National Park Service geologic type section inventory: Southeast Coast Inventory & Monitoring Network

Henderson, Tim; Santucci, Vincent; Connors, Tim; Tweet, Justin

doi:10.36967/2293928

Type sections are one of several kinds of stratotype. A stratotype is the standard (original or subsequently designated), accessible, and specific sequence of rock for a named geologic unit that forms the basis for the definition, recognition, and comparison of that unit elsewhere. Geologists designate stratotypes for rock exposures that are illustrative and representative of the map unit being defined. Stratotypes ideally should remain accessible for examination and study by others. In this sense, geologic stratotypes are similar in concept to biological type specimens, however, they remain in situ as rock exposures rather than curated in a repository. Therefore, managing stratotypes requires inventory and monitoring like other geologic heritage resources in parks. In addition to type sections, stratotypes also include type localities, type areas, reference sections, and lithodemes, all of which are defined in this report. The goal of this project is to consolidate information pertaining to stratotypes that occur within NPS-administered areas, in order that this information is available throughout the NPS to inform park managers and to promote the preservation and protection of these important geologic heritage resources. This effort identified two stratotypes designated within one park unit of the Southeast Coast Inventory & Monitoring Network (SECN): Chattahoochee River National Recreation Area (CHAT) contains two type localities representing the Neoproterozoic–Ordovician(?) Powers Ferry Member of the Stonewall Gneiss and the Cambrian(?) Chattahoochee Palisades Quartzite. Table 1 provides information regarding the two stratotypes currently identified within the SECN. There are currently no designated stratotypes within Cape Hatteras National Seashore (CAHA), Cape Lookout National Seashore (CALO), Canaveral National Seashore (CANA), Castillo De San Marcos National Monument (CASA), Congaree National Park (CONG), Cumberland Island National Seashore (CUIS), Fort Caroline National Memorial (FOCA), Fort Frederica National Monument (FOFR), Fort Matanzas National Monument (FOMA), Fort Pulaski National Monument (FOPU), Fort Sumter and Fort Moultrie National Historical Park (FOSU), Horseshoe Bend National Military Park (HOBE), Kennesaw Mountain National Battlefield Park (KEMO), Moores Creek National Battlefield (MOCR), Ocmulgee Mounds National Historical Park (OCMU), and Timucuan Ecological and Historic Preserve (TIMU). However, HOBE contains important rock exposures that could be considered for formal stratotype designation, as discussed in “Recommendations”. The inventory of geologic stratotypes across the NPS is an important effort in documenting these locations in order that NPS staff recognize and protect these areas for future studies. The focus adopted for completing the baseline inventories throughout the NPS has centered on the 32 inventory and monitoring (I&M) networks established during the late 1990s. Adopting a network-based approach to inventories worked well when the NPS undertook paleontological resource inventories for the 32 I&M networks and was therefore adopted for the stratotype inventory. The Greater Yellowstone I&M Network (GRYN) was the pilot network for initiating this project (Henderson et al. 2020). Methodologies and reporting strategies adopted for the GRYN have been used in the development of this report for the SECN. This report includes a recommendation section that addresses outstanding issues and future steps regarding park unit stratotypes. These recommendations will hopefully guide decision-making and help ensure that these geoheritage resources are properly protected and that proposed park activities or development will not adversely impact the stability and condition of these geologic exposures.

National Park Service geologic type section inventory: Southeast Coast Inventory & Monitoring Network

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