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Wooster undergraduate researchers expand their professional networks with cross-college collaboration

June 14th, 2019

Carlisle, PA – Our geochemistry research team spent this week at Dickinson College.

Hannah and Marisa analyzed the compositions of volcanic glasses and crystals using the scanning electron microscope (SEM-EDS).

They worked closely with Dr. Ben Edwards and Rob Dean (technician) to learn how to use the instrument. As with any new technique, it took a few days of practice to figure out how to obtain high quality data, but now we have hundreds of measurements to process when we return to Wooster.

Layali and Kendra processed major and trace element geochemical analyses of diabase from some Pennsylvanian rift basins.

They presented their work to Dr. LeeAnn Srogi and Dr. Tim Lutz, collaborators from West Chester University who visited us at Dickinson for a day. Layali and Kendra are contributing data to an oral presentation that Dr. Srogi will make at the 2019 IUGG General Assembly in July.

In the first two weeks of our undergraduate research project, our students have collaborated with scientists from three different institutions. They are building their professional networks and expanding their future opportunities.

In addition to all of the network-building and research productivity, we had a chance to sneak to nearby Hershey for a short visit (and some milkshakes).

The end of week 2 is bittersweet. Kendra, Layali, and Hannah head back to Wooster, parting ways with Marisa until we meet again in Iceland.

Thanks to everyone who made our Dickinson visit a success. We thank Dr. Ben Edwards and his family for their hospitality, Rob Dean for all of his assistance, Dr. LeeAnn Srogi and Dr. Tim Lutz for making the time to visit us and for excellent discussion, and the Dickinson Earth Science Department for their warm welcome.

A new paper has appeared: A rugose coral – bryozoan association from the Lower Devonian of NW Spain.

June 14th, 2019

I’m proud to be an author with my two Spanish colleagues, Consuelo Sendino and Juan Luis Suárez Andrés, of a paper just out in the latest issue of Palaeogeography, Palaeoclimatology, Palaeoecology (we call it “Palaeo-cubed”). I’ll let the abstract tell the story (with some embedded links):

“A new rugose coralcystoporate bryozoan association is here described from the Devonian of NW Spain. This is the first evidence of intergrowths between Devonian rugose corals and bryozoans. In this case bryozoans provided a suitable substrate for the settlement of corals, which were subsequently encrusted by the bryozoans. The hypothesis of intergrowth between living organisms is supported by the absence of encrustation of the rugose coral calices by the cystoporates. We suggest that the association was specific and developed through chemical mediation. This symbiosis was facultative for the bryozoans but likely not for the corals. The association provided the bryozoan host with additional substrate for encrustation as well as protection from various predators, and it allowed the rugose corals to grow in a muddy environment and benefit from the feeding currents of the bryozoans.”

The above images show some of these specimens of corals intergrown with bryozoans. The caption from Figure 2: Intergrowth of fistuliporid bryozoans and rugose corals from the Aguión Formation of Asturias, NW Spain. A. General view of DGO12902. B. General view of MMAGE0033. C. Detail of the corallite, MMAGE0032. D. Magnified corallite of the right side, MMAGE0033.

This cartoon from the paper shows the process in which a coral larva (planula) lands on a living bryozoan, somehow survives the encounter, and then the coral grows together with the surrounding bryozoan colony. The fun part is sorting out the biological and evolutionary context of this relationship.

I thank my colleagues Consuelo and Juan for inviting me into this project. I learned a lot that will be applied to similar intergrowing situations in the fossil record.

Sendino, C., Suárez Andrés, J.L. and Wilson, M.A. 2019. A rugose coral – bryozoan association from the Lower Devonian of NW Spain. Palaeogeography, Palaeoclimatology, Palaeoecology 530: 271-280.

New publication on an Alaskan glacier – coauthored by a Wooster student, staff and faculty member

June 11th, 2019

Dr. Ben Gaglioti (Lamont-Doherty Tree Ring Lab and University of Alaska – Fairbanks) just published an article entitled: Timing and Potential Causes of 19th-Century Glacier Advances in Coastal Alaska Based on Tree-Ring Dating and Historical Accounts. Three of the coauthors include Wooster Earth Scientists and Tree Ring Lab workers, Josh Charlton (’19), Nick Wiesenberg (Department technician) and Dr. Wiles (Earth Sciences faculty). This contribution describes the Little Ice Glacier History of LaPerouse Glacier on the outer coast of Glacier Bay National Park and Preserve.

