Core description diagrams are the primary record of the cylindrical rock samples that result from the scientific drilling process. Typically, these diagrams are drawn by hand in field books and then drafted up in a graphics program for publication. Very rarely are the actual data encoded in the diagrams, e.g., depth in core, grain size, and lithology, captured in a format that can be manipulated and analyzed. This thesis introduces the Paleontological Stratigraphic Interval Construction and Analysis Tool (PSICAT), an interactive, cross-platform environment for creating, viewing, and editing core description diagrams, and discusses the design and implementation of its extensible software architecture and data model which allows it to seamlessly capture and visualize core description data. PSICAT was used to log nearly 1300 meters of sediment core drilled during ANtarctic DRILLing (ANDRILL) project's McMurdo Ice Shelf expedition.