Ten Days in Glacier Bay National Park and Preserve

After spending a day in Juneau gearing up, we flew over to Gustavus, Alaska and then got a ride to Bartlett Cove in Glacier Bay National Park and Preserve. We then rented kayaks and headed into Glacier Bay.

Shortly after being dropped off by the Day Boat at Mount Wright, the team (left to right, Jacob Hassan, Nick Wiesenberg, Jack Whitehouse and Greg Wiles) packed two kayaks and headed for the East Arm (Muir Inlet) of Glacier Bay. The primary objective of this trip is to recover wood that will allow the team to bridge a gap in a 2,000 year long tree-ring record. The age of the wood needs to be about 2000 years old. We know from previous studies where we need to go to optimize our chances of finding that age wood.

Jack and Nick enthusiastic to get paddling north into Muir Inlet (aka the East Arm).

Much of the work was done by examining stream cuts through various glacial and fluvial landforms and working our way up and down outwash fans and streams in the area.

Jacob standing on the bank of a part meandering – part braided stream. He is preparing to crash the brush on the right to make headway.

Jack along the shore of Adams Inlet is optimistic that this section of a fan and delta may contain wood needed for his thesis.

Nick directing the sample collection of a large sitka spruce – likely run over by ice about 1500 years ago during a cold time now known as the LALIA (Late Archaic Little Ice Age). It may be that this cool interval was forced, in part, by major volcanic eruptions and various associate feedbacks in the mid 500s CE.

The group taking a well-deserved rest after a morning of exploring a fan.

One of key deposits that the team investigated were extensive Gilbert type deltas that overlie flooding surfaces from lakes. The lakes (in this case Adams Lake) were formed about 1500 years ago when glaciers in the West Arm advanced damming up the East Arm of Glacier Bay. These lakes preserved forests of that age, and now with ice retreat, isostatic uplift, and erosion the lake are gone and the glaciolacustrine sediment sequences are being eroded away liberating the logs.

This is the same photo – a closeup showing the gray lacustrine clays and silts that are varved (to the right of Jack) and the dipping sands of the foresets overlying the lake clays. Beneath the clays is the flooding horizon that preserved the wood.

Descending a delta from above – here Jacob is walking down the delta foresets into the paleobasin.

The sampling team – yes we have a permit with the National Park Service for chainsaw use. Nick is a chainsaw expert and is able to minimize the saws impact and take high quality samples.

One of the more demanding legs of the trip was thrashing our way up the Casement Glacier outwash plain. We started from its delta in Adams Inlet and headed north with the hopes of setting a camp 8 or so miles from the sea to sample wood at the glacier and on its outwash. Unfortunately, the massive outwash river was pegged along the west side of the valley making travel through the brush difficult. We spent one day sampling washed out logs in the hopes that the complex glacial and fluvial history of the valley might preserve the logs in the age range that we sought. It was slightly miserable with poor weather as well.

Jacob managed to look optimistic as he takes an increment core from a log on the Casement Fan.

Near the delta of Casement River the tidal effects are evident. Here the ebbing tide with a fluvial, unidirectional rippled surface reworks the intertidal mudcracks. Note too, the bubbles evident along the hexagonal boundaries of the mudcracks.

We give a big shout out to Glacier Bay Sea Kayaks for their help with logistics and equipment. These well-maintained boats are necessary for this work as most of the waters we worked in were non-motorized water,  meaning no motor boats.

Here is a shot of the two double kayaks at our Nunatak Fan camp in Muir Inlet. Nick anticipated all the gear and food we would need for the trip and carefully did the planning to ensure that we could fit all we needed in these two boats for the entire 10 days. He also made sure that it would stay dry in the often very wet conditions in this coastal rainforest setting.

The group plans a launch out of one camp on the way to the next. Note the head nets on all the crew. Bugs were an issue and head nets were worn frequently.

A view looking west from he Nunatak camp toward Muir Inlet.

Jack scoped out this barnacle encrusted log – the core was excellent and may be part of the gap-filling ring – width series.

Camped at Muir Point in Muir Inlet. The glacier was here at this fan in 1880 when John Muir has his cabin close to our camp. Only the stone chimney is left to the cabin now and it is well hidden in a nearby forest. Here the group enjoys a nice evening in the intertidal burning driftwood from the beach.

At Muir Point, Nick picked a pile of strawberries that were just right in terms of ripeness and sweetness.

For lunch we had wraps of strawberries, honey peanut butter and nuts. Nick outdid himself with the meal planning.

This is a Bear Highway on top of a storm berm. Each time a bear passes over the berm it steps in the same spots keeping the moss from growing in the footprints.

