Wooster Geologists

Wooster Memorial Park has been a great resource for The College of Wooster Earth Sciences (ESCI), Biology among others. Here the ESCI course in Paleoclimate, under permit from the Friends of Wooster Memorial Park, sampled 20 second growth Eastern Hemlock with the aim of determining the climate response of the species in the Park. A recent publication by the Wooster Tree Ring Lab incorporated results from past sampling in the park that was concerned with the changing climate response of white oak trees. This oak study can be found here Wiles et al., 2025.

Lidar Map of Wooster Memorial Park – the green field in the west of the park is the approximate location of tree-ring sampling.

The class took advantage of a spectacular day for the sampling.

Nick demonstrating the coring technique using an increment borer.

Another perfect core, once trained, the five groups went into sampling mode.

For most of the group, this was their first experience coring and it was clear some were naturals at the technique.

First-ever core reveal photo – a proud dendrochronologist.

Another first.

Coring for the first time.

Coring and at the same time keeping a sharp eye out for wildlife.

A first – ever core safely archived in a reusable plastic straw.

Even the TA was caught working in this photo.

Deep in the hemlock forest – group three assesses another hemlock.

On the cliff’s edge tree workers and tourists confer.

Another core reveal photo.

Here five sizeable hemlocks lie in a row – blown down by the summer storm of 2022.

All the root throw from hundreds of downed trees is significantly changing the sediment budget in the tributaries.

From the storms and trees killed by the emerald ash borer there is plenty of wood for log jams.

A portion of the park was used for raising shade trees back in the day. Here is one of the shade trees that remains.

Reflecting on the completed coring and anxious to get to the lab work.

One of the many, diverse rocks in Rathburn Run. Special thanks to the Friends of Wooster Memorial Park and the City of Wooster for maintaining the park and allowing us to sample there.

The Macedonia Missionary Baptist Church was established in 1849 and is Ohio’s first Black church and the only surviving antebellum Black church in the state of Ohio. The building is now being restored under the direction of Hardlines Design, Columbus Ohio. The Wooster Tree Ring Lab was contacted to help in the dating of the timbers in the church’s structure.

Charles Linthicum, Macedonia Trustee and Charissa Durst standing in front of the church in the summer of 2023 before the renovation began.

A scene also prior to renovation showing the interior of the church. The structure was moved and rebuild likely in the late 1800s so tree-ring dates on the timber may help to distinguish the portions of the structure that were original.

Renovation underway in February of 2025.

Nick Wiesenberg made a trip in February to the site to core the now-exposed beams during the renovation. Here Nick is sampling flood joists made from white Oak.

Nick points out the waney edge of this timber – the waney edge is the outer ring (bark year) and once assigned a calendar age indicates the calendar year the tree was cut.

Straps keep the walls of the church in tact as the restoration proceeds.

A historical marker and sign explain the history and the restoration of the Church. The work is funded, in part, by a Save America’s Treasures Grant from the Historic Preservation Fund administered by The National Park Service along with several other foundations and donors.

The College of Wooster Paleoclimate Class was fortunate to visit, Dr. Lonnie Thompson, director and founder of the Byrd Polar Ice Core Lab during lab. Here Dr. Thompson give the class the rundown of all the “firsts” in tropical and ice core lab history. We are looking forward to viewing the relatively recent movie about Dr. Thompsons’ epic career – Canary. 

Dr. Thompson describes the core collections from the tropics and from higher latitudes and the findings that are relevant to ongoing climate changes of today and into the future. His core sites include high altitude ice caps and glaciers in Peru, Bolivia, Tanzania, New Guinea, Tibet and Alaska. The class will be using his data from Quelcaya in Peru as projects and labs. Published data from the ice core lab is freely available for download and use through the NCEI (National Center for Environmental Information) maintained by NOAA.

Ice coring in remote and logistically challenging field sites depends on the understanding the physics of ice and glaciers as well as the mechanical behavior of metals and other materials. The team has been able to rack up the records of “Firsts” through experience and collaboration.

For example, understanding the rheology of ice in vital. Like the Earth’s crust, glaciers have a brittle zone near the surface and a more ductile zone at depth. The temperature of the ice and its behavior is critical to designing and machining the drills that work to successfully recover these frozen archives.

One of the highlights of the trip is touring the freezer where the ice cores are archived. The temperature is maintained at -30F and the scientist work under these conditions.

Ice core shopping at -31F.

The group is blown away thinking about how an ice cores can reveal information about the variability of the monsoons on a variety of timescales.

Special thanks to Nick Wiesenberg for arranging the trip and for providing snacks. The Paleoclimate class is lucky to have such able logistical support. Dr. Thompson would agree that logistics is more than half the battle in a successful expedition.

