My primary research interests lie in the intersection between geomorphology, tectonics/structural geology, sedimentology, and paleoanthropology. I perform basin analysis of the East African Rift System using cosmogenic radionuclides and detrital thermochronology. I also have a secondary volcanology research project at the Pinacate volcanic field in Sonora, Mexico, and have previously completed research at the Brussels Hill (Wis.) meteorite impact* structure during undergrad.
*The more research that is done at the site, the more confusing it becomes! Brussels Hill lacks certain diagnostic characteristics and can best be described as a cryptovolcanic structure.
Hominin Sites and Paleolakes Drilling Project (HSPDP)
The East African Rift Valley serves as host to fossil assemblages fundamental to our understanding of hominin evolution. From the numerous specimens of Australopithecus afarensis, like “Lucy,” found in Afar, Ethiopia, to specimens of Homo ergaster, like “Turkana Boy/Nariokotome Boy,” found near Lake Turkana in Kenya, the Rift Valley provides a record of nearly six million years of hominin evolution. One long-enduring pursuit of scientific and public interest is understanding the relationship between Earth system history and human evolution.
The Hominin Sites and Paleolakes Drilling Project (HSPDP) collected drill cores from lacustrine depocenters near key Plio-Pleistocene paleoanthropological sites in Ethiopia and Kenya to establish a highly resolved paleoenvironmental record which surface outcrops may otherwise be unable to preserve. I use core sections collected from the Chew Bahir, Ethiopia (620 ka–present), Northern Awash, Ethiopia (3.3–2.9 Ma) and West Turkana, Kenya (1.9–1.4 Ma) drill sites to reconstruct paleoerosion rates, thermal history, and sediment provenance.
I reconstructed millennial-scale (10^3-4 yrs) erosion rates using cosmogenic radionuclides (CRNs), and (U-Th)/He and U/Pb laser ablation double dating analyses on detrital zircons yields a provenance record in addition to thermal history. I am interesting in assessing how the landscapes have changed over time and responded to variable climatic and tectonic forcings.
Pinacate Volcanic Field (Sonora, Mexico)
The Pinacate volcanic field (PVF), located in the El Pinacate y Gran Desierto de Altar Biosphere Reserve of Sonora, Mexico, comprises a 1,500 km2 area of Pleistocene lava flows and contains nearly 400 cinder cones and eight maars. I reconstructed the third youngest eruption in the PVF. The eruption products include prominent lava flows and two tephra units that extend >10 km from the probable vent—Tecolote volcano (latitude 31.877, longitude -113.362). The sequence represents a wide range of eruption styles, including significant explosive activity. In terms of dispersal area and reconstructed column heights, this eruption is among the most explosive documented eruptions from a basaltic monogenetic scoria cone. Reconstructing the temporal evolution of the eruption sequence, their individual and combined volumes, and associated eruption rates provides important data for better understanding: (1) transitions between (or simultaneous) eruption styles in basaltic and monogenetic volcanism, (2) the range in explosive eruption scales at mafic volcanoes, including monogenetic fields, and (3) trends in eruptive activity in the Pinacate volcanic field.
Brussels Hill (Wisconsin) meteorite impact structure (?)
Brussels Hill is an anomalous area of intensely fractured, faulted, and folded bedrock in a region of otherwise undeformed lower Silurian dolostone in Door County, WI. The area of disturbed rock coincides with a distinctive, nearly circular, flat-topped topographic high ~2 km in diameter, standing 40 m above the surrounding landscape and ringed by rugged tree-covered slopes. Bedding orientations vary dramatically over distances of meters. Both mono- and polymict breccias occur, commonly as wedges that seem to have been intruded between bedding planes. Silurian dolostone is the only bedrock normally exposed in this area, but fault-bounded blocks of sandstone occur at Brussels Hill. This atypical rock likely comes from Cambrian strata that lie up to 300-400 meters below the surface.I conducted a focused microscopic study of the dolostones, breccias and sandstones found at Brussels Hill to look for shock-metamorphic features that could be diagnostic of an impact origin. By examining thin sections made from samples collected in the field and running an XRD analysis of the breccias, my goals were to (1) determine the stratigraphic origin of the in situ sandstones, (2) examine deformational characteristics of the breccias on the micro-level, (3) classify and describe any shock-metamorphic features found in the samples, and (4) determine if an impact origin is the best fit for explaining the disturbance at Brussels Hill.