Marine Interglacial Deposits in the Cuxhaven Area, NW Germany: A Comparison of Holsteinian, Eemian and Holocene Foraminiferal Faunas

Es werden interglaziale Foraminiferen-Faunen aus dem Holstein, dem Eem und dem Holozän für den Raum Cuxhaven beschrieben. Bei den bearbeiteten Proben handelt es sich um Material aus Kernbohrungen. Die Vergesellschaftungen werden mit vorliegenden Publikationen entsprechender Vorkommen aus Nordwestdeutschland und Dänemark verglichen. Jede der 3 untersuchten Faunen hat typische Züge. Von besonderem Interesse ist die Tatsache, daß die Anwesenheit und/oder Häufigkeit bestimmter Taxa für das Gebiet der südlichen Nordsee stratigraphische Korrelationen ermöglicht.researc

Marine High Resolution Records of the Last Interglacial in Northwest Europe: A Review

The last Interglacial in Northwest Europe (the Eemian) corresponds to stable oxygen isotope substage 5e (ca. 130-115 ka BP). Foraminiferal studies from northern Denmark suggest that déglaciation after the Saalian Glacial (stage 6) occurred gradually over a period of about 3000 years. Data from borings on the island of Anholt show that the déglaciation was interrupted by a climatic fluctuation equivalent to the Allerod-Younger Dryas-Preboreal cycle at the Weichselian-Holocene transition (stage 2/1). The environmental interpretation of the foraminiferal data when compared to that of the deep sea stable isotope stratigraphy indicates that this climatic oscillation may have been a global event. An initial sea level rise of about 50-60 m occurred at the Saalian-Eemian transition (stage 6/5e at about 130 ka BP) and the assemblages indicate that the sea level rose further in the middle part of the Eemian prior to a gradual drop in sea level in the Late Eemian. The Eemian/ Weichselian boundary (stage 5e/5d at about 115 ka BP) was characterized by a major sea level drop and a temperature decrease from lusitanian to boreal conditions. The final change to fully glacial conditions did not occur until the Early-Middle Weichselian transition (stage 5/4 at about 74 ka BP).Le dernier interglaciaire dans le nord-ouest de l'Europe (l'Éémien) correspond au stade isotopique 5e (d'environ 130-115 ka BP). Les études sur les foramini-fères effectuées dans le nord du Danemark indiquent que la déglaciation s'est réalisée graduellement sur environ 3000 ans après le Saalien (stade 6). Les données obtenues des forages dans l'île de Anholt démontrent que la déglaciation a été interrompue par une fluctuation climatique correspondant au cycle Allerod-Dryas inférieur-Préboréal à la transition Wechselien-Holocène. L'interprétation environnementale des données sur les foraminifères comparée à la stratigraphie isotopique marine démontre que cette oscillation climatique était à l'échelle mondiale. La hausse initiale du niveau marin de 50 à 60 m a eu lieu à la transition entre le Saalien et l'Éémien (stade 6/5e vers 130 ka BP) et les assemblages montrent que la hausse s'est poursuivie à l'Éémien moyen avant une baisse graduelle à l'Éémien supérieur. Aux confins de l'Éémien-Weichselien (stade 5e/5d vers 115 ka BP), il y eut une importante baisse du niveau marin accompagnée d'une diminution des températures, passant ainsi de conditions climatiques lusitaniennes à des conditions boréales. L'établissement des conditions glaciaires ne s'est fait qu'à la transition entre le Weichselien inférieur et le Weichselien moyen (stade 5/4 vers 74 ka BP).Die letzte Interglazialzeit in Europa (Eem) ent-spricht dem stabilen Sauerstoff-lsotopen-Unterstadium 5e (vor rund 130,000-115,000 Jahren). Foraminiferen-Untersuchungen von Nord-Danemark deuten darauf hin, dass das Abschmelzen nach der Saale-Eiszeit (Stadium 6) allmàhlich ùber eine Période von ungefâhr 3000 Jahren erfolgte. Bohrdaten von der Insel Anholt zeigen, dass das Abschmelzen durch Klimaschwankungen àhnlich denen des Allerôd-Jungere Dryas-Prâboreal Zykluses zur Zeit des Weichsel-Holozân Ùberganges (Stadium 2/1) unter-brochen wurde. Korreliert man Foramini-feren-Befunde von Bohrungen auf Anholt mit isotopenstratigraphischen Daten aus der Tiefsee, ergibt sich, dass dièse Klimaschwankungen vermutlich von globalem Ausmass waren. Wàhrend des Saale-Eem Ùberganges (Stadium 6/5e vor rund 130,000 J.) stieg der Meeresspiegel zunàchst um 50-60 m. In der mittleren Eem-Zeit hob er sich môglicherweise erneut, bevor er im spâ-ten Eem allmàhlich zurùckging. Der Ùber-gang vom Eem zur Weichsel (Unterstadium 5e/5d vor rund 115,000 J.) war gekenn-zeichnet durch eine starke Senkung des Meeresspiegels bei einem gleichzeitigen Rùckgang der Temperatur von lusitanischen zu borealen Verhâltnissen. Der endgùltige Wechsel zu vollstândig eiszeitlichen Bedingungen erfolgte erst am Ùbergang von der Frùhen zur Mittleren Weichselôiszeit (Stadium 5/4 vor rund 74,000 J.)

