People on the Earth History team
Anne-Sofie Ahm, Assistant Professor (CV)
As an Earth Historian, I am interested in how we can use the chemistry of rocks to gain insight into the surface conditions of Earth in the past. The chemistry of marine carbonate sediments has been used to reconstruct the evolution of global biogeochemical cycles for a wide range of elements throughout the entirety of Earth history. However, one of the main limitations in using this geochemical archive is the susceptibility of carbonate sediments to diagenesis, as unlithified sediments are transformed into the rocks we can study in the geological record. Using multiple isotope systems and numerical models of diagenesis, my research seeks to extract the primary chemical information from ancient carbonate sediments by better understanding the diagenetic processes. I am particularly interested in the co-evolution of climate and life during fundamental transitional periods in Earth history such as the Great Oxidation Event, Neoproterozoic Snowball Earth events, the Cambrian explosion of animal life, and the end-Ordovician mass extinction.
Keyi Cheng, Postdoctoral Researcher
Understanding biogeochemical cycles in ancient oceans not only satisfies our curiosity, but also contributes to humanity’s future—by improving our ability to predict the ocean’s response to climate change, and guiding the search of potential habitable worlds in exoplanets. However, this endeavor is meanwhile a challenging task due to sparsity of preserved rock records and limitations in our understanding of these biogeochemical cycles in both seawater and sediments. My research aims to reveal a comprehensive picture of oceans in the past, with emphasis on—but not limited to—redox structure, nutrient dynamics, and weathering flux through integrating isotopic and elemental proxies, sedimentological analysis, and earth system models. Particularly, I am interested in exploring the co-evolution between ocean chemistry and life evolution during the Mesoproterozoic—the dawn of diversification of eukaryotic species which laid the foundation for today’s ecosystems.
Jinfeng (Henry) Hong, MSc student
I am interested in exploring the co-evolution of climate, geochemistry, element cycling, and life throughout Earth history. My research interests also lies on understanding the interactions between geochemical processes and environmental changes, particularly during periods such as the Great Oxidation Event and the Boring Billion. Thus it is essential to try to reconstruct past biogeochemical cycles and unravel the complexities of diagenetic processes that influence the preservation of primary geochemical signals during the Boring Billion. In general, my goal is to gain a better understanding of why Earth's biosphere and climate have behaved in the ways they did, and how these interactions have impacted the evolving chemistry of our planet over time.
Rizzieri Balestra, MSc student
I am interested in how paleoenvironments, biogeochemical cycling, and the evolution of life have influenced one another throughout Earth’s history. I approach solving these questions by using stratigraphy and sedimentological observations coupled with geochemical proxies to build up spatiotemporal reconstructions of basins and their seawater chemistry. My research is focused on carbonate rocks from the Mesoproterozoic Belt-Purcell Supergroup and the Late Triassic Quatsino Formation. In particular, I will be determining the degree to which these rocks have been altered by diagenesis to differentiate between local and global signals.
Brooke Taylor, Honours student and NSERC Undergraduate Student Research Award
I am interested in reconstructing ancient environments through the geochemistry of carbonate rocks. My honours research focuses on the formation and distribution of stromatolites and molar tooth structures in Mesoproterozoic carbonates as means of constraining environmental conditions. Molar tooth structures are particularly interesting because they are unique to Proterozoic carbonates and their appearance and subsequent disappearance remain poorly understood. By integrating stratigraphy and geochemistry, I aim to better understand their formation and reconstruct the environments in which they developed.
Peyton Yip, VKURA Undergraduate Student Researcher
I am interested in the intersection point between ocean systems and Earth systems, specifically in the form of marine sediments. I look forwards to learning more about the history of the earth and am keen to understand more about geochemical and marine science and all their applications to climate change.