Dr Gaglioti did a great job putting together the glacial chronology for the site, and then coming up with some new ideas explaining why this glacier advanced to its Holocene maximum between CE 1850 and 1890. This was a time when it was not as cold as some other times within this broad interval (~ CE 1250-1850) we call the Little Ice Age. Dr. Gaglioti draws on some new and not-so-new proxy records that show a strengthening of the Aleutian Low over the past several 100 years and he suggests that the cooler summer temperatures aided by increased winter snowfall forced this glacier to its maximum extent. His methods and presentation in this paper are new and provide some excellent possibilities for future work by Wooster students. We look forward to continuing our collaboration with Dr. Gaglioti.

The photos below are from Dr. Gaglioti and show (top) the location of the glacier, (middle) the setting of the buried forest he discovered, and (bottom) what the amazing pristine trees look like as the ice retreats. Within this buried forest is also the first Alaskan Cedar paleo-forest that has been discovered. Here is a link to a National Geographic sponsored blog describing some of the field work. Special thanks to Lauren Oakes for her excellent blog. The project was partially supported by the National Geographic Society, the Lamont-Doherty Earth Observatory and the National Science Foundation.



Wooster and Dickinson students team up for geochemistry research

June 7th, 2019

[Wooster, OH] – A team of students from Wooster and Dickinson are working together on geochemistry research this summer. We’re using the compositions of Earth materials to understand geologic processes. Our main goal is to study the formation of volcanic ridges that were erupted beneath glaciers in Iceland, but we have a few other projects that we’ll be working on, too.  Thanks to Sherman Fairchild funding, we have 8 weeks to learn a lot of different lab techniques and travel to Iceland to get more samples.

We began our work with a weeklong marathon of preparing samples for analysis in the Wooster X-ray and Dickinson SEM labs.

Kendra and Layali prepared geochemical samples by melting powdered rocks and forming them into glass disks.

Marisa is examining samples of volcanic glasses under the microscope, selecting the freshest chips.

Kendra and Hannah are in the first stages of polishing the fresh glass chips so that they are perfectly smooth. This will let us analyze their compositions on Dickinson’s scanning electron microscope. We can also use the polished glass chips to measure the water contents later in the project.

Layali is tracing images of thin sections. We’ll use the tracings to do some quantitative mineralogical analyses.

It looks she is having fun doing all of this hard work!

The team has been working so hard that they have needed reminders to take breaks. So what to do on a break? How about a game of lab-bench-dino-mancala?


Dundee Falls: A beautiful waterfall in northeastern Ohio

June 4th, 2019

Dundee, Ohio — One of the joys of summer for a geologist is the time to take short trips in the neighborhood to explore nature. This afternoon Greg Wiles, Nick Wiesenberg, Greg’s adventurous dog Arrow, and I drove about 45 minutes into Tuscarawas County to visit Dundee Falls, which is in the Beach City Wildlife Area. It was a gorgeous day. The falls are formed by a creek rushing into a gorge walled by the Dundee Sandstone (= Massillon Sandstone), part of the Pottsville Series of Upper Carboniferous age. I hadn’t heard of this place until Alexis Lanier (’20) recommended it.
The vertical sandstone walls are impressive. This particular face is used by rock climbers. I learned on this visit that the climbers occasionally scrub the cliff face with wire brushes to remove slippery moss and the inevitable graffiti.

The sandstone shows several sedimentary structures, including dramatic cross-bedding. These are like lateral accretion deposits from meandering streams in a delta complex.

The sandstone has layers of iron oxide concretions reminiscent of the Moqui Marbles we saw in the Navajo Sandstone on our Utah Expedition this spring.

Nick”s right hand is on a quartz-pebble conglomerate within the sandstone. These core beds are common throughout the Pottsville Series. They likely represent braided stream deposits and classic molasse. The reddish color is what remains of spray-painted graffiti.

The unscrubbed, unpainted walls host a wonderful moss-fern flora.

One of the goals of this hike was to determine the ages of the oldest trees. Nick and Greg (and Arrow) are here scoping out the woods for the largest oak trees.

Greg and Nick worked hard inserting their coring devices. The process makes some incredible squawking noises as the bit is screwed into the tight wood. I also learned that taking the corer out of the tree can be much harder than putting it in! So far the dendrochronology team found trees only about 200 years old, which is too young to interest them.

Arrow the Dog was a great companion as always! He seems to have a very good time on these outings.

