Wooster Geologists

The global tree-ring community is racking up the papers investigating the utility of the relatively new proxy using blue intensity of annually-dated tree rings. This latest effort is a blue intensity investigation followup of a recent study on ring widths also led by Dr. Santosh Shah of Birbal Sahni Institute of Palaeosciences in Locknow, India. Blue intensity is a proxy that has added a new dimension to thermal histories across the globe including efforts at the The College of Wooster Tree Ring Lab. Shah et al. (2025) used cores extracted from three sites of the Western Himalayan Fir (Abies pindrow) from the Kashmir Valley.

Map from the study showing the location of the three tree-ring sites and the meteorological station (Srinager). The centrally-located Srinager climate station has records of precipitation and temperature spanning 1901-2024, one of the longest in the region.

A figure from the paper showing the beautiful images of earlywood (above) and latewood (below) blue light reflectance for individual rings from the Western Himalayan Fir (Abies pindrow). 

The upshot of the work is that time series of blue intensity values from the latewood of A.Pindrow are strongly correlated with monthly average and maximum temperature series  from nearby climate station (Srinager).  Ring-width are more strongly correlated with summer precipitation and thus blue intensity with its response to late summer temperatures promises to provide a new proxy for thermal histories for the region. These collaborations with Dr. Shah and colleagues have enriched our efforts at the Wooster Tree Ring Lab and we look forward to future efforts.

HYDRO25 the class. On a beautiful fall day the class investigated the South Wellfield – the mission was to take water levels from 15 observation wells and sample the groundwater, surface water and water emanating from the airstrippers. Isotopic analyses of these waters are pending. The photo above is the Falls at Apple Creek aka Effluent from an Airstripper.

HYDRO25 – here is a photo of the hand-picked teams assigned the tasks described above. The team is united by the bucket auger that was used to auger down to the confining layer of the Wooster Aquifer.

The confining layer is that far down – this group made short work of the task and brought up the pristine lake clay that is the confining layer.

Here is the clay brought up by the team. It is organic rich and we really should pick it for organics.  Radiocarbon ages of the organics will help us understand the timing of the lake that existed in the valley – Glacial Lake Killbuck.

Our primary objective was measuring water levels in the confined Wooster Aquifer, however here we are measuring the water table that is a perched aquifer on top of the clay. Just a kilometer aways is a BTEX plume on top of the clay that is actively being remediated.The observation wells are all completed in the confined Wooster aquifer, and here the team is sneaking up on observation well #4. The levees to Apple Creek are in the background.

We also had a team in the Apple Creek measuring discharge and probing the bottom of the stream for the clay confining layer. What a welcoming team of stream gaugers.

The team bailed a few of the wells to sample the water.  We will obtain the stable isotopes of the various waters sampled to investigate the origin of the waters. This was last done by the USGS decades ago.

The airstrippers, installed to remove VOCs from the water, are filled with these “wiffle balls” designed to atomize the waters which are then “stripped” of contaminants via compressed air blowing through the column.

One last shot of the Auger team under a big Wooster sky with their feet firmly planted in a recently harvested no-till soybean field with the water treatment plant and its anaerobic digested in the far background.

Special thanks to our bus driver Bud and to the Water plant for permission to enact this lab for HYDRO25.

At the alumni reception – a reunion.

Elliot Miller (Wooster) presenting his IS work on geochemical analyses of palagonite and potential applications to Martian exploration.

Mary Palmieri (Wooster) investigates the linkages of tree rings and cloudiness in Northeast US.

Lynnsey Delio (Wooster) is investigating the linkages between coastal Alaskan tree-ring records and the monthly Lake Huron and Michigan levels.

Lauren Segura (Wooster) presents her work using crystal size distributions to help determine the origin of extrusive rocks in Iceland.

Ihaja Metz (Wooster) is working on using the XRF at Wooster in determining water chemistry in natural groundwaters.

In addition to the presentations by Wooster students and faculty – four Keck Geology Consortium students who worked at Wooster in the summer of 2025 presented results. Here Dexter Pakula (Carlton College) presents his study linking modes of climate variability in the Indian Ocean to climate variability in Alaska.

Lev Sugerman-Brozan (Colorado College) explains the results of his work comparing tree-ring reconstructions Gulf of Alaska temperature variability and model simulations focusing on intervals of strong volcanic forcing.

