The completion of the global time scale by the International Commission on Stratigraphy (ICS) is of paramount and pressing importance. Until there are definitions for all stages, the time scale cannot be adequately calibrated with radiometric age dates. Without a reliable and calibrated time scale, efforts to study a host of paleoclimate and paleobiologic and other issues that involve the deep-time geologic record will be limited. The International Commission of Stratigraphy has set 2012 as the deadline for all stages to be defined - and time is running short to get the job done. The requested funds will support a field and lab study of two sections, (Trapper Creek, Cassia Mountains, southern Idaho, and Rockland, Pequop Mountains, northern Nevada), which were proposed recently as the most promising sections to establish a GSSP to define the base of the Kungurian Stage in the Global Chronostratigraphic Scale. Trapper Creek and Rockland are the only easily accessible sections known at the moment where Uralian, N. American and Tethyan conodont faunas co-occur and thus provide global correlation and the only sections where considerable isotopic results are already available. Rockland section is already measured, but PIs will re-measure the transitional beds in both sections at centimeter scale. Additional isotope studies will be performed at geochronology and geochemistry labs in Boise State University. The team of world conodont and fusulinid experts is committed to complete this project as a high priority.
The purpose of this project was to establish global section stratotype and point (GSSP) for the base of the Global Kungurian Stage (279.3-272.3 Ma) in the International Geologic Time Scale. The Stage historic type area is in the Urals, Russia, where Mechetlino section studied and proposed as a potential GSSP. But the rocks and fossils there is not entirely sufficient to distinguish the boundary global wide. Two sections Trapper Creek, Cassia Mountains, southern Idaho and Rockland, Pequop Mountains, northern Nevada in addition to the section in the type region in Russia as potential candidates for the GSSP. The rocks and environments within the boundary beds in Trapper Creek, Cassia Mountains, southern Idaho are not appropriate and this section was considered unacceptable. The section in Pequop Mountains, northern Nevada was studied in great details, including sedimentology, conodont and fusulinid biostratigraphy, and geochemistry. The succession of conodonts that proposed being the defining group of the fossils, in Pequop Mountains turns to be the same as in Mechetlino section in the Urals. Abundant fusulinids were recovered within the transitional beds including first discovery Tethyan fusulinid Pamirina that provides the direct link with the sections in China, Japan and elsewhere within the tropics of the eastern hemisphere. In addition Carbon, Oxygen and strontium isotopes were studied from Pequop section that increases the usability of the section for the global correlation. The proposal to establish Pequop section as a GSSP of the Kungurian Stage has been submitted to the Permian Subcommission for evaluation and voting. In the first vote (July 2013) the voting was splitted 50/50 and Permian Subcommission suggest to perform additional study in both Pequop and Mechetlino sections and submit second proposal by the end of this year. The final vote and decision will be made in 2014.
