AN ABSTRACT OF THE THESIS OF

Seafloor lithologic maps have been widely used to identify conservation sites. In this study, a lithologic interpretation of Oregon’s territorial seafloor was created as an interim product in response to the need for a comprehensive lithologic map that will be used in the identification, evaluation and design of marine reserves in Oregon. While future multibeam mapping of the Oregon Territorial Sea will likely replace this product in the next few years, the ground truth data from which the map is constructed will continue in use in future efforts. This mapping project utilized a classical geologic approach aided by GIS technology in which all relevant thematic geologic layers were applied to interpret patterns of seafloor lithology. The discovery of approximately 9,600 NOS bottom samples from the National Ocean Service (NOS) historic hydrographic smooth sheet archives has tremendously improved upon the original sample dataset (305 bottom samples) used in previous characterization of Oregon’s territorial seabed. Supplementing the NOS bottom samples, other existing datasets including historic kelp distribution (used as proxy for rock), a triangulated irregular network (TIN) surface model derived from bathymetric soundings