Bored marbles, slate mines, and a castle in North Wales

June 12th, 2018

Aberystwyth, Wales — Let’s start with the castle as my tour of Wales with Tim and Caroline Palmer continues. Above is the storied Harlech Castle in North Wales. It was built of sandstone blocks by Edward I in the 13th century, passing through four major conflicts: The Revolt of Madog ap Llywelyn (1294–95), the Revolt of Owain Glyndŵr (1400–09), the Wars of the Roses (1460–68), and the English Civil War (1642–47). The siege in 1468 apparently inspired the stirring song “Men of Harlech“. (Hear it and read the lyrics on this YouTube page. The song is unforgettable in the 1964 film Zulu.)

When built, Edward I made very sure Harlech Castle could be supplied by sea, so there was a water-gate on the shore. This is now the view of the ocean from the castle — it is far away, with a significant dune field along the shore. I could not find out why the shoreline retreated from the castle; it may have been a combination of sedimentation and isostatic rebound of the land in slow response to the end of glaciation.

In 1709 a ship sank off the coast of Barmouth, Wales, submerging an expensive load of 43 blocks of Carrara Marble from Italy. One two-ton block was recovered after centuries on the seafloor and sculpted by an artist (Frank Cocksey) to celebrate the millennium. It is called The Last Haul, representing three generations of fishermen pulling in a net.

It is beautiful carving … but you know I’m not showing it for the art. Check out the holes throughout!

This marble block is heavily bioeroded by marine organisms, producing the clavate borings Gastrochaenolites (by bivalves), a network of connected small chambers (Entobia, made by sponges), and long narrow cylindrical borings known as Trypanites (by worms). There is a cool story to sort out here about the pattern and rate of bioerosion in these cold seas. [UPDATE: The Curious Scribbler has a new post on these marbles with lots of information and ideas. You may even recognize some people in the images.]

Our last site of the day was the Welsh town of Blaenau Ffestiniog. Slate mining made this place, starting in the middle of the 18th century. The surrounding mountains have a rich grade of Welsh slate useful for many industrial and structural applications. The town square (above) has a monument to its slate heritage.

This mountain above Blaenau Ffestiniog has been heavily carved for its slate.

One quarry remains operational. The Welsh slate industry declined significantly during World War I and never fully recovered. Note the massive mounds of slate debris.

Slate mining produces large amounts of waste rock. Up to 90% of the slate removed from a quarry is unusable and piled up. Blaenau Ffestiniog is surrounded by man-made mountains of loose slate debris.

Thus ended another diverse day of Welsh experiences with Tim and Caroline Palmer.

A narrow-gauge train trip in Mid Wales

June 11th, 2018

Aberystwyth, Wales — Caroline Palmer provided Tim and me a wonderful experience in a scenic Welsh valley on a perfect Welsh day. She is Trustee of the nearby Hafod Estate ( … one of the finest examples in Europe of a Picturesque landscape.”) This estate is one of the places where pine martens have been re-introduced to Wales from Scotland. In that office she received three tickets (and lunches) for us to take a ride on one of the “Great Little Trains of Wales” to a celebration of a new train carriage and a Pine Marten center. It was delightful for both the natural views and the people involved.

We took the Vale of Rheidol Railway with this coal-fired steam engine pulling our narrow-gauge carriages. We sat in the open car directly behind the engine, so I could watch the crew in action and feel the occasional cool droplets condensed from the steam (and a whiff or two of coal smoke).

This was our route from Aberystwyth to Devil’s Bridge. (Map from Wikipedia.)

A view from the train traveling up the Vale of Rheidol. Very green and steep.

This valley has numerous silver and lead mines from the early 20th century and before, leaving scattered tailings piles like this one, along with significant heavy-metals pollution in some places.

We were greeted in Devil’s Bridge by the Mynach Community School Choir singing Welsh songs. They were fun. I felt the red-headed boy’s discomfort, though!

We ended the delightful day with a quick visit to the 13th century Aberystwyth Castle, a remnant of which was brilliantly lit by the setting sun.

