A cultural day in southern Sicily

June 6th, 2013

1. Noto Duomo 060613SCIACCA, SICILY, ITALY–Most major conference geological field trips have a portion devoted to the culture and history of the region being explored. You can imagine the delights of this nature possible on a Mediterranean island. Today we started with the main square in the city of Noto in southern Sicily. This city had been destroyed by a 1693 earthquake and was completely rebuilt. The Noto Cathedral (above) was finished in 1776. It is such a classic of Baroque architecture that it was declared a World Heritage site by UNESCO. It is striking, especially since it is hemmed in by other buildings and so provides a sudden surprise when turning a corner. Hard to believe parts of it collapsed from disrepair in 1996.

2. Noto Street 060613A Noto street leading to a church. The many balconies are characteristic of the city. Since the city center was rebuilt in one go, it has a consistent architectural theme.

3. Casale Mosaics 060613Our second visit of the day was to an archaeological site revealing the astonishing remains of a 4th Century Roman building called Villa Romana del Casale on Mounte Mangone near the Gela River. This huge complex is most famous for its exquisite mosaic floors, the details of one shown above (“The Little Hunt”). This features a theme throughout the structures: hunting. This is another UNESCO World Heritage site. Such culture vultures we geologists are.

4. Female Pentathalon 060613Certainly the most photographed of the mosaics is this scene popularly known as “Girls With Bikinis”. It is more properly described as “women participating in the female pentathalon” because of the distinctive athletic activities shown.

5. Giant Mosaic 060613My favorite mosaic is probably the most violent: a series of giants killed by Hercules with poisoned arrows. Note that the dying giants have snakes for feet. It is astonishing what these craftsmen could do with millions of tiny colored stones — and that their art has survived so vividly.

 

 

Wooster Geologist at Valley Forge, Pennsylvania

March 20th, 2013

ValleyForgeHuts032013BRYN MAWR, PENNSYLVANIA–While visiting my friends and colleagues Katherine and Pedro Marenco at Bryn Mawr College, I visited the nearby Valley Forge National Historical Park. Everyone will remember, of course that this is the place outside Philadelphia that the Continental Army made its rough winter quarters in 1777-1778. The huts above are reconstructions of the soldiers’ quarters on the windy and cold fields. Commander-in-Chief George Washington chose this place because it was easily defensible, had plenty of timber for construction and fuel, and was close enough to British-occupied Philadelphia to keep an eye on the enemy — yet not so close to be likely attacked.

LedgerOutcrop032013

As a geologist, of course, I also looked for the rocky bones beneath the landscape. They were easily found in the above cliff near the main parking area. This is the Ledger Dolomite, a Cambrian unit found throughout this part of eastern Pennsylvania.

LedgerDolomite032013The Ledger Dolomite here is distinguished by these fine laminations visible on its weathered cross-sections. These are apparently stromatolites: laminar structures built by bacterial mats. We’ve met Cambrian stromatolites before in this blog.

Smilodon_gracilisI was surprised to learn that there is also a significant middle Pleistocene fossil deposit in Valley Forge called the Port Kennedy Bone Cave. This is a sinkhole deposit within the Ledger Dolomite. A particularly large sinkhole apparently trapped a variety of animals, including the gracile sabre-tooth Smilodon gracilis, the skull of which is on display in the Valley Forge Historical Park visitor center. S. gracilis was the smallest and earliest member of its genus. The Port Kennedy Bone Cave was one of the first fossil assemblages that the famous paleontologist Edward Drinker Cope studied. The location was lost to science until its rediscovery in 2005.

ValleyForgeCannon032013This is the requisite cannon image, even though no battle was fought here. It is nevertheless a dramatic place for the privations the soldiers suffered during the darkest days of the Revolutionary War. It is hard to imagine the conditions in 1777-1778 now since highways and casinos surround the old encampment.

The Grianán of Aileach

December 20th, 2012

GriananOutsideDONEGAL, IRELAND — In the northeastern part of the county, about 7 km west of Derry in Northern Ireland, is Greenan Mountain. On its very top is a spectacular ringfort called The Grianán of Aileach (“the Solarium of Aileach”, shown above). From it are spectacular views of the countryside 360° around. It is a majestic and yet rather lonely place, maybe because my new friend Andy Quinn and I were the only ones there. It was probably built in some form around the beginning of the common era and no doubt occupied by many successive groups. There is a burial mound on the site (a tumulus) that may date back to 3000 BCE. The local story is that it was originally a place to honor the sun (which I would not have minded seeing today).

The fort’s most prominent days were when it was the royal citadel of the northern Ui Neill sept of Aileach from the 5th to the 12th century. The stone portion of the fort was destroyed in 1101 by Murtogh O’Brien, King of Munster. His soldiers were ordered to take the fort apart and scatter its stones widely. In 1870 it was substantially restored to its present state.