Nick finding a creative way of crossing the stream in search of the wood.

At the end of the 10 days we were picked up by the day boat and completed our time in Glacier Bay with a trip up the West Arm. The day was brilliant and sunny and we met guides from Alaska Mountain Guides and shared stories of adventures in Alaska.

A sea star revealed itself as we waited at low-tide for the Day Boat.

The group onboard the Day Boat headed back to Gustavus via the West Arm.

Flying back to Juneau a view of the Chilkat Mountains.

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Wooster’s Fossils of the Week: Lingulid brachiopod trace fossils from the Middle Jurassic Carmel Formation of southwestern Utah

This is a short trace fossil story with two disappointments, one much more than the other. It involves trace fossils made by lingulid brachiopods, a marine invertebrate group with a very long geological history. The earliest appeared in the Cambrian, and, as you can see from the top image, they are very much alive today. (Image of Lingula anatina from Wikipedia.)

Lingulid brachiopods have two chitino-phosphatic valves (shown at the left end in the image above) and a long fleshy pedicle (the right end). Unusually for brachiopods, they are infaunal, living with the pedicle vertically down in the sediment. They can flex this pedicle to move their valves up and down in the sediment, maintaining access to seawater which they filter for their food. They have been doing this for hundreds of millions of years with little evolutionary change. Since they are infaunal, they can leave evidence of their burrowing in the sediments, making a particular variety of trace fossil. This is where our story begins.

While doing fieldwork in the Middle Jurassic Carmel Formation this summer with Team Utah 2022 near St. George, Utah, I found numerous small slabs of sandy-oolitic limestone with roughly circular pits a centimeter or so in diameter (above).

This is the steep slope where these particular trace fossils are found. This is our Dammeron Valley location (C/W-773) in “Member D” about a meter above the C/D boundary. It is in the record of a significant transgression Lucie Fiala (’23) is currently studying for her Senior Independent Study project at Wooster. It is also a part of Vicky Wang‘s (’23) Carmel trace fossil Senior IS project.

As shown above back in the Wooster lab, the circular pits have an inverted cone shape, with their diameters decreasing evenly with depth. Most are circular to oval in cross-section.

Critically, some, like the largest shown above, are oval with sharpish ends, which matches what we expect to see with the compressed valves of lingulid brachiopods moving vertically in the top couple centimeters of the sediment on the seafloor. Now, do they also show traces of the long pedicle below them? Of course they do.

This is an eroded cross-section showing the conical pit and a constriction on the bottom end.

And here is the smoking gun for a lingulid trace. I sawed through one of the pits, which exposed the long sediment-filled trace of the pedicle. Several other cuts showed that this a repeated feature. Lingulid traces they are, and the first found in the Carmel Formation. Note that the sediment here consists of sand-sized particles composed mostly of ooids, then quartz sand grains, and finally fragments of crinoids (the little white bits). Helpfully, the sediments also contain fragments of phosphatic brachiopod shells.

What is the official ichnotaxonomic name for a lingulid brachiopod trace fossil? This is where the first, and most significant, disappointment enters the narrative. In 1976, Eugene Szmuc of Kent State University, Richard G. Osgood of The College of Wooster (and at the time my undergraduate academic advisor), and Deborah Meinke, a Wooster alumna, published a paper describing lingulid trace fossils from the Devonian of Ohio. They christened them Lingulichnites. Unknown to these authors, William Hakes at the University of Kansas was also working on lingulid trace fossils, and also in 1976 he published his name for them: Lingulichnus. Two names for the same trace fossil published in the same year. Which name to use? Or in official terms, which name has priority and which is a junior synonym not to be used except for historical purposes? Turns out the Hakes publication appeared one month before the Szmuc et al. paper. Lingulichnus has priority and is the accepted name for these lingulid trace fossils. Such is science, but the added disappointment is that the issue of Lethaia that carried the Szmuc et al. (1976) paper was delayed in publication by a bad batch of printing paper — a delay of more than a month, thus losing priority on the name. Szmuc et al. had to write a short note in 1977 officially consigning Lingulichnites to junior synonym status. The editors apologized in a statement published with that note.

The second, and minor, disappointment is all on me. I got so excited about these lingulid traces in the Carmel Formation that I started a project to describe them as a new ichnospecies of Lingulichnus. My hypothesis was that these had cone-shaped tops because the brachiopod was twisting its pedicle as it fed, carving out a roughly circular to oval pit different from the sharp-ended slits in the typical Lingulichnus. I did measurements, statistics, saw cuts and photographs as I explored these structures. Lots of exciting work. I should, though, have done my literature searching first …

This magnificent figure above is from Zonnenveld et al. (2007). This paper, along with Zonnenveld and Pemberton (2003), provides an extraordinary analysis of lingulid brachiopod trace fossils, including new ichnospecies and accounting for all sorts of behavior, even twisting the pedicle. If I had read these papers earlier I would have saved myself a lot of work, work which would have had no novelty for publication. A minor disappointment, but I did learn a lot about lingulids in the process.

