Grant: Research Tools and Instruments

We are requesting funds to replace our obsolete and failing Beckman-Coulter (B-C) LS 13 320 laser diffraction instrument with the newly developed Beckman Coulter LS 13 320XR, which offers significant improvements in ease of use, a broader particle size analysis (PSA) range, and faster sampling times. Particle size distribution is a fundamental parameter for assessing the types and history of physical sedimentary processes (e.g. provenance, transport, deposition) in marine, lake, or other sedimentary environments. Laser diffraction PSA instruments offer a fast, reliable, and precise method for obtaining detailed and highly resolved particle size distributions from sediments. Since its acquisition in 2008, the existing B-C LS 13 320 laser diffraction instrument in the Patterson Lab has been indispensable for analyzing a wide variety of lake and marine sedimentary records. It has been used to measure climate change-related variations in catchment erosion, influenced by changes in precipitation, spring freshet, and reworking of bottom sediments by major storms affecting wave base depth. It has also been used to study human-induced land use changes and climate variability-driven shifts in flow regimes within karst cave environments. Precise provenance determination has been enabled by the application of newly developed End-Member Modeling Analysis (EMMA), which helps decompose and unmix observed particle size signatures to identify specific formation and transport regimes. The instrument's capacity to produce abundant, high-quality PSA data at a low cost has made it indispensable for providing critical environmental proxy data. This, in turn, has supported the research and training of numerous Highly Qualified Personnel (HQP) each year, ranging from B.Sc. students to post-doctoral researchers. However, the current instrument is now 16 years old, is increasingly prone to extended shutdowns for repairs and is at the end of its expected operational lifespan. Multiple repair shutdowns totaling five months this year have disrupted the research of many undergraduate and graduate students, and a postdoctoral researcher, leading to significant delays in data collection, publications, thesis work, and the completion of undergraduate projects. These issues have largely stemmed from Beckman-Coulter's difficulty in sourcing increasingly scarce parts. Beckman-Coulter has informed us that the instrument is obsolete and will no longer be serviced after August 2026. Without a replacement, our ability to conduct PSA will be halted, affecting both ongoing research and HQP training.