A Wooster Geologist in Wales (continued)

June 10th, 2018

Aberystwyth, Wales — After the successful Larwood Meeting in Cardiff, I took a train to Carmarthen and met my friends Tim and Caroline Palmer for a delightful few days in Wales seeing building stones and geological sites. I’ve known Tim and Caroline since 1985, and Tim and I have published much together. Not only was I again adding to my knowledge of geology (and as always thinking of student Independent Study projects), but I was seeing old friends with whom I have much in common.

Above is Laugharne Castle in the town of Laugharne of Dylan Thomas fame. The castle was originally built by the Norman lords as part of a chain of strongholds to constrain the Welsh. You can read about the history of the site here.

The rock on which the castle was built was even more interesting, of course. It is Old Red Sandstone (Devonian), showing a facies a bit mysterious to us. It has trace fossils (Diplocraterion?), climbing ripples, and what may be dewatering structures.

One of my favorite activities is to go into Medieval churches with Tim and study the building stones and other stonework. Here is Tim examining an effigy in the Llanfihangel Abercywyn church interior. Tim is an expert on building stones in Great Britain, especially the sedimentary ones used most often in Medieval and earlier structures.

The baptismal font is usually the oldest stone object in a church because it can survive longer than larger, more complex parts.

A very special treat was seeing this stone at the end of our day. It is a monolith 1.4 meters high inscribed with “CORBALENGI IACIT ORDOVS”. This translates to: “Here lies Corbalengi the Ordovician”. It is thus called the Corbalengi Stone. It is Celtic and probably from the sixth century. It is one of the very few inscriptions mentioning the Ordovices tribe, from whom the geological period Ordovician is named. For those of us who work in the Ordovician, this is special. We like to think of Corbalengi as the Last of the Ordovices, although there is no other evidence for this.

A closer view of the Corbalengi Stone.

A much better image of the Corbalengi Stone, taken from this site. What a great start for the second half of my explorations of Wales.

Finally, I had to add this image of driving in Wales. This is a two-way road. Tim is a superb driver, for which I’m grateful!


A Smith Map in Wales

June 9th, 2018

Cardiff, Wales — Today Caroline Buttler and I met in the National Museum Wales and worked on an Ordovician bryozoan project together. There was nothing very picturesque going on until Caroline asked if I wanted to see their original William Smith 1815 geological map of England and Wales. The map that changed the world? Of course! There is part of it carefully unfolded above.

I professionally intersected with The Map on its 200th anniversary in 2015. I participated in a celebratory symposium at the annual Geological Society of America meeting, giving a talk entitled: “William Smith as a paleontologist: his views on the origin of fossils, their preservation and the history of life.” (Geological Society of America Abstracts with Programs 47(7): 24.) It was fun and I’ve closely followed studies of Smith and his map since then. This was thus a treat! Thanks, Caroline.

Last day of the Larwood meeting: Museum collections and a coal mine tour

June 8th, 2018

Cardiff, Wales — On our last day of the Larwood Meeting, we finished up business in the morning and then had guided tours of the marine, mollusc, and fossil collections in the National Museum Wales (above).

Highlights for me included this modern gastropod shell (a cold-water whelk from Alaska) collected by my hero Captain James Cook in 1778 a year before he was killed. A quote from Cook: “Ambition leads me … farther than any other man has been before me”. James Kirk of Star Trek is partly modeled after him.

Here’s another evocative modern shell: Conus gloriamaris, once thought to be the rarest shell and thus enormously valuable.

Here is the label for the specimen. It lists the 12 known specimens at the time. It is still popular among collectors, but now much more common. The excellent mollusc type collection of the Cardiff Museum is online.

The last activity for the Larwood crew was a tour of a coal mine turned into a museum: The Big Pit. Coal in South Wales played a huge role in the Industrial Revolution, as did Welsh iron ore. This mine tells the story of coal in Wales by taking visitors underground into the workings.

We couldn’t take images in the mine itself because of fire hazards, but Hans Arne Nakrem got a shot of the group prepared to go down the shaft. We had a great time with our story-telling guide. Our walk through the tunnels was punctuated by the loud bangs of my helmet on the ceilings. (It’s not just that I’m tall — it’s also that I bend far less!)

And that was the end of the 15th Larwood Meeting. Thank you again to Caroline Buttler and her team for such an excellent event. We all learned more about our precious bryozoans, with the bonus of getting to explore parts of beautiful South Wales.

