USE OF SCALABLE THIN SECTION IMAGING IN LABORATORY ACTIVITIES

Basic analysis and classification of rock thin sections commonly involves the use of a petrographic microscope. Analyses like mineral identification and determination of grain size distribution are important hands-on teaching activities in face-to-face classes, but access to microscopes is generally not possible for students in an online laboratory setting. Instead, use of newer imaging technology can allow students to view and work with thin sections regardless of course modality and without a microscope. For this project, six rock samples were collected and sectioned from a suite of Paleozoic rocks near Molas Lake, Colorado. The structure of this suite is commonly mapped by students during summer field camp exercises, so collecting and sectioning these rocks was useful for creating additional ways to interrogate these samples while not in the field. High-resolution scans of these rock thin sections were uploaded to a website which hosts user-uploaded zoomable images. After images are uploaded, students were able to remotely investigate these thin sections using a computer or mobile device. An example laboratory activity was written to make use of these high resolution scalable images. This activity involves having students produce qualitative observations such as angularity and uniformity, and simple statistical analyses to determine phi sorting value, extent of sorting, and maturity of the grains present in the thin sections. Here we present the method for uploading and referencing these scalable images, the example activity that was created to make use of these images, and several additional possible laboratory activity ideas that could also make use of this image technology.