The Grianán of Aileach was an excellent location to visit and have a look at the countryside of eastern County Donegal. The rocks exposed here are among the oldest in Ireland (Late Proterozoic to Early Cambrian).

GriananInsideThe inside of the circular Grianán of Aileach. There are three interior platforms connected by narrow stairs. There is some dispute over whether this was the original architecture of the ringfort before its destruction in 1101.

GriananRocksThe stones are mostly without mortar. They appear to be some kind of quartz mica schist.

GriananPanorama585I tried a panorama of Lough Swilly to the west of the ringfort. It doesn’t convey the real sweeping vista in 585 pixels wide, but you get the idea of a cool view!

GriananHolyWellThis is a “holy well” to the southeast of the ringfort. It is said to have been visited by St. Patrick himself. Then again, everyone wants a connection to The Man!

An Irish myth says that The Grianán of Aileach was built by King Daghda of Tuatha de Danann, and that the grave of his son lies beneath the fortress forever guarding it. In any case, we were suitably respectful of this ancient site.

 

The wild northwest of Ireland

December 19th, 2012

DonegalBaySunset121912DONEGAL, IRELAND — Above is an image of Donegal Bay at sunset. It is striking with its still water, wheeling gulls and glacially-rounded rocky islands. I am in County Donegal for a couple of days simply to see the place and get some hints of what is said to be the most complex geology in Ireland. There is also some evidence that the Wilson part of my family comes from the northwest of Ireland, so I might be seeing a bit of ancestral homeland. I am staying in the town of Donegal in the south of the county and will be visiting sites in the north and west tomorrow. Today, after a very bumpy flight and landing (Donegal airport is known for its high winds), I am exploring the town and its surroundings.

DonegalArrival121912This is the little County Donegal airport in the north. It is in one of the most isolated spots in the county — no bus line goes to it and taxis have to be ordered in advance from nearby towns. There were seven people on the plane, including the crew.

AbbeyHotel121912The Abbey Hotel in downtown Donegal. My home for a couple of days.

DonegalAbbey121912The ruins of the Franciscan Abbey in Donegal along the southern shore of the bay. It was built in 1474. As with many such structures in Ireland, it has a long history of sieges and intrigue. This portion has been used as a graveyard for centuries.

DriftDonegal121912The geology just along the shores of Donegal Bay seems complicated enough. There are some rocky outcrops I could not reach, along with exposures of boulder-studded glacial drift such as here.

AbbeyGraveyard121912The stones used in the local walls and in the remaining Abbey structures are diverse. Most are dark gray metabasalts or amphibolites, as seen in this graveyard wall lit by the setting sun.

AbbeyStone121912One prominent stone in the Abbey walls appears to be a quartzite metaconglomerate. Both these rock types are derived from local pre-Paleozoic outcrops.

Aodh_Ruadh_Ó_Domhnaill_585Finally, here is a dramatically-lit statue of Aodh Ruadh Ó Domhnaill (1427-1505) at the head of Donegal Bay and mouth of the River Eske. He was the subject of one of my favorite book-movie combinations as a kid: The Fighting Prince of Donegal. I also think he looks a lot like me, wouldn’t you say?

Three Amigos in Dublin

December 18th, 2012

ThreeAmigos121812_585DUBLIN, IRELAND — I have paleontological legends on either side of me, and the best of friends. Paul Taylor is on the left. He and I met in 1985 when I visited The Natural History Museum in London while on my first research leave. My Oxford host, Stuart McKerrow, said I just had to meet a young paleontologist at the museum because we had so many common interests. Indeed. Paul and I have had many adventures since through our long friendship. Also while at Oxford, Jim Kennedy told me that if I was interested in hard-substrate fossils I should take the train to Aberystwyth, Wales, and see Tim Palmer (above on the right). I did and have enjoyed a long and deep friendship and collaboration with him ever since. I think the world of these gentlemen and am grateful for all that they’ve taught me and the many research opportunities I’ve had with them. We had a very special dinner of traditional Irish stews this evening in Ireland’s oldest pub, The Brazen Head (established in 1198 — and I didn’t reverse any digits).

The Annual Meeting of the Palaeontological Association has now ended. Tomorrow morning I leave Dublin for a brief visit to County Donegal in the far northwest of Ireland. I hope to make a blog post or two from there, but I’m not sure I’ll have an internet connection. If not, the next posts will come from home in about a week. Slán agaibh!