Ultimately the importance of these trace fossils for our Carmel Formation paleoenvironmental analysis is that Lingulichnus is the kind of trace that shows an animal living in sediments that were moving frequently enough that it had to adjust its position to increased or decreased sediment levels. That tells us something about the initial stages of this transgression. No research is ever wasted.

References:

Hakes, W.G., 1976. Trace fossils and depositional environment of four clastic units, Upper Pennsylvanian megacyclothems, northeast Kansas. University of Kansas Paleontological Contributions, Article 63, p. 1-46.

Szmuc, E.J., Osgood, R.G. and Meinke, D.W., 1976. Lingulichnites, a new trace fossil genus for lingulid brachiopod burrows. Lethaia 9: 163-167.

Szmuc, E.J., Osgood, R.G. and Meinke, D.W., 1977. Synonymy of the ichnogenus Lingulichnites Szmuc, Osgood & Meinke, 1976, with Lingulichnus Hakes 1976. Lethaia, 10(2), pp.106-106.

Zonneveld, J.P., Beatty, T.W. and Pemberton, S.G., 2007. Lingulide brachiopods and the trace fossil Lingulichnus from the Triassic of western Canada: implications for faunal recovery after the end-Permian mass extinction. Palaios 22:74-97.

Zonneveld, J.P. and Pemberton, S.G., 2003. Ichnotaxonomy and behavioral implications of lingulide-derived trace fossils from the Lower and Middle Triassic of Western Canada. Ichnos 10: 25-39.

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Alaska Day 5 – Juneau

There are two legs to the project this summer. Lilly and Fred are headed back to the Wooster Tree Ring Lab with samples from Kake and Jacob and Jack have arrived. Jack, Jacob, Nick and I will now travel to Glacier Bay for 10 days of sampling ancient forests. As a warmup, the group hiked to Mendenhall Glacier. The glacier is rapidly retreating but we are still able to find solid ice to take the team photo.

The hike to the glacier is great and the day was perfect.

Mendenhall Glacier from the forefield.

Fred found some ancient stumps and logs likely dating back to about 2.5 ka, the forests continue to be unearthed with the ice recession.

The West Mendenhall Trail has a variety of streams and falls.

Across the glacial lake is Nugget Falls and part of the group poses next to this popular stop.

The group getting organized and enjoying the katabatic breeze.

 

After all it was the 4th of July.

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Alaska Day 4

A view from the porch of the Forest Service cabin out into the Sound.

Day 4 started in the intertidal zone at low tide. Identification of the various intertebrates included the limpet above.

This large cockle was squirting water through its syphon and was easily captured.

Sea stars are abundant – this one was named Patrick.

This sea anemnome was filtering through the rocks.

This squillamantis was a mystery and most of us had never encountered it before.

Sea cucumbers were abundant and colorful.

Another sea cucumber.

Another sea star with tenticles flaring.

Beach asparagus was a big hit and we plan to pickle a few jars.

Here is a chiton called a gumboot by the folks in Kake.

After the beach we went to get coffee at Tribal Grounds.

Berry picking under the shadow of Alaska’s tallest totem pole – here salmonberries and strawberries were picked for the elders in town.

The afternoon was spent coring living and dead yellow cedar trees – here Lilly is coring a living cedar, many that are over 500 years old.

The Wooster group at the cedar site.

The final photo of the two groups combined at the Lodge was the farewell. More is to come as Lilly and Fred return to the tree-ring lab to work on the red and yellow cedar cores.

A bear passed by the lodge on his way to work.

 

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Alaska Day 3

Coring the furthest north stand of Western Redcedar (Thuja plicata).

Celebrating another successful core extraction by Siah.

Banana slug on the forest floor.

Mounting the redcedar cores at the Forest Service cabin. Also examining cores taken in previous years.

Long Beach at Macartney Point. An afternoon of tossing the frisbee and trash cleanup.

Salmonberry and blueberry ensemble.

 

 

 

 

 

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Alaska Day 1

We arrived in Juneau on Sunday flying from Cleveland to Juneau. The goal of the trip is to work with the AYLS youth group of Kake Alaska (formerly known as TRAYLS) coring trees with both the Wooster group of faculty, staff and students and AYLS learning more about the forests of Southeast, Alaska. Lilly took a great picture of the dock on Auke Lake just down from our lodging at the University of Alaska Southeast campus. We spend two nights in Juneau getting staged for our trip south.

