MAG LAB Slotznick Research Group Department of Earth Sciences
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Digging into the Details of the Great Oxidation Event

During the Paleoproterozoic Era, the Earth and its biogeochemical cycles underwent dynamic changes—the Great Oxidation Event (~2.3 billion years ago), global glaciations, continental fragmentation, increasing ocean sulfate levels, and extreme carbon cycle excursions (e.g., the Lomagundi-Jatulli Event).  Major first-order questions still remain about these events though.  For example, the levels of atmospheric oxygen in the time following its initial appearance are poorly constrained and it is unknown how many global "Snowball Earth" glaciations occurred.  We seek to address these questions through stratigraphic observations, paleomagnetism, rock/environmental magnetism, and geochemistry. As complete a picture as possible of Earth during this critical time period is necessary to test hypothesized causal links between these events and the Great Oxidation Event.  Current field areas include Canada and South Africa.

Iron Mineral Transformations in Modern Rivers and Lakes

Tracing the chemical and structural evolution of minerals from their formation through deposition is vital since many of the geochemical records tracking environmental change over time depend on single minerals.  Better understanding of the abiotic and microbial processes that form and alter these key minerals is vital to our understanding of Earth History. We are working to understand the biogeochemical cycling of iron from a mineralogical view during weathering, transport, deposition, and early diagenesis  to shed light on the preservation of ancient bio- and environmental signatures.  Of special interest are modern terrestrial systems due to their variability and potential for excellent preservation.  Current field areas include New Hampshire.

Pyrrhotite Formation

Pyrrhotite, although sometimes detrital or early diagenetic in origin, usually forms during low-grade metamorphism (at temperatures as low as 75˚C) from pyrite desulfurization during water-rock interactions or from decomposition of iron oxides and iron silicates.  This mineral transformation may affect a multitude of geochemical proxies based on sulfur, iron, or siderophile/chalcophile transition elements (Mo, Ni, Mn, Zn, etc.)    Newly developed techniques such as micron-scale magnetic microscopy and synchrotron-based "tender" x-ray spectroscopy microprobe beamlines could provide a unique, unexplored tool for understanding formation mechanisms and metal partitioning during this process. The field of rock magnetism can provide methods for quick non-destructive identification of pyrrhotite, and we are working to standardize a technique for wide-spread usage in sample screening.  Current field areas include Montana.

Paleogeography and Magnetostratigraphy near Mass Extinctions

Mass extinctions during the Phanerozoic Eon often co-occurred with changing environmental conditions.  As   the scientific community explores the global nature of these events and causal linkages, it is critical to understand the timing and ancient location of distinct stratigraphic sections.  Correlations between stratigraphic sections (without radiometrically-datable units) are often performed based on biostratigraphy or isotopic stratigraphy; however, this can be limited by local features producing blurred global signals. Magnetostratigraphy can provide an independent global chronometer for these types of sections.  Similarly, work on refining paleomagnetic data for paleogeography during these critical time periods can provide a better picture of the entire Earth.   Current field areas include Antarctica, Mongolia, Nova Scotia, and California.

 © 2024 by Sarah Slotznick
MAG LAB Slotznick Research Group Department of Earth Sciences
MAG LAB Slotznick Research Group Department of Earth Sciences
MAG LAB Slotznick Research Group Department of Earth Sciences

Paleogeography and Magnetostratigraphy

near Mass Extinctions

MAG LAB Slotznick Research Group Department of Earth Sciences

Digging into the Details of the

Great Oxidation Event

Iron Mineral Transformations in

Modern Rivers and Lakes

MAG LAB Slotznick Research Group Department of Earth Sciences
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 © 2024 by Sarah Slotznick
MAG LAB Slotznick Research Group Department of Earth Sciences
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    HomePeopleResearchPublicationsFacilitiesTeachingContact
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