A visit to the Devonian of the Czech Republic. And then Prague, of course.

June 15th, 2019

Liberec, Czech Republic — Today the IBA field party visited the Koněprusy area, including the Koněprusy Caves. Inexplicably I took no pictures, probably because I was trying not to bump my head in the wet and narrow passageways.

Nearby is a quarry in Devonian limestone. We squatted in what shade we could find to look for fenestrate bryozoans with considerable success.

The final stop of our field trip was beautiful Prague. It was a hot, hot summer day, and a sea of tourists flowed through the streets. I will forego sharing images of the spectacular sights, except for a few personal shots.

Our host managed to find a quiet corner where we could enjoy iced coffee (without ice) and lemonade (without ice or anything lemon, but I’m not complaining).

The suitably kinetic sculpture of Prague icon Franz Kafka.

Finally, the statue of Saint Wenceslas overlooks Wenceslas Square, scene of such Czech political and social history. It is most famous for hosting massive rallies during the 1989 Velvet Revolution that ended the communist regime. St. Wenceslas has seen much else as well. You can feel the drama lodged in the stones.

Just as a thunderstorm began (note the clouds), we left Prague for an uneventful drive to Liberec, where we will spend the next week a the 18th conference of the International Bryozoology Association. It was a great excursion. Thank you to our host Kamil Zágoršek!

 

Wooster Geologist in the High Tatras Mountains of northern Slovakia

June 11th, 2019

Bratislava, Slovakia — Today our continuing IBA field trip adventure started in the High Tatra Mountains at this spectacular glacial lake called Štrbské pleso. This is  very popular ski destination in central Europe. The sharp mountain peaks are granitic.

Another view of Štrbské pleso.

This was our modernistic hotel near Štrbské pleso. Excellent views.

We stopped for a tour of Bojnice Castle after leaving the mountains. It has essentially been built and rebuilt since the 11th century and is currently popular in films and weddings needing a fairy-tale castle background. It is ostentatious, of course, with ridiculous sums of money spent by generations of aristocrats to encrust it with gold and artworks.

The castle didn’t impress me, but the fact that it overlies a natural cavern did!

I like my castles in dramatic ruins, and Beckov Castle in western Slovakia  fits that bill well. The castle sits on a limestone klippe, which is an erosional remnant of a thrust sheet.

We went way, way high up through the ruins to the castle’s top.

The bedrock is integrated into the castle walls, as we’ve seen often.

This was the last stop of the day before we reached Bratislava and our next hotel.

 

Wooster Geologists in Southwestern Utah (March 2019)

March 21st, 2019

During our 2019 Spring Break, Dr. Shelley Judge, our ace technician Nick Wiesenberg, and I took two students (Anna Cooke ’20 and Evan Shadbolt ’20) to southwestern Utah for Independent Study (IS) research and geologic exploration. We had a great time, and as always we’re planning the next expedition. Anna and Evan collected nearly a hundred pounds of rocks from the Middle Jurassic Carmel Formation for their IS projects. Here are links to our daily blog posts in classic superpositional order (youngest on top):

March 20: Local culture on our last day in Utah
March 19: A free day spent geologically in southwestern Utah
March 18: Wooster Geologists return to Zion National Park
March 17: Last day of fieldwork for Team Jurassic Utah 2019
March 16: East of Zion
March 15: Fieldwork continues for Team Jurassic Utah, plus a museum visit
March 14: A much more pleasant day in southwestern Utah
March 13: Team Jurassic Utah endures polar conditions
March 12: A productive first day for Wooster Geologists in Utah
March 11: Team Jurassic Utah 2019 begins its adventure

(You can also search the tag “Utah2019”.)

This is the local stratigraphic column (modified from that on the Zion National Park website). The area is dominated by the magnificent Navajo Sandstone. The Carmel Formation (red dot) is one of the few carbonate units.

This expedition builds on the work of last year’s Team Jurassic Utah, Galen Schwartzberg ’19 and Ethan Killian ’19, along with a past generation of Wooster students in the 1990s. We thank them for their contributions to this continuing geological adventure. Thank you also to Patrice Reeder, our Administrative Coordinator, for all her help. Our colleague lab technician Nick Wiesenberg was a superb trip organizer, driver and field geologist. We are also grateful to the very generous landowners Hyrum & Gail Smith and Jay & Judy Leavitt.

