A Wooster Geologist at Austerlitz and other Czech places

June 13th, 2019

Olomouc, Czech Republic –At our very first site, Holubice in the Czech Republic, the Miocene celliporid bryozoans are like baseballs.

The site is in the middle of a vineyard, with the fossils eroding out of the loose sediment at our feet.

This is a shadow-selfie on the fossiliferous ground between the grape vines. As I was taking this artistic image, the field trip bus took off without me! I chased after it but lost hope as it pulled away in the distance. Geez. I had time to consider my few options (my pack with water and passport was on my lonely seat), but then the bus returned for me. My friend the Chinese paleontologist Jun-ye Ma had noticed I was missing. Lesson learned.

The dramatic chapel and memorial for the Battle of Austerlitz (1805) was our next stop. It is situated on one of the critical hills during the battle. The campaign is too complex to summarize here (thus the link), but in short it was a huge victory for Napoleon and it dramatically changed the map of Europe.

The stones in the memorial chapel are rich with Miocene domal bryozoans (the white objects).

Some of the bryozoans are penetrated by borings.

The chapel was constructed during the early 20th century and shows an Art Deco style.

The altar. The chapel doesn’t seem to account for non-Christian fallen soldiers, but that’s not surprising.

The dead from the battle were mostly buried in shallow graves where they fell. The soil of the battlefield continues to yield bones, especially after plowing. The remains are collected and brought to the chapel for eventual burial underneath in a crypt.

The Austerlitz battlefield.

Our first field group photo! We are at the Austerlitz chapel.

This miserable site  is Holubice, where a Miocene bryozoan marl is exposed. The hike in led by Kamil (above) was through a long stretch of high grass and woody brush. The mosquitoes were excited that mammals had suddenly appeared, while nettles stung exposed skin. Plus I didn’t see the bryozoans. I left early to make sure the bus didn’t abandon me here.

Wooster Geologist in Slovakia and Austria

June 12th, 2019

Mikulov, Czech Republic — We have been very fortunate with the weather on our long IBA field excursion. Dazzling sunlit days and relatively cool evenings. Above is our first stop of the day — the Sandberg site with Miocene fossils in a loosely-bound sand.

This is a cool geological setting where a Miocene shoreline is preserved against Jurassic carbonate cliffs. The Miocene sand is the yellowish unit above superimposed on the blue limestones.

Some of the Jurassic carbonates are exposed as boulders that tumbled down the slopes. This boulder has a surface that was exposed to the Miocene ocean and accumulated round bivalve borings (ichnogenus Gastrochaenolites, which has been seen a lot in this blog).

The limestones also have external molds of snails and bivalves.

Another castle! This one very dramatic in its position commanding the confluence of the Morava and Danube rivers. It is the Devin Castle, which was destroyed by Napoleon himself in 1809.

This is the Maiden Tower, a cultural symbol of Slovakia.

River confluences are so cool. The Morava on the right is joining the Danube.

At this important confluence, at the border between what was Czechoslovakia and Austria during the Cold War, is a moving memorial to the over 400 people shot while trying to escape through the Iron Curtain.

The long list of names of those killed by the Soviets and their allies along the border.

The last stop of the day was the type section of the Hartl Formation (Middle Miocene, Badenian) near Eisenstadt, Austria. It is another loose sand, this time with common brachiopods and some bryozoans. This section is eroded back, forming a cave. The roof will collapse some day.

These are beach sands with spectacular cross-beds. I collected some sediment to challenge my sedimentology students next year.

Tonight we stay in the historic Czech city of Mikulov on the border with Austria.

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 Geologist in Hungary and Slovakia

June 10th, 2019

Štrba, Slovakia — Today our field party drove from Budapest through northern Hungary into Slovakia. The day was brilliantly sunny. Our first stop was at a holy well near Szentkút, Hungary, to examine Miocene fossils (mostly bryozoans). High up in the surrounding hills is a shelf where the mrl is best exposed. Long ago a community of monks established living quarters and a chapel by carving the soft stone. Our outcrop was well exposed because of their work.

Our leader Kamil emerging from one of the stone rooms.

There is some sedimentology and structural geology going on here as well as paleontology. Inside one of the rooms the walls cut through soft-sediment deformation and a normal fault oblique to the corner.

The bryozoans are numerous and well-preserved in the stone walls.

Szentkút was especially religious on the day we visited. It was Pentecost for the Greek Catholic faith, so there were large crowds and colorful clerics around the shrines. I hope we were not noticed walking through.

In case you wondered what a border crossing between Hungary and Slovakia looks like.

We next stopped in Fiľakovo, a Slovakian town with a magnificent castle. We will see a lot of castles on this trip, and as Kamil told us, most were built in the 13th century and destroyed in the 16th. This castle was most impressive to me because of the bedrock it is built on: a Miocene ignimbrite, which is a rock resulting from volcanic eruptions. Most geologists would call it a welded tuff. he Miocene volcanoes still ring the town as wooded hills.

A close view (with my field trip roommate Hans Arne Nakrem for scale) shows the complex stratigraphy of the unit.

There are numerous volcanic bombs and other volcaniclastic bits in the welded tuff.

A view of the town from the castle. When the Ottoman Turks were here I’m sure they couldn’t imagine having a Catholic church in sight.

One of the Miocene volcanoes.

Our last stop of the day was near Štrba, Slovakia, for this small outcrop of Miocene bryozoan marl. ots of high grass.

The High Tatra Mountains of northern Slovakia and southern Poland are now in view! We’ll look at these in more detail tomorrow.

 

Wooster’s Pseudofossil of the Week: It’s not what it looks like

September 30th, 2016

Pseudocoprolite 585Impressive, isn’t it? You can practically smell it steaming on your screen. Hard to believe this object is Miocene in age, about 6 million years old.
Pseudocoprolite top view 585Here’s another similar specimen in a top view, if we can say that.
Pseudocoprolite side view 585And here’s a side view. Notice the rich color, long, parallel striations, and “pinched” ends. If these aren’t fossil feces, officially known as coprolites, they’re excellent imitations. They’ve been prime attractions in our first paleontology lab.

These evocative objects are primarily made of siderite, making them dark and heavy. Our specimens above come from the Wilkes Formation (upper Miocene) in southwestern Washington state. They are enormously abundant and thus common in rock shops and museums around the world. In that is your first clue: how can feces with such exquisite detail be preserved so perfectly in such enormous numbers in so few places? My answer, along with many other geologists, is that these are pseudocoprolites made by inorganic means. Their extrusive nature and appropriate color gives us the illusion of poop.

I’m highlighting these objects this week because a paper appeared last month in the journal Lethaia making a case that they actually are biological in origin. Broughton (2016), in a long bit of prose and analysis, concludes that the Wilkes Formation objects are a mix of giant earthworm “mineralized intestinal remains (Type 2)” and coprolites “from unknown vertebrates” (Type 1). I don’t buy Broughton’s interpretations, but found them fascinating enough to make his paper part of a reading exercise in my paleontology class this month. The most relevant references are below so you can do your own reading and decide what these curious extrusions (or intestinal casts) are.

Let’s start with this excellent 2014 article by Brian Switek for National Geographic: “Was Six-Million-Year-Old Turd Auctioned for $10,000 a Faux Poo?” Yes, one of these curiosities actually sold for $10,370 at an auction … and it is over 100 centimeters long! (Check out the images in this NPR article on the auction. That would be an epic poop for anyone.) This auctioned specimen is an example of what Broughton (2016) calls Type 2; he believes they are essentially mineralized guts of really large burrowing earthworms. He makes his case by interpreting the striations as muscle fiber impressions, and the shapes as resulting from peristaltic motions inside the worms. (Seilacher et al., 2001, had similar ideas.) The smaller “faecal-like specimens”, like we have at Wooster, are his “Type 1”. As far as I can tell, only length separates Type 1 from Type 2 in Broughton’s classification and, as might be expected, “Some fragmentary Type 2 specimens may be misidentified as Type 1.” It is odd that Types 1 and 2 are identical in every feature but size, yet are given very different origin stories.

Critical observations to keep in mind as you explore this mystery: (1) These siderite objects have no inclusions of organic material — not a seed, woody bit, or bone fragment; (2) There are no associated vertebrate skeletal remains or other traces, and no evidence for earthworms either; (3) They are incredibly abundant in limited horizons, and unknown elsewhere; (4) They range in size from a centimeter or less to over 100 centimeters long; (5) You’d think you’d find a few squashed, now and then, or burrowed by insects, but they are in spectacular three-dimensional preservation.

I support the earlier interpretations of these excrement-appearing rocks as deformations of soft, plastic sediments by inorganic processes, as thoroughly developed by Spencer (1993), Mustoe (2001) and Yancey et al. (2013). They may have been extruded through rotting hollow logs by compaction, liquified by seismic activity, or squirted through cracks by natural gas emissions (which would be ironic!). That these pseudocoprolites were squeezed through something seems obvious; it is unlikely they came to us by way of animals.

References:

Broughton, P.L. 2016. Enigmatic origin of massive Late Cretaceous‐to‐Neogene coprolite‐like deposits in North America: a novel palaeobiological alternative to inorganic morphogenesis. Lethaia (early view)

Mustoe, G.E. 2001. Enigmatic origin of ferruginous “coprolites”: Evidence from the Miocene Wilkes Formation, southwestern Washington. Geological Society of America Bulletin 113: 673-681.

Seilacher, A., Marshall, A., Skinner, C. and Tsuihiji, T. 2001. A fresh look at sideritic ‘coprolites’. Paleobiology 27: 7–13.

Spencer, P.K. 1993. The ‘coprolites’ that aren’t: the straight poop on specimens from the Miocene of southwestern Washington State. Ichnos 2: 231–236.

Yancey, T.E., Mustoe, G.E., Leopold, E.B. and Heizler, M.T. 2013. Mudflow disturbances in latest Miocene forests in Lewis County, Washington. Palaios 28: 343–358.

Wooster’s Fossils of the Week: Another molluscan assemblage from the Miocene of Maryland (side two)

August 19th, 2016

1 Calvert 2 585Last month we featured a fossil slab kindly donated by Dale Chadwick of Lancaster, Pennsylvania. Dale is an enthusiastic fossil collector with a very useful website for his favorite sites and specimens. I promised to show the other side of this rock, and here it is.

Again, this is a fine sandstone from the famous Calvert Formation (lower to middle Miocene) exposed at the Calvert Cliffs, Plum Point, Calvert County, Maryland, in the stratigraphic Shattuck Zone 10. Some horizons are especially fossiliferous with large numbers of gastropods and bivalves. This is what we refer to us a death assemblage, meaning these shells are not preserved in their life positions but how they accumulated just before final burial. These rocks and their fossils were the initial basis of Susan Kidwell’s important work on taphonomic feedback, or how shell accumulations affect the succeeding living communities.

So what are the prominent fossils in this slab? Dale has the answers on his website. I’ve annotated the image and made a list below:

2 Calvert 2 585 labelsA Astarte sp. (a veneroid bivalve)
B Glycymeris parlis (an arcoid bivalve)
C Siphonalia devexa (a buccinid gastropod)
D Turritella variablis (a turritellid gastropod)

Thank you again to Dale Chadwick for this gift! I will use it in my paleontology course this very month.

References:

Kelley, P.H., 1983, Evolutionary patterns of eight Chesapeake Group molluscs: Evidence for the model of punctuated equilibria: Journal of Paleontology 57: 581–598.

Kelley, P.H. 1988. Predation by Miocene gastropods of the Chesapeake Group: stereotyped and predictable. Palaios 3: 436-448.

Kidwell, S.M. 1986. Taphonomic feedback in Miocene assemblages: Testing the role of dead hardparts in benthic communities: Palaios 1: 239–255.

Kidwell, S.M., Powars, D.S., Edwards, L.E. and Vogt, P.R. 2015. Miocene stratigraphy and paleoenvironments of the Calvert Cliffs, Maryland, in Brezinski, D.K., Halka, J.P. and Ortt, R.A., Jr., eds., Tripping from the Fall Line: Field Excursions for the GSA Annual Meeting, Baltimore, 2015: Geological Society of America Field Guide 40, p. 231–279.

Wooster’s Fossils of the Week: A molluscan assemblage from the Miocene of Maryland

July 15th, 2016

1 Calvert Zone 10 Calvert Co MD 585Earlier this month a gentleman stopped by The Department of Geology and donated the above beautiful slab of fossils to our program. Dale Chadwick of Lancaster, Pennsylvania, is an avid amateur fossil collector with a very useful website and considerable generosity. His gift to the department makes an excellent Fossils of the Week entry. Later I’ll show you the equally-impressive other side of this specimen!

We have here a fine sandstone from the famous Calvert Formation (lower to middle Miocene) exposed at the Calvert Cliffs, Plum Point, Calvert County, Maryland, in the stratigraphic Shattuck Zone 10. As you can see, some horizons are densely fossiliferous with large numbers of gastropods and bivalves. This is what we refer to us a death assemblage, meaning these shells are not preserved in their life positions but how they accumulated just before final burial. These rocks and their fossils were the initial basis of Susan Kidwell’s important work on taphonomic feedback, or how shell accumulations affect the succeeding living communities.

So what are the prominent fossils in this slab? Dale has the answers on his website. I’ve annotated the image and made a list below:

2 Calvert Zone 10 Calvert Co MD 585 labeledA Turretilla variabilis (a turritellid gastropod)
B Stewartia sp. (a lucinid bivalve)
C Turritella plebia (a turritellid gastropod)
D Cardium laqueatum (a carditid bivalve)
E Siphonalia devexa (a buccinid gastropod)

So how did several of these animals die on that seafloor long ago? You’ve probably guessed predation by looking at that round hole in specimen B, a lucinid bivalve.

3 Naticid borehole Calvert 585The beveled nature of this round drillhole tells us it was made by a predatory naticid gastropod, which used its radula (a tongue-like device with sharp teeth) to penetrate the calcareous shell and damage the muscles holding it tight against the attack. About half the specimens in this slab show similar predatory penetrations. Wooster alumna Tricia Kelley did critical work on predation styles, intensities and evolutionary patterns with Calvert specimens like these.

Thank you again to Dale Chadwick for his gift!

References:

Kelley, P.H., 1983, Evolutionary patterns of eight Chesapeake Group molluscs: Evidence for the model of punctuated equilibria: Journal of Paleontology 57: 581–598.

Kelley, P.H. 1988. Predation by Miocene gastropods of the Chesapeake Group: stereotyped and predictable. Palaios 3: 436-448.

Kidwell, S.M. 1986. Taphonomic feedback in Miocene assemblages: Testing the role of dead hardparts in benthic communities: Palaios 1: 239–255.

Kidwell, S.M., Powars, D.S., Edwards, L.E. and Vogt, P.R. 2015. Miocene stratigraphy and paleoenvironments of the Calvert Cliffs, Maryland, in Brezinski, D.K., Halka, J.P. and Ortt, R.A., Jr., eds., Tripping from the Fall Line: Field Excursions for the GSA Annual Meeting, Baltimore, 2015: Geological Society of America Field Guide 40, p. 231–279.

A geological obstacle course in Ada Canyon, southern Israel

March 19th, 2016

1 Ada canyon startMITZPE RAMON, ISRAEL — As part of our Shabbat trip today, Yoav Avni wanted to take me up Ada Canyon (N30.32973°, E34.91417°) to explore the Hazeva (Miocene) and Arava (Pleistocene). He cryptically said, “There will be places we can barely get through”. True, that. Above is Yoav at the start of the hike. Turns out this is a slot canyon with challenges.

2 Arava narrows begin“The narrow part begins”, he says helpfully.

3 Narrowing AravaAt this point I have to take off my pack to reduce my sideways width.

4 Narrow AravaAnd sideways with a twist is the only way through as the walls close in. Pro tip: Never do this when it is raining.

5 Problematic Arava sectionNow it gets problematic with boulder scrambling and claustrophobia.

6 First ladder aravaA ladder! I never did mention my aching shoulder.

7 Second ladder AravaSteps cut in the rock and then a second ladder. Going down is always easier than going up, right?

8 Rope climb AravaA knotted rope to climb the cliff! Note the shadow of successful me at the top of the last obstacle. Wondering, though, what these climbs are like on the way back.

9 Ada view 031916The view at the top of the mountain, though, really was spectacular. This is a view towards Be’er Ada, with the fault described in the previous post running diagonally across the background.

10 Hazeva cobbles 585And yes, the geology along the way! It was very impressive. The Hazeva Formation is mostly sandstone with some layers of sandy conglomerate as in the above image. It was deposited in a wetlands with occasional floods (which produced the coarse layers). The cobbles are rounded cherts derived from Jordan to the east.

11 Arava faciesThe Arava Formation was deposited in a desert much like what we see today. It is interbedded gravels (from wadis) and unconsolidated silts (from playas and saline lakes). Classic sed/strat material. It was all well worth the adventure for this aging geologist!

 

A Shabbat trip to Be’er Ada in the southern Negev

March 19th, 2016

1 Road to Beer AdaMITZPE RAMON, ISRAEL — Yoav Avni and I have a tradition on Shabbat. We drive somewhere to explore interesting geology and history unconnected to current projects. It’s not really work — it’s geotourism. We are, though, always talking about new ideas. Today we traveled south of Mitzpe Ramon into the “deep desert” of the Arava below the Negev Highlands.

2 MR view to JordanThe morning view south across Makhtesh Ramon was spectacular. It isn’t conveyed very well through an image only 585 pixels wide, but it is a perspective of unusual clarity. The purple streak at the top represents mountains in western Jordan. The haze just below them is in the Arava Valley. We are looking across most of the Negev.