Our first full day was a break-in hike up the Thunder Ridge trail.

It was slow going at first – we took a few cores on the way sampling mountain hemlocks along the way to keep in shape.

Fred and Lilly led the way.

There was an endless up hill.

Tuesday was a travel day – we took a short hour flight from Juneau to Kake to meet up with the AYLS group in Kake (more to come).

Kake from the air – another day of brilliant sunshine on the water.

Irises grace the area around the lower Mendenhall River in Juneau.

 

 

 

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Reflecting on the Earth Sciences Department’s Community Climate Change (CCC) Project

Editor’s note: The following is by Caitlyn Denes (’23).

The Community Climate Change Project sought to document the changes in climate in Wooster, Ohio and surrounding communities. Through the collection, analysis, and interpretation of climatological data, we summarized our findings and developed recommendations to improve the resiliency of the community in the face of climate change. Having served a wide variety of local clients, we are hopeful that our findings will educate community members and foster strong connections with community partners.”

When a group of rising sophomores entered Scovel 116 on May 16th, I do not think they realized how much they would grow as students, researchers, and as people. Tasked with researching the dynamic interactions between climate variability and the local community, the CCC Team had their work cut out for them from the beginning of their AMRE project. As a peer advisor to the work that was completed, I watched our group come together to form an effective, successful, dynamic research team in just six weeks. Supervised by Dr. Pollock and Dr. Wiles, our team encountered some great experiences. It is impossible to cram six weeks of research and field experience into just one post, so here are just some of the highlights!

From left to right: Front- Kelvin Ansah, Skylar Barnett, Tyrell Cooper, and Desiree Smith; Back-Caitlyn Denes.

Week One-  Introduction to AMRE

This group deserves a shout-out for maintaining a great work ethic for the entire first week! The first week of AMRE is usually an adjustment period, as 40-hour workweeks can be a bit draining. Despite the lingering end-of-semester fatigue and introductory AMRE events, the group made great progress. To prepare for an upcoming tree-core gathering trip to Secrest Arboretum, Dr. Wiles demonstrated the tree coring process on trees just outside the doors of Scovel. For two group members, this was the first time they had ever cored a tree, so we made sure to document the momentous occasion! We then took the samples to the basement to practice mounting and sanding the cores—a skill that would come in handy later on!

Skylar records the conditions in a field notebook as the others prepare to core.

Having covered the basics of tree coring on campus, the group set off for Secrest Arboretum (SA) the following afternoon. The goal of the trip was to collect tree cores from a plot of White Oak trees. Native to Northeast Ohio, White Oaks are considered a keystone species, recognized for their role in supporting the ecosystem. Additionally, they put on a reliable annual ring, making them excellent indicators of climatic change over time, specifically regarding precipitation and temperature changes. Joined by tree coring experts Fred Zhao and Jerry Fu, a total of 20 cores were taken from the White Oak plot, allowing the team to develop a chronology that could then be correlated with local climatological changes. The group also collected soil cores that were sent off to the OARDC for analysis to determine their carbon sequestration potential.

Despite the thick vines of poison ivy surrounding the trees, Skylar and Desiree plot the coordinates of a White Oak in their field notebooks as Tyrell begins coring.

Kelvin and Jerry hard at work plotting the tree’s location

Week Two- Rings, Rings, and More Rings!

With the SA White Oak cores back in Scovel, carefully mounted and sanded, the hard work could begin. Supervised by Dr. Wiles, Fred, and Jerry, the team got to work cross dating the samples in the Tree Ring Lab. While learning to use the measuring software was tricky at times, the team successfully created a chronology from the SA cores.

Kelvin and Tyrell pondering over significant correlations between tree cores

To take a break from all of the ring counting, measuring, and analyzing, the group was joined by the rest of Scovel’s summer student employees for a Wilderness First Aid training course. After this course, we learned basic first aid techniques and strategies to provide aid in the case of a medical emergency in the field.

As Dr. Pollock’s Instagram post illustrates, we were prepared to handle any emergency in the field, such as venomous snake bites, broken legs, and CPR

With a tree ring chronology successfully created, the team had a great figure to include in their first internal presentation. Joined by several other AMRE groups, the team presented their initial findings and goals moving forward. After the success of the morning’s presentation, Dr. Wiles led the group on a field trip to the L.C. Boles Golf Course to look at ancient soils and collect cores for analysis at the OARDC.