Dr. Eva Lyon ((photo above on June Lake, CA) Wooster Earth Sciences Professor and Wooster Alum.) has recently published her work “A high-resolution record of Late Holocene drought in the eastern Sierra Nevada (California, USA) from June Lake carbonate geochemistry” in Quaternary Research. With the backdrop of some of the worst recent droughts being experienced in the last millennium in the American Southwest (Williams et al., 2022), Lyon and her team extends the drought history for the Sierra Nevada (Figure 1) back almost 5000 years using well-dated sediment cores from lakes (Figure 2). They used oxygen and carbon stable-isotopes rations combined with X-ray fluorescence counts of calcium and titanium to identify six intervals of past droughts.

Figure 1. (A) Regional map showing location of study area: ML, Mono Lake; SM, Stonehouse Meadow; PL, Pahranagat Lake. (B) Lakes and streams of the study area, which are found along CA State Route 158 (the June Lake Loop). Water isotope values for locations indicated by white squares (oxygen, deuterium). (C) June Lake bathymetric map. White circles indicate locations of the lake cores.

The lake record (Figure 2) that is dated using radiocarbon, reveals the dry times that include many of the famous drought in the American West including the Current Warm Period, the Medieval Climate Anomaly (about 1000 years ago, also a warm time in the West) and three pulses of drought earlier during the Late Holocene Dry Period (~3500-2000 cal yr BP).  Records like these provide a perspective to the ongoing drought in the American West. Those scientists that model hydroclimate use such well-dated records of past changes in lakes as a way of better anticipating future climate. This work is particularly important as the world moves into the greenhouse climate of the future.

Figure 2. Plot of changes in core geochemistry with time. From left to right: (A) total inorganic carbon (%TIC), sampled every 2–3 cm; (B) ratio of calcium to titanium (Ca/Ti), sampled every 1 mm; (C) oxygen isotope values in per mil (δ¹⁸O_carb), sampled every 2–3 cm where %TIC was high enough to permit measurement; (D) carbon isotope values in per mil (δ¹³C_carb), sampled every 2–3 cm where %TIC was high enough to permit measurement. Here, the six dry intervals described in the text are particularly prominent as increases in oxygen isotope values—these are denoted by horizontal yellow or red bars. The horizontal blue bars indicate the wetter intervals, including the pluvial between the two peaks of the Medieval Climate Anomaly (MCA) megadrought and the Little Ice Age (LIA) (~500–100 cal yr BP, as defined in IPCC, 2021). LHDP, Late Holocene Dry Period.

Reference:
Lyon EC, Erhardt AM, Streib LC, Zimmerman SRH, McGlue MM. A high-resolution record of Late Holocene drought in the eastern Sierra Nevada (California, USA) from June Lake carbonate geochemistry. Quaternary Research. Published online 2025:1-15. doi:10.1017/qua.2024.38.

Williams, A.P., Cook, B.I., Smerdon, J.E., 2022. Rapid intensification of the emerging southwestern North American megadrought in 2020–2021. Nature Climate Change 12, 232–234.

The group posing in front of some generations of draglines at the Zollinger Pit in Rittman. Many thanks to the operators for giving us permission to spend a spectacular afternoon at the site.

Figure 1. Map showing some the the local topographic features. A lake resided in the valley prior to the Laurentide ice advance into the basin. The lake at some point drained down the Killbuck Spillway to the west.

Figure 2. This stylized sedimentary sequence from T.V. Lowell provides a framework for the site. Preglacial lacustrine setting overrun by the ice sheet.

Figure 3. The base of the sequence is a series of varve-like sediments consisting of silt-clay couplets. The group determined that is this high sediment charged environment these were likely not annual but diurnal (daily).

Figure 4. The swallows build their nest into the silt and this sequence overall is coarsening upward. Note the vertical downcutting along the boundaries of joint in this unconsolidated sediment pile.

Figure 5.  An introspective moment reflecting on the environment at the bottom of a proglacial lake just prior to advance of the Laurentide ice sheet into the basin.

Figure 6. The group working our the direction of the paleocurrent based on a series of climbing ripples with clay drapes – could they be daily couplets?

Figure 7. This facies model is a good conceptual cartoon of the setting.

Figure 8. A rare moment when the entire class was working. The upper unit record the glacial tills recording the ice advance and retreat from the site.

Figure 10. As the ice advanced and thickened over the site it smear the sediments into a deformation till, and as the ice thickened and effective normal stress increased the till was lodged onto the sediment pile.

Figure 11. The lodgement till at the top of the sequence, which, in turn, is capped by a melt-out till. The class was able to determine the ice was not absent from the site.

Figure 12. The melt-out till showing fluid escape structures and ball and pillow structures indicating loading and melt out.

Figure 13. Closeups of the ball and pillow structures.

Figure 14. Dropstone were evident and here we see a dropstone made of a stone and a till clast. This indicates icebergs in the lake dumping sediments into the lake.

