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.
Applications of an in-situ optical surface exposure dating technique on glacial erratic quartzites from the Columbia Basin and Scotland
Abstract: Optically stimulated luminescence (OSL) depth profiling utilizes an OSL-at-depth signal to extrapolate an exposure age from a rock’s surface. The method offers the ability to date a variety of both geologically and archaeologically significant rock, artifact, and building surfaces exposed up to the last 100,000 years using only a few centimeters of the sample subsurface. However, poorly generalized techniques are commonly used for determining bleaching and attenuation variables for the OSL depth profiling equation, most commonly the use of a non in-situ proximal rock sample to derive bleaching and attenuation parameters. These tend to produce inconsistent ages among similarly sourced samples. This proposal tests a modified technique aiming to correct depth profiling method practices. First, a new depth profiling procedure using controlled exposure experiments will be tested on quartzite rocks with the aim of reliably determining bleaching and attenuation variables directly from the rock surface of interest. Upon success of in-lab testing, the procedure will be applied to quartzite rock surfaces of known ages at Lane Mountain Quarry (Valley, Washington) and from studied deglaciation surfaces in northwest Scotland to ensure that accurate variables and dates are derivable. Further, surfaces from erratic quartzites from the Foothills Erratics Train in Alberta, important for the issue of the initial settlement of the Americas, will be dated using the procedure and compared to independent dating sources. To address potential inconsistencies found between ages from using the new procedure, longitudinal core profiles of OSL intensity will be imaged to identify varied zones of luminescence bleaching. Depth profiling calculations can then be altered to accommodate for piecewise attenuation-depth properties and refine procedural accuracy.