QRC members lead and participate in a wide range of disciplinary and interdisciplinary research projects from the study of past earth climates and glaciations to shifts in the geographic distributions and evolution of vegetation and faunal communities, to the evolution and dispersals of the genus Homo and the increasing scales of human modification of earth environments through the Holocene. QRC provides a venue for meeting and collaborating with scholars across Quaternary disciplines. We are also fortunate to be able to provide seed funding and small grants for member research projects. We are especially happy to support grad student and junior scholar research activities, much of which leads to larger, external funding from agencies like the National Science Foundation. Since the program’s launch in 2014, we have funded over 100 research projects.
Using Stable Isotopes of n-Alkanes to Track the Uplift of the Cascade Mountains of Washington, USA
Abstract: The Cascade Mountains are one of the dominant geographic features of the Pacific Northwest. The Cascades produce a large rainshadow effect, which is expressed as a regional dichotomy in climate and vegetation. This dichotomy has been a major controlling factor on the natural history and biogeography of the area, which in turn has strongly influenced local cultures and economies, yet the timing of the Cascade orogeny is poorly constrained. This project endeavors to better constrain the uplift chronology of the Cascade Range of Washington State by determining the onset of its orographic rainshadow, as recorded in the d2H and d13C values of leaf wax n-alkanes in sedimentary rocks both east and west of the range’s crest. These isotopic values are controlled, ultimately, by the local climate: leaf-wax n-alkane d2H has been shown to correlate strongly with local atmospheric d2H across the Cascades (Sisley et al. 2023). These biomarkers are persistent in the rock record and can be used to elucidate past climate conditions and, by extension, the presence or absence of the Cascade rainshadow through time. Our results will provide important context for researchers studying local tectonic and evolutionary history.