Updates on our progress with these projects will be in future blog entries.

For our records, here are our collecting and measuring localities —

N Latitude Longitude Wooster Locality
Location name
37.25407499 -113.60516 C/W-751 WT Water tank
37.308755 -113.73653 C/W-142 EMR Eagle Mtn Ranch cliff
37.25500 -113.60436 C/W-756 WTR Water Tank Road
37.27629 -113.63712 C/W-757 DV Dammeron Valley
37.27747 -113.64420 C/W-758 DVN Dammeron Valley N
37.30882 -113.73883 C/W-759 Strom-mat Eagle Mtn Ranch
37.21548 -112.68215 C/W-760 CC Carmel Cove
37.22521 -112.68095 C/W-761 MCJ Encrinite at MCJ
37.12206 -113.39977 Air BnB Hurricane Air BnB
37.27629 -113.63712 C/W-762 DVN@DV DVN unit below DV

A much more pleasant day in southwestern Utah

March 14th, 2019

Hurricane, Utah — This is our morning view to the north from our Team Utah headquarters in Hurricane. The snowy Pine Valley Mountains were especially beautiful as the clouds lifted overnight. Such colors. A much warmer day was ahead of us after our freeze-fest yesterday.

Today we returned to the Water Tank location we briefly visited yesterday. This time we concentrated on this meter-thick set of cross-bedded oolites. We described this little column, took four samples, and named the location WTR (for “water tank road”). The coordinates are: N 37.25500°, W 113.60436°.

Anna is here examining the top of the sequence, which appears to represent an ooid shoal.

A very covered Evan does the same. Today he is not protecting himself from the cold as much as the sun.

Dr. Judge, with Anna’s help, collected measurements of the cross-beds to eventually calculate current flow direction, which will be very interesting.

While on a scouting trip for the team, Nick found this mysterious quartzose sandstone unit 5.4 meters above the WRT oolite. It is very much an oddity in an otherwise carbonate sequence. In some parts the sand is loose enough to later run through the Ro-Tap sieves.

For lunch we went to a favorite Wooster restaurant — Veyo Pies! Very appropriate (and crowded) on Pi Day. Photo by Shelley.

Every time I visit this region I make a pilgrimage to the 1857 Mountain Meadows Massacre site north of Central, Utah, on Highway 18. Today it was snow-covered, which made the place seem even lonelier. Please read the historical account of what happened here.

The rock cairn over the mass grave. Lest we forget.

Wooster Geologist in Southwestern Utah (April 2018)

April 21st, 2018

St. George, Utah — I visited southwestern Utah for a week to prepare for an Independent Study expedition next month to study the Carmel Formation (Middle Jurassic). I wanted to update locality information I had collected in the 1990s (ancient times!), find different sections, and meet new people. It was much fun and very productive. The daily blog entries are linked below —

April 16: A Wooster Geologist returns to the Jurassic of southwestern Utah
April 17: Another geological scouting day in southwestern Utah
April 18: Another day in the shallow Jurassic seas of southwestern Utah
April 19: Delightful fossils in the Middle Jurassic Carmel Formation on my last field day

Next month we will have posts from the project!

Delightful fossils in the Middle Jurassic Carmel Formation on my last field day

April 19th, 2018

St. George, Utah — Today I met Jerry Harris, Professor of Geology at Dixie State University in St. George. He was very friendly, generous and knowledgeable, guiding me to two fantastic Carmel outcrops I would not have approached on my own. Shown above is one complete section of the Carmel Formation in the Dammeron Valley. The reddish rocks in the lower right are the underlying Temple Cap Formation; the top of the ridge is the end of the Carmel here — it is unconformably overlain by the Iron Springs Formation (Upper Cretaceous). This is an extensive exposure perfect for exploring.

The red unit here in the Dammeron section is the top of the Temple Cap Formation. I’m not sure if the Carmel commences with the green marls, but classic Carmel limestone is found immediately above.

A curious unit within the lower few meters of the Carmel is this bedded gypsum deposit. It represents a significant accumulation of evaporite minerals, and thus the evaporation of a lot of seawater in an enclosed basin.

The Carmel limestones show normal (but restricted) seawater and lots of evidence of high energy. These carbonate crossbeds are almost herringbone.