Geological fieldwork on the streets of Dublin

December 16th, 2012

DublinRainbow121612DUBLIN, IRELAND — What could be more Irish than a rainbow over Dublin? (I know better than to write of leprechauns and pots of gold.)  It certainly crowned the end of a delightful afternoon spent with my friend Tim Palmer looking at building stones.

I am in Dublin attending the annual meeting of the Palaeontological Association. After a long editorial meeting, Tim and I went to the center of the city to look for a particular kind of stone that may have been used in the Medieval portions of the two Dublin cathedrals: St. Patrick’s (National Cathedral of the Church of Ireland) and Christ Church (also for the Church of Ireland but claimed by Roman Catholics — it’s confusing, especially since they are only a short walk from each other). Tim was looking for a limestone called Dundry Stone, part of the Inferior Oolite (Middle Jurassic) in Great Britain. It is notable as a non-oolitic part of the Inferior Oolite, made mostly of tiny fragments of crinoids and calcite cement. Tim quickly found the stone in both cathedrals.

StPatricks121612This is St. Patrick’s Cathedral. Its exterior is mostly restored, but the interior still retains part of its Medieval core. It dates back to 1191.

StPatricksChapelDoorway121612We asked at the door to see the oldest part of St. Patrick’s, and were immediately directed to this small chapel. At the time the cathedral was filling with people for a choir concert, so we were surrounded with the sounds of bells and children practicing their pieces. This chapel was used as a storeroom as well as a tourist site, so there are some incongruities (such as the folding chairs!). Almost all the stone is either covered with cement or replacements except in a few places, like the frame of this small doorway. That white rock is Dundry stone.

ChristChurchCathedral121612This is Christ Church Cathedral, just down the road from St. Patrick’s. (A rivalry between the two dates back to the 12th Century. Two cathedrals in one city is very rare, apparently.) Christ Church is the older of the two cathedrals, dating back to about 1040 when a Viking king of Dublin started construction. It also has a mostly restored exterior, and it too has Dundry stone making up surviving doorways and lintels.

ChapterHouse121612This is an excavated “Chapter House” just outside Christ Cathedral on the grounds. Tim Palmer can be seen in the corner making notes. Apparently monks, priests and other church notables would meet in this building and sit on the stone benches just like Tim. The stones in this ruin include original materials (like the Dundry) and a variety of other lithologies.

I had a great time learning about stonework, Medieval building techniques, and the various structural properties of limestones, all thanks to Tim. Tomorrow I’ll be back in the more secular pews of the paleontological meeting. I’m happy to have had this spot of unexpected fieldwork!

Wooster Geologist in Ireland

December 15th, 2012

IrishFlag121512DUBLIN, IRELAND — In a very quick transition from grading final exams in Wooster yesterday morning, I find myself now in downtown Dublin. I flew in last night to attend the 56th Annual Meeting of the Paleontological Association. I’ve been a member of this wonderful organization since 1985 — in fact, I’m one of the North American Representatives — and I love my rare visits to the main meetings. They are held throughout Europe to recognize the international base of the Palaeontological Association, with an emphasis on its European core. I am here representing the Paleontological Society in my role as Secretary. I am looking forward to meetings with my paleontologist colleagues, and to learning more about our craft and passion.

DublinPostOffice121512Since my first meeting is tomorrow morning, I spent some time looking at some of the historical places in the Dublin City Centre. Most impressive to me is the evocative Post Office, site of the failed Easter Rising by Irish nationalists in 1916. Above is the post office today. Below is the burned-out shell after the 1916 battle with British troops. Bullet scars are still visible in the stonework.

Dublin_Post_Office_1916

FourCourts121512The Four Courts, Ireland’s main court complex. The original structure was built in the 18th Century. The River Liffey is in the foreground.

The last holdouts of pagan Europe

July 14th, 2012

KÄINA, ESTONIA–The little island of Muhu between Saaremaa and the Estonian mainland, had a large prehistoric population — much larger than it has today. The Muhu Estonians built a large fort of stone heaps near the western coast opposite Saaremaa so that they could control the traffic and trade through the Small Strait. The remains of that fortification are seen above. In January 1227, Teutonic Crusaders cornered the last of the pagan Estonians in this stronghold. (They were, in fact, among the last pagans in all of Europe.) Reports say that 20,000 soldiers besieged 2500 Estonian warriors for six days here. All the Estonians were killed save one, who escaped by pretending to be a victorious crusader. Most of the stones of the fort were removed to build the causeway between Muhu and Saaremaa, but the site remains as a ring of earthen walls and a stone monument (below) marking the bloody battlefield.

