Archive for August, 2010

Another Wooster Geologist in Montana

August 15th, 2010

In an earlier blog, Jesse Davenport (2011) described some of this experiences this summer while working on his Keck project in Montana. Jesse is still in SW Montana, although his official last day in the field is August 16. He should have plenty of great geology stories to tell from his time out here in Big Sky Country.

Speaking of Big Sky Country…
Earlier this month (August 8), I also came out to Montana State University to attend two On the Cutting Edge Workshops. The first workshop (August 8-11) was called “Using GIS and Remote Sensing to Teach Geoscience in the 21st Century”. This workshop has revolutionized the way that I will teach GIS in spring 2011, and it also has contributed to significant changes to other courses that I teach in the curriculum. I am so glad that I was able to participate with other faculty from all over the country who teach GIS and Remote Sensing courses.

The second workshop, which I am still participating in this week, is called “Teaching Geoscience in the Field in the 21st Century”. I love teaching in the field, so this workshop will help my activities each year with our I.S. program and with field camp. In fact, I gave a presentation on Wooster’s I.S. program twice to the audience of geologists, and it seemed to be well-received. There is definitely some commonality between capstone courses at various institutions, but there are some distinct differences, too. For example, no other school boasts of an I.S. Monday in which the Registrar dresses as a Tootsie Roll and the Dean dresses in the MacLeod tartan!!

In between each workshop, we spent a day in the field in which we were shown several different uses of technology in the field. I was able to play with (1) a tablet PC that ran GeoMapper software, (2) a toughbook that ran ArcMap, (3) a Trimble Juno that ran ArcPad, and (4) a GeoClino that allows simultaneous measurements of strike and dip (of bedding) and trend and plunge (of a lineation) within seconds!! The day was fantastic, because you typically do not get to try so many different digitial mapping technologies in one setting.

The military advantage of holding the Upper Cretaceous chalk highlands

August 15th, 2010

Upper Cretaceous chalk exposure in the gloomy Argonne Forest.

VIENNE LE CHATEAU, FRANCE–There is one strong geological control of warfare in northern France: the high areas are often thick, resistant Upper Cretaceous chalk while the valleys and plains below are usually poorly-consolidated greensands and clays. We’ve already seen these remarkable chalks this summer in Mississippi, Israel, and Germany. Cretaceous Chalk is nearly global in its extent (The White Cliffs of Dover in England and the Chalk Buttes of Kansas are made of it) and it tells us that there was something very different in oceanic chemistry and biology compared to today.

The Argonne Massif is a range of chalk hills running roughly north-south with the Aisne and Aire Rivers cutting through it, along with many smaller streams. The Champagne-Ardenne/Lorraine regional boundary runs through the long axis of the massif. In World War I the Germans occupied most of the highlands in the north since capturing them in 1914. They built relatively spacious and dry bunkers and trenches in the chalk, whereas the French and then later the Americans were mostly confined to the unstable clay-rich lowlands. The most bitter battles here were over the possession of key high points, and the geology of the rocks and soils was a critical factor in success or failure.

The Argonne Massif covered mostly by forest. North is at the top of the image.

Wooster Geologist in France

August 14th, 2010

Landscape near Vienne le Chateau, France.

VIENNE LE CHATEAU, FRANCE–I’m on the last part of my European trip this summer. The International Bryozoology Association post-conference field trip ended in Frankfurt yesterday. I rented a car at the Frankfurt airport and drove southwest into northeastern France where I will spend three days. I am visiting the World War I Meuse-Argonne battlefield to find those places where my Grandfather fought in the 345th Tank Battalion of the American Expeditionary Force (September and October, 1918). I hope to have posts related to the geology of the battlefield and how it affected events. I am staying in a small hotel in the Argonne Forest (N 49.19130°, E 4.88281°), so I’ll have plenty of time to explore.

An overgrown World War I entrenchment near my hotel.

