If you’ve ever walked past the back of the Geology Building, diagonal to Luddy Hall, you might have noticed a rock garden at the corner of Cottage Grove and Forrest Avenues.

Perhaps “garden” is too generous a word. The spot is regularly mowed, but there’s no discernible design or purpose to the pile, and no marker explaining what the rocks are or why they’ve been deposited here.

Two IGWS employees believe they’ve dispelled some of the mystery of this place without really intending to.

At least three of the rocks on this corner are 300-million-year-old pieces of petrified wood. They used to sit outside Owen Hall, with a sign explaining what they were, back when the geology department and IGWS personnel were housed in that building. The current Geology/IGWS Building opened in 1964. It’s unknown how long the specimens sat against the foundation of Owen Hall or when they moved to the corner where they are now.

Digitization Imaging Specialist Kristen Wilkins has been going through photo negatives of IGWS history and adding new images to IGWS Digital Collections. She came across the Owen Hall images and got to wondering where those fossils ended up once the geologists moved out of that building. She asked IGWS Education and Outreach Coordinator Polly Sturgeon for help. “One of them looked weirdly familiar,” Sturgeon said. She used to walk past the pile behind the IGWS building as a grad student and wonder what it was.

Wilkins took her camera to the corner, snapped some new photos, compared them with the vintage photos, and marked notable striations. IGWS Director Todd Thompson said he’s confident that the current and historical photos are a match. See the photo collection at this link.

The sign that accompanied the collection outside Owen Hall read: “Indiana petrified wood, 300,000,000 years old, Callixyon newberryi, Devonian Age, Clark Co., Ind. An evergreen tree floated into the sea from nearby land buried in the New Albany Black Shale and replaced molecule by molecule by silica from ground water.”

Callixyon newberryi is the fossil name; Archaeopteris is the name of the “first modern tree” from which the fossils came. In a recent paper by researchers at Indiana University Purdue University Indianapolis (IUPUI), the evolution of Archaeopteris roots was suggested as a possible trigger for a series of mass extinctions. The fossil samples used in that study were from Europe, though, not the ones in the IGWS’s backyard.

“The next step would be to hopefully protect them so they could stop getting hit by cars and lawnmowers,” Sturgeon said. She has reached out to Dr. David Polly of the IU Department of Earth and Atmospheric Sciences to start a conversation about the specimens.

“They need to reevaluated by Dr. Polly and his paleontology curator (Jess Miller-Camp), and their disposition determined,” Thompson said. “Regardless, a new sign should be made.”

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A new IGWS Advisory Committee is meeting quarterly in Bloomington and virtually. The makeup and duties of this committee were defined in SB 278/Public Law 108, which went into effect in July. Previously, state law allowed the president of Indiana University to appoint an IGWS advisory council; this bill codified its establishment, as well as specified representation from specific agencies and who is to appoint those people.

At the Oct. 12 committee meeting at the IGWS, presentations were given about ongoing and needed geological mapping, energy, and water research. The committee also toured the current core, chip, and lithstrip collection facility and visited the interim collection facility spot for the foreseeable future.

IGWS Advisory Committee members are:

• IU School of Public and Environmental Affairs: Dr. Joe Shaw, associate professor and associate dean for research

• IU Department of Earth and Atmospheric Sciences: Dr. David Polly, professor and department chair

• IU Office of the Vice Provost for Research: Dr. Brea Perry, interim associate vice president for research and interim vice provost for research

• Indiana House Utilities: Rep. Ed Soliday, chair, Utilities, Energy, and Telecommunication Committee, District 4

• Indiana Senate Utilities: Sen. Eric Koch, chair, Utilities Committee, District 44

• Indiana Department of Natural Resources: Ryan Mueller, deputy director of regulatory services

• Indiana Department of Environmental Management: Andrew Pappas, technical environmental manager

• Indiana Economic Development Corporation: Ben Smith, vice president of energy innovation and solutions

• Indiana Finance Authority: Jim McGoff, COO and director of environmental programs

• Geologist: Robert Duncan, principal geologist, Atlas Technical Consultants

• Geologist: William Karban, senior geologist, EnviroSolutions Inc.