Landon Vaughan (Trinity University) explored the record of volcanic cooling of the late 1690s volcanic event(s) their signature in the rings of yellow cedar trees and linkages with Tlingit oral histories.

Izzy Held worked on the feasibility of using costal tree-ring records from the Gulf of Alaska to reconstruct Mendenhall River flow from Juneau Alaska.

We are grateful to the many alumni for their support and their contributions that helped to fund the travel and stay in San Antonio.

Guest bloggers: Ihaja Metz and Cooper Norwell: On  September 29th, 2025 Dr. Wiles’s Hydrology class (along with Dr. Ison’s Field Botany class) took a trip out to Fern Valley, a College of Wooster monitering station on Wilkin run, a stream that flows North into Odell Lake. Throughout the time in the valley, the class observed numerous geological features that speak to the history and formation of the valley. 

Figure 1. The Hydro25 class on a scarp in Fern Valley. This Scarp likely formed from glacial sediments sliding down the clay surfaced beneath them when the galacial sediment become filled with water. 

Figure 2.  A human made wooden post, allowing us to determine that these layers of sediment are Legacy sediments, or sediments that have been deposited after European arrival in the area around 200 years ago. 

Figure 3. Dr. Wiles sliced a clump of clay out of the side of the bank to show the class.  Within the clay, se identified many layers of alternating silt and clay particles, known as varves. Varves are found within fine–grained sediments to reveal a year–by–year record of environmental conditions, and frequently indicate the presence of a paleo-lake, likely before the Last Glacial Maximum 20,00 years ago. 

Figure 4. Located in Fern Valley is an oxbow lake, seen in the background of this image. This oxbow lake formed when a storm knocked down a few trees, blocking off a section of the stream. The difference in the surface of the water between the lake and the stream is an indication of the rate at which the stream is downcutting in this region.

The geological features shown in the figures above, as well as few others not shown here, paint a picture of how Fern Valley formed into what it is today. This area was likely a lake before the Last Glacial Maximum, giving us the clay layers that we know see at the bottom of the stream. The area was then buried by glaciers during the Last Glacial Maximum 20,000 years ago, and when those glaciers retreated, the left behind thick layers bright sand and gravel. The ancestral Wilkin Run then cut down through these sands and gravels, creating a valley. Afterwards, rainfall has cause the slopes to gradually slump down into the valley, and human influences have caused a mixture of soils to runoff into the valley, making the valley into what we see today.  

Figure 5. The Field Botany class taking notes and wrapping up their projects before leaving.

Figure 6. The Class leaving the site at the end of the trip 

Looking down on the group from the normal fault scarp. We thank Matte for driving the bus and for showing us some of the sites in Shreve on our return.

Guest bloggers: Luke Woodfill and Francis Nwokonko (HYDRO25)

On 9/22/25, Dr. Wiles’ Hydrology class (plus our wonderful ESCI technician Nick Wiesenberg) had the opportunity to tour the Wooster, Ohio Water Treatment Plant. On the way there, we stopped to see weather monitoring station at the Secrest Arboretum at OSU CFAES (Figure 1).

Figure 1. The HYDRO25 class at the OSU CFAES weather monitoring station.

This weather monitoring station constantly measures temperature, wind speed and direction, precipitation, and solar radiation. OSU has been collecting data at this location since the 1860s, and this weather data is publicly available through the CFAES website. As hydrologists, weather data and where it comes from is very important to us, so we took the opportunity to visit a station in our very own backyard – and of course get a group picture. Then, we hurried off to our main stop: the Wooster Water Treatment Plant.

Upon arriving at the facility, we were met at the door by our tour guide Derek Sigler, a lab technician at the treatment plant. Our class was taken on a roughly 1-hour tour of the facility and got very detailed explanations of all the different machines on site and their functions.

The water used in the City of Wooster comes from a glacial aquifer. Under the area is an ancient riverbed which now holds our groundwater. The Wooster aquifer can pump up to 36 million gallons a day. Currently, the plant pumps around 3-5 million gallons a day. They used to pump much more, but more water-efficient technologies like dishwashers and laundry machines have reduced the water demand. This decrease is also a result of repairs to leaky lines.