This is a view west from the top of the Dammeron Valley section. In the distant left you can see the familiar Square Top Mountain and pointy Jackson Peak. On the right is the majestic Veyo Volcano. The Gunlock exposures are just a few kilometers away, but no outcrops connect them to the Dammeron Valley.

Jerry Harris also showed me large exposures of the Carmel Formation in Diamond Valley, a few kilometers south of the Dammeron Valley location. It is not picturesque, but there is plenty of Carmel under that sagebrush. The excavation for that water tower turned out to be especially good for shelly fossils, so Jerry took me there right way.

The most common fossil is the pectenid bivalve Camptonectes. It has calcitic valves, so they are well preserved, unlike the numerous aragonite-shelled mollusks in the Carmel that are seen only as ghostly molds.

To my delight, some of the bivalves at this locality are encrusted by small cyclostome bryozoan colonies. Jurassic bryozoans are very rare in North America. In fact, Paul Taylor and I have described most of them from the Carmel! (Taylor, P.D. and Wilson, M.A. 1999. Middle Jurassic bryozoans from the Carmel Formation of southwestern Utah. Journal of Paleontology 73: 816-830.) The exquisite bryozoan colonies above are as good as any we’ve found before. A thorough study of all the Carmel sclerobionts is worth pursuing.

There are also nice wedge-shaped limid bivalves at the water tank exposure in Diamond Valley.

These fossiliferous slabs have lots of treasures. I only wish they were more common in the Carmel.

Here’s a simple Google Maps image of my three main areas of study north of St. George. 1 = Gunlock, 2 = Dammeron Valley, 3 = Diamond Valley. Curiously, the most fossiliferous part of the Carmel Formation (the upper unit of the Co-op Creek Limestone Member) differs significantly between Gunlock on the west and the two valleys on the east, even though they are only a few kilometers apart. The Gunlock area has oyster balls and hardgrounds, which are absent in the east. The trace fossils are also more abundant and diverse in Gunlock than in the other two sections. Shelly fossils, though, appear to be more common in the east. It will be fun to sort out these facies differences in more detail.

Finally, I wanted to include an image of the cinder cone and lava flows at the entrance to Diamond Valley. They are within Snow Canyon State Park and have been dated at an astonishingly young age of 32,000 years.

Great day, great scouting trip. Thanks again to Jerry Harris and Andrew Milner!

Another day in the shallow Jurassic seas of southwestern Utah

April 18th, 2018

St. George, Utah — Back to the Gunlock region for me to revisit old Carmel Formation research sites to check for access issues and new exposures. This trip has also given me a chance to update my images of the unit. Most of my previous images are shockingly on film. I’ve been in this business a long time.

Above is one of my favorite Carmel outcrops, the cliff at Eagle Mountain. The white and buff layers are the Co-op Creek Limestone Member of the Carmel Formation (Middle Jurassic). They are topped by a thick, well-cemented conglomeratic sandstone, The Iron Springs Formation (Upper Cretaceous). This is a nice example of an erosional disconformity between the units with an interval of time unrecorded (a hiatus). The cliff is on private land, so I’m in the process of finding the owners. The image was taken looking northeast from: 37°18.428’N, 113°44.408’W.

Today I looked at some smaller details in the Carmel sections. I found these exquisite mudcracks near the Eagle Mountain locality. This is solid rock, even though the cracks look modern. This shows, of course, that this patch of muddy seafloor dried out, producing the cracks by desiccation of clay minerals.

On top of the mudcracked layer is a thin carbonate bed with vugs and cracks filled with gypsum. This represents a hypersaline environment where gypsum and/or anhydrite was precipitated as evaporite minerals. We thus went in time from a dry seabed to one covered by shallow briny water.

Within the gypsum-rich layers are intraclasts of carbonate mud derived from the mudcracked layer below. When the seawater returned it had enough energy at times to rip up pieces of the hardened mud below.

Finally, on top of the gypsiferous layer is a limestone rich in star-shaped crinoid debris (ossicles of Isocrinus nicoletti). This represents the influx of normal marine water, albeit in a restricted context. As far as I can tell, there are multiple triplet layer sets like this near the middle of the Carmel in the Gunlock area. What was controlling these changes in sealevel and chemistry?