Figure 15. A portion of the class spent much of the time mining gypsum crystals. The presence of gypsum crystals at the pit indicate a desert environment? We explained the gypsum as a case of saturated groundwater and, of course, kinetics.

Figure 16. Some healthy skepticism about the site and the origin of the sediments.

The Geomorphology (GEOM24) class posing along the Little Killbuck River Valley. Looming in the background is the delta built into Lake Killbuck during immediate post-glacial times about 14,000 years ago. The sediments are so well exposed, in part, due to some recent illegal hydraulic mining  for sand and gravel.

Figure 1. Two versions of the measured section showing the coarsening upward sequence of sediment making the Gilbert-type delta built into the paleolake. This sequence of unconsolidated sediments sits on the Mississippian siltstones and shales.

Figure 2. The shale is evident to the left of the class members. Clays, silts and colluvium marks the flooding of the valley and the beginning of the bottomset beds in the delta.

Figure 3. The foreset beds are composed to silt and sands with frequent clays and deformation reflecting changes in water levels and the high rates of sedimentation and slumping.

Figure 4. A “flow roll” of a mix of foreset sands and lacustrine clays likely deformed through slumping along the delta front. Note the liesegang rings in these likely 14,000 year old sediments.

Figure 5. A somewhat enigmatic fracture clay layer is likely due to a ephemeral increase in lake level, or a change in the delta depocenter. There was some discussion of a ice readvance, however, this is unlikely.

Figure 6. Front lower left to upper right – the photo captures the disconformity at the bottom, the foresets to the upper right and the cut and fill structures of the topsets. The diagram below summarizes the overall structure of the delta.

Thanks for Nick Wiesenberg for helping with logistics in all the Geomorphology fieldtrips this past semester and for digging many holes.

The group gearing up to describe and map soils in the old growth stand just east of the College Golf Course.

Guest bloggers: Lynnsey, Cate, Evie, Chanel, Lilly and Amanda

Figure 1. Diagram showing the formation of the glacial landform that the Wooster soils is formed on – it is a kame terrace with parent material of sand and gravel with a venerr of loess.

Figure 2 – the College golf course soils – they are mapped as the Wooster – Riddle silt loam and they are photogenic – the A horizon is on the right, B in the middle and on the left is the C horizon (partially weathered parent material).

Figure 3. the stars on this ternary diagram are the A (orange star), B (red) and C (blue star).

Geochemistry of the soils (Figure 4):

• In the A horizon: Calcium and Phosphorus build up from fertilizers used applied to the nearby golf course 
• Sodium likely from road salt
• Barium, Cobalt, Sulfur, Manganese and Lead from past coal burning in the former campus coal plant t
• In B horizon: Translocated Aluminum and Iron  

Figure 5. Describing the soil in the pit and taking measurements of magnetic susceptibility.

Figure 6. The coring team described a transect of soils cores along the kame terrace.

Figure 7. A representative soils core described and keyed into the soil pit via mapping.

Figure 8. As it turns out there are old growth forest (this white oak is over 300 years old) this indicates  that the soils were were examining have not been plowed.

Figure 9. An example of the relatively newly-invasive asian jumping worm. This critter is non-burrowing and has the behavior of a snake as much as an earthworm. It quickly east leaf litter and does not mixed the soils as a result the surface of the soils in this forest now consists of a mantle of worm castings. Note in the scenes above there is very little undergrowth.

Figure 10. Somehow Cate found a golf ball and a club and finished the day on the 7th fairway.

Guest bloggers: Grace, Hayden, Vince and Ethan

The group working with soils at Browns Lake Bog Preserve. The goal was the dig three soils pits and examine the soil catena from the top of a kame to the base controlling for the topographic control on soil’s texture, structure and composition.

Figure 1. A nearby kame (hill of sand and gravel of glacial origin) within the kame and kettle topography of the region.

Figure 2. The kame and kettle topography of the Browns Lake site the kame in the middle of the image was the location of the soils transect. We chose the north-facing side of the kame as the southern faces are strongly bioturbated by groundhogs (aka whistle pigs) and other varmints.

Figure 3. Soils pit at the apex of the kame showing the loess cap on the kame sand and gravel is the parent material.

Figure 4. At mid slope a highly trained team eagerly digs a pit in the kame.

Figure 5. Team 2 somewhat further downs slope taking careful observations.

Figure 6. At the based of the kame the team noted an onlapping sequence of detrital peat, which changed the parent material and suggested that the water levels in the bog have been variable.

Figure 7. The dendro team cores trees on the flats to get an idea of the age of the substrate.

Figure 8. More tree ages.

Figure 9. Nick downloaded a pressure transducer installed in a well in the bog. These data show a full three years of hourly data that includes water levels (black line) and the water temperature records (blue line).

The team looking a bit skeptical about the idea of a soil catena, a healthy does of critical thinking.