Update from Dr. Wiles, ace dendrochronologist: “Nick worked up the five cores we took and below is the Dundee Ring Width Series – inner ring 1823, second growth. Looks like a slow release up until 1900 and then a big release – selective logging and the big logging at 1900? Maybe the quarry was set up ~1900.”


Constructive & Destructive Landforms at Mount Rainier National Park

May 30th, 2019

One common frame used to introduce landforms in introductory Geology courses is the idea of constructive and destructive forces that create and change them. (See, for example some K-12 resources here and here.) Constructive processes like the the deposition of sediment and extrusion of lava build landforms by adding material at the surface. Destructive processes like weathering and erosion and explosive volcanism shape the surface by removing material.

If you go to the Paradise Visitor Center in Mount Rainier National Park, you can observe this dichotomy at work just by comparing the north and south. Looking to the north is the park’s namesake: Mount Rainier. The smooth, rounded shape of this composite stratovolcano is primarily the result of layered ash, rubble, and lava over the past 500,000 to a million years, piling up over 14,000 ft high (NPS). There are glaciers eroding the flanks of Mount Rainier, but the recent volcanism of the past few thousand years means the overall shape is more reflective of volcanism than glaciation.

View to the North: Mount Rainier

Contrast this with the view to the south. Rather than a single smooth and rounded profile, the Tatoosh Range is characterized by several jagged peaks with names like “The Castle” and “Pinnacle Peak”. This mountain range is the result of extensive weathering of an ancient pluton, which was originally emplaced in the Miocene (14 million years ago; USGS 1963; Mattinson 1977). The Tatoosh pluton was exposed at the surface and actively eroded by Pleistocene glaciers long before Mount Rainier existed.  With millions of years of erosion at work, destructive forces are more obvious in the Tatoosh Range than on Mount Rainier. It displays classic glacial features like the horn of Pinnacle Peak, the col between Plummer Peak and Denman Peak, and the converging U-shaped troughs below Plummer Peak.

View to the South: Tatoosh Range (Paradise Visitor Center in foreground).

Lots of Rain v. Many Rainy Days

May 16th, 2019

The other day while on the phone with my sister, she complained about how bad the weather was. “It’s rained like every day since April 1st” was the statement. That was an exaggeration, so she then modified that statement to say it’s been really wet this spring, and she’s had few opportunities to let the boys play outside in the sun. So then I wondered… is she right? Or is she just participating in a favorite past time of complaining about the weather? She lives north of Boston, so I decided to take a look at the data from a long-running station at Lowell, Massachusetts.

Distribution of total precipitation between April 1 and May 10 in Lowell, Massachusetts

It’s true that 2019 has had a wet spring. Of the 127 years of data at Lowell, 9 years had enough missing data I had to toss them.  That leaves 118 years.  Of those, 2019 has seen the 12th most precipitation between April 1 and May 10 (7.73 inches; the 91st percentile). However, my sister has only lived near Lowell for about 15 years, and in those 15 years, 2019 ranks 5th… so above average, but nothing special.  In fact, neither of her sons has experienced fewer than 6 inches of rain from April 1 through May 10… all they know is wet springs!

Before I called her back to tell her she’s exaggerating, I decided to dig a little deeper.  You see, my sister didn’t actually say there’s been a lot of rain; she said there had been many rainy days. That’s different. If we track the percentage of days on which rain (sometimes with snow) fell in Lowell since April 1, we find that my sister is on to something.  It has rained 25 days — about 62% of the days since April 1 — and that is a record.  Yup, in 118 years Lowell has never had so many rainy days between April 1 and May 10.  My sister’s smart, but I didn’t expect she’d be that good.

Distribution of the days between April 1 and May 10 with precipitation greater than 0.01 inches in Lowell, Massachusetts

Anyway, the lesson here is that my sister, like many people, would rather have a lot of rain on a few days than a little rain on many days. It’s not the rain so much as lack of sun that gets to people. This is partly why a city like Seattle (36 inches/year) is famous for being rainy even though cities like Cleveland (39 inches/year), Boston (44 inches/year), and New York City (50 inches/year) all receive more precipitation.  It’s not that Seattle gets a lot of rain; it’s that it’s often raining. Seattle has 152 days with precipitation a year, but Boston only has 126, and New York has only 122. Think about that — NYC gets 38% more precipitation but 30 extra days without any precipitation!