Mr. Sigler shared many different water treatment processes, but at the very end, we were shown two containers of water (Figure 2). The lab technician said, if we couldn’t retain anything from the hour-long tour, we should at least take home the following message. The water on the left is the water being pumped out of the ground, and the water on the right is the clean, treated water being distributed to the residents of Wooster.

Figure 2. A comparison of untreated water pumped out of the ground (left) and water that has been treated at the plant and is distributed to Wooster residents (right).

To treat the water, the plant uses the lime-soda ash softening method (Figure 3). Lime removes the hardness from carbonates, and the soda ash removes the non-carbonate hardness. The lime-soda ash removes the hardness by precipitating the calcium carbonates out of the water.

Figure 3. This machine adds the lime and soda ash to the water to precipitate out carbonates.

These solids will settle on the bottom of the storage tanks (Figure 4). This process of adding 99.6% soda ash, helps control the pH of our water which protects the pipes from corrosion.

Figure 4. Derek Sigler showing us a block of calcium that built up when the tank wasn’t cleaned for a long time.

The water comes into the facility at around a pH of 7.5. Lime is added to raise the pH to about 11.5 before it is dropped back down to a pH of 8.5 (the pH that the water is distributed to the public). This process removes iron, manganese, and other solids in the water. The water moves through the plant and continues to be treated.

Figure 5. One of three tanks that hold chemical solutions that are added to the water to purify it; this tank holds sodium hypochlorite.

There were about 3 tanks similar to the one shown in Figure 5, that all held different chemical solutions that were put in small quantities into the water to further purify the water. The tank shown in Figure 5 holds a sodium hypochlorite solution.

Mr. Sigler shared that, currently, the biggest challenges the Wooster water treatment plant is facing include PFAS (aka “forever chemicals”) and VOCs (volatile organic compounds) in the groundwater. These contaminants are frequently tested for and monitored in the water. The EPA regulates the concentrations that are allowed to be in the water. The Wooster plant has had to pump from different locations due to plumes in the area. The well located behind the plant (Figure 6) is no longer being used due to VOC plumes.

Figure 6. The well in red brick structure in this image used to pump water into the Wooster Water Treatment Plant, but it is no longer used due to a VOC plume.

Mr. Sigler noted that contaminants like PFAS and VOCs are challenging for water treatment facilities, but it presents an opportunity for chemists and hydrologists to work towards a solution. Our tour of the Wooster Water Treatment Plant reminds us of the importance of hydrology in the real world. While PFAS and VOCs pose a challenge to water treatment facilities, they also provide a future for aspiring hydrologists or chemists. Perhaps a Wooster HYDRO25 student will be the one to figure out how to effectively remove these contaminants from our water supply.

On behalf of the College of Wooster’s 2025 Hydrology class, thank you to Derek Sigler and the Wooster Water Treatment Plant for opening your facility to us and giving us a great tour. Thank you, Dr. Wiles for a great opportunity to see how hydrology affects our everyday lives.

Guest bloggers: Adam Wood and Arjan Chahal.

College of Wooster Hydrology team at the Airport artesian spring.

On September 8, 2025, the College of Wooster ESCI-28000-01 (Hydro) team visited two artesian wells/springs (Kinney and Wayne County Airport site). Above the group is shown taking notes on the location, the depth to bedrock, and the elevation at well head. An artesian well/spring is an spring in which water is contained within a confined aquifer and emerges from an opening freely under intense pressure. They have been used since the pre-Columbian period, and by early European settlers for accessible water. At the Airport site, tubing was placed over the artesian spring to permit members of the community to draw water into containers. This spring is used heavily by the surrounding community.

Members of the College of Wooster Hydrology team taking sips from the artesian spring.This water was perfectly potable from the source, and members of the Wooster Hydrology team even took a few sips.

Sugar Creek at Airport site.

The stream at the airport site, otherwise known as Sugar Creek (above), is directly recharged by the artesian spring nearby, with water coming down the hill. In the distance, barely visible, is a graveyard, where sand and gravel have been laid down to prevent the stream from reaching it.

GoogleEarthPro satellite view of the Airport Spring (40.87842, -81.89743) site. Field of view ~2 kilometers.

