Tracing Water Through Earth's Critical Zone and Atmosphere with Stable Isotopes
Water governs how carbon moves between land and atmosphere, where organisms can live, how elements are dissolved, carried, and concentrated, and how the sedimentary record itself is built. Plants show the connection most directly: every time they open their stomata to take in carbon dioxide, they lose water, so following water also means following productivity.
How warming redistributes water across continents remains one of the least certain parts of climate projection, and Earth system models still disagree on it. Testing those models under warmer-than-modern conditions requires observations from past climates. Measuring the same processes in today's ecosystems improves how models represent them and how we read the geologic record.
Stable isotope geochemistry is my core toolkit, and a remarkably versatile one. Nearly every step water takes, from evaporation and mixing to uptake by plants and crystallization into minerals, leaves an isotopic fingerprint, and each isotope system captures a different part of the story. Hydrogen and oxygen isotopes are part of the water molecule itself, so they record where water came from and what happened to it along the way. Beyond water itself, I follow water and its impacts through the materials it passes through or leaves behind: plant tissues in modern ecosystems, and organic matter and minerals that formed in soils, sediments, and living organisms in the geologic record.
My expertise spans conventional isotope systems, oxygen (δ¹⁸O) and carbon (δ¹³C), and newer ones: triple oxygen isotopes (Δ′¹⁷O), which help isolate evaporation, and clumped isotopes (Δ₄₇, Δ₄₈), which recover the temperatures at which minerals formed. Used together, they separate the effects of temperature, evaporation, and water source, and connect water to its effects on carbon and life. I continue to expand my stable isotope toolkit so that each study can constrain as many parts of a system as possible.
Multi-proxy Paleoecological Reconstruction
of the mid-Cretaceous Cloverly Formation
Figure: Oxygen isotope compositions of vertebrate taxa from the Cloverly Formation. Body water reconstructions for ectothermic taxa suggest possible ecological partitioning among crocodyliforms, indicating differential water sourcing or habitat use within the community.
As part of my PhD research, I developed a multi-proxy study of the Cloverly Formation in Wyoming and Montana to investigate how terrestrial ecosystems responded to climate change during the mid-Cretaceous greenhouse interval. Despite its relevance as an analog for future climate and its importance for the emergence of modern terrestrial lineages, the mid-Cretaceous remains poorly understood in terms of continental climate variability. The Cloverly provides a rare opportunity to help fill that gap.
With my collaborators, I integrated:
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carbon isotope stratigraphy and U–Pb zircon geochronology to refine the chronostratigraphic framework;
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clumped and oxygen isotope analyses of palustrine carbonates to reconstruct surface temperatures and water isotope values, along with bulk geochemistry of paleosols to estimate precipitation rates;
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and δ18O analyses of fossil vertebrates to assess ecological niche partitioning of water and habitat resources.
This is the most comprehensive and detailed study of paleoclimate and hydrology in the Cloverly Formation to date—and one of very few to target a terrestrial section of this age with this level of temporal resolution. The results provide new empirical insight into mid-Cretaceous climate variability and will help refine Earth system models under greenhouse conditions. One paper from this project has been published, with two additional manuscripts currently in advanced stages of preparation. This work also lays the foundation for expanded regional comparisons across the Western Interior Basin and future applications of quantitative water isotope models to mid-Cretaceous North America.
Other Projects
Systematics and Macroevolution of Permian Ammonoids
My master’s research focused on describing middle Permian ammonoid faunas from the Guadalupe Mountains region of West Texas, where I developed new morphometric techniques to quantify suture complexity and shape. Since then, I have acquired many additional specimens from the same region—including undescribed taxa—and now maintain a backlog of taxonomic and macroevolutionary questions to pursue. I ultimately aim to revive this part of my research portfolio to investigate how functional diversity and ecological structure in ammonoids evolved across major environmental perturbations leading up to the end-Permian mass extinction.
Quantitative Vertebrate Faunal Comparisons Across mid-Cretaceous North America
I am leading a regional synthesis of mid-Cretaceous vertebrate assemblages across the Western Interior Basin. Using standardized occurrence data, diversity estimators, and community similarity metrics (e.g., shareholder quorum subsampling and Sørensen index), this project aims to clarify patterns of biogeographic turnover and ecological differentiation during the Aptian–Turonian interval. These comparisons provide new insight into the tempo and structure of vertebrate faunal change between the iconic Late Jurassic Morrison fauna and early Late Cretaceous assemblages like the Mussentuchit Member of Utah.
Paleocene Paleoenvironmental Reconstruction in the Bighorn Basin, WY
In collaboration with Dr. Anna Wisniewski, I am investigating environmental change across the middle to late Paleocene of the Bighorn Basin—a critical but understudied interval leading up to the PETM and early Eocene. We combine geochemical and sedimentological proxies to reconstruct terrestrial hydrology and surface conditions, with the goal of refining the environmental context for pre-PETM mammalian evolution. Our analyses include fossil tooth enamel, pedogenic carbonates, paleosols, and gar scales, while new fossil collections by Anna are improving biostratigraphic resolution. Together, we are developing a detailed paleoecological record to better understand how ecosystems responded to changing climate prior to the PETM.
Isotope Paleoecology of Paleocene Mammal Communities in the Bighorn Basin
Also in collaboration with Dr. Anna Wisniewski, I am piloting a multi-taxon, multi-proxy study to evaluate cryptic (non-morphological) niche structure in mammalian communities prior to the Paleocene–Eocene transition. This work uses isotopic data from tooth enamel to reconstruct ecological partitioning, including differences in water sourcing and dietary strategies across co-occurring taxa. Ultimately, we aim to identify shifts in niche structure across the PETM by comparing our results with existing multi-taxon datasets from the early Eocene of the same region.
Using Δ′17O to Detect Cave-Process Biases in Speleothem δ18O Records
In collaboration with Dr. Annabel Wolf, I am contributing to an effort to test Δ′17O as a proxy for detecting kinetic isotope effects in Holocene speleothem carbonates. Building on the work of Tyler Huth and others, this project aims to distinguish non-equilibrium processes—such as CO2 degassing and prior calcite precipitation—from equilibrium signals in the δ18O record. Because Δ′17O is relatively insensitive to temperature, it offers a promising way to isolate cave-process overprints that can obscure climatic interpretations. This work supports the development of more reliable proxies for paleo-humidity and cave hydrology.
Future Directions
Δ′17O Framework Development
Moving forward, a central focus of my research will be the use of triple oxygen isotope geochemistry to better understand how water availability responds to climate change. A key priority is advancing the emerging framework for interpreting Δ′17O across the water cycle, so these proxies can be applied with confidence to both modern systems and the geologic record.
Novel Δ′17O Proxies for Terrestrial Hydroclimate
In parallel, I aim to develop and apply new triple oxygen proxies that capture hydroclimate patterns in terrestrial environments. Backed by a robust empirical framework, these tools will allow me to reconstruct hydroclimate variability and dynamics at high spatial and temporal resolutions.
These records can help answer fundamental questions such as:
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How spatially variable were changes in terrestrial water balance during periods of global climate change?
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What was the relative role of water availability versus temperature in driving major evolutionary and ecological shifts on land?
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In greenhouse climates, was the terrestrial water cycle relatively stable or prone to extreme fluctuations?
Applied Directions: Lithium Brines
I also see opportunities to apply this toolset to resource challenges. My combined background in exploration geology, paleohydrology, and low-temperature geochemistry positions me to bring new perspectives to the study of lithium brine systems—linking basin history, hydroclimate, and geochemistry to refine exploration models and support sustainable development.