Exploring the Estonian island of Hiiumaa

July 12th, 2012

KÄINA, ESTONIA–The Wooster/OSU geology team took a break today from our usual field routine. We spent the morning consolidating notes and specimens (yes, that means the students slept very late) and then the afternoon seeing some of the major Hiiumaa sites. The highlight was visiting Hiiumaa’s iconic attraction, the Kõpu Lighthouse on the Ristna Cape. It is the oldest lighthouse in the Baltic states and reported to be the third oldest continuously-operated lighthouse in the world. It was completed in 1531 and has been working ever since. The Hanseatic League demanded a lighthouse here beside the most important trade route in the Baltic Sea. The original light was a fire that required 1000 cords of firewood every year, nearly deforesting the surrounding peninsula. The Germans bombed it in 1941, but only damaged its optical structures on top. It was an important navigational aid until 1997 when it was replaced by a modern radar system.

A model of the medieval version of the Kõpu lighthouse in the Tallinn Maritime Museum. Access to the top platform was by a long ladder. The light was a bonfire of pine wood.

The lighthouse staircase is incredibly narrow and steep, being cut into the structure in the 19th century. (Prior to this there was a wooden staircase on the outside.) Richa is better built for such a place than me!

Richa and Jonah wanted an answer to the famous “O-H-I-O” pantomime our OSU friends like to construct, so they made a C-O-W version. The lighthouse window here at the top is the “O”, you see. Maybe it will catch on. Maybe …

Near the end of the afternoon we visited the Ristna Lighhouse and one of the westernmost points on the island. (This is where Alyssa found her famous trilobite.) Richa and Jonah noted that large igneous boulders make excellent posing platforms at the edge of the sea.

As a brief nature vignette, here is a dung beetle (Geotrupes stercorosus) we saw deep in the Estonian woods at our lunch spot. I’m sparing you the dung itself!

Wooster Geologist at Fort Ligonier, Pennsylvania: Choosing your ground geologically

June 5th, 2012

Fort Ligonier was built by the British in 1758 during the French and Indian War (or Seven Years’ War) along the Loyalhanna River in what is now Westmoreland County of southwestern Pennsylvania. It is a spectacular site today with a fully reconstructed fortification and an excellent museum. It gives us a chance to see how a military engineer used the local geology to build a successful fort in a difficult terrain.
The purpose of Fort Ligonier was to serve as the forward base for the capture of the French Fort Duquesne at the forks of the Ohio River. This was the most strategic site on the western frontier. The French and their Indian allies desperately wanted to preempt this attack by destroying the advancing British columns in the woods before they could assemble. The British and American colonists needed a robust road through the wilderness approaching Fort Duquesne, along with defensible strongholds. Fort Ligonier was the most critical of these positions, then, for both sides.
You would expect a fort to be built on the highest ground, yet Fort Ligonier is in a valley surrounded by commanding heights. The British knew, though, that the French and Indians did not have significant artillery in this theater. They could give up the heights so that they could use the Loyalhanna River as a defensible barrier against the inevitable infantry attacks. The site of Fort Ligonier also has small ravines on its other sides, forming a kind of moat. Most importantly, sandstone cliffs on the river side provide an unbreachable wall and an overview of the most likely approaches to the fort by the enemy. The British placed their largest cannon at the top of this cliff, surrounding them with an elaborate wooden stockade and sharpened obstacles.
The exposed rock of the Fort Ligonier cliffs is the Casselman Formation, a Late Carboniferous (about 300 million years old) mixture of shale, siltstone, sandstone and occasional coal beds. The particular unit here is a fine micaceous sandstone with cross-bedding. It was formed in an ancient river system. The cross-bedding and abundance of mica is a clue to this environment: the cross-bedding shows high-energy seasonal flooding; the mica flakes (the white grains seen below) show ebbs in water energy to near zero.
The French and Indians attacked Fort Ligonier on October 12, 1758, and very nearly took it. The British artillery sited on the sandstone cliffs was the deciding factor, though, and the besiegers retreated. Fort Ligonier swelled in population as British troops assembled for the attack on Fort Duquesne. In fact, in November 1758 it was the second largest city in Pennsylvania! (Among the British forces was the young George Washington.) The French saw the score and retreated from Fort Duquesne. The British captured this most strategic location and renamed the site “Pittsburgh”. Building and defending Fort Ligonier was key to this victory. By March 1766 the fort had served its purpose and was decommissioned.

References:

Fowler, W.M., Jr. 2005. Empires at War: The French and Indian War and the Struggle for North America, 1754–1763. Walker & Company, 360 pages.

Sipe, H.C. 1971. Fort Ligonier and Its Times. Ayer Company Publishers, 699 pages.

Stotz, C.M. 2005. Outposts of the War for Empire: The French and English in Western Pennsylvania: Their Armies, Their Forts, Their People, 1749-1764. University of Pittsburgh Press, 260 pages.

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