Undergrunden ved Skagen

Intet resum

Ergebnisse der Foraminiferenanalyse zur Quartärstratigraphie in Skandinavien

In Skandinavien sind zahlreiche quartärstratigraphische Untersuchungen mit Hilfe fossiler Foraminiferen durchgeführt worden. Im folgenden wird eine Übersicht über die foraminiferenstratigraphischen Untersuchungen und deren Resultate in Dänemark, Norwegen und Schweden gegeben.researc

Late Quaternary foraminiferal record in Murchisonfjorden, Nordaustlandet, Svalbard

Peer reviewe

Formal ratification of subseries for the Pleistocene Series of the Quaternary System

The Pleistocene Series/Epoch of the Quaternary System/Period has been divided unofficially into three subseries/subepochs since at least the 1870s. On 30 January, 2020, the Executive Committee of the International Union of Geological Sciences ratified two proposals approved by the International Commission on Stratigraphy formalizing: 1) the Lower Pleistocene Subseries, comprising the Gelasian Stage and the superjacent Calabrian Stage, with a base defined by the GSSP for the Gelasian Stage, the Pleistocene Series, and the Quaternary System, and currently dated at 2.58 Ma; and 2) the term Upper Pleistocene, at the rank of subseries, with a base currently undefined but provisionally dated at ~129 ka. Defining the Upper Pleistocene Subseries and its corresponding stage with a GSSP is in progress. The Middle Pleistocene Subseries is defined by the recently ratified GSSP for the Chibanian Stage currently dated at 0.774 Ma. These ratifications complete the official division of the Pleistocene into three subseries/subepochs, in uniformity with the similarly subdivided Holocene Series/Epoch

The genetic diversity, phylogeography and morphology of Elphidiidae (Foraminifera) in the Northeast Atlantic

Genetic characterisation (SSU rRNA genotyping) and Scanning ElectronMicroscope (SEM) imaging of individualtests were used in tandem to determine the modern species richness of the foraminiferal family Elphidiidae(Elphidium, Haynesina and related genera) across the Northeast Atlantic shelf biomes. Specimens were collectedat 25 locations fromthe High Arctic to Iberia, and a total of 1013 individual specimenswere successfully SEMimagedand genotyped. Phylogenetic analyses were carried out in combination with 28 other elphidiid sequencesfrom GenBank and seventeen distinct elphidiid genetic types were identified within the sample set, sevenbeing sequenced for the first time. Genetic types cluster into sevenmain cladeswhich largely represent their generalmorphologicalcharacter. Differences between genetic types at the genetic, morphological and biogeographiclevels are indicative of species level distinction. Their biogeographic distributions, in combination with elphidiidSSU sequences from GenBank and high resolution images from the literature show that each of them exhibitsspecies-specific rather than clade-specific biogeographies. Due to taxonomic uncertainty and divergent taxonomicconcepts between schools, we believe that morphospecies names should not be placed onto molecularphylogenies unless both the morphology and genetic type have been linked to the formally named holotype,or equivalent. Based on strictmorphological criteria,we advocate using only a three-stage approach to taxonomyfor practical application in micropalaeontological studies. It comