Sierra was recently quoted in a Science News article about climate change and extinction at the end of the Cretaceous! Link to Article
Category: Uncategorized
New Paper Update: Tropically Hot Cenomanian temperatures in the Western Interior Seaway
The latest SCIPP-Lab paper comes from former SCIPP-lab postdoc Dr. Matt Jones (now at the Smithsonian Institute), publishing the work he did while at UM. Dr. Jones looked at fossil oysters from the Cretaceous Western Interior Seaway and used clumped isotope to reconstruct seaway temperatures during the time they lived.
We found that temperatures during the Cretaceous Thermal Maximum (Cenomanian-Turonian period, ~95 Million years ago) reached upper 20’s to lower 30’s Celsius in what is now modern day Utah and Wyoming. This is very hot! These water temperatures, which occurred in the mid-latitudes during the Cretaceous, are today only found in the warmest areas of the ocean like the Western Pacific Warm Pool. It makes you wonder how hot the tropics were if the mid-latitudes were >30C!! But that’s for another day…


LINK TO PAPER: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G49998.1/613546/A-tropically-hot-mid-Cretaceous-North-American
LINK TO UM PRESS RELEASE: https://news.umich.edu/bali-like-temperatures-in-wyoming-fossils-reveal-tropically-hot-north-america-95-million-years-ago/
LINKS TO OTHER PRESS: Futurity article, Science Daily article,
MGU Conference 2022
MGU (Michigan Geophysical Union) is a 1-day conference completely run by UM students, bringing together students studying earth sciences in the Earth and Environmental Science, Chemistry, and Climate and Space Sciences and Engineering departments across campus. This has historically just been a poster session, but this year a few live talks were held as well.
The SCIPP Lab had a very strong representation at MGU 2022! ALL members of the SCIPP Lab presented (4 grad, 4 undergrad posters) and Sierra volunteered as a judge. Two of our group members (Alex and Allison) were also on the organizing committee! Everyone did an awesome job creating their posters and presenting their results. Two of our undergrads were awarded “best undergrad presentation” awards! Congratulations Cecilie and Samantha!










Photo credit for all photos (except the selfie) goes to MGU Photographer and Earth PhD student, Mike Machesky.
SCIPP Lab welcomes two new members!