Snapshot taken from an Airplane flying over the College of Wooster Hydrology team at the artesian spring near the Wooster Airport and sugar creek. Courtesy of Neil Edmiston 26′.

Kinney artesian spring encapsulated by shed.  The Kinney artesian spring is situated at the headwaters of Christmas Run. Christmas Run flows into the confluence of both Killbuck and Apple creek. Surrounding the artesian spring is topographically hummocky land (fig. 1b), composed of an overburden of unconsolidated glacial sediment, underlain by a layer of clay. Three tests conducted by Cooper Norwell 27’ recorded temperature for the spring: 14.7^o C (57.2 F), 58^o F, and 59^o F respectively.  Whilst conducting these tests, a tile probe was inserted into the ground to measure the depth to bedrock. The tile probe will not penetrate sand or gravel, thereby indicating bedrock. Before leaving, our group technician, Nick, inserted a transducer which would collect data on the discharge (water level and temperatures) of the spring per hour.

GoogleEarthPro satellite view of Kinney Spring (40.83067, -81.94129) and Christmas Run (40.825014, –81.940587). Field of view ~2 kilometers.

Block diagram illustrations of varying geologic settings for springs.The geologic setting most resembling what the College of Wooster Hydrology team encountered is block “b”, as the underlaying layer under the clay is composed of hard bedrock (low permeability).

Guest Bloggers: Li Winner and Aaron Walters

Dr. Wiles’s 2025 Hydrology class visited Spangler Park this past Monday. The day was sunny and warm. The main objective was to study the geological history and hydrology of the park. Especially with how it relates to its glacial and post glacial past, from around 15,000 to present.

Figure 1: Pointing  a disconformity of the top fluvial sediments and the glacial till. The contact is about where Luke’s thumb is located.

Luke (above) is pointing to a disconformity between the top fluvial alluvium and bottom glacial till. The top layer was mainly brought from land use changes beginning during settlement 200 years ago or previous aggradation of Holocene Alluvium. European settlement in the area caused an increase of erosion and sediment deposition from clear cutting of all of the trees in the area and from mill ponds in the area. The bottom is glacial deposition made up mostly of sand and gravel. This glacial sediment formed during the ice retreat of the last ice age around 15,000 years ago. This sediment is impermeable meaning water has trouble to move through it. During rain events water moves through the permeable top alluvium. The water has to move horizontally once it reaches the impermeable till at the disconformity. This horizontally moving water lubricates the alluvium causing it to move and erode.

Figure 2. Killbuck River flow from 1930-2024. This is the annual flow that reflects the increases in precipitation in the basin.

Erosion from increasing precipitation as shown in the figure above is occurring more often in the park. This is because climate change is increasing precipitation (figure 2). Increased precipitation also increases the strength of the streams around the park leading to more downcutting. Over time in, figure 2, more bedrock will be exposed from this downcutting. The more downcutting that occurs, the more the streams get disconnected from their floodplains, meaning they can’t flood. Flooding is important to slow down and empty the load of the stream. If they can not do this the water stays constrained in the stream leading to even more downcutting and therefore erosion. Ecological effects can also be caused by increased downcutting due to the lowering of the water table. This can dry up ponds and stress plants that rely on water from the water table. Riparian vegetation which helps prevent erosion is especially susceptible to the lowering of the water table.

Figure 5: Shale from the Mississippian period. ~330 million years ago. The fractures in this shale, the dominant bedrock in the area, allow water to infiltrate into groundwater, making this area a recharge area. A recharge area is an area where more water enters into groundwater than leaves the groundwater. Fractures on this particular outcrop were formed and are getting larger as it slowly creeps downhill.

The two photos above depict an outcrop of glacial sediment complex that includes debris flows, fluvial, loess and tills. The area is a buried valley. Around 20,000 years ago, Wooster was covered by the Laurentide ice sheet. Around 15,000 years ago, the ice retreated, carving out this area into a valley. Glaciers drag sediment with them, depositing their glacial till in their wake. The sediment depicted in fig. 5 is brighter than sediments native to Ohio, indicating the sediments were brought here from Canada via glacier. After the glacial till was deposited, a stream formed from leftover glacial lakes made from melted ice and general precipitation. The red line in fig 5b approximates the path the ancient stream took. The sediment below the red line is glacial till, and the sediment above is river deposited alluvium, with young organic rich soil on the very top from the recent vegetation. Also seen above the red line in fig. 5b is an almond shaped hole where sediment has fallen off. A shadow cast makes the weathered area resemble an eye. Figure 5c provides a view of the same area but slightly to the right, highlighting accordion-like vertical patterns on the outcrop. These lines indicate where water seeps out of the outcrop, making this another recharge location.

