As a field geologist, my research integrates stratigraphy and sedimentology with geochronology, basin modeling, and stable isotopes to interpret changes in tectonics, eustatic sea level and climate.
Ongoing and Future Research
Evaluating tectonics, eustatic sea level, and magmatic effects on basin and orogenic evolution
Southern Patagonian Andes, Argentina
The effects of tectonics and eustasy on the sedimentary record are a constant challenge to unravel. Eustatic sea level rise can often be misinterpreted as basin deepening from tectonic loading, and vice versa. Further, both climate-induced erosion and accelerated rock uplift and slope steepening can cause an increased basin sediment supply. I am especially focused on resolving the relative contributions of these processes as it is of fundamental importance to understanding past climates and how tectonic signals are preserved in the sedimentary record. In one of my current projects, the Magallanes-Austral Basin has experienced spatially variable uplift relative to continuously subsiding areas during the Late Cretaceous. However, the mechanism and magnitude of basin uplift is unclear and subsequent fold and thrust belt propagation has overprinted much of the earlier history. Tectonic and magmatic processes may play a key role in orogenic uplift and basin inversion (i.e., changes between arc magmatism and intraplate plateau magmatism). I use sedimentary analysis and geothermochronology to model basin subsidence histories to evaluate the interplay of these processes.
Quantifying the timing and tempo of crustal fluid flow from the thrust belt to basin record
Offset calcite veins in western Maryland
O Radiogenic and stable isotope geochemistry elucidates faulting histories and paleofluid sources and can thereby provide valuable information about orogenic wedge evolution and links between deep crustal and shallow fluid migration pathways. Detailed chronology of fault motion is critical for resolving whether or not deformation occurred contemporaneously across portions of the thrust belts or if deformation migrates episodically. In addition, improved chronology of faulting is important for constraining timing of fluid migration pathways. Fluid source and migration pathways are important for assessing competing processes during thrust belt evolution i.e.) deep burial and expulsion of metamorphic/magmatic fluids under high pressure and temperature conditions and/or infiltration of meteoric water from topographic gradients. Recent advances in U-Pb carbonate geochronology allow dating of deformational phases of individual structures on Myr timescales. Further, carbonate clumped isotope data from cements in synorogenic basin fill and fault surfaces has been used to determine origin of paleofluids and fluid migration pathways important for identifying natural resources and recognizing competing geofluid migration processes. I plan to conduct a faulting chronology study to assess deformation patterns across fold and thrust belts and understand paleofluid origin from thrust belt to basin using fault surfaces and synorogenic sedimentary basin fill cements. Ongoing work is being conducted in western Maryland.
Ice sheet dynamics and future climate are of great concern given our warming oceans and atmospheric temperatures. The Arctic is one of the fastest warming regions influencing climate change. Thus, histories of northern hemisphere ice sheets are crucial for recognizing how climate influences iceberg rafting, erosion, and global ocean circulation reorganization, and testing model predictions about future climate change. Around the north Atlantic, provenance is key to interpreting the iceberg calving record and differentiating Greenland Ice Sheet and other northern hemisphere ice sheet dynamics from one another. Detrital provenance studies provide a metric for source of ice rafted debris and qualitative assessment of glacial erosion. Further, low temperature thermochronology bedrock studies provide a direct means of quantifying cooling histories, and hence, erosion and exhumation. Ultimately, I seek to resolve how, where, and when glacial erosion is taking place using the offshore marine record of east Greenland and what that means for our future climate.