Climate Monday: NERSC Surface Pressure Observations

February 12th, 2018

Although we often care more about the temperature and precipitation when we talk about weather, the most basic weather observation we can make is atmospheric pressure. Atmospheric pressure is really a measure of how much air is above you. That might not seem like a big deal, but clear skies are characterized by high pressure (e.g., 1020 hectopascals, or hPa) whereas storms are characterized by low pressure (e.g., 980 hPa). So air pressure was an early method of short-term weather prediction. If the pressure is dropping, a storm will likely follow. And once the pressure starts rising again, the worst is likely over. That’s useful. What’s also useful is that air pressure is easy to measure. Evangelista Torricelli made a functional mercury barometer back in the 1600s.  Today, air pressure is still one of the basic variables used to characterize weather and make forecasts.

The surface pressure network as of January 1851 (beginning of the animation).

Today’s climate visualization is 160 years of weather observations by Philip Brohan.  It’s a gargantuan 13-minute animation of all surface pressure observations dating back to 1851 that are currently freely available to the scientific community. Every frame shows all measurements for a 3-day period. That is precise! And some of the patterns are fascinating. At the beginning of the record, most of the data are from ship observations. The only land stations are in North America and Europe, and even those are limited.  Throughout the late 1800s, the USA, Europe, Russia, and Australia all see increasing coverage. At sea, changes in ship technology is apparent, as individual ships make a greater range of observations as time progresses.  The opening of the Suez and Panama Canals is also obvious. Several countries show abrupt increases in the density of their pressure networks. Japan suddenly has ample coverage in 1901; Germany increases density in the 1930s that far exceeds France. During WWII, India suddenly has a broad network, and Germany’s network reaches a peak in coverage that suddenly drops after the war. eastern China’s network becomes large in the 1950s, falls back in the 1960s, and then stays dense for good in the 1970s. Finally, the breakup of the USSR in 1991 was accompanied by a major decrease in surface pressure observations.

I have not dug too deep into the history of these observations, but this animation is a good window into how human technology and society can impact the availability of scientific data.  We are still reliant on shipping lanes to this day for pressure observations, and we know more about the North Atlantic than the South Pacific.  For more information about the data source, check out Internatonal Surface Pressure Databank.

The surface pressure network as of March 1970 (9:45 in the animation).



Wooster Geologist/Historian on the San Andreas Fault

June 17th, 2017

Berkeley, California — Brandon Bell (’18) is a double major in geology and history at Wooster. He has a classic double-major thesis that combines both disciplines: the early history of modern seismology following the Great San Francisco Earthquake in 1906. He is focused on the growing international communications among scientists about earthquakes, especially between Japan and the United States. Brandon thus is studying the geology of earthquakes as well as original documents generated through these international discussions. Brandon received Copeland Funding from the college to visit the Bay Area of northern California to work in the libraries and visit the San Andreas fault itself. The above image is of the beautiful University of California campus in Berkeley.

Brandon has his own detailed and illustrated blog describing his adventures. Check it out! He is still adding to it.

Special thanks to Dr. Peter Roopnarine at the California Academy of Sciences for meeting with Brandon and adding to his knowledge and experiences.

Wooster Geologists visit Saint-Émilion in southwestern France

June 8th, 2017

La Barde, France — On our last full day in southwestern France, Independent Study student Macy Conrad (’18) and I had a cultural visit with our host Paul and Patricia Taylor to the ancient town of Saint-Émilion. This town, set in a place that has been inhabited for millenia, is a World Heritage site amidst extensive vineyards and wineries. It has many architectural and historical treasures, which we could only touch upon during our short visit.

This wall is all that remains of a 13th-Century monastery demolished in 1337. It is referred to as the “Great Wall”. The building stones in this wall and most of the town itself are Oligocene limestones, some rich with fossil fragments.

The interior of the Collegiate Church, a mix of Romanesque and Gothic architecture.

12th-Century frescoes still survive in the Collegiate Church of Saint-Émilion. This set shows the grisly story of Saint Catherine.

The cloisters of the Collegiate Church. Imagine the characters who walked through these passages, from Crusaders of the 12th Century to occupying German soldiers of the 20th.

More 13th century frescoes in the cloisters.

The building stones show magnificent weathering over the last 700 years or so.

