THE GUADALUPIAN SERIES: IDEAS TO HIGHLIGHT THE GSSP AND GEOLOGIC CONTEXT OF THE WORLD STANDARD MIDDLE PERMIAN SERIES IN GUADALUPE MOUNTAINS NATIONAL PARK

The International Union of Geological Sciences, Commission on Stratigraphy ratified the Guadalupian Series to be the world reference standard for the Middle Permian—a major unit of the geologic time scale. It is one of the few chronostratigraphic references within U.S. borders. A factor in the Guadalupian's successful candidacy was the U.S. Park Service agreement to set aside the reference strata as a geologic preserve with dedicated international scientific access. That access includes sampling by international specialists, following a vetting process, at the defining boundaries, called GSSPs (Global Stratotype Section and Points). The basal Guadalupian GSSP occurs 42.7m above the base of the Cutoff Formation in Stratotype Canyon, where the fossil conodont Mesogondolella idahoensis evolved into Jinogondolella nankingensis. Middle Permian time is recognized world-wide by the presence of Jinogondolella, which evolved in west Texas.

GSSPs in other countries are treated in a spectrum of ways, from a lack of any official recognition to extravagant museum construction. Guadalupe Mountains National Park and adjacent federal lands, including Carlsbad Caverns National Park and Lincoln National Forest, comprise a geologic rarity: rocks that formed in a continuum of ancient environments from the shoreline into deep basin waters--all of the same age--without complication by faulting, excessive burial (and heating), or other geologic events. This and the robust evolutionary definition were the other strengths of the Guadalupian's successful candidacy. This unique paleogeographic setting is far too large to enclose at any one site, but could be the focus of an integrated progression of interpretative trails through the region that teach stratigraphic geology by the experience of hiking through distinctive paleoenvironments, much like the McKittrick Canyon Geology Trail already does with the Capitan Reef and related fore- and back-reef environments. Benchmarks mounted into the GSSPs at the base of the Guadalupian Series (basal Roadian Stage) and the intermediate stage boundaries (Wordian and Capitanian stages) could serve as ultimate destinations for interested hikers, who could then justifiably claim to have been to three foci of world-wide scientific research in Guadalupe Mountains National Park.