Despite the cloudy skies, the group set off, only to quickly become victims of a total downpour. Sheltered by the trees, Dr. Wiles, Fred, and Tyrell worked to dig a pit, exposing the parent material. In the meantime, Desiree, Skylar, Kelvin, and Jerry took a collection of soil core samples that would also be sent to the OARDC for analysis. After a check of the radar, it looked like the rain was not letting up, so we left the site.

Tyrell and I documenting a very soggy field trip to the golf course!

Week 3- Fieldtrips, Climatological Analyses and More Fun!

After collecting soil samples at two different plots, the team started the week with a trip to the STAR Lab at the OARDC. Lab manager Sunny Park led us on a tour, showing us the equipment used to test water, soil, and other types of samples. It was very cool to see the machines that would be testing the soil samples that we collected, and the students asked very insightful questions about laboratory operations.

With a tree ring chronology created, the group received a crash-course in KNMI Climate Explorer, a software used to correlate climatological variables. The group was able to correlate their white oak chronology with local precipitation and temperature records, which yielded promising results. With help from Dr. Wiles and myself, the group was able to interpret what the climate variability in Wooster was doing to the white oak species. After this, the group developed graphics that would then be used in their AMRE presentation at the end of the week.

To learn more about white oaks in the urban setting, the group was prepared to take a mid-week trip to Cleveland. Unfortunately, the trip was cancelled at the last minute, so we decided to visit a few local sites to make the most of the day. Our first stop was the spring house at Kinney Fields, where Dr. Wiles educated us about the complexities of groundwater and how it is impacted by human activity. After gathering a water sample for isotopic analysis, we discussed debris flows and how they shaped the landscape near the spring house. With our newfound knowledge, we traveled to Grosjean Park to learn about stream gauging. Under Nick’s instruction, the group practiced using instruments that measured flow velocity and depth across a section of the Apple Creek. The group finished out the week by working with Climate Explorer and started drafting a report about the climate response of the Secrest white oaks. After another excellent AMRE internal presentation, we could see how far this group of students had come in just three short weeks!

The group observes the aftermath of Desiree sinking in some debris-flow mud near the spring house.

Tyrell, Skylar, and Desiree watch as Nick instructs on how to measure flow velocity.

Week 4- Trout Unlimited Stream Survey, Report Writing, and Tionesta Preparations

After Friday’s jaunt to Apple Creek, the group found themselves back at Grosjean Park. This time, they joined representatives of Trout Unlimited to conduct a macroinvertebrate survey. The goal of the survey was to determine the overall health of the stream, which was also completed by last year’s AMRE group. After spending the morning working with the folks from Trout Unlimited, the group had a good understanding of stream monitoring and the role in plays in the preservation of bodies of water like Apple Creek.

The AMRE group, joined by Fred and Jerry for the day, take part in the stream survey.

With the help of Trout Unlimited and its volunteers, a successful stream survey took place. Based on the macroinvertebrates found on this day, the stream health was determined to be “excellent.”

After Monday’s trip to Apple Creek, the group continued to make progress on a report detailing the climate response of white oaks in Secrest Arboretum. For some students, this was their first time writing a technical report, so we were sure to provide lots of feedback and suggestions during the drafting process. In doing so, the group developed a template that could be used when examining white oaks elsewhere. This was of great help later on, as they looked at the climatic response of two other white oak plots—Wooster Memorial Park and Johnson Woods. With the tree ring chronologies already developed for these two locations, reports could be written without even traveling to the sites. The group’s efficiency was impressive to see as they drafted these reports with ease. At the same time, preparations for an upcoming camping trip to Tionesta, Pennsylvania were well underway.

By end of the week, the group was eager to leave for their Sunday-Monday overnight trip to Tionesta. After gathering enough gear and supplies for the excursion, excitement was high.

After making sure all the tents were in working condition, Tyrell decided to do some quality control (or was it napping on the job?)

As the resident Pennsylvanian of the group, I created a PowerPoint presentation to inform the group about the wonderful things the Keystone State has to offer. Topics included: state geography, flora and fauna, notable natural and man-made disasters, famous Pennsylvanians, culinary delicacies, and more! With a 7:30 AM departure planned for Sunday morning, the group was eager to set off on a great adventure.

Week 5- Tionesta, Client Meeting, Report Writing, and More!

Unfortunately, I was unable to join the group on the Trip to Tionesta. That being said, it is only right to include the thoughts of the students regarding their experiences with some of the greatest minds in the field of dendrochronology, including none other than Mr. Ed Cook.

Here is what the students had to say:

Desiree Smith: “The trip to Tionesta was a really great experience for me. With interest in going into this field later in life, it was great to be able to talk to and work with professionals in the field (outside of my own organization). I also loved having the opportunity to interact with my team in a more casual sense, having fun and going on little adventures together around the campsite was great and made for lots of great laughs. I learned a lot while we were out there and if I had the chance, I’d definitely go back again!”