Figure above shows the highly fractured bedrock: the Wooster shale. Wooster shale formed during the Mississippian, making it around 330 million years old. Wooster shale is a sedimentary rock formed from marine sediments during the ancient ocean that covered modern Ohio during the Mississippian. Its blue color indicates that the conditions when it was formed were anoxic, or low in oxygen. The longer a shale is exposed to oxygen, the more red it turns. Wooster often makes use of this shale, firing it to create a bright red Wooster brick! Shale contains clay minerals in its makeup. When wet, the clay expands, and when dry, the clay shrinks. This process makes shale susceptible to weathering when exposed to changes in hydration, causing it to crumble.

The figure above contains an alluvial fan, which is a fan-shaped flow of poorly sorted sediment. Figure 4a displays the alluvial fan in its natural state, which, to the untrained eye, is hard to see. The red lines highlights the path of the sediment down the fan. As a recharge spot, alluvial fans add water into the groundwater below, supplying the aquifer. An aquifer is a collection of water underground with a permeable layer of sediment on top and a nonpermeable layer below. In this case, the clay-rich sediment and shale bedrock and sediment hold Wooster water, while the alluvium above allows water to drain into the aquifer. Wooster aquifers provide water for many of her people—the rest relying on personal domestic wells, which still come from groundwater, just not the main aquifer. Alluvial fans are such powerful recharge systems that pig farming had to be banned on them in Wooster because the waste drained through the Alluvial fans, contaminating the aquifer.

This is a glacial erratic, a non-native rock that was deposited from a glacier. It was deposited from the Huronian ice age from around 2.2-2.5 billion years ago. These are important to study the range of previous glacial events.

Dr. Lyon and one of her IS students accompanied us to Wooster Memorial Park. Roo (Dr. Lyon’s dog) studied the hydrology diligently with us. Figure on the left shows her sampling the water quality. She fertilizes local flora in middle panel and on the right, Roo uses her canine hearing to pay full attention to the lecture. Roo is a very good hydrologist, and a very, very good girl.

The group at the final stop.

The HYDRO25 Macroinvertebrate team.

Guest bloggers: Phillipp Drappatz and Elliot Miller, the Hydrology class at the College of Wooster performed a macroinvertebrate survey on 8/25/25 on Apple Creek in Wooster. The first lab of the semester was a trip to Grosjean Park in Wooster. The class was joined by and guided by macroinvertebrate expert Carry Elvie from the CFAES who is also the director of the Bug Zoo. Apple Creek unusually for Ohio is a freestone trout stream under the stewardship of the Clear Fork River chapter of Trout Unlimited, which has been performing surveys since 2012. The purpose of this fieldtrip was to add on the current Trout Unlimited record and to gain insight into the health of the stream based on the assemblage of macroinvertebrates.

Students using D-nets and kick nets to sample. Aaron in the foreground takes water temperatures and geochemical measurements. Note in the background the stream has been recently modified in an ogoing stream restoration project.

In the tray above we can see a variety of macroinvertebrates separated into groups. On the top row left to right are caddis fly larvae, another different species of caddis fly larvae and a water penny. On the bottom row left to right are yet again another species of caddis larvae, more caddis larvae, annelid worms/leeches, a mayfly larva, and a different species of mayfly larvae.

Pictured above is a bycatch of small fish including shiners, stoneroller minnows, and mosquito fish. Macroinvertebrates pictured include a crayfish, a snail and a water slider climbing up the side

Carrie gave the group a debrief and we headed back to the lab to summarize the data and write the report.

The upshot of the data is the pollution tolerance index at two sites in Apple Creek shows high water quality. This measure is based on the occurrence of the various species mentioned above. The ratings of the mid 20s is an excellent rating in terms of water quality and we have discussed the possible impact the stream restoration and early fall sampling. Note that there is a decline in the curves above at both sites and this will be closely watched as future surveys are done.