Total annual precipitation and number of days with greater than 0.01 inches water equivalent of precipitation in four US cities

Cleveland, for the record, has 154 days with precipitation a year on average thanks to it frequent lake effect snow. All data are from NOAA’s Climate Data Online.

New paper on crinoids of the Kalana Lagerstätte (Early Silurian) of central Estonia

May 14th, 2019

Bill Ausich (The Ohio State University), Oive Tinn (University of Tartu) have a paper that has just appeared:

Ausich, W.I., Wilson, M.A. and Tinn, O. 2019. Kalana Lagerstätte crinoids: Early Silurian (Llandovery) of central Estonia. Journal of Paleontology

It was an absolutely delightful project that was thoroughly documented in this blog. Last summer Bill and I traveled to Tartu, Estonia, to work with Oive on describing the extraordinary crinoids of the Silurian Kalana Lagerstätte. A Lagerstätte is a sedimentary deposit with exceptional fossil preservation. It is a privilege as a paleontologist to work on one. As you can see from the images, the crinoids here are well preserved indeed. I’ll let the paper’s abstract tell the story:

Abstract.—The Kalana Lagerstätte of early Aeronian (Llandovery, Silurian) age in central Estonia preserves a diverse shallow marine biota dominated by non-calcified algae. This soft-tissue flora and decalcified and calcified crinoids are preserved in situ in a lens of microlaminated, dolomitized micrite interbedded in a sequence of dolomitized packstones and wackestones. Although the Lagerstätte is dominated by non-calcified algae, crinoids (together with brachiopods and gastropods) are among the most common organisms that were originally comprised of a carbonate skeleton. Two new crinoids are described from this unit, Kalanacrinus mastikae n. gen. n. sp. (large camerate) and Tartucrinus kalanaensis n. gen. n. sp. (small disparid). Interestingly, these two crinoids display contrasting preservation, with the more common large camerate preserved primarily as a decalcified organic residue, whereas the smaller disparid is preserved primarily in calcite. Preservation was assessed using elemental mapping of C, Ca, S, and Si. Columns have the highest portion of Ca, once living soft tissue is indicated by C, S was dispersed as pyrite or associated with organics, and Si is probably associated with clay minerals in the matrix. This new fauna increases our understanding of the crinoid radiation on Baltica following Late Ordovician extinctions.

The top image and that above shows the new crinoid Kalanacrinus mastikae. Look at those gorgeous arms and the carbon films in the calyx that may represent internal organs. The species is named in recognition of Viirika Mastik, an Estonian graduate student who helped us in innumerable ways, and she was very patient with the sometimes clueless Americans! The genus, of course, is named for the deposit. (Scale bar is 5.0 mm.)

Here is another specimen of Kalanacrinus mastikae. Note the small angular, twiggy fossil below the calyx. I think it may be a green alga similar to the modern Hydrodictyon but marine and with larger cells.

Say hello to the new crinoid Tartucrinus kalanaensis. It’s pretty obvious how we came up with these names. Note again a carbon film in the calyx that may be from internal organs, possibly the anal sac. (Scale bar is 5.0 mm.)

The location and stratigraphy of the Kalana Quarry.

Several slabs of Kalana material. What a joy it was to study them for long, uninterrupted days.

The paleo lab at the University of Tartu, with Bill working in the background.

I loved this brand new Leica photomicroscope (model S9i).

Oive does excellent geochemistry, so she handled the elemental mapping. This example shows a close view of a Kalana crinoid column, with the elements C, Ca, S, and Si mapped. As stated in the abstract, columns have the highest portion of Ca, once living soft tissue is indicated by C, S was dispersed as pyrite or associated with organics, and Si is probably associated with clay minerals in the matrix.

Thank you to our excellent Estonian colleagues!

From the left is Oive Tinn, Mare Isakar, Bill, and Viirika Mastik.

Warming at the Third Pole – A New Record of Climate Change from Kashmir, Northwest Himalaya

April 28th, 2019

The Wooster Tree Ring Lab collaborated on a publication describing the recent thermal history of the Lidder Valley, Northwest Himalaya. Dr. Santosh Shah, the lead author, is a multitalented paleoclimatologist at the Birbal Sahni Institute of Palaeosciences in Locknow, India. He and his colleagues led the study that appeared in Climate Dynamics and is titled: A winter temperature reconstruction for the Lidder Valley, Kashmir, Northwest Himalaya based on tree-rings of Pinus wallichiana. Here is the abstract from the study:

Abstract: A regional, 175 year long, tree-ring width chronology (spanning 1840–2014 C.E.) was developed for Pinus wallichiana A. B. Jacks. (Himalayan Blue pine) from the Lidder Valley, Kashmir, Northwest Himalaya. Simple and seasonal correlation analysis (SEASCORR) with monthly climate records demonstrates a significant direct positive relationship of tree growth with winter temperature. A linear regression model explains 64% of the total variance of the winter temperature and is used to reconstruct December–March temperatures back to 1855 C.E. The most noticeable feature of the reconstruction is a marked warming trend beginning in the late twentieth century and persisting through the present. This reconstruction was compared with instrumental records and other proxy based local and regional temperature reconstructions and generally agrees with the tree-ring records and is consistent with the marked loss of glacial ice over the last few decades. Spectral analysis reveals a periodicity likely associated with the Atlantic Multidecadal Oscillation and El Niño–Southern Oscillation. Spatial cor- relation patterns of sea surface temperatures with the observed and reconstructed winter temperatures are consistent with larger scale warming in the region.

Map showing the location of the study in the Lidder Valley in Kashmir, Northwest India.

The rivers of the Lidder Valley are fed by glaciers from the Himalaya, which are becoming increasingly impacted by climate change and population pressures. The people within the valley depends on the water from the rivers and managing the water in this rapidly warming region is an increasing challenge. The results in this work show the increasing pace of the recent warming (see figure below).

Temperature reconstructions (above) based on tree-rings for the Himalaya. The curve on the top is from the new publication. 

Dr. Shah is now working on using tree-rings to reconstruct river flow in the region. This is work that he presented last year at World Dendro in Bhutan and which we are are also collaborators. We are grateful to Dr . Shah for introducing us to climate change research in the Himalaya AND for his help to our former students of the Wooster Tree Ring Lab.

Jeff Gunderson,  who recently completed his masters thesis at The Ohio State University in Geography used tree-rings from the Peruvian Andes to reconstruct climate. Jeff collaborated with Dr. Shah who shared his computer code and guidance in calibrating his Peruvian tree-ring records.



New paper: Borings from the Silurian of Sweden — possibly the oldest deep-boring bivalves

April 27th, 2019

It was a delight to be a junior member of the team that produced this recent paper:

Claussen, A.L., Munnecke, A., Wilson, M.A. and Oswald, I. 2019. The oldest deep boring bivalves? Evidence from the Silurian of Gotland (Sweden). Facies 65: 26.

This may be the first paper for me where I’ve not yet met my co-authors. They are all from the GeoZentrum Nordbayern, Fachgruppe Paläoumwelt, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany. This is where our recent graduate William Harrison is a graduate student. (He is clearly having a wonderful time there!)

Our team leader was the remarkable Lene Claussen. She did a prodigious amount of working and thinking for this study, which combines many of paleontology’s most recent tools, from isotopic analysis to micro-computed tomography. The abstract give us a synopsis of the story —

Abstract: Compared to modern counterparts, bioerosion is rare in Paleozoic reefs, especially macro-bioerosion. The unique and enigmatic Silurian reefs from Gotland (Sweden), composed of bryozoans and microbial laminates, show evidence of a large amount of bioerosion. The samples contain Trypanites trace fossils, as well as a large number of undescribed macroborings. Small articulated bivalve shells are preserved in some of these macroborings, identified from thin-sections. Three-dimensional images from micro-computed tomography (microCT) reveal an additional bivalve, which is occupying a bioerosion trace. This specimen is possibly contained in a different boring that can be classified as possibly clavate-shaped. Furthermore, evidence of nestling, such as a subsequent modification of the ichnofossils, the presence of bivalves that are much smaller than the trace, or the presence of additional specimens, is missing; therefore, it is most likely that the bivalves made the borings. This is evidence for the existence of deep-boring bivalves in the Silurian.

Top image is from Figure 3: Bioerosion traces from Nors Stenbrott, boreholes with bivalve shells in thin-section; a lateral cut through a bivalve shell (sample P3); b lateral cut through a bivalve shell (sample P13B).

From Figure 6: Processed three-dimensional microCT images of different boring traces from Nors Stenbrott, Trypanites borings in blue and the unknown ichnofossil in green; a all contained boreholes from sample SNS1; b all contained boreholes from sample Z9A, boring with bivalve with arrow.

I learned a great deal from this study and my new colleagues, especially about new techniques and the surprises they can reveal. Thank you, Lene and crew.

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