The most elaborate weathering accentuates burrow systems in the Oligocene limestones. Later building stones in other regions were actually carved to show apparent weathering patterns like these.

Our lunch view. The bell tower is for a church carved into the limestone below. This is another underground church like the one we visited in Aubeterre.

Our lunch in Saint-Émiliion. Yes, fieldwork is tough in southwestern France. Macy Conrad (’18) is on the left, with Patricia and Paul Taylor and then me.

I want to add an image of the war memorial in Saint-Émilion. Every French village, town and city has at least one. They were erected after World War I and usually inscribed with hundreds of names. The World War II local dead are often inscribed later on the bases.

Finally, a few images from our delightful lodgings in the Taylor home at Bard’s End, La Barde. This is the lounge, which held livestock when this was a farmhouse in the 19th and 20th centuries.

The lounge from the other side, with Paul Taylor entering from outside.

The multi-talented Macy was a great help to the Taylors as they assembled a set of furniture from Ikea.

All our dinners were outside on the patio facing the River Dronne. Delightful!

Thank you again to Paul and Patricia Taylor for making this research expedition such a success and pleasure. We will report our results in later posts!

Macy and I leave tomorrow morning on a long train trip to Paris. I then fly home and Macy continues her European adventure with a visit to friends in Norway. Team France is done with fieldwork. The extensive labwork begins this summer with our specimens.



A Wooster Geologist on the Somme Battlefield

May 30th, 2017

Amiens, France — I had two days between the bryozoan meeting in Vienna and the fieldwork in southwestern France, so I decided to visit the World War I battlefields in the Somme Valley of northern France. It was a somber experience of natural beauty, stark and effective memorial architecture, and one of the deepest historical tragedies. I had a similar journey in 2010 to my Grandfather Snuffer’s World War I battlefield in the Meuse-Argonne. Above is a view of the cemetery at the Australian National Memorial near Villers-Bretonneux.

There were two major battles between the Allies and the Germans in the Somme Valley. The first, between July 1 and November 18, 1916, was the largest in terms of soldiers involved and lost. There were more than a million casualties, about even on each side, during those four and a half months of battle. A large proportion of those losses occurred on the first day; indeed, the first few minutes. The results were a draw. The second Battle of the Somme took place August 21 through September 2, 1918, and was an overwhelming Allied victory. This brief blog post is about my impressions of the battlefields a century later, so please follow the links for the historical background.

Gravestones at the Australian National Memorial. These are primarily for Australian soldiers, but there were also stones for New Zealanders, South Africans, Britons, and Canadians.

Flanders poppies grow naturally in this region, and they are also used decoratively in cemeteries. See the famous poem by John McCrae: In Flanders Fields.

An emblem of the soldier’s unit is engraved at the top of each stone.

The memorial building has walls of Portland Limestone (Jurassic of southern England) listing the thousands of missing Australian soldiers in the first battle.

In a compounding irony, the Australian National Memorial buildings and gravestones were shot up in turn during a skirmish here between Allied soldiers and invading Germans in 1940.

This is the small Proyart German Cemetery from the 1918 battle. There are over 450 cemeteries from all the involved nationalities throughout the valley. This one is seldom visited but immaculately maintained. The town of Proyart saw much fighting from the beginning of the war to its end.

An unknown German soldier. There are tens of thousands of unknown graves on the battlefields, matched by long, long lists of the missing.

Lochnagar Crater is a massive hole produced by the explosion of a British mine under the German lines on July 1, 1916 — the first day of the first battle. The bedrock is Cretaceous chalk, which was easy to tunnel with simple tools except that it had to be done in silence. No pickaxes were allowed. The last part of the explosives tunnel was dug under the German trenches with bayonettes alone. It is said that one soldier would pry a flint from the wall as another caught it before it struck the floor. The mine explosion was at that time the largest man-made sound in history.

You’ve heard that French farmers still find live artillery shells in their fields? Here’s one of them. About 60 tons a year of WWI explosives are removed from the Somme battlefields. The one above was marked for disposal with a red plastic cup. Demolition teams drive through the countryside in armored ammunition disposal vehicles removing munitions.

The local farmers repurpose many WWI items. Here a modern barbed wire fence is constructed with German barbed wire stakes from the war.

