Chattian

Chattian
Name	Chattian
Color	#F4A460
Unit	Age
Era	Cenozoic
Period	Paleogene
Epoch	Oligocene
Time start	28.1
Time end	23.03
Chronology	International Commission on Stratigraphy

Chattian The Chattian is a late Oligocene chronostratigraphic age and corresponding stage widely used in Neogene and Paleogene stratigraphy. It is defined by international bodies such as the International Commission on Stratigraphy and is correlated globally with regional frameworks used in marine and continental successions across continents including Europe, North America, Asia, and Africa. The Chattian records significant biotic turnovers and tectono-sedimentary reorganizations that link to events elsewhere such as those preserved in the Eocene–Oligocene transition and later in the Miocene.

Definition and Chronostratigraphy

The formal definition of the Chattian as an age in the International Chronostratigraphic Chart is bounded by Global Boundary Stratotype Section and Points tied to biostratigraphic and magnetostratigraphic markers recognized by institutions like the International Commission on Stratigraphy and research published in journals associated with societies such as the Geological Society of America and the European Geosciences Union. Its lower boundary follows the Bartonian–Chattian succession established through comparisons with sections in England, Germany, and Italy, and the upper boundary is calibrated against isotopic frameworks used by laboratories at universities such as University of Cambridge, Bonn University, and University of Vienna. Chronostratigraphic correlation employs techniques developed at facilities including the US Geological Survey and the British Geological Survey and leverages magnetostratigraphy tied to polarity chrons used in the Geomagnetic Polarity Time Scale.

Nomenclature and Type Locality

The name derives from the historic region and locality of Chatt in southern England where pioneering stratigraphers from institutions such as the British Museum and figures associated with the Geological Society of London described lithologies and faunas. The type sections and stratotypes referenced in classic monographs by researchers connected to the University of Oxford and the Natural History Museum, London were later refined through international working groups convened by the International Commission on Stratigraphy and regional committees such as the Commission de la Carte Géologique du Monde. Designation of neostratotypes and auxiliary sections has involved cooperative studies across institutes including the French National Centre for Scientific Research and the Max Planck Society.

Global Stratigraphic Distribution and Correlations

Chattian deposits are documented in marine basins and continental basins recorded in formations studied by teams from the Russian Academy of Sciences, Smithsonian Institution, and the University of California, Berkeley. Correlations link Chattian marine successions in the North Sea Basin, Mediterranean Basin, and Paratethys to continental sequences in the Great Plains, Siwalik Hills, and the Ebro Basin using biostratigraphy, magnetostratigraphy, and chemostratigraphy developed at centers including ETH Zurich and Scripps Institution of Oceanography. Stratigraphic charts produced by national surveys such as the Geological Survey of India and the Geological Survey of Canada incorporate Chattian subdivisions to align regional stage names like the Duchesnean and Arikareean for mammal zones and marine stages in the Tethys realm.

Paleoenvironments and Climate

Paleoenvironmental reconstructions for Chattian intervals draw on stable isotope studies from cores recovered by programs like the Deep Sea Drilling Project and the Ocean Drilling Program and on palynological and sedimentological investigations from teams at the University of Tokyo and the Australian National University. Climate signals recorded during the Chattian include trends toward cooling and Antarctic glaciation phases that relate to work by researchers affiliated with the British Antarctic Survey and the National Oceanic and Atmospheric Administration, paralleling shifts seen in oxygen isotope records studied at the Woods Hole Oceanographic Institution. Sedimentary facies range from shallow carbonate platforms in areas studied by the Mediterranean Geological Survey to siliciclastic shelves documented by the Florida Geological Survey.

Biostratigraphy and Fossil Assemblages

Fossil assemblages defining Chattian biostratigraphy include benthic and planktonic foraminifera, nannofossils, and mollusks used by paleontologists from institutions like the Natural History Museum, London, Smithsonian Institution, and the Museo Nacional de Ciencias Naturales. Vertebrate faunas from continental Chattian deposits have been described by researchers at the American Museum of Natural History, Field Museum, and the Institut Català de Paleontologia and include mammals referenced in North American land-mammal ages such as the Arikareean and European land mammal zones coordinated through the International Stratigraphic Guide. Microfossil zonations established by labs at the Bremen University and the University of Barcelona are routinely used to correlate marine sections to regional stage schemes like the Sarmatian and Messinian in broader Mediterranean stratigraphy.

Tectonics, Sea-level Changes, and Sedimentation

Tectonic activity affecting Chattian sedimentation is recorded in foreland basins and rift systems documented by researchers at the University of Bonn, University of Oslo, and the University of Granada, with links to Alpine orogenesis studies involving institutions like the Institut de Physique du Globe de Paris. Eustatic sea-level fluctuations during the Chattian are inferred from sequence stratigraphy developed by scholars associated with the University of Leeds and Texas A&M University and are correlated to global sea-level compilations maintained by groups at the US Geological Survey and the International Ocean Discovery Program. Sediment provenance studies tying detrital records to uplift in source regions such as the Alps, Pyrenees, and Himalaya have been advanced through collaborations involving the GFZ German Research Centre for Geosciences and the Centre National de la Recherche Scientifique.

Significance and Usage in Geologic Studies

The Chattian is widely used as a reference interval in multidisciplinary research spanning paleoclimatology, paleobiology, and basin analysis by organizations like the European Geosciences Union, American Geophysical Union, and national geological surveys. Its boundaries are applied in calibration of molecular clocks in studies from universities including Harvard University and Stanford University and in paleoenvironmental syntheses informing models developed at centers like the Potsdam Institute for Climate Impact Research and the National Center for Atmospheric Research. The stage remains central to correlations between regional chronostratigraphic schemes and the international timescale maintained by the International Commission on Stratigraphy.

Category:Oligocene