The American mastodon, Indiana’s new state fossil, is the theme of the 2023 IGWS calendar.

If you have not received a delivery of this poster-sized calendar in the past and would like a print copy, a limited supply will be available at the IGWS office in mid-December. As an Early Bird Special, you can get a calendar for 99 cents (plus $7.50 shipping if needed) through Jan. 31; email igwsinfo@indiana.edu to make a shipping request.

The calendar also will be offered as a free digital download from the Indiana Journal of Earth Sciences, Vol. 5, starting Jan. 3, 2023.

The 2023 calendar creation team included Sara Clifford, Jenna Lanman, Matt Johnson, Casey Jones, Will Knauth, Polly Sturgeon, and Kristen Wilkins.

Editor’s note: The E-Geo News has been walking readers through the various steps required to turn physical data such as core samples into a functional geologic map. This is the third installment in this series; core collection was covered in September and core describing in November.

In a corner of the third-floor lab, a heavy shelving unit near the freight elevator is nearly full with core boxes. Each day, laboratory technician Katherine Tucker selects a box to start with—she could go through as many as five in a day—to document details that will aid geologists in discerning one type of bedrock from very similar-looking others.

One of her tools is a camera rig; the other is a specialized X-ray machine called the pXRF (portable X-ray fluorescence spectroscopy).

Tucker photographs each box of rock samples in controlled light conditions alongside a color bar and a ruler for scale. Photos are uploaded to IGWS Digital Collections to make it possible for anyone in the world to see what the Survey has sampled. IGWS geologists will take those photos and match them up with chemical composition readouts which come from pXRF testing on the same samples.

In the next room, Tucker places a bedrock sample over the 8-mm hole in the pXRF test window. The controlled X-ray aimed at it will cause fluorescent X-rays to beam off the material; a computer program determines the elemental composition of each sample based on the “fingerprint” the rays put off.

IGWS laboratory technician Katherine Tucker places a bedrock sample in the pXRF testing window. (The coffee cup is not part of the analysis; it was used to help position a sample earlier.) | Sara Clifford, IGWS

PXRF does not read whole chemical compounds, like CaCO3 (calcium carbonate, or limestone); it reads certain elements, like the calcium. It is able to measure dozens of elements in parts per million, but Tucker tracks just 20, in particular groups, in a spreadsheet. She’s looking for shifts in intensity in one or a group of elements over the depth of the core.

“So, this core was weird because we have a very large, relatively speaking, chlorine signature,” she says, pointing at the readout on the screen. “Chlorine is not common in the rocks that we have around here, and normally what it means … is somebody went a little crazy with the hydrochloric acid when they were running samples (doing tests at the describing stage), because the hydrogen will evaporate but the chlorine will not. But these are way too high and way too scattered to be that, so we have a bit of a mystery. It could be deposits left behind when there used to be a big saltwater sea here, or it could be something else. It’s unknown.”

When there’s a point in the core when geologists aren’t sure what they’re looking at, Tucker might take samples closer together than every foot to give them more data to work with. “Most people, what they’re looking for is a stratigraphic range of information”—for instance, data markers that would help determine if a piece of limestone is from the Paoli Formation or the Ste. Genevieve Formation within the Blue River Group.

Tucker is neither a chemist nor a geologist; she holds an English degree from Ohio University. She picked up this hourly job in July 2020 when her now-husband was getting his Ph.D. in chemistry. Yet, she knows the machine and the process, and the data she provides to geologists—to her co-workers and to outside companies seeking analysis—can be a key factor in helping to resolve geologic questions.