 Tyrell Cooper: Our trip to the Allegheny National Forest was very successful in meeting professionals and working with them in the field. I was able to get a sneak peek into my future career with this opportunity and I am glad to say that I am ready for what’s to come.”

 Kelvin Ansah: On the second day of our trip, we journeyed from the campgrounds to The Allegheny National Forest to core trees at a particular site. As we walked into the forest, we witnessed many fallen trees and large swampy patches of land. We separated into two groups to core White Oak trees and Cherry trees before meeting up at our starting point.”

Skylar Barnett: “Though I am not planning on pursuing a career in Earth Sciences, this trip provided a unique opportunity to interact with pioneers in the field which was eye-opening and enjoyable. It was inspiring to see how passionate everyone was about caring for the environment, and lovely to experience the eagerness of everyone to learn about each other’s research, from the undergraduates to industry professional.”

Kelvin and Tyrell take in the sights of the reservoir near the campsite.

Desiree, Dr. Wiles, Fred, and Laura (a PhD candidate from Harvard Forest) take in the sights of the forest.

Wooster Earth Sciences takes on Allegheny National Forest!

After returning from the Tionesta trip, the group got back to work on their white oak reports. Looking at the results of three different white oak analyses, it was clear that each site was positively correlated with the increasing precipitation and negatively correlated with the rising temperatures observed in Wooster. With these promising results, it was decided that that the group’s findings needed to be shared with the science community. The group spent the remainder of the week drafting an abstract to be submitted to the American Geophysical Union’s 2022 Fall Meeting.

Midweek, we met with Tate Emerson, the executive director of the Killbuck Watershed Land Trust. It was a great opportunity for the students to develop their professional skills and expand their networks. Our conversation was useful in many respects, but most importantly, it established the need for updated, easy-to-understand information about climate change in the Wooster area. Tate though that being able to hand a brochure to landowners about the downfalls of climate change would be a useful outreach tool. After this meeting, it was decided that a “Climate Change in Wayne County, Ohio” brochure would be added to the list of project deliverables.

As the project was winding down and two new deliverable ideas were introduced, there was a lot of uncertainty looming in Scovel 116. Was it possible to accomplish all that they wanted to do? Could they realistically turn out an abstract and brochure in addition to the required AMRE deliverables in the time remaining? At this point, I observed some of the best collaboration among the team. Having realized that active collaboration and assignment of tasks was a necessary step in completing the to-do list, the students quickly organized themselves into teams. Skylar and Desiree took charge of drafting/editing the abstract and working on some of the AMRE deliverables, whereas Tyrell and Kelvin oversaw the development of the brochure. Once the workload was divided, it did not seem as daunting, and the groups started work in their respective areas. With constant feedback from Dr. Pollock, Dr. Wiles, and myself, great progress was being made. By the end of the week, it was clear that the students had adapted to the change in the workload and were on track to finish all deliverables by June 24th.

Week 6- The End is Near!

At our daily check-in on Monday, it was hard to believe six weeks had passed since the beginning of the project. After a brief review of the week’s goals, the students set off to accomplish their remaining tasks. They approached these tasks with such enthusiasm and illustrated the productivity that can only be created by group collaboration. As our time together wound down, we took time to reflect on our experiences over the project. Despite data collection, analysis, and interpretation being pillars of the program, it was equally important to consider the personal and professional development that our AMRE Associates experienced. We talked about updating our résumés to reflect this growth, as well as how to describe this project to potential employers. To finish out the week, the team delivered their final presentation to the other AMRE groups and worked on their abstract/the submission process and their poster.

As we spent one final lunch hour together (with some yummy food from Spoon Market), it was great to reflect on the experiences we shared as a team. It was bittersweet to say goodbye, but I am sure that this was a memorable experience for all our group members.

As for me, I am grateful to Dr. Pollock and Dr. Wiles for the opportunity to be a peer advisor to this project. I enjoyed my time working with these students, helping them grow not only as geoscientists, but also as researchers and aspiring professionals. This AMRE team made amazing progress and I can’t wait to see what lies ahead for them all!

 

 

 

 

 

 

 

 

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New paper: Early Neoproterozoic stromatolites from south Liaoning Province, China

I’m pleased to announce the online publication of a new paper from a Chinese-American geological team (Zhang et al., 2022). I’m the sole American! My role was minor, being mostly useful for literature review and writing. The senior author is my friend Yong-Li Zhang from Northeastern University, Shenyang. He was my host on my adventurous (and painful) trip to China in 2014. We’ve been colleagues ever since and have authored additional papers together.

