EVALUATION OF GEOLOGIC SITES AS NATIONAL NATURAL LANDMARKS: PROCESS AND CASE STUDY

The National Natural Landmarks (NNL) Program, established in 1962 and administered within the National Park Service, identifies and provides recognition to the best examples of geological features and biological communities that comprise the nation’s natural heritage. The NNL Program encourages the preservation of nationally significant areas, enhances the educational and scientific value of sites, and works to strengthen public awareness and appreciation of natural history. Property under any ownership, public or private, may be designated, with owner consent.

Following a decade-long hiatus in new designations, the NNL Program is re-engaged in assessing areas for possible designation. At present, the Program considers a much more complete representation of geology, as contrasted with a focus on scenic landforms and geologic history during the first decades of the Program. Current national significance criteria emphasize the scientific merits of sites considered as possible landmarks. National significance is determined on a regional basis. That is, sites are evaluated to determine whether or not they represent one of the best examples of a type of geological feature within a particular region. Site evaluations are collaborative efforts of geo- and bio-scientists. Recommendations on national significance are subject to a peer review process.

An area in southern California is being simultaneously evaluated for its stratigraphic and paleontologic significance and as an illustrative example of a chaparral- coastal sage scrub community. The proposed landmark includes a thick section of Cretaceous to Quaternary marine and non-marine sedimentary strata. In addition to assessment of the site’s geologic merits, initial studies are revealing close associations between geologic substrate and vegetation. The process and results of this evaluation will be discussed.