I am a Ph.D. candidate in biogeochemistry in the University of Michigan’s Department of Earth & Environmental Sciences. My research focuses on how terrestrial nutrient cycling, life, and the atmosphere have co-evolved through geologic time. I am particularly interested in studying iron and phosphorus – two essential nutrients – and how changes in their cycles may have impacted productivity through time. Additionally, I study controls in nutrients in modern soils, and how modern soils can be used as analogues for early terrestrial systems. I have worked in Utah, Wyoming, Iceland, and India, and hope to add Hawaii to my dissertation fieldwork, as well as return to Iceland for a more exhaustive sampling trip.
Characterizing the iron content of modern soils
I am working to constrain the climatic and environmental factors that primarily control the distribution of iron in modern soils under varying climatic regimes, using a novel combination of chemical extractions and analytical techniques (AGU 2016). Presented at Goldschmidt 2018, session 12e. In prep.
Collaborating with Adrianna Trusiak (Cory lab, UMich) to characterize soil iron redox cycling in Arctic soils (North Slopes, AK).
Constraining changes in terrestrial phosphorus through geologic time
I am compiling a long-term record of phosphorus in terrestrial systems to examine how terrestrial nutrient cycling, the atmosphere, and marine productivity/life co-evolved. In prep.
Look for me at Midwest Geobiology 2018 at Northwestern University!
Modern soils as Precambrian analogues
A subset of my modern soil work focuses on landscapes similar to those that could have been found on early Earth. Iceland, with its frequent volcanism, incipient soils, and robust microbial/lichen/moss soil crusts, makes for a fascinating potential analogue environment. Soil crusts in other dry environments may also serve as analogue communities, and understanding their metabolisms and roles in nutrient cycling (C, P, Fe) informs our understanding of early terrestrial life and nutrient transport. Collaborating with the Dick Lab (UMich) to characterize microbial communities using 16s RNA sequencing.
Fieldwork: Utah & Wyoming, July 2017; Iceland, August 2018
Funded in part by the American Philosophical Society Lewis & Clark Grant, GSA Graduate Student Research Grant, and Univ. of Michigan departmental awards
Terrestrial Indian paleoclimate across the K-Pg
In 2017, I visited India to sample paleosols formed at the edge of the Deccan Traps before, during, and after the end-Cretaceous extinction event, for the purpose of paleoclimate reconstruction (GSA, October 2017; Dzombak et al., in prep.)
Field sites: central India (March 2017)
Wyoming paleoclimate during the EECO
I am also working on the Early Eocene Climatic Optimum (EECO), a period of abrupt warming around 56 Ma, as recorded in floodplains in Wyoming.
Field sites: Wind River Basin (June 2017); GREECO project fieldwork (June 2019).
Advising: SE Michigan wetlands soil chemistry
In addition to my own research, I am working with an undergraduate research assistant to determine seasonal changes in nutrient cycling in wetland soils in Michigan; this work is part of the University of Michigan’s Undergraduate Research Opportunity Program and was sparked by field trips led as part of the Soils & Surface Processes class taught with my adviser in Fall 2017.
(UROP 2016 project: Reconstructing vegetation in Wyoming at the EECO using carbon isotopes.)