Wooster Geologists

Nigel Brush and colleagues have assembled a record of human history in the Walhonding Valley of Ohio (see map below). Along with Jeffrey Dilyard and others, Brush has worked in the region for decades  examining the history of human occupation throughout the Holocene in this part of Ohio. In this latest contribution Brush and colleagues (2025), along with Wooster geologists, has pieced together a story of hunting point technology, resource use, and climate change. A key question of this work focused on the technology of the lanceolate point (see figure below), which was widely used in the Great Plains for hunting bison early in the Holocene (late Paleoindian interval).  Why this same technology was used later in the Holocene about 4.4 to 4.0 ka (~4,400 to 4,000 years ago) in Ohio is a mystery given that bison were not thought to be plentiful. Perhaps the reason was, that during this time of known climate shifts (ie. the 4.2 ka event) bison migrated east into the region and residents adopted the lanceolate technology to exploit this change in resource. The dry conditions in the central plains during this time and expanded prairies into Ohio might explain the lanceolate workshops in the Walhonding River valley and the need for these points. This is one of the hypotheses that the authors put forth to explain the presence of these points in the Walhonding Valley and an idea that could be tested further.

The cover of the Archaeology of Eastern North America (AENA) – the points on the upper left (red background) pertain to the article showing the manufacture of the lanceolate points.  

Map showing the Walhonding River site at the confluence of the Mohican and Kokosing Rivers. The Cox South E-Site is crucial in this study. Downstream also shown are the Honey Run and McConnell sites, which also have documented lanceolate point workshops.

A next-step in this study might be to investigate the ~4.2 ka interval in lake cores from Northeast Ohio to better understand the environmental changes at this time. A strong candidate would be to recover and study that interval as recorded in the sediments of  Browns Lake in southern Wayne County where the other two other abrupt climate changes that define the Holocene are evident. The Younger Dryas (Shane and Anderson, 1993; Lyon et al., 2025) and the 8.2 ka event (Lutz et al., 2008) are well-documented in the lake, why not then the 4.2 ka event? Perhaps a student in Earth Sciences or Archaeology at Wooster will take this on as their Independent Study.

References:

Brush, N., Dilyard, J., Burks, J., Kardulias, P.N., Wiles, G. and Wiesenberg, N., 2025, The Cox South-E Site (33-CS-986): a Late Archaic Lanceolate Workshop in the Walhonding Valley, Coshocton County,Ohio, Archaeology of North America, 53: 129-162: ISSN 0360-1021.

Lutz, B., Wiles, G.C., Lowell, T.V., and Michaels, J., 2007, The 8200 abrupt climate change in Brown’s Lake, Northeast Ohio: Quaternary Research. 67, 292-296, doi:10.1016/j.yqres.2006.08.007.

Lyon, E. C., Wiles, G. C., Wilson, M. A., Lowell, T. V., & Diefendorf, A. F. A HIGH-RESOLUTION LAKE RECORD OF THE YOUNGER DRYAS FROM NORTHEASTERN OHIO. Geological Society of America Abstracts with Programs, 57(7), Abstract #7848.

Shane, L. C. K., and Anderson, K. H. (1993). Intensity, gradients and reversals in late glacial environmental change in east-central North America. Quaternary Science Reviews, 12(4), 307–320.

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.