Many processes in nature and human-made settings rely on the unique properties of charged metal oxide:aqueous interfaces. Despite their ubiquity, these buried interfaces are challenging to study, since any analytical technique aiming to overcome the relatively small number density of interfacial versus bulk species must be highly sensitive and surface-selective....
This dissertation investigates processes controlling the Ca isotope geochemistry (δ44/40Ca) of Icelandic samples, from an atomic to island-wide scale. These studies embody the range of applications for which the Ca isotope proxy can apply in surficial environments, and I offer novel δ44/40Ca data for Icelandic rivers, rocks, minerals, soil, and...
If life exists on Mars, it likely resides in a deep subsurface environment. The Martian rocky subsurface is a primary target for the search for extraterrestrial life because it offers a stable habitat for microbial life. On Earth, the continental subsurface is a key astrobiological analog for understanding what properties...
The studies presented in this dissertation integrate stable calcium (Ca) and radiogenic and stable strontium (Sr) isotope geochemistry to understand how the Earth system responds to significant perturbations in the global carbon cycle. The primary focus is on the effects of massive releases of volcanic CO2 for ocean carbonate geochemistry...
Carbonates constitute Earth's largest carbon (C) reservoir, with most shallow marine deposition occurring on the low-latitude carbonate platforms covering ~800,000 km2. The Yucatán Platform situated between the Western Caribbean and Gulf of Mexico basins, is one of the largest present-day carbonate platforms. As with post-Paleozoic carbonates generally, it is readily...
This dissertation researches the Cenomanian, Turonian, and Coniacian Stages (100.5 - 86.3 Ma) of the Cretaceous Period, a geologic interval of interest due to its extreme global warmth, iconic faunas, and oceanic anoxic events (OAEs). Five globally dispersed geochemical and stratigraphic case studies reconstruct interactions of the mid-Cretaceous carbon cycle...
This dissertation explores Holocene climate change along the west coast of Greenland and late Holocene climate variability in the subpolar North Atlantic region using paleolimnology. Lake sediment archives and the climate proxies contained within them provide a valuable window into past temperature change on Greenland, home to one of Earth’s...