We are very excited to welcome our two newest members, Lucas Gomes and Alex Quizon, both PhD students. Lucas will be working on reconstructing paleoceangraphic conditions in the Pliocene of Florida looking at extremely fossil-dense beds of the Tamiami Fm./Pinecrest beds and Caloosahatchee Formation. Alex will be working on fossil seashells from South Carolina dating to the Last Interglacial and calibrating the clumped isotope paleothermometer in modern marine gastropods. Welcome welcome!
We are also sad to (sort of) say goodbye to our postdoc Matt Jones, who has left us for a fancy postdoc fellowship at the Smithsonian Institute in Washington DC (congrats Matt!). We will still be collaborating closely with Matt in our efforts to reconstruct Cretaceous paleotemperatures, especially in the Western Interior Seaway. He plans to leverage the extensive Cretaceous fossil collections of the Smithsonian and send us samples to analyze for clumped isotopes.
Heidi submits her thesis and manuscript!
Despite setbacks due to COVID, our very own Heidi O’Hora submitted her masters thesis this week to graduate end-of-summer, and then turned around and submitted her manuscript to a top-tier journal for peer review and (hopefully) eventual publication in the scientific literature. Congratulations Heidi, you did it! We are so proud of the progress you’ve made over the past 2 years, especially considering it was such an unusual time.
Heidi’s thesis project involved reconstructing Late Cretaceous ocean temperatures in the modern-day region of Maastricht, the Netherlands. Her samples come from the type section of the Maastrichtian (ENCI quarry) among other locations. She found that temperatures in that area were much warmer than they are today (as expected for the greenhouse world of the Cretaceous) and that interactions between different water masses had a strong control on local ocean temperature and salinity.
Stay tuned for publication announcement later on!
Sierra awarded the Sloan Research Fellowship
SCIPP Lab is excited to announce that Sierra has been selected as a 2021 Sloan Research Fellowship.
Paraphrasing from the Sloan website…
The Sloan Research Fellowship seeks to stimulate fundamental research by early-career scientists and scholars of outstanding promise. These two-year, $75,000 fellowships are awarded yearly to 128 researchers in recognition of distinguished performance and a unique potential to make substantial contributions to their field. Their achievements and potential place them among the next generation of scientific leaders in the U.S. and Canada.
Sierra plans to use the funds to push forward our paleo-seasonality projects in the Pliocene and elsewhere.
New Paper Update: Community-Wide Clumped Calibration Efforts
Sierra wrapped up a community-wide effort to reprocess and update clumped isotope calibration data from 11 different laboratories, including over 1200 individual replicates, to bring it into the same framework. This involved updating the fundamental parameters R13_VPDB, R17_VSMOW, R18_VSMOW, and λ used to calculate raw D47, using a consistent and updated set of theoretical equilibrium values (D47_TE) to tie things into the absolute reference frame, and applying a single set of acid fractionation factors (D*90-25) across all studies. We found that agreement is quite good between labs, once all the data processing is done uniformly and the “two-slope” or “multi-slope” problem that plagued the clumped community in the early days has all but disappeared in more recent studies.
As part of this effort, we also developed a data template and began a relationship with the EarthChem database to house future clumped isotope datasets in a long-term storage location. For more information on that, see this page.
Job Posting: Lab Manager for SCIPP Lab – FILLED
The SCIPP Lab is looking to hire a full-time lab manager to oversee daily operations, train students, and run samples. Our group works in a 3-PI shared lab space that was fully renovated in 2018-2019.
Day to day responsibilities include:
- Oversee daily operations for a lab that operates two (2) mass spectrometers, including sample preparation and analysis, data quality control, instrument troubleshooting and repair, and compliance with safety standards.
- Train and assist graduate and undergraduate students on the mass spectrometers including demonstrating various laboratory techniques and best practices for the instruments.
- Prepare standard materials, maintaining supplies, and organize shared usage of equipment by lab members.
Required qualifications: Bachelor’s degree in a natural science discipline such as earth science, chemistry, or environmental sciences or engineering with secondary educational knowledge in geoscience as a plus. The candidate should have experience and expertise in stable isotopic analysis of carbonate materials, diagnosing and repairing lab equipment, laboratory management, and standard lab safety protocols. The ideal candidate is organized, have a strong attention to detail, with the ability to work well with others in a shared lab space environment.
Desired Qualifications: Master’s degree and/or previous working experience with Nu Perspective + NuCarb and Thermo MAT 253 instruments and/or the clumped isotope technique.
The salary range for this position is $37,600 – $47,000. Wage will be determined based on candidate qualifications.
TO APPLY:
Please contact Prof. Petersen by email at sierravp@umich.edu. Please provide a CV and a cover letter describing relevant prior experience and/or particular reason for interest in the position (if appropriate). We will begin reviewing applications August 1, 2019, continuing until the position is filled.
The University of Michigan is an equal opportunity/affirmative action employer.

Our New Nu Instrument arrives in Michigan!
The SCIPP Lab has acquired a Nu Perspective + Nucarb to perform automated clumped isotope analyses (to the great happiness of everyone who has worked hours doing manual sample prep on our vacuum line). The crates arrived in Ann Arbor last week, and made it to our building today.
We had an exciting (and sometimes stressful) time welcoming our “new baby”.
At times, feet were up in the air…
(not pictured, these same feet teetering over the edge of the truck bed 4 feet off the ground, when “mama” Sierra almost had a heart attack)
…but “Midwife” Craig, our building manager, had steady hands, and with the help of many others…
…our baby girl landed safely in her new home! Waiting to be unpacked when the Nu Engineer arrives in a few weeks.
Weighing a few tons in total, mom and baby are both doing well now that all feet are safely on the ground. We still haven’t decided on a name…

SCIPP Lab welcomes 4 new group members
The SCIPP Lab/Petersen Group is very excited to welcome four new members for the coming year. Julia Kelson will arrive as a postdoc under the NSF Postdoctoral Fellowship to study paleoclimate and paleohydrology using clumped and triple oxygen isotopes, in conjunction with the IsoPaleo Lab. Two incoming Masters students, Allison Curley and Heidi O’Hora, will be working on Cretaceous paleoclimate projects. Finally, undergraduate Steve Wedel will join our ranks to work on reconstructing climate during the Last Interglacial in Turks and Caicos.

Phase 1 of Reno complete!
Phase 1 of the Stable Isotope Lab renovation is complete! Over spring break, mass specs were moved from the back room (our temporary place of operation) to the newly renovated main lab area. Everything looks so bright and clean! Our prep line now faces a window instead of a dark corner and the mass spec has a nice new corner to live in.
Julie Cole and Kacey Lohmann are also settling their machines and equipment into the shared space. Phase 2 will renovate the back room into a sample prep area with drills, microscopes, table and sample storage space, weighing room, and lab manager office space.