PXRF, though, is not a diagnostic tool; it is an exploratory tool, Tucker stresses, and, ideally, one of a suite of tools a geologist could use to determine what, exactly, they’re looking at. Other tools geologists could use in-house include heavy liquid separation (to isolate and identify microscopic fossils only found in certain ages of rock), or optically-stimulated luminescence (OSL) dating (which we explained last year). Tests geologists could run elsewhere include X-ray diffraction (examining the crystalline structure of compounds in a sample), ICP-MS (inductively coupled plasma mass spectrometry, incinerating a sample and reading the heat signature as elements disintegrate), or carbon isotope sampling (determining a biosignature by measuring the amounts of three types of carbon present).

Every box of core goes through the photography station, and all boxes of bedrock core for STATEMAP projects pass through the pXRF room, plus any requests from outside companies, keeping Tucker constantly busy.

Digitization Imaging Specialist Kristen Wilkins has assembled a new photo archive in IGWS Digital Collections called Staff at Work. “I continue to find new images to add to it, but there are already more than 300 photos up there dating from 1948 to the early 1980s,” she says.

“Some are candid while others are carefully composed for use in publications or as reference for illustrations. For example, Bill Stalions used “Woman examining specimens with a viewing scope” to create the cover art for Special Report 25 in 1982.

“One of my favorite photo sequences is from the rare color negatives in our collection from the late 1950s/early ‘60s. It shows a woman working with a computer. I have seen lots of images of our early computers in black and white, so imagine my delight to find out these interesting refrigerator-looking things were actually a charming blue, as is the dress of our survey employee working with it. And the typewriter terminal one uses to interact with the machines is also blue.

“Of course, color film at this time wasn’t used very much because it tended to color-shift as it aged. As a result, our image leans towards a blue-yellow spectrum, enforced by the mint-green paint which was so popular on campus for decades. Her skin tone is a little sickly (from the film), while her punch of red lipstick has lasted for 60 years.

“And despite posing like a robot to demonstrate the machines, her crossed ankles draw my eye to her own reaction to being photographed. Is she self-conscious? Is she trying to make her feet look more feminine for the picture? Is she awkwardly trying to balance in her high heels, hoping to get the picture over with so she can sit back down?”

View the collection by clicking here. You might see someone you used to know!

• The IGWS hosted Dr. David Applegate, 18th director of the U.S. Geological Survey, on Nov. 28 as part of a daylong visit to the IU Bloomington campus. He offered a lunchtime seminar to IU Department of Earth and Atmospheric Sciences faculty and students and IGWS staff titled “The USGS Hazards Mission: Bringing science to bear when (and where) it matters most,” then visited the IGWS Learning Lab to talk informally with IGWS staff about their projects. Later, Applegate gave a lecture at the Indiana Memorial Union titled “Science in Service to Society: The evolving role of the U.S. Geological Survey.”

• IGWS research geologist Isaac Allred and a coauthor published an article in the Journal of Sedimentary Research on Oct. 5. It’s titled "Demarcation of Early Pennsylvanian Paleovalleys in Depozones of the Appalachian Foreland-basin System Based on Detrital-zircon U-Pb and HF Analysis.” Their research demonstrates that about 320 million years ago, two distinct river systems in the eastern U.S. fed deep-sea fans in present-day Arkansas and Oklahoma.

• IGWS Director Todd Thompson was the keynote speaker at the annual meeting of Professional Geologists of Indiana on Nov. 9. More than 40 geologists attended. Thompson spoke about recent and future activities at the Survey.

The staff of the Indiana Geological and Water Survey wishes you a very happy holidays.

If you have items from our bookstore on your gift list which require shipping—such as coal for people on your naughty list—those orders must be received by Wednesday, Dec. 14.

Our office, and most offices on the IU campus, will be closed Friday, Dec. 23 through Monday, Jan. 2. We will reopen Tuesday, Jan. 3.

The Indiana Geological and Water Survey, a longstanding institute of Indiana University, conducts research; surveys the state; collects and preserves geologic specimens and data; and disseminates information to contribute to the mitigation of geologic hazards and the wise stewardship of the energy, mineral, and water resources of Indiana.

• To join the monthly E-Geo News mailing list, please click here.

• To ask a question of IGWS staff or suggest an E-Geo News topic, email scliffo@iu.edu.