THE U.S. NATIONAL PARK SERVICE STRATOTYPE INVENTORY: A NATIONAL REPORT SERIES AND GEOHERITAGE MAP

Beginning in the summer of 2020, the National Park Service (NPS) began systematically documenting the occurrence of stratotypes within, partially within, or near its administrative boundaries. Stratotypes consist of type (sections/localities/areas) or reference (sections/localities/areas) exposures where formally recognized geologic units were first described, measured, and named. Thus, a vast majority of the stratigraphic nomenclature alludes to geologic or geographic features that are also stratotype namesakes. As an important component of our nation’s geologic heritage (“geoheritage”), stratotypes are inherently scientific in nature but also possess significant historic, educational, cultural, and aesthetic values that make them a valuable part of a geologic resource inventory. The geoheritage significance of stratotypes is analogous to libraries and museums, in that they are geologic landmarks of Earth history and record the prodigious forces and evolving life forms that shape our understanding of the planet.

The NPS stratotype inventory has published 32 inventory and monitoring network (I&M) reports that are free and publicly available online. These reports (1) document NPS stratotypes compiled from published reports or maps; (2) provide precise geographic locations of stratotype exposures; (3) include park-specific stratotype descriptions, photographs, figures, tables, and maps; and (4) contain recommendations that address potential land management issues. Stratotypes across the 32 I&M networks have been combined to form a national map that currently includes more than 700 stratotype designations across the National Park System, including parks of Alaska, Hawaii, Guam, American Samoa, and the U.S. Virgin Islands. Information about NPS stratotypes can be sorted or analyzed geographically by park, I&M network, or state, in addition to geologic age. A majority of the top ten NPS parks with the greatest number of stratotypes contain geologically diverse landscapes that are considered some of the most popular in the country. Given their geoheritage significance, the NPS hopes to raise awareness of stratotypes by educating staff and the public so that they may better understand, recognize, monitor, and protect these important park resources.