and the owner of the estate is very proud that he has such a famous treasure in his backyard. The name ‘le coquillat’ means ‘the place with the shells’ and it is indeed extraordinarily rich in fossil seashells, mostly molluscs and gastropods.

But we had an even more interesting experience visiting the ‘type section’ of the underlying Aquitanian Stage, not far away. It is the base of the Miocene. The type locality is an outcrop along the river in the ‘vallon de Saint-Jean-d’Etampes’ (vallon = valley) at on old mill called the Moulin de Bernachon near the village of Saucats. We had already had a long day when we arrived at the Moulin. We could see the exposure of sediments outcropping across the river. A farmer lived in the old Moulin, and we explained that we were geologists and asked him if we could park our car here, on his land, next to the river while we visited the outcrop on the other side of the river. He too was delighted to have us visit; a number of geologists had been here over the years. The car was parked facing the outcrop. We started wading into the river; it wasn’t flowing fast, but the water was well above my waist. Also we soon learned that there were deep holes, where the water was over our heads. But the farmer knew the river well, and from shore directed us where to go to avoid the holes. Evening was approaching, and we had our work cut out for us to measure the strata and collect samples before it got dark. We had about 100 pounds of samples each in our rucksacks when we were ready to cross back over. By now it was dark, and the farmer thought he could help by turning on the headlights of Hans’s car. Now we were trying to cross back heavily weighted down and looking straight into the blinding headlights. The farmer again tried to help us avoid the holes, but now when he said ‘to the left’, we didn’t know whether he meant to his left or to our left. By the time we got back across, both of us had gone in over our heads, and we were thoroughly soaked. It was about 10 p.m when we got everything loaded back into the car, and thanking the farmer for his help, started back to the main highway.

We had planned to drive on to Dax that evening, but that was several hours away, and we figured that all the hotels would be closed for the night. Bordeaux was closer so we decided to drive back into the city. We realized we were going to arrive about midnight. Now we had a dilemma. Our clothes were wet and partly covered with mud. Hans said ‘We have two choices, we can go to a second class hotel, near the train station, and hope they will take us in, but then we will be awakened early by the trains—or we can go to a first class hotel and see how they react. We chose the latter approach; after all I had plenty of travel expense money to dispose of.

I got out my Guide Michelin and, using a flashlight, selected what was listed as the best hotel in Bordeaux, the Splendid. We arrived just at midnight. I walked in hoping my muddy boots didn’t leave a trail across the impeccable red carpet. I introduced myself to the desk clerk as Dr. Hay and told him that Professor Schaub and I were geologists, had been studying the rocks and collecting fossils, and that we would like two rooms for the night if they were available. Academic titles are worth as much as nobility in Europe, and the clerk was pleased to have such distinguished visitors. He did a great job of not noticing any of my wet, muddy clothing. ‘Of course’, and he handed me two keys. I asked “I don’t suppose the restaurant is still open”. “We usually close at midnight, but we will be happy to remain open if you can come down shortly”. I assured him we would be down as soon as we changed our clothes. Then, the only indication he had noticed my muddy clothing. "Perhaps you would like to take the elevator from the garage directly to your room”.

We showered and changed quickly and went down for dinner. We were the only ones in the dining room. I had seen that the specialty of the house was tournedos Bordelaise, so that is what we ordered for a main course. The waiter went back to the kitchen, and the chef appeared. He was delighted with our order, and made suggestions for appetizers, salads, vegetables, and desert. Then the sommelier appeared with the wine list. It was very impressive. In those days Bordeaux wines were not nearly as expensive as they are today, and we ordered two bottles, a 1945 Chateau Lafite, and a 1929 Chateau Margaux, both great and very rare vintages. As I recall, each bottle cost around $35.

By now the desk clerk, and waiter had joined us at the table, and Hans regaled them with stories of collecting fossils in the south of France and the glories of nummulites. The sommelier brought the bottles and decanted the wines using a candle. We insisted on sharing a glass of wine with each of our new-found friends, which they greatly appreciated. It was a meal never to be forgotten. After the tournedos were prepared, the Chef joined us at the table. But the highlight came when a fly that had been buzzing around made a straight shot down the neck of a decanter into the 1929 Margaux. The sommelier immediately disappeared and came back with a small sieve, and poured the wine into another decanter, removing the fly with the sieve. The meal and stories went on until about 3 a.m.

There was another memorable culinary experience on that trip. We had ended another long day of sample collecting in the cemetery of the village of Minerve, east of Carcassonne. It was already dark, but Hans had some newspaper to make a torch, and we used that for illumination of the rock outcrop on the edge of the cemetery. I’ve often wondered what the people in the village must have thought seeing two strange figures working by torchlight, hammering away at the rocks in the cemetery. We finished about 10 p.m and drove to Carcassonne.

Carcassonne is a modern city, but it has a magnificent, medieval, walled old-town on a hill, and we had decided to try our luck with a hotel there. Using the trusty Guide Michelin, we chose the Hotel de la Cité. Again we arrived about midnight. I tried my “I don’t suppose the restaurant is still open?”. “Non” the clerk replied, but he suggested that he could bring out a few cold things if we needed something to eat. We sat down in the darkened restaurant, and the clerk brought out huge trays of patés, cheeses, olives, tomatoes, and fruit. With good wine from the Corbières, it was a feast to rival the Splendid in Bordeaux.