The Battle of Thiepval Ridge was a complicated and bloody operation in September, 1916. The ridge which cost so many Allied lives was selected as the site of the Anglo-French Memorial to the Missing of the Somme. Over 72,000 names are engraved on the limestone panels. The architectural design itself is moving. Its high arches reflect the missing space in lives after so many personal tragedies without even grave for compensation.

A departure from the grim narrative with a brief paleontological note: The Jurassic crinoid Apiocrinites can be identified in the steps of the memorial. I know it well from other contexts.

There is a very well maintained part of the 1916 battlefield at Beaumont-Hamel. Here the Newfoundland Regiment attacked the German lines on the first day of the first Battle of the Somme. The regiment was destroyed in less than twenty minutes after they emerged from their trenches. Six-hundred and seventy men were casualties.

These are remnants of the first line of British trenches.

The killing field of the Newfoundlanders. It is estimated 300-400 of their bodies still remain in the churned soil.

There was an original blasted trunk here called the Danger Tree. It is midway between the British and German lines, about as far as the Newfoundlanders got on July 1, 1916.

A caribou memorial faces the old German positions from the trenches of the Newfoundlanders. All the stones below it are from Newfoundland. The site is maintained by the government of Canada.

The end of my journey was to Hawthorn Ridge, site of a German position blown up by another British mine on the first day of the 1916 battle. The explosion was filmed.

This is the same perspective as the famous photographs and films of the 1916 Hawthorn Ridge explosion. The trees are growing on the crater rim.

This is a famous photo of British soldiers awaiting the Hawthorn mine explosion on July 1, 1916. They had tunneled out of a trench into a sunken lane in no-man’s-land to get as close to the German lines as possible for their attack.

That sunken lane is still present 101 years later.

I wanted to add more about the geology of the battlefield, but the human tragedy is so overwhelming I decided to leave it for later. For now, see the geological cross-section below. Also consider the remarkable observation that the intensity of the artillery bombardments actually changed the geology of the region. “Bombturbation” is a term that has been proposed in our clinical scientific way.

Wooster Geologist in Vienna

May 28th, 2017

VIENNA, AUSTRIA — As is the tradition of Larwood meetings of the International Bryozoology Association, time is set aside for a guided tour of the most interesting parts of the host city. Given the incredible diversity of Vienna, we had just a taste today of its attractions and monuments in the city center. Above is the elaborate city hall (Wiener Rathaus).

Vienna’s Imperial Palace, the Hofburg, was for centuries the home of the Habsburgs, rulers of Austria and its empire until their epic collapse at the end of World War I. Apparently almost every emperor since 1275 added or otherwise changed the place, making it an astonishing mix of architectural styles (Gothic, Renaissance, Baroque, Rococo, and Classicism to start). Much of it is unfinished since the ambitions of the last emperor were dashed with the fall of the monarchy in 1918.

Elaborate Roman ruins about 2000 years old were recently found near the palace. The local rumor is that these are the remains of a brothel!

This is the Natural History Museum (Naturhistorisches Museum), Vienna, where we had a limited guided tour.

We had an extended tour of the myriapod collections (essentially millipedes and centipedes), concentrating on various aspects of curation and preservation.

As with most European museums, there is a significant human skull collection. This is a small part of Vienna’s. I never did hear exactly how these skulls were acquired.

During my afternoon tea with friends, this was our view to the left towards the center of the museum.

This was our view through the window to the right. In the square is the elaborate Maria Theresa monument (the empress surrounded by her generals and statesmen). The building on the other side is the Kunsthistorisches Museum, an art and history museum. It was the last place I visited this day.

This was the most impressive art object I saw in the Kunsthistorisches Museum: the first-century Gemma Augustea. It was cut from a double-layered Arabian onyx stone, making an elaborate cameo. The link tells the long story of this figured stone, along with an interpretation of the grim scene.

Earlier in my Vienna visit I toured the Heeresgeschichtliche Museum (Museum of Military History). I practically had the place to myself on this weekday.

The most evocative object in this museum is the car that carried Franz Ferdinand, heir to the throne of the Austro-Hungarian Empire, and his wife Sophie to their assassinations by the anarchist Gavrilo Princip on June 28, 1914. This was one of the triggering events of World War I.

The assassination scene in Sarajevo on June 28, 1914.

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