95 research outputs found
Formal ratification of the GSSP for the base of the Calabrian Stage (second stage of the Pleistocene Series, Quaternary System)
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Middle Pleistocene glacier behaviour in the Mediterranean: Sedimentological evidence from the Pindus Mountains, Greece
IUGS ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma
The International Union for Geological Sciences (IUGS) on 29 June, 2009 ratified a proposal by the International Commission on Stratigraphy that the base of the Quaternary System/Period and the base of the Pleistocene Series/Epoch be lowered to that of the Gelasian Stage/Age. The Gelasian is transferred accordingly from the Pliocene to the Pleistocene. The Global Stratotype Section and Point at Monte San Nicola, Sicily, Italy, with an estimated age of 2.58 Ma, defines the lower boundary of the Gelasian, Pleistocene and Quaternary. Details of the ratification are given, and implications discussed.LâUnion Internationale des Sciences gĂ©ologiques (IUGS) a ratifiĂ© le 29 Juin 2009 la proposition faite par la Commission Internationale de Stratigraphie (ICS) de descendre la base du Quaternaire en tant que SystĂšme/PĂ©riode et celle du PlĂ©istocĂšne en tant que SĂ©rie/Epoque pour la faire coĂŻncider avec celle de lâEtage/Age GĂ©lasien. En consĂ©quence, le GĂ©lasien est transfĂ©rĂ© du PliocĂšne dans le PlĂ©istocĂšne. La coupe et le point de rĂ©fĂ©rence du stratotype global (GSSP) de Monte San Nicola, en Sicile, Italie, avec un Ăąge estimĂ© Ă 2,58 Ma, dĂ©finit la limite infĂ©rieure du GĂ©lasien, du PlĂ©istocĂšne et du Quaternaire. Les dĂ©tails de la ratification sont donnĂ©s et les implications discutĂ©es
Rediscovery and stratigraphic calibration of the classic Nihewan Fauna, Hebei Province, China
The classic Nihewan Fauna, as the representative of early Pleistocene Asian Land Mammal Age Nihewanian, has long been cited for bio- and chronostratigraphic correlation. However, its precise provenance and stratigraphic horizon have remained unsolved till now. The authors successfully extracted the vital information by rediscovering 30 of the original excavation localities. The fossils were catalogued with their provenance through an extensive field survey and comprehensive inspection of the Tianjin Natural History Museum collection. A review of the original description of these fossil localities, using satellite images, and subsequent lithological examination of the Xiashagou strata in the field verified the new findings. The survey produced the first stratigraphic profile calibrated with fossil horizons of the Nihewan formation in the Xiashagou section. Correlated with the published magnetostratigraphical profile of the section, an age of similar to 2.4-1.8 Ma is estimated for the classic Nihewan Fauna.Peer reviewe
The Anthropocene is best understood as an ongoing, intensifying, diachronous event
Current debate on the status and character of the Anthropocene is focussed on whether this interval of geological time should be designated as a formal unit of epoch/series rank in the International Chronostratigraphic Chart/Geological Time Scale, or whether it is more appropriate for it to be considered as an informal âeventâ comparable in significance with other major transformative events in deeper geological time. The case for formalizing the Anthropocene as a chronostratigraphical unit with a base at approximately 1950âCE is being developed by the Anthropocene Working Group of the Subcommission on Quaternary Stratigraphy. Here we outline the alternative position and explain why the time-transgressive nature of human impact on global environmental systems that is reflected in the recent stratigraphical record means that the Anthropocene is better seen not as a series/epoch with a fixed lower boundary, but rather as an unfolding, transforming and intensifying geological event
Land-ocean changes on orbital and millennial time scales and the penultimate glaciation
Past glacials can be thought of as natural experiments in which variations in boundary conditions influenced the character of climate change. However, beyond the last glacial, an integrated view of orbital- and millennial-scale changes and their relation to the record of glaciation has been lacking. Here, we present a detailed record of variations in the land-ocean system from the Portuguese margin during the penultimate glacial and place it within the framework of ice-volume changes, with particular reference to European ice-sheet dynamics. The interaction of orbital- and millennial-scale variability divides the glacial into an early part with warmer and wetter overall conditions and prominent climate oscillations, a transitional mid-part, and a late part with more subdued changes as the system entered a maximum glacial state. The most extreme event occurred in the mid-part and was associated with melting of the extensive European ice sheet and maximum discharge from the Fleuve Manche river. This led to disruption of the meridional overturning circulation, but not a major activation of the bipolar seesaw. In addition to stadial duration, magnitude of freshwater forcing, and background climate, the evidence also points to the influence of the location of freshwater discharges on the extent of interhemispheric heat transport
A practical solution: the Anthropocene is a geological event, not a formal epoch
The Anthropocene has yet to be defined in a way that is functional both to the international geological community and to the broader fields of environmental and social sciences. Formally defining the Anthropocene as a chronostratigraphical series and geochronological epoch with a precise global start date would drastically reduce the Anthropoceneâs utility across disciplines. Instead, we propose the Anthropocene be defined as a geological event, thereby facilitating a robust geological definition linked with a scholarly framework more useful to and congruent with the many disciplines engaging with human-environment interactions. Unlike formal epochal definitions, geological events can recognize the spatial and temporal heterogeneity and diverse social and environmental processes that interact to produce anthropogenic global environmental changes. Consequently, an Anthropocene Event would incorporate a far broader range of transformative human cultural practices and would be more readily applicable across academic fields than an Anthropocene Epoch, while still enabling a robust stratigraphic characterization
The Anthropocene is best understood as an ongoing, intensifying, diachronous event
Current debate on the status and character of the Anthropocene is focussed on whether this interval of geological time should be designated as a formal unit of epoch/series rank in the International Chronostratigraphic Chart/Geological Time Scale, or whether it is more appropriate for it to be considered as an informal âeventâ comparable in significance with other major transformative events in deeper geological time. The case for formalizing the Anthropocene as a chronostratigraphical unit with a base at approximately 1950 CE is being developed by the Anthropocene Working Group of the Subcommission on Quaternary Stratigraphy. Here we outline the alternative position and explain why the timeâtransgressive nature of human impact on global environmental systems that is reflected in the recent stratigraphical record means that the Anthropocene is better seen not as a series/epoch with a fixed lower boundary, but rather as an unfolding, transforming and intensifying geological event
The penultimate deglaciation:protocol for PMIP4 transient numerical simulations between 140 and 127 ka, version 1.0
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