The Messel Fossil Pit: A world-class experience

August 13th, 2010

FRANKFURT, GERMANY–Last year at this time I had the privilege of visiting the Middle Cambrian Burgess Shale on an expedition led by my friend Matthew James of Sonoma State University in California. It was an extraordinary opportunity to visit one of the most important fossil sites in history. Today our IBA field trip had a tour of another UN World Heritage fossil locality: the Messel Pit near Darmstadt, Germany. These Eocene oil shales were formed under very unusual conditions. They are maar deposits formed in a volcanic crater. Catastrophic releases of poisonous gases, the hypothesis goes, occasionally killed the surrounding fauna, causing many to tumble into the anoxic lake to be preserved in amazing detail. This is the home of Ida (Darwinius masillae), the controversial primate fossil now in Oslo (which I also saw last summer).

Our field party was taken down into the center of the maar to an excavation site run by the Senckenberg Museum in Frankfurt. There we watched a team of paleontologists excavate blocks of the shale and examine them for fossils.

Paleontologists extracting large blocks of Messel oil shale to examine for fossils.

Close-up of the Messel Shale. It contains about 40% water in outcrop, and so dries quickly in the sun. Fossils must be kept wet until preserved by various chemicals.

One of the paleontologists splitting Messel Shale with a large knife. The waste pile of examined pieces is behind her. Note the spray bottle of water beside her chair. The fossils must be kept from drying out until they are preserved.

Bits of an Eocene bird found in the Messel Shale while we were visiting.

An artesian well in the center of the Messel structure made when geologists drilled over 400 meters into the shales below. Yes, the tradition is to drink a glass of the water! (And I did.)

An outcrop of the Messel Oil Shale near the eastern side of the pit.

With this memorable paleontological experience our International Bryozoology Association field trip ended. I am grateful to Priska Schäfer of Kiel University for the fantastic (and complicated) organization and leadership. My teaching and research has been greatly enhanced, and I made wonderful new friends as well.

Tunnels yet again — and a loess connection

August 13th, 2010

OPPENHEIM, GERMANY–This jewel of a town, with its large cathedral, half-timbered buildings and narrow streets, share surprising geological connections with Vicksburg, Mississippi — a city visited by Wooster geologists earlier this summer. Both are river towns which profited in good times as trade centers, and both are underlain by Pleistocene loess sediments. Loess is wind-deposited silt and clay that can be easily excavated yet retain vertical walls because of the angular nature of its grains. Residents of both cities dug caverns into their loess deposits to store goods and to escape the dogs of war above them.

Model of a family hiding in a loess cavern underneath Oppenheim, Germany.

Oppenheim is almost completely undermined by up to 200 km of connected tunnels and cellars known collectively as the Kellarlabyrinth. The digging began sometime in the Middle Ages as a way to safely store and transport goods between buildings in the prosperous town. When the religious wars of the 17th century began, Oppenheim was almost continually besieged and occupied by one side or the other. The labyrinth below became a good place to hide from marauding soldiers. The system continually grew as the Oppenheimers dug laterally through the thick bed of loess below their town. The tunnels are still in partial use today after renovation and structural enhancement. In 1945 the American Army successfully crossed the Rhine near Oppenheim. As one of General George Patton’s tanks moved through the streets of Oppenheim, it crashed through the street into a tunnel below. Heavy vehicles have been rerouted around Oppenheim ever since!

You can't have an extensive Medieval cavern system in Continental Europe without some part of it turned into an ossuary. There are the remains of at least 20,000 people in the Oppenheim bone caverns.

A rainy day in the Mainz Basin

August 12th, 2010

View of the vineyards near Wöllstein, Germany.

View of the vineyards near Wöllstein, Germany.

OPPENHEIM, GERMANY–I want this termed Wilson’s Law: “The amount of mud encountered at an outcrop is inversely proportional to the quality of the fossils found.” Maybe it is my desert heritage, but I absolutely detest mud on my boots. Especially deep sticky quarry mud that grips lug soles and builds a progressively larger glob with every step. I try very hard to avoid slogs through it, but I’ve been spectacularly unable to avoid it in some places. Far too often I’ve slipped and slid through the glutinous stuff to find the rocks at the end to be distinctly unfossiliferous. Well mudded for little reward. Such was the case at the Rüssingen Limestone Quarry pictured below:

Today was a wet one in the Mainz Basin, and my fossil bag remained relatively empty except for some mollusk shells with borings (many of which are well described on this amateur’s page). Still, the geology was very interesting. The Mainz Basin is not a true basin in the geological sense. It is better described as a fracture zone at the western border of the Upper Rhine Graben. We were most interested in the shallow marine and brackish water Oligocene sediments deposited within these boundaries. Some of the sediments rested directly on sea cliffs of Permian rhyolite which was spectacular (but alas, not photogenic).