This paper is a description of well-preserved stromatolites (sedimentary structures formed by microbial mats in supratidal and intertidal environments) in the Ganjingzi Formation (southern Liaoning Province), which was deposited about 930 Ma during the Tonian Period of the early Neoproterozoic Era. The Neoproterozoic is a fascinating time interval spanning the transition from single-celled to multicellular life. The lower stromatolite mounds formed in a transgression, while the stromatolite columns in the more complex upper biostrome changed vertically from dispersed to clumped growth. Biostratigraphic analysis shows that the stromatolites in the Ganjingzi Formation are similar to those from coeval strata in the Xuzhou-Huainan Region and in southern Jilin. Comparisons of the morphotype genera of stromatolites and the sedimentary setting between different areas imply that sea-level was fluctuating in the east of the North China Craton (NCC) during the Ganjingzi interval and that the transgressions were beneficial to stromatolite growth, as indicated by the increased number of stromatolites in the study area. Ultimately this work adds another piece to the puzzle of Neoproterozoic environments and life in northeastern China.

The image at the top of this post is figure 7 from the paper: Morphological characteristics in the lower stromatolite mound of the Ganjingzi Formation and stromatolites at three stages: I = supratidal; II = shallow intertidal; III = medium intertidal.

Fig. 1. Geology of the study area. (A) Paleogeographic location of the North China Craton in the early Neoproterozoic about 900 Ma (after Li et al., 2008). (B) Location of the study area in NCC. (C) Geological map showing the location of the measured section from a (121°36′22.96″E, 39°29′33.43″N) to b (121°36′54.37″E, 39°29′14.15″N). (D) Satellite view of stromatolite distribution and the measured section on Google Earth. [History-minded readers will note this site is near Port Arthur of the Russo-Japanese War.]

Stratigraphic column for this study (Fig. 2).

Distribution of stromatolite morphotypes in the Ganjingzi Formation and the water depths (Fig. 11).

Reference:

Li, Z.X., Bogdanova, S., Collins, A.S., Davidson, A., De Waele, B., Ernst, R.E., Fitzsimons, I.C.W., Fuck [his real name!], R.A., Gladkochub, D.P., Jacobs, J. and Karlstrom, K.E. 2008. Assembly, configuration, and break-up history of Rodinia: a synthesis. Precambrian Research 160: 179-210.

Zhang, Y-L., Lai, G-M, Gong, E-P., Wilson, M.A., Huang, W-T., Guan, C-Q. and Yuan, D-C. 2022. Early Neoproterozoic well-preserved stromatolites from south Liaoning Province, North China: characteristics and paleogeographic implications. Palaeoworld (in press as a pre-proof pdf).

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The Diatom Lake Adventure: Ice ages, hotel titrations, and the Midwest

Editor’s note: Rising Wooster senior Richard Torres (’23) had a spectacular opportunity this summer (May 31 – June 12, 2022) to participate in a National Science Foundation-funded research trip with Dr. Tom Lowell (on the right) and his team from the University of Cincinnati. Below is Richard’s account. Unless otherwise noted, all the images are from his phone. (Above photo by Aaron Diefendorf.)

Why am I here? Out in the choppy waves of a lake in the middle of Minnesota hunting diatoms. It is all part of an expedition going to 20 different lakes in Minnesota, North and South Dakota, and Wisconsin to see how different conditions effect diatoms. It was quite the adventure not getting to explore much of the Midwest, barely getting out of Wooster. But with funding from the National Science Foundation, me, Tom Lowell (Professor at the University of Cincinnati), Aaron Diefendorf (Professor at the University of Cincinnati), Meg Corcoran (PhD student at the University of Cincinnati), and Watts Dietrich (Masters student at the University of Cincinnati) went off to core, probe, sample, and take many more tests and observations of the lakes of the Midwest.

Diatoms are single-celled aquatic plants that make their cell walls out of glass, once they die, they fall to the bottom of the lake and because of their siliceous shell (called a frustule) they preserve well and can be found going back in time through the lake core sediments. At each lake we took a core, some went deep, and some only went down a few centimeters. The diatoms and their traces will then be examined in the lab once we get back.

And this is Rover the ROV (remotely operated vehicle), he would help us look at the lake bottom and collect samples of plants with that claw, or at least that was the plan, we seemed to have more luck pulling samples out of the propeller. We sent Rover down to get a stick from a sunken tree and after giving up trying to wrestle one out and coming back to the surface we found a stick lodged in a propeller, which we lovingly named Mr. Stick.

