METHODOLOGICAL ASSESSMENT OF QUANTITATIVE SMEAR SLIDE TECHNIQUES FOR USE WITH GEOLOGIC SAMPLES

Smear slides of geologic samples have been used primarily for qualitative analysis and the rapid characterization of sediments and soils. When applied to marine or lacustrine sediment cores these qualitative data can help identify environmental or provenance changes over time. Efforts to use smear slides as a quantitative tool have largely come from the medical and biological fields. However, recent efforts by LacCore to develop an online smear slide reference library have extended these data into the realm of semi-quantitative analysis. In this methodological work we seek to expand on the efforts of the LacCore group to add smear slides as a quantitative proxy for paleoclimate, environmental and sedimentologic studies. Our initial work is promising, we have been able to show high repeatability in our counting methods despite inconsistent density and distribution across the smear slides. Using lacustrine sediment core slides from Flathead Lake, Montana we can show statistical changes over depositional time. The work clearly shows the potential of smear slides as a quantitative tool as well as some of our current limitations, including to need to expand the reference library.