An IS student gathering at the end of a busy school year

Mark Wilson May 3, 2023 5:12 pm

This afternoon Gloria and I hosted my Junior and Senior Independent Study students for a dessert reception in our home. We haven’t done this since 2019, and it is the first time we joined the juniors and seniors. It was so much fun. I am enormously proud of these young people, and honored to be their advisor.

Posted in Uncategorized | Tagged , | Leave a comment

Wooster Junior Independent Study students shine with their project poster presentations

Mark Wilson April 20, 2023 7:56 am

The College of Wooster has a required Independent Study system for all students, and it is a marvelous program. Each student, usually in the spring semester of their junior year, signs up for the Junior Independent Study course. It is taught as a tutorial in the Earth Sciences department, so each student chooses an advisor and a project that will likely form the basis of their later Senior Independent Study thesis project. It is a delight to see our students starting their research lives with independence, curiosity and enthusiasm.

Today the juniors presented posters on their work to date. Nick Wiesenberg, our ace geological technician, took these photos in Scovel Hall. We didn’t get everyone, but you can get a good impression of the events.

Garrett is here presenting his poster on sponge spicules in Brown’s Lake cores. He is going to see if these sponges can serve as proxies for environmental changes associated with European settlement.

Natalie is working on a joint anthropology/environmental geoscience investigation of Lake Erie and the various stakeholder communities involved with it environmental protection and conservation.

Athena, another double major with Anthropology and a self-designed major, is studying climate change in the Arctic and its environmental and geopolitical effects on stakeholder communities.

Mike is studying conflict minerals, especially in Africa.

Van is doing paleoseismology in the Caribbean associated with a summer internship he recently earned.

Corey is looking at the origins and properties of the mud used on baseballs in major league games.

Jameson, a double major with Chemistry and environmental geoscience, is studying the distribution of PFAS pollutants in rainwater.

Jimmy (in the gray shirt) is investigating drainage and tile systems on an Ohio farm.

Good luck to these intrepid Juniors as they pursue their research dreams!

Posted in Uncategorized | Tagged , | Leave a comment

Fossil of the Week: A thoroughly bored bivalve from Florida

Mark Wilson March 11, 2023 3:32 pm

The Fossil of the Week series is no longer weekly, and the gnarly specimen above is not actually a fossil, but the brand is so embedded in this blog that I’m still using it for occasional contributions.

Like the specimen posted last week, the above holey shell is a gift from my friend Al Curran, an emeritus professor at Smith College, He collected it on Anastasia Island, Florida, at the Matanzas Inlet. This location has very strong tidal exchanges and a mix of shells from the inter-coastal waterway and the open Atlantic Ocean.

The calcareous shell is from a bivalve, probably the common Mercenaria merenaria. The network of holes are borings of clionaid sponges, producing the trace fossil Entobia. This surviving remnant of this bivalve shell shows the incredible destructive power of bioerosion. The missing carbonate has been converted to microscopic chips, contributing to muddy carbonate sediments along the Florida coastline.

The wonderfully complex interior of these clionaid sponge borings.

Thanks again to Al Curran!

Posted in Uncategorized | Tagged , , , | Leave a comment

Fossils of the Week: An encrusted and bored oyster from Florida

Mark Wilson March 4, 2023 12:14 pm

The Fossil of the Week series is no longer weekly, and the beautiful specimen above is not actually a fossil, but the brand is so embedded in this blog that I’m going to use it!

My friend Al Curran, an emeritus professor at Smith College, sent me this specimen he collected on Anastasia Island, Florida, at the Matanzas Inlet. This location has very strong tidal exchanges and a mix of shells from the inter-coastal waterway and the open Atlantic Ocean. The shell is from an oyster that most likely lived in the inlet, and the brown-orange encruster is a cheilostome bryozoan from the ocean proper. The abundant holes are borings of clionaid sponges, also fully marine in origin.

The underside of the oyster shows more of the bryozoan. It is heavily eroded, showing the sequential layers of its growth. Inside the cavity is a thin encrusting tube from a serpulid worm. These worm tubes are often found in cavities like this because they prefer cryptic spaces.

These are among my favorite types of organisms in the fossil record and the Recent. They are sclerobionts — organisms that live in or on hard substrates.

Thanks for this fun little community, Al. It is now part of Wooster’s paleoecology collections!

Posted in Uncategorized | Tagged , , , | Leave a comment

A new paper on the Middle Jurassic paleoecology of southern Israel

Mark Wilson February 20, 2023 3:35 pm

I am delighted to announce that a new paper has appeared in the journal Lethaia on Middle Jurassic paleoecology in southern Israel. The senior author is Yael Leshno Afriat, and it was part of her PhD dissertation at Hebrew University in Jerusalem. It is magnificent work, and I’m proud to have had a role in it. I spent thirteen delightful field seasons in Israel, and one of my dreams was that an Israeli graduate student would take on the diverse and complex fossil communities in the Middle Jurassic of the Negev. Yael did just that, completing her PhD last year and now publishing a major part of her dissertation. Beow are some excerpts.

Abstract— Middle Jurassic reefs are known and studied from a wide range of palaeolatitudes, yet southern Tethyan reefs have been relatively understudied. The high abundance of stromatoporoids in southern Tethyan reefs was suggested to indicate a tolerance to oligotrophic and overheated waters. Recent studies affirmed the longtime hypothesis of a warm equable climate in low palaeolatitudes during the Jurassic, which could account for the documented low diversities of low-latitudinal coral reefs during this time interval. We present a case study showing possible evidence for the suggested connection between heat stress, low coral diversity and the success of stromatoporoids in the southern Tethys. The study focuses on the unique erosional depression of Makhtesh Gadol, southern Israel, which preserves a continuous section of the Callovian (Middle Jurassic). It is rich in fossils of benthic macrofauna, especially patch reefs of corals and stromatoporoids. Our quantitative analysis shows for the first time: (1) a variation between a low- and high-diversity of coral patch reefs; and (2) a major shift from coral-dominated patch reefs in the lower part of the section to dominating stromatoporoids in the upper part. The faunal assemblage is used to reconstruct the depositional environment, indicating a shallowing upwards and increasing warmer waters. Patch reef beds showing low coral diversity are correlated with isotopic reconstructions from the same section, providing evidence for elevated water temperatures. The faunal transition from corals to stromatoporoids is correlated with a similar shift in Saudi Arabia, improving the regional correlation to the Arabian Carbonate Platform.

The two Yaels in the field. Yael Edelman-Furstenberg, Yael Leshno Afriat’s primary advisor, is on the left and Yael Leshno Ariat is on the right (along with my intruding shadow). We are standing at GPS location 055, where fossils from Subunit 51 of the Matmor Formation are abundant. Student Yael is presently surveying the Middle Jurassic sections in Makhtesh Gadol to find suitable places to do stratigraphic fossil collecting and quadrat measurements.

From Figure 1 of the paper: A, palaeogeography and sedimentology of the Arabian Platform in the Callovian (Middle Jurassic) showing Israel on the southeastern margin of the Tethys close to the palaeo-equator and a satellite view of Makhtesh Gadol.

From Figure 7 of the paper: Some characteristic corals. 1, Enallocoenia; GSI 3711. 2, Adelocoenia; GSI 3701. 3, Coral genus 10, a-c- lateral view; GSI 3709.

From Figure 7 of the paper: Some characteristic sponges. 6, stromatoporoids, a- aggregation of branching stromatoporoids in subunit 60-61, b- longitudinal thin section (subunit 60-61), c- branching stromatoporoid (subunit 60-61); GSI 3721. 7, longitudinal section of a massive stromatoporoid; GSI 3719. 8, terminal end of bulbous stromatoporoid; GSI 3718. 9, bulbous stromatoporoid surface with visible astrorhizae; GSI 3720.

Senior author Yael Leshno beginning her fieldwork in Makhtesh Gadol in 2014. Since then she got married, had two children, and finished her dissertation!

For me this paper represents the culmination of my fieldwork in Israel. I’m not sure when I will be able to return. I have wonderful memories of work there with adventurous Wooster students, Yoav Avni of the Geological Survey of Israel, and Yael, all of which is documented in this blog.

Reference:

Leshno Afriat, Y., Lathuilière, B., Wilson, M.A., Rabinovich, R. and Edelman-Furstenberg, Y. 2023. Transition from coral to stromatoporoid patch reefs in Middle Jurassic equatorial warm waters. Lethaia, v. 56 (https://doi.org/10.18261/let.56.1.1).

Posted in Uncategorized | Tagged , , , | Leave a comment

Review paper on the fossil record of symbiotic organisms in bryozoans has just been published

Mark Wilson February 18, 2023 11:23 am

Olev Vinn, Andrej Ernst, and I have been working for years on various case studies of symbiotic endobionts (organisms that live within the skeletons of others) in the fossil record. This week our data-rich review paper has been published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology. Olev led us through the complex literature to produce this compendium and analysis. It contains some of my favorite concepts, like boring, bioclaustration and the Ordovician Bioerosion Revolution. Here is the abstract:

Trepostome bryozoans, with their thick calcitic skeletons, formed the largest number of symbiotic associations with endobionts in the Phanerozoic. Such associations were also formed by cystoporates, fenestrates, cyclostomes and cheilostomes. Bryozoans formed most of their symbiotic associations with endobiotic cnidarians, and markedly fewer with endobiotic worms and endobiotic lophophorates. The majority of Ordovician endobionts colonized borings in living bryozoans, or bored themselves into living hosts, during the Ordovician Bioerosion Revolution, which created new niches for the evolution of symbiotic relationships. The bryozoans likely became more selective and less symbiont-tolerant over the time. Assumed mutualistic endobionts were more common than likely parasites in Phanerozoic bryozoans. The decrease in diversity of parasitic associations and the increase in the number of mutualistic associations from the Ordovician to Devonian can be explained by the evolution of possible bryozoan defense mechanisms likely in the form of chemical secretions. Paleozoic endobiont faunas were more diverse than their Mesozoic and Cenozoic counterparts because of endobiont-friendly Paleozoic trepostomes, and because of the peak in diversity of bryozoans with massive colonies in the early and middle Paleozoic.

Bryozoans are excellent subjects for the study of symbiosis over time because they usually have thick skeletons of stable calcite that record many of the critters that lived on and in their colonies. This is especially true in the Paleozoic. Within the Paleozoic the Ordovician had by far the most recorded symbiotic relationships, which is not surprising considering the abundance of bryozoans then.

Caption for the top image, which is from Figure 4 of the paper: Ordovician symbiotic endobionts. A, Sanctum laurentiensis in Batostoma? sp. with opening at the typical bifurcation point from the Decorah Formation (Ordovician: Mohawkian) of Minnesota (modified from Erickson, 2020). B, Anoigmaichnus zapalskii in Mesotrypa expressa from Kullaaru ditch, Oandu Stage (Katian) northern Estonia (GIT 770–39). C, Kuckerichnus kirsimaei in Diplotrypa sp. from Kohtal-Järve, Kukruse Stage (Sandbian), northern Estonia (TUG 72–826-2). D, Bioclaustration in Orbiramus sp. from the Fenhsiang Formation (Tremadocian), China (Modified from Ma et al., 2020, Fig. 7B).

This was a very satisfying project because it summarizes two decades of our work and, of course, that of many others. It is also, by the way, a product of the recent pandemic. We all spent far more time than usual writing in our offices and labs during 2020-2022. This is why I’m posting an unusual number of new papers during the first few months of 2023.

Reference:

Vinn, O., Wilson, M.A. and Ernst, A. 2023. Macroscopic symbiotic endobionts in Phanerozoic bryozoans. Palaeogeography, Palaeoclimatology, Palaeoecology 615: 111453.

[Click the link for a free pdf for the next 50 days; after that you can ask me for a copy.]

Posted in Uncategorized | Tagged | Leave a comment

A new paper on symbiosis between brachiopods and bryozoans in the Late Ordovician of Estonia

Mark Wilson February 10, 2023 7:56 am

I’m pleased to announce another paper has appeared from our ongoing Estonian-German-American collaboration on symbiosis in the fossil record. The beautiful specimen above is the trepostome bryozoan Esthoniopora subsphaerica growing around a bioclaustration, forming a distinctive tube (Katian, Rakvere, northern Estonia; TUG 1824-8). Some alert Wooster students and alumni will remember similar features in trepostome bryozoans from the Cincinnatian in Ohio, Indiana and Kentucky.

The abstract —

Valves of the strophomenid brachiopod Sowerbyella tenera are often encrusted by trepostome bryozoan colonies in the lower Katian of Estonia. In some cases, the encrustation of Sowerbyella likely took place syn vivo. A single Sowerbyella tenera contains three Palaeosabella prisca borings that were bored post mortem into the interface between the encrusting trepostome colony and the ventral valve of Sowerbyella. The encrusting trepostome colonies contain a large bioclaustration in a tubular outgrowth of the bryozoan colony, Anoigmaichnus-like bioclaustrations, Kuckerichnus-like bioclaustrations, A. zapalskii, A. bretti, and a symbiotic conulariid. The bioclaustrated soft-bodied organisms and the conulariid colonized living bryozoans.

It is a pleasure as always to work with this happy team led by the indefatigable Olev Vinn of the University of Tartu, Estonia.

Reference:

Vinn. O., Ernst, A., Wilson, M.A., Tinn, O., Isakar, M. and Toom, U. 2023. Symbiosis in brachiopods and brachiopod-attached trepostome bryozoans from the Katian of Estonia. Neues Jahrbuch für Geologie und Paläontologie 307/1: 41-50.

Posted in Uncategorized | Tagged , , | Leave a comment

The delightful Fall 2022 Paleoecology class at Wooster

Mark Wilson December 13, 2022 2:20 pm

I was so impressed with the post by Professor Greg Wiles about his Fall 2022 Geomorphology class that I decided to highlight the Fall 2022 Paleoecology class as well. It was a great group of students, and we did an extraordinary amount of scholarly work: 26 quizzes, two tests, one final exam, two essays, a research paper, a research presentation, an extensive field project, and three other lab reports. They flourished and in turn through their research taught me quite a bit about many paleoecology topics. We were assisted throughout by our brilliant, patient, tireless, cheerful Teaching Assistant Brianna Lyman.

Early in the course we had a day-long field trip to southeastern Indiana (locality C/W-148 near Richmond) described in an earlier post. The goal was for each student to make a large collection of fossils from the upper Whitewater Formation (Upper Ordovician) that would be the raw material for a detailed paleoecological report due at the end of the semester. Nick Wiesenberg, our geological technician, was invaluable in the planning and successful completion of this little expedition.

These are the filled sample bags from the field trip, one for each student.

The next step was to wash the specimens for further analysis.

One of the student trays with typical specimens from the trip, including brachiopods, bryozoans, bivalves, gastropods, corals, cephalopods, monoplacophorans, and a few rare trilobites. There were also trace fossils, including numerous borings in the calcitic shells.

This is a completed tray at the end of the semester. Specimens are cleaned, labeled, and identified. Each student made at least two acetate peels, one from a rugose coral and the other from a bryozoan. Each student then wrote a report on the taxonomy, taphonomy, and paleoecology of their collection, supplementing their observations with the discoveries and ideas of their classmates. It was a nice mix of individual research and group discussions.

Another lab exercise detailed the ontogeny of the rugose coral Grewingkia canadensis from the same field site. We clearly have enough specimens for each student to measure the dimensions of numerous corals. They then used a statistical package (Past4) to make various graphs for interpretations.

We also had a foraminiferan “picking” exercise. Each student had a vial of sediment from a drill hole in the Gulf of Mexico (Frio Formation, Oligocene). They then collected foraminiferan tests with a thin wet brush and placed them on slide covered with water-soluble glue.

The process required careful hand-eye coordination to not lose the little critters in the transfer from sediment to tray!

This image shows a sediment vial, a picking brush, and a completed slide. Each number on the slide has a tiny specimen glued by it. The students then identified the foraminiferans and assessed the likely depth that the benthic forms lived.

The final exercise involved identifying shark teeth from the Cretaceous Menuha Formation of southern Israel. We have a large collection of these teeth from the Independent Study thesis of Andrew Retzler (’11). We used Retzler et al. (2013) as our guide for identification of these sharks and their paleoecological context.

I had an excellent time in this course with these creative, hard-working, resilient, happy students.

Posted in Uncategorized | Tagged , , | Leave a comment

Local Geomorphology and What We Learned

gwiles December 8, 2022 12:19 pm

This is a post outlining some of the work we did in Wooster’s class in Geomorphology. One of the early labs was Browns Lake Bog and the Soil Catena.

The landforms in the area are spectacular – here is a kame, a photo taken  as we ventured down into the bog.

The group shares a light moment before the 20+ species of mosquitos descended on them in the forest.

The soils from the top of the kame to the base varied more than the group predicted.

We also sampled soils just east of the campus golf course.

Nick and Jerry in the soil pit measuring magnetic susceptibility as Des records the data.

The C-horizon on the left is a sandy, silt gravel – the B-horizon in the middle is blocky loam and the A is a more brown silty material.

The team coring an old growth (300+ year) tree growing on top of the soil site. The landform is a kame terrace that has likely been weathering in place for the last 14,000 years with additional windblown silt being added (or removed) from time to time during the Holocene.

At Zollinger’s Sand and Gravel – posing at the base of the section which is Mississippian bedrock. A big thank you to the Zollinger family for allowing us to work here and for showing us around.

This side of the pit is still being mined, whereas other portions serve as land fill. We learned that lodgement till can be fractured and that it also can be mined and serve as a landfill liner.

On the way back to campus we stopped at the artesian spring near the Wayne County Airport.

Of course not class would be complete without a trip to Spangler. Here the group is standing inf ront of one of the unconformities, which is composed of a lodgement till overlain by fluvial and alluvial sediments.  The interface of these units is where the geochmistry is just right to generate concretions.

The increasingly greater precipitation events are moving larger and large block of bedrock. Here the Wooster Shale is being excavated by 1-2 inch storm events. Our hypothesis is that erosion rates over the last few decades are unprecedented perhaps over much of the Holocene.
Big blocks are moved routinely – they are plucked out by the stream along planes of weakness (fractures). Note how the shales break up readily. A block like those above will be mud again in a matter of months. Swelling clays and strong wetting and drying does the job.

Here is a series of debris flows (gray sediment) – we obtained two radiocarbon ages that show intervals of mass movements about 2.5 ka, these are dates on charcoal that may be from fires used in land management by native Americans at the time.

Stream gaging along Apple Creek. The group gets some hand-on experience with the equipment and puzzles over the various facies of a fining upward fluvial sequence.

Nick and Tyrell take turns in the deep end.

Jack giving the group the rundown on riparian vegetation.

As it turn out the floods here get pretty high, this tree was scarred when a log (or a washing machine) floated by during a high flow.

 

The class at Fern Valley standing in front of Columbia Gas’ well-head for the natural gas storage field. The group was investigating the possibility that mass movements at the site might impact the infrastructure and pipelines in the area.

The slump block at Fern Valley is clearly seen from above. It is a series of glacial ice-contact stratified drift deposits overlain by a thick (40+ foot) layer of varved lacustrine clays. What you see in the woods is a major 2-3 meter scarp (normal fault) as the block descends into the valley.

The class at Fern Valley. A big thank you Nick Wiesenberg for arranging the logistic for the trips. We would also like to thank bus drivers Mark Livengood and Fred Potter for getting us to and from the sites safely. A special thanks to Fred who will be retiring soon – we appreciate your expertise and knowledge of the Wooster area.

Posted in Uncategorized | 1 Comment

Paleoecology field trip to the Upper Ordovician of eastern Indiana: Haven’t done this for awhile!

Mark Wilson September 4, 2022 10:58 pm

Richmond, Indiana — Today Nick Wiesenberg (our invaluable geological technician), Brianna Lyman (my excellent Teaching Assistant), and I took the 15 students in the Paleoecology course to the fossiliferous Upper Ordovician of eastern Indiana (upper Whitewater Formation). It’s a location (C/W-148) that I’ve taken students to many times, but not since 2019 because of … you guessed it … pandemic. We had a wonderful time collecting bags of specimens for exercises and reports this semester. It was a wonderful day, even if it was seven hours of driving for one hour of fieldwork!

This is a typical view of the fossils available here in abundance. Note the bryoimmurations!

Bags of fossil treasure waiting to be opened in lab. First step will be washing and sorting. This is going to take awhile!

Posted in Uncategorized | Tagged , , | Leave a comment