Guadalupian–Lopingian

Contents

Guadalupian–Lopingian The Guadalupian–Lopingian interval encompasses the middle to late Permian succession that precedes the Permian–Triassic extinction event and follows the early Permian. It is represented by a suite of chronostratigraphic, biostratigraphic and lithostratigraphic markers recognized across the Pangea supercontinent and in classic sections such as the Capitan Reef of the Guadalupe Mountains National Park, the Meishan section of Zhejiang, and the Karoo Basin of South Africa. Correlation during this interval ties together stratigraphic work from the International Commission on Stratigraphy, regional surveys like the United States Geological Survey, and paleontological studies from institutions including the Smithsonian Institution and the Natural History Museum, London.

Definition and stratigraphic framework

The interval is defined by international stratigraphic boundaries ratified through proposals to the International Commission on Stratigraphy and anchored in Global Boundary Stratotype Sections and Points (GSSPs) such as the type sections in the Guadalupe Mountains and the stratotypes used in South China and Tethys margins. Formal boundaries are tied to first and last appearances of index fossils recognized by workers at institutions like the Geological Society of America and the Palaeontological Association. Key biostratigraphic markers include conodont and ammonoid lineages correlated with studies by the British Geological Survey, the Chinese Academy of Sciences, and teams publishing in journals associated with the American Geophysical Union.

Correlation across regions—linking sequences in the Zechstein Basin, Sakmarian successions, and the Russian Platform—relies on integrating magnetostratigraphy, isotopic dating from laboratories at the Max Planck Society and UC Berkeley, and ammonoid biostratigraphy developed by paleontologists affiliated with the University of Tokyo and the Geological Survey of Canada. Marine sections from the Tethys Ocean margins are correlated with terrestrial records in the Ordos Basin and the Paraná Basin through chemostratigraphy and datable ash beds analyzed at facilities like the Australian National University and the University of Western Australia. This multiproxy approach allows alignment with sequences described by the Russian Academy of Sciences, the Society of Economic Paleontologists and Mineralogists, and regional stratigraphic charts compiled by the International Union of Geological Sciences.

Paleoclimatic reconstructions for this interval draw on oxygen and carbon isotope studies produced by researchers at ETH Zurich, the University of Oxford, and the University of California, Los Angeles, as well as climate model simulations run on supercomputers at the National Center for Atmospheric Research and the European Centre for Medium-Range Weather Forecasts. Evidence points to progressive aridification across interiors of Pangea, sea-level fluctuations recorded in the Permian Basin (North America), and episodic warming associated with large igneous province emplacement such as the Siberian Traps. Vegetation and coal records from the Coal Measures of United Kingdom and the Donets Basin indicate shifts observed by botanists connected to the Royal Botanic Gardens, Kew and palynologists at the University of Göttingen.

Faunal turnovers during this span include declines in fusulinid foraminifera documented by teams at the University of Vienna and trilobite disappearances catalogued in collections at the Field Museum. Therapsid diversification in the Karoo Basin and vertebrate assemblage changes in Siberia and China are central to studies by researchers from the Chinese Academy of Geological Sciences and the Museum für Naturkunde, Berlin. Marine crisis intervals preceding the end-Permian crisis are tied to anoxic events recorded in black shales of the Nanpanjiang Basin and reef collapses at the Guadalupe Mountains, with paleoecological analyses contributed by the Smithsonian Institution and the Natural History Museum, London.

Classic stratotypes and key sections include the Guadalupe Mountains National Park carbonate platforms, the Meishan GSSP beds in Zhejiang, the Karoo Supergroup fluvial and floodplain deposits, and carbonate-evaporite successions of the Zechstein Sea documented by the British Geological Survey and the Geological Survey of the Netherlands. Important outcrops in Australia (e.g., the Sydney Basin), Japan, and the Russian Far East provide complementary records used by regional geological surveys such as the Geological Survey of Japan and the Federal Service for Hydrometeorology and Environmental Monitoring of Russia.

Stratigraphic intervals within the Guadalupian–Lopingian host hydrocarbon reservoirs in the Permian Basin (North America), evaporite sequences exploited by mining firms in the Zechstein Basin, and coal and phosphate deposits worked in the Donets Basin and Brazil; companies and agencies such as the U.S. Energy Information Administration and national geological surveys document these resources. Salt and potash layers serve as seal and source rocks for petroleum systems evaluated by the American Association of Petroleum Geologists, while carbonate reservoirs in the Guadalupe Mountains analogs inform exploration models used by energy companies and research groups at the Bureau of Economic Geology.