3 Acacia grove Beer AdaOur mission today was to visit Be’er Ada (Bir Abu ‘Auda), an historic well, and the geology around it. (N30.32229°, E34.90701°, if you’re following at home.) The top image on this post is a view from the road to the well. Just above is a grove of acacia trees near the well. The abundance of these trees, and their good health, is an indication of accessible water.

4 Yoav at Beer AdaHere is Yoav peering down into Be’er Ada. (“Be’er” means well.) It is at least twenty meters deep. The base is filled with silt, so it will have to be dug out to supply water again. This well is thousands of years old and has been a critical watering spot in the Negev for traveling groups. The next nearest well is to the east about 40 km away. Another 40 km or so to the west is another well. Be’er Ada was active as late as the 1950s, and likely had sporadic use afterwards. The water here accumulates on the impermeable clays of the Taqiya Formation (Paleocene).

5 Acacia outcrop view 031916This is a view from near Be’er Ada to the main geological interest for me: the the orangish Hazeva Formation (Miocene) topped unconformably by the gray Pleistocene Arava Formation. We will spend much more intimate time with these units in the next post. Note the graceful acacia trees.

6 Beer Ada faultThis area is next to a complex fault system. On the left is a down-dropped block of Hazeva and Arava, with Cretaceous rocks on the right. The fault is also part of the reason for the subterranean water resources at Be’er Ada.

7 Ada profileIn the middle of the image is an example of the pareidolia so common in stark landscapes. Some people see a face in profile. Apparently tour guides like to call this the head of “Ada” for whom the well was named. However, there never was such a woman!

Note the excellent weather in these images. A perfect Negev day! Thank you to Yoav for being such a generous host.

Wooster’s Fossil of the Week: Sponge and bivalve borings from the Miocene of Spain

February 13th, 2015

Miocene Bored Cobble OutsideThis week we have a rather unimposing limestone cobble, at least from the outside. It was collected way back in 1989 by my student Genga Thavi (“Devi”) Nadaraju (’90) as part of a Keck Geology Consortium field project in southeastern Spain. It comes from the Los Banós Formation (Upper Miocene) exposed near the town of Abanilla. The holes are borings excavated into the carbonate matrix by marine animals. This cobble was tossed about in a coral reef complex that was part of the ancient Fortuna Basin.
Miocene Bored Cobble CutSeeing the cobble in cross-section makes it much more interesting. (Geologists love their rock saws!) We now see two categories of borings: one is large and flask-shaped, and the other a small network of spherical cavities. The large borings were produced by bivalves that tunneled into the limestone to make living chambers (domichnia) from which they could filter-feed. As the bivalve grew, the hole became deeper and wider. There was no escape — making and living in a boring like this is a lifetime occupation. These bivalve borings are classified as the trace fossil Gastrochaenolites lapidicus Kelly and Bromley, 1984. The smaller borings were made by clionaid demosponges that used acid to create a series of connected chambers, also for filter-feeding. These sponges could only penetrate about ten mm or so before their filtering became ineffective, so they are confined to the outer periphery of the cobble. The sponge borings are given the trace fossil ichnogenus Entobia Bronn, 1837.

On the inside surface of the largest boring (right side), encrusting tubes of a serpulid worm are just visible. This serpulid was also a filter-feeder. It took advantage of the cozy hole after the bivalve borer died and decayed. It is called a coelobite, or cavity-dweller. Serpulids would have had a rough time cementing to the outside of the cobble as it rolled around in this high-energy environment.

References:

Bronn, H.G. 1834-1838. Lethaea Geognostica (2 vols., Stuttgart).

Kelly, S.R.A. and Bromley, R.G. 1984. Ichnological nomenclature of clavate borings. Palaeontology 27: 793-807.

Mankiewicz, C. 1995. Response of reef growth to sea-level changes (late Miocene, Fortuna Basin, southeastern Spain). Palaios 10: 322-336.

Mankiewicz, C. 1996. The middle to upper Miocene carbonate complex of Níjar, Almería Province, southeastern Spain, in Franseen, E.K., Esteban, M., Ward, W.C., and Rouchy, J.-M., eds., Models for carbonate stratigraphy from Miocene reef complexes of the Mediterranean regions: Tulsa, SEPM (Society for Sedimentary Geology), p. 141-157.

Nadaraju, G.T. 1990. Borings associated with a Miocene coral reef complex, Fortuna basin, southeastern Spain. Third Keck Research Symposium in Geology (Smith College), p. 165-168.

Taylor, P.D. and Wilson, M.A. 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103.

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