Because we were going to run out of alkalinity bottles (bottles of lake water to be tested for its alkalinity) before we ran out of lakes, we had to run a series of titrations to reveal the alkalinity of the samples to free up some more bottles for later. We brought all the chemistry equipment into Watts and I’s room making sure to close the curtains (who knows what people would think we are doing) and got to work.

Traveling around the Dakotas we were stunned by the amount water levels have risen. Seeing flooded fields and roads, grain silos and farmhouses crumbling into lakes. Homes once built on hills atop a field struggling to get water during the dustbowl are now cut off on their own islands. Where google maps shows multiple lakes, we came to find one big lake encompassing areas. Above you can see how one of our sites, Devil’s lake, and its area changed from 120 square miles to 820 in just 20 years.

Then there was Lake Kylen. We plunged our truck and SUV deeper and deeper into the Wisconsin woods, off on dirt roads. We saw them, an uncountable, ungodly number of mosquitos swarming us and our vehicles. We took a rubber dingy and our equipment down a trail off the road, into the mud, then took turns going out into the lake. This was a short reprieve since there was not many mosquitoes or biting flies, it was almost peaceful out there with the swans, otters, and scenery except for the terror we knew awaited us on returning to shore. We trudged back to the car and awaited the truck, swatting all those monsters that wanted to hitch a ride with us. Finally safe at last. WRONG! The truck was stuck in mud and had to be pulled out, back to the blood donation center. We could still see them that night at the hotel, even when we closed our eyes.

After the traumatizing experience of the day before, we were prepared for the worst on our last day of lake scienceing. But when we got to the lakes, dragonflies were patrolling the skies, keeping us safe and eating anything that would want to take a bite of us. Dragonflies are my new best friends. They are so sweet letting me get close to take pictures and literally saving our skins. That night we then treated ourselves to a lakeside restaurant and I got to complete my goal of trying Wisconsin cheese curds, yes, they are as good as you would think.

So why did we have to travel all around the Midwest to collect diatoms? Well, we want to uncover past conditions through diatoms but first we need to find out how different changes in their environment affects them. The Cincinnati group is looking at a biomarker called HBI to reconstruct past hydrologies, and I am looking at how the different diatom species can be used to look for evidence of different climate events in history. This trip, with the data, experiences, and motivations, is essential to achieving the goals we have set out for looking at diatoms through time.

But above and beyond the best experience of the trip was being able to meet Tom Cruz at all the Applebee’s we went to.

Group photo (from left): Me, Aaron Diefendorf (Professor at the University of Cincinnati), Meg Corcoran (PhD student at the University of Cincinnati), Tom Lowell (Professor at the University of Cincinnati), and Watts Dietrich (Masters student at the University of Cincinnati).

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Old dogs, old tricks: A very pleasant day of paleontology in the Lower Carboniferous of northeastern Ohio

The weather was perfect today in verdant northeastern Ohio. Bill Ausich (retired paleontologist from The Ohio State University), Nigel Brush (retired geologist/archaeologist from Ashland University), and I (not retired!) have started a project examining the crinoids and associated fossils of the Wooster Shale (Lower Carboniferous) in northeastern Ohio. Nigel guided us to this magnificent outcrop along Quaker Springs Run near Hayesville (N 40.770573°, W 082.221390°; private land — permission required). This blog has been here before.

We put on our wellies and sloshed across the creek to the outcrop. I was reminded how very different this countryside is from where I was working just last month. Bill (on the left) and Nigel wasted no time coming to grips with the slippery rocks.

The shale outcrop near the base has many siderite (iron carbonate) concretionary layers, which show up as red-orange ledges standing free from the eroding shale. These were the rocks in which I expected we would find most of our fossils.

And indeed, they are full of fossil bits, from crinoid stems (shown above) to brachiopods, bivalves and other goodies. They show evidence of storm deposition, being mostly fragmentary. One of our questions: Did the crinoids live on the clayey substrate (the dark shale today) or were they transported in as debris?

Above is the moment Nigel discovered a crinoid stem in the shale that was over a half meter long. At one end was …

the calyx! It doesn’t look like much in the image above, but trust me on this. We’re looking at the biserial arms of a camerate crinoid, indicating the filter-feeding head (or calyx) of the crinoid. Thus a complete crinoid in the shale itself, showing us it lived there and was not transported in after death. Question asnwered.

There are also layers of crinoid-rich limestones in the middle and top part of the section. The bases of these limestones have numerous gray chips of shale (called intraclasts). This is an indication that the limestones were formed by storms that swept across the clay seaflooor, ripping up pieces that were incorporated in the base of the succeeding unit.

Yes, we did note the dramatic tree fall, which happened just a few days before we arrived. This is a good example of a stream eroding away its aptly-named cutbank.

It was a fun day of exploring, chatting, and making scientific plans.

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