I would be neglecting my duties as a geologist if I didn’t mention that there is much more to the geology here than the Carmel Formation. Above we see the underlying Navajo Sandstone with its massive cross-bedded eolian dune features. The Navajo is topped here by thick basaltic lava flows of Pleistocene-Holocene age (the Santa Clara Volcanic Field).

Lovely place for a geologist!

Another geological scouting day in southwestern Utah

April 17th, 2018

Kanab, Utah — My day began with a visit to the St. George Dinosaur Discovery Site at Johnson Farm, where I met Andrew R.C. Milner, the Site Paleontologist and Curator. This museum is built over an extraordinary set of dinosaur trackways. These tracks were not even discovered when I started working in the area, and now this building houses a busy and productive center for vertebrate paleontology in the region.

Andrew is a dinosaur paleontologist and an expert on vertebrate trace fossils, and he also knows a lot about the Carmel Formation and its outcrops in Utah. He gave me local contacts, and will join us in the field when we start the official Utah Jurassic expedition next month. He has been very helpful.

I then drove to Mt. Carmel Junction on the eastern side of Zion National Park, about two hours from St. George. It is a small place with a surprisingly long Wikipedia page. It sits in the center of several extensive exposures of the Carmel Formation, including this cross-bedded unit made almost entirely of crinoid ossicles. These rocks are called encrinites. This particular Middle Jurassic encrinite is one of the youngest known. This exposure is at Stop #5 of Tang (1997). It is still easily accessible at the northwest corner of the junction.

Alas, this great expanse of Carmel Formation, known as Stop #6 in Tang (1997) is no longer accessible, at least not easily. If you look carefully you can see a barbed-wire fence at the base of the outcrop. I could find no evidence of who owns this land, and jumping a fence out here can have serious consequences! Unfortunately there are far more such fences here than were present in the easy-going 1990’s. This makes taking students here harder for casual examinations of the rocks.

I spent the night in nearby Kanab, Utah, where I got to spend excellent time with my Father, who was in the area hiking with two friends. I then drove back to St. George the next morning, passing through a long stretch of northern Arizona. This included driving by the storied Colorado City of FLDS fame. Follow those links if you don’t know the story!

A day of geology on the coast of southwestern France

June 2nd, 2017

La Barde, France — Today we traveled west to the Gironde Estuary on the southwest coast to continue our survey of Campanian fossils. It looks like we will be working on the sclerobionts found with the extensive Pycnodonte oyster beds. Macy is above examining one of the best exposures of these fossils at a roadcut above Plage des Nonnes.

Our first stop was a roadcut in Mortagne of the Segonzac Formation, the oldest of the Campanian units we’ve seen so far.

The next outcrop was of the Biron Formation at the southern side of Caillaud. It is flanked by a salt marsh, with more open ocean conditions farther along.

Macy stands here on the fossiliferous Biron Formation at Caillaud south.

Another place where the ocean would love to kill me.

The Caillaud north locality was very fossiliferous, including excellent cheilostome bryozoans like Onychocella above. Despite the diversity of fossils here, there aren’t enough encrusted and bored oysters for us.

The cliffs just south of Plage des Nonnes. Definitely a location to visit at low tide.

These are some of the abundant Pycnodonte oysters we saw in the roadcut above Plage des Nonnes. We will certainly return to this outcrop later.

Besides the research, there were of course many other sites of interest. I took several images of this salt marsh at Caillaud south, for example, to use in my Sedimentology & Stratigraphy course.

We found this large jellyfish at Plage des Nonnes. The thickness and rigidity of the “jelly” is amazing.

This is the Talmont church perched on an outcrop above the sea.

The Romanesque, intricately carved entrance to the Talmont church.

It was an excellent day of culture and geology in France!

Location GPS Unit Position
Mortagne 160 Segonzac – lower N45° 28.763′ W0° 47.496′
Cliff north of Mortagne 161 Segonzac – upper N45° 28.963′ W0° 47.943′
Caillaud south 162 Biron N45° 31.805′ W0° 53.629′
Caillaud north 163 Biron N45° 31.916′ W0° 54.206′
Plage des Nonnes 164 Aubeterre N45° 33.534′ W0° 57.895′
Roadcut above Plage des Nonnes 165 Aubeterre N45° 33.627′ W0° 57.894′

 

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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