2024 Houtermans Award Citation

Thomas Algeo, citationist for Feifei Zhang.

Citation by Thomas Algeo

It is my privilege to be the citationist for Dr. Feifei Zhang, of Nanjing University, who is being honored today with the European Association of Geochemistry’s F. G. Houtermans Award—an award that is given for exceptional contributions in the field of geochemistry to an early career scientist.

I have known Feifei for quite a long time, from his early student days, so I would like to take this opportunity to present to you an outline of his professional development and career. Feifei’s undergraduate studies were in the field of Economic Geology at the China University of Geosciences in Wuhan, China, where he finished his B.S. degree in 2011. Subsequently, he undertook a Master’s program in Isotope Geochemistry at the Chinese Academy of Geol. Sciences, which he completed in 2014 under the guidance of Prof. Xiang-kun Zhu. Feifei’s Master’s research focused on utilization of iron isotopes to trace the oxygenation history of the Cryogenian ocean, initiating his interest in understanding the long-term evolution of Earth systems and, in particular, the coevolution of life and environments through time.

Feifei came to the United States in the fall of 2014 to pursue a Ph.D. in Geological Sciences at the Arizona State University working with Prof. Ariel Anbar. His dissertation project developed the carbonate U-isotope proxy for analysis of global ocean redox conditions in the Earth’s past. This was a major breakthrough in paleoenvironmental research because nearly all other geochemical proxies allow assessment only of local redox conditions, whereas the carbonate U-isotope proxy provided a record of globally averaged ocean-redox conditions. In support of his Ph.D. research, Feifei undertook fieldwork on Permian-Triassic boundary sections globally. Among the locales he has studied are the classic Permian-Triassic boundary sections at Abadeh in Iran and at Shangsi in China. Feifei published the results of his doctoral research in a series of studies. His 2018 paper in GEOLOGY featured results from Kamura, Japan—a shallow carbonate section in the Panthalassic Ocean that showed an identical uranium isotope excursion to those of previously studied sections in the Tethyan Ocean region. This study thus demonstrated that the carbonate uranium isotope proxy was indeed recording a global ocean redox signal and not one of merely regional significance. Feifei also published parts of his doctoral research on the Permian-Triassic boundary in Science Advances and Geochimica et Cosmochimica Acta. These studies validated the robustness of the carbonate U-isotope proxy and yielded key insights into interrelationships between ocean-redox variation and other environmental and biotic records during the end-Permian extinction and its aftermath.

In the course of his Ph.D. studies, Feifei began to branch out into other geologic periods, applying the carbonate uranium isotope proxy to studies of the Lower Triassic, the Devonian, the Ediacaran, and older stratigraphic units. This work included a study of the Smithian-Spathian boundary—an event marking the termination of the most intense stage of the Early Triassic environmental crisis. His research on global-ocean redox changes during the Ediacaran-Cambrian transition led to several publications, including papers in Science Advances and Geobiology. These studies provided evidence that changes in oceanic redox conditions modulated bioevolutionary developments throughout the Ediacaran Period and, in particular, that widespread oceanic anoxia at the end of the Ediacaran may have contributed to the demise of the Ediacaran Biota.

Subsequently, Feifei tested the application of the carbonate uranium isotope proxy to even older stratigraphic units—specifically, those of Tonian (or early Neoproterozoic) age. This study demonstrated the existence of more extensive shallow-marine anoxia during the early Neoproterozoic than seen in younger Neoproterozoic marine sediments, consistent with a gradual but large rise in oceanic oxygenation prior to the Cambrian Explosion. Feifei published a review paper in Geochimica et Cosmochimica Acta in 2020 offering a state-of-the-art look at the carbonate uranium isotope proxy, an impressive accomplishment for a scientist who had just completed his Ph.D. degree.

Following completion of his Ph.D. degree in 2019, Feifei spent two years doing postdoctoral research—first with Prof. Noah Planavsky at Yale University, and then with Prof. Tais Dahl at the University of Copenhagen. The latter postdoctoral stint led to a paper on the Late Devonian Hangenberg Event. This study revealed three cyclic episodes of widespread oceanic anoxia during the latest Devonian, demonstrating a greater complexity for this event than previously known, and indicating a possible relationship to contemporaneous glaciation. All of Feifei’s studies based on uranium system geochemistry have incorporated cutting-edge biogeochemical models in order to quantitatively constrain relationships of uranium-isotope variation to changes in ocean-redox state.

Feifei returned to China in 2020, joining the faculty of Nanjing University. There, he constructed and made operational a cutting-edge geochemistry lab for the study of metal isotopes. This laboratory is equipped with latest-generation instrumentation, including a Neptune XT MC-ICP-MS, an Element XR HR-ICP-MS, an iCAP TQ ICP-MS, an iCAP Pro ICP-OES, and an ultraclean prep lab. This represents a significant enhancement to the still-nascent global infrastructure for analysis of heavy metal isotopes.

In recent years, Feifei’s research interests have broadened into isotopic systems beyond uranium. He is currently studying paleoenvironmental change in carbonates by applying the Li, Ca, and Sr isotope systems to track continental weathering, the Ba and Zn isotope systems to track marine productivity, and the Fe, U, Ce, and Tl isotope systems to track marine redox conditions. For example, his recent paper in EPSL made use of Ba isotopes to understand interactions between productivity and redox changes during a major bioevolutionary event. His most recently published paper examines covariation among Sr, Li and U isotopes to document the timing and extent of diagenesis in shallow-marine carbonates in the Bahamas and South China Sea. Ultimately, such work is critical for reading through diagenetic overprints to isolate primary marine isotopic signals in ancient carbonate rocks. These tools serve his larger goals of understanding the long-term chemical evolution of the oceans and atmosphere, the causes of major glacial and hyperthermal events, and the environmental backdrops leading to mass extinction events in Earth history.

At Nanjing University, Feifei has assembled a dynamic team of young geoscientists to pursue his ambitious research goals. He has led field excursions to many field sites in China, and he has mentored a series of aspiring young geoscientists interested in cutting-edge research in metal isotopes.As one of the leading scientists in the field of Earth-systems analysis, Feifei has developed collaborations with other world-class scientists, both in China and globally, in order to take his research to the “next level”.

In summary, the unifying theme of Feifei’s research is to better understand life-environment co-evolution and the secular development of the Earth as a habitable planet. To achieve these goals, he combines isotopic tracers with numerical models to address the underlying problems in a quantitative manner. His achievements to date have greatly refined our knowledge regarding the timing, duration, and intensity of major episodes of oceanic anoxia in the Earth’s past, as well as their relationship to contemporaneous carbon-cycle and biospheric perturbations. Despite his youth, Feifei has already established himself as one of the leading researchers in the fields of isotope geochemistry and Earth-systems analysis. His achievements to date make him an eminently worthy recipient of the 2024 F. G. Houtermans Award. In addition to his ambitious research agenda, Feifei is also a highly active participant in what is generally known as “professional service”—meaning all those thankless tasks that must be performed in order to sustain the progress of science. Please join me in welcoming, and thanking, this year’s winner of the EAG’s Houtermans Award—Professor Feifei Zhang.