Wooster Geologists begin fieldwork in southwestern France

June 1st, 2017

LA BARDE, FRANCE–Macy Conrad and I began our paleontological fieldwork in what may be the most beautiful part of Europe: southwestern France. Our superb guide and colleague is Natural History Museum scientist Dr. Paul Taylor, a long-time friend who has a home in this region with his wife Patricia. Above is a view of our first location: Aubeterre-sur-Drone. Extraordinary. And note the weather!

French food is indeed all it is said to be. This was my lunch: Gallette au Thon. Simple, I know, but very good.

This is our first outcrop. Macy is standing at an exposure of the Biron Formation, a Cretaceous (Campanian) limestone full of fossils, especially Pycnodonte oysters. Many of these oysters are encrusted by bryozoans. This is the “Garage Esso” location, also known as Route D17, in Aubeterre. We are in the exploratory phase of the project — essentially sorting out projects.

The overlying Barbezieux Formation (also Campanian — all the units are Campanian today) has well-exposed Pycnodonte oyster banks. These are of particular interest to us, especially if they are bored or encrusted. This is the “Chemin” section in Aubeterre.

More Barbezieux Formation further up the lane.

Our third unit is the Aubeterre Formation, which dominates the top of the city. This is the “car park outcrop”. All of these rocks are cliff-forming white limestones with abundant fossils.

Paul knew a field near Le Maine Roy where fossils from the Maurens Formation are exposed. This did not sound like a productive site, but it was the best of the day. Above you see a pile of rocks marked by a stake. These are larger stones removed from the fields by farmers. (I was reminded of what many French farmers in the north continually extract from their soil: World War I artillery shells!)

The many fossils include numerous large rudistid clams. It is  hard to imagine these large cones as bivalves, but they are. Rudists go extinct at the end of the Cretaceous.

This is a view of the top of a rudist with its right (capping) valve intact. It has a beautiful mesh structure.

Our last stop of the day was a roadcut near Chalais exposing the Biron Formation. It had a great diversity of fossils, including echinoids, sponges, oysters, and ammonites. It did not have an abundance of sclerobionts, so it probably won’t be a site for us in the future.

In Aubeterre we visited two fantastic churches. The first was St. Jacques. Most of it had been destroyed in the 17th century religious wars, but the Romanesque facade remains. This is the main entrance.

The primary attraction of the remnants of St. Jacques is a set of Medieval carvings. They are extraordinarily detailed, depicted all sorts of mysterious fantastical animals and people.

The second church in Aubeterre is very geological. St. Johns is underground, being carved as a cavern from the Barbezieux Formation. Here is a view of the entrance to what remains.

Inside is a huge space in which the sanctuary is carved. This is one of the largest such underground structures known.

The centerpiece is this reliquary, designed to look like the structure over the tomb of Jesus in the Church of the Holy Sepulchre in Jerusalem. Again, all this is carved out of the limestone.

We are staying in the gorgeous French home of Paul and Patricia Taylor in La Barde. It is an 1820 converted farmhouse, both beautiful and comfortable. The River Dronne is just a few steps away. We’ll have more photos of this wonderful and peaceful place in later posts.

I’ll end this day’s post with a view of some peaceful French woods near a field site.

Location GPS Unit Position
Garage Esso, Route D17, Aubeterre 153 Biron N45° 16.212′ E0° 10.274′
Route D17, Aubeterre 154 Barbezieux N45° 16.127′ E0° 10.268′
Chemin, Aubeterre 155 Barbezieux N45° 16.088′ E0° 10.257′
50 m up lane, Aubeterre 156 Barbezieux N45° 16.115′ E0° 10.229′
Back Chateau entrance, Aubeterre 157 Aubeterre N45° 16.362′ E0° 10.262′
Car Park, Aubeterre 158 Aubeterre N45° 16.344′ E0° 10.176′
Le Maine Roy 159 Maurens N45° 19.383′ E0° 07.885′
Chalais roadcut 160 Biron N45° 16.642′ E0° 02.395′

 

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