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

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

doi:10.36967/2294339

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 four stratotypes designated within two park units of the Gulf Coast Inventory & Monitoring Network (GULN): Big Thicket National Preserve (BITH) contains one type locality, and Vicksburg National Military Park (VICK) contains one type section, one type locality, and one type area. Table 1 provides information regarding the four stratotypes currently identified within the GULN. There are currently no designated stratotypes within Gulf Islands National Seashore (GUIS), Jean Lafitte National Historical Park and Preserve (JELA), Natchez Trace Parkway (NATR), Padre Island National Seashore (PAIS), Palo Alto Battlefield National Historical Park (PAAL), and San Antonio Missions National Historical Park (SAAN). The inventory of geologic stratotypes across the NPS is an important effort in documenting these locations so that NPS staff may 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 GULN. 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: Gulf Coast Inventory & Monitoring Network

Series