Clasts in the Alzey Formation (Oligocene, Rupelian) exposed near Wöllstein, Germany. The large pebble by the two-Euro coin is a Permian rhyolite; the white pebbles are from quartz veins in metamorphic rock. Both clast types were derived from nearby rocky cliffs during deposition.

Our last stop of the day was the Naturhistorisches Museum Mainz (Mainz Natural History Museum). This was much fun, especially since we had a special dinner with the director and staff in the galleries. The collection and displays are very good. I could have the usual photo of some vertebrate fossil in a case, but instead I was taken with a humble drawer of fossil snails packed in cotton so that they appeared to be floating in clouds:

Wooster Geologist on the Rhine

August 11th, 2010

OPPENHEIM, GERMANY–Our International Bryozoology Association field trip started the day in the little town of Prüm looking at Devonian limestones and shales, and then we drove to Boppard where we boarded a Rhine River ferry for a trip upstream to Bacharach. The weather threatened rain but held off, giving us excellent views of the steep sides of the middle Rhine Valley with its little villages, precipitous vineyards, and numerous castles.

One of the attractions of this voyage was the “Loreley“, a large cliff at the narrowest point of the Rhine. It has historically been the site of many accidents because of the shallow, fast waters over the rocky river bed near the outcrop. There is a thick crust of Germanic sentimentality over this place which I don’t quite understand. In our case it involved the ferry loudspeakers playing a song based on a poem by Heinrich Heine that is a traditional favorite. At least I know this: the rock is a Lower Devonian quartzite, part of the Taunus Formation, and derived from tidal flat sediments!

The Loreley exposure on the right bank of the Rhine River, Germany.

Geology and religion: le Grand Animal de Maastricht

August 10th, 2010

The discovery of a mosasaur in the Maastricht tunnels (1770). Engraving by G. R. Levillaire; image from Wikipedia.

MAASTRICHT, THE NETHERLANDS–Next month I am giving a talk on campus about evolution in a lecture series on “science and religion”. I was particularly intrigued, then, to hear a story about the famous mosasaur discovered in the Maastricht tunnels that highlighted tension between geology and the religious establishment long before Charles Darwin started rocking boats. It was a delight to be in the very tunnels where the drama began.

In 1770 a group of quarrymen in Maastricht discovered the skull of a very large and toothy animal. It was brought to the attention of Johann Leonard Hoffman, a local surgeon and fossil collector, who immediately knew it was very curious and would be of great interest to the savants of Europe. He corresponded with many, producing what we would call a buzz today about this creature. It clearly represented an animal which went extinct — a new concept at the time. How do you explain the existence of a large fossil like this deep underground in The Netherlands? Was it an animal which missed Noah’s Ark? Did God create some animals doomed to extinction?

In 1794 an army from revolutionary France occupied Maastricht. Some officers wanted to seize the fossil and put it on display in Paris because of these questions about God and Creation. They wanted to use this mosasaur (the name came much later) to show that either there was no God or that God was a distant deity unconcerned with Creation. Apparently through bribery and rewards, they found the fossil and indeed shipped it off to Paris. To this day it is in the Paris Museum of Natural History and only a cast of it is in the Maastricht Natural History Museum. (The Dutch have various ways to remind visitors that the French stole the original specimen. European unity only goes so far!)

Cast of the famous Maastricht mosasaur in the Maastricht Natural History Museum.

In Paris the famous geologist Georges Cuvier took an interest in “le Grand Animal de Maastricht” and correctly identified it as a reptile — specifically a kind of marine lizard (a conclusion still supported today). Cuvier used it as evidence for his catastrophic ideas of disasters followed by re-creations of life on Earth.

The Maastricht mosasaur, now known as Mosasaurus hoffmanni, thus was one of the first fossils to be used in the science-religion debates, and this was well before the modern theory of evolution emerged.

Mosasaur skeleton reproduction in the Maastricht Museum of Natural History.

The best Cretaceous-Paleogene boundary yet

August 10th, 2010

MAASTRICHT, THE NETHERLANDS–The Cretaceous-Tertiary boundary (K/T, or as I should be writing, the “Cretaceous-Paleogene” boundary, or K/Pg) has been one of the Wooster Geology themes this summer. We saw it in Alabama and Mississippi in May, and in Israel in June. The view of it here in The Netherlands, though, is far different. We explored it from below in the Maastrichtian tunnels at Geulhemmmerberg (N50.86692°, E5.78357°). This three-dimensional view, combined with the fact that this boundary section may be the most complete ever found, made today very special. We had a secular geological pilgrimage to the mysterious global events at the end of the Cretaceous.

After walking a long distance through the maze of tunnels guided by John Jagt of the Maastricht Natural History Museum and Rudi Dortangs, a very keen and accomplished amateur paleontologist (with a new mosasaur to his credit), we came upon excavations at the roof line which uncovered a thick sequence of clays and carbonate sand mixed together. The K/Pg boundary is a highly-irregular hardground surface with many Thalassinoides burrows penetrating up to two meters below. Carbonate sands are directly above the boundary, with the clay layers of varying vertical distances but rarely sitting on the hardground. There are at least seven clays, with the largest (Layer D) several centimeters thick. Since this boundary is near the roof of the tunnels, the bottom layers were often the ceiling above us so that we could see the very latest Cretaceous and earliest Paleogene exposed as a kind of upside-down bedding plane.

Two big surprises for: I knew there were multiple clay layers in some places, but to finally see them made them real for me. The traditional view since 1980 has been one clay layer representing the dust and debris from the meteorite impact settling back to Earth. Multiple clay layers makes this story much more complex, especially since some of the layers combine and split laterally. Maybe they were reworked during the storms of that “Global Winter”?

The second surprise was to learn that there were ammonites which definitely survived the extinction and lived briefly in the Paleogene. When these fossils were first found it was assumed they had been reworked from the Upper Cretaceous, but new studies show that they contain sediments which are indisputably Paleogene. Whether this is enough for us to change the textbooks is an interesting question: there are so few of the fossils, and in even fewer places. Nevertheless, some ammonites extend into the Paleogene.

Andrej Ernst and John Jagt at the boundary section in the Maastrichtian tunnels at Geulhemmmerberg.

This is a day I will always remember. For a historical geologist like me, it doesn’t get better!

Now I know why they call it Big Sky country…

August 9th, 2010

Guest Blogger: Jesse Davenport

That is, when you look outside all you see is sky for miles upon miles upon miles upon…well you get the picture. It is extremely beautiful here. In Island Park, Idaho, we are sitting right on the border of Montana. Yellowstone is just a mere 30 miles away. It is one thing to read and study an area like I did for my junior thesis, but is an entirely different to actually be able to see the areas that I read about.

After a shaky first two days of traveling arrangements at the lovely Bozeman airport, everyone was finally together. Everyone including me, Caleb Lucy from Williams College, Danielle Lerner from Mt. Holyoke, Kristina Doyle from Amherst, Parker Haynes from the University of North Carolina, and Ali Walker from Smith College. And of course our two lovely professors, Tekla Harms from Amherst and John Brady from Smith. Saturday, Sunday and Monday we traveled out into our field areas in the Antelope Basin of the Gravelly Range to conduct some reconnaissance work. We familiarized ourselves with the rock formations, practiced our Brunton skills, and talked about the upcoming month.

Today, we sat down with Tekla and John to discuss our specific projects and what we would be doing individually. I will be doing geochemistry in what is termed the Madison Mylonite zone to try to determine the protolith of these highly sheared rocks by also doing the geochemistry on some of the other rock types around the region. These include diorite, schist, marble, phyllite, and many others.

The rock here is a biotite schist. The main significance, however, are the wonderful crenulations in the rock (very small folds in the rock).

The rock here is a biotite schist. The main significance, however, are the wonderful crenulations in the rock (very small folds in the rock).

The rock you are looking at here is one of the many mylonites in the area, which I will be taking samples from to do my analyses.

The rock you are looking at here is one of the many mylonites in the area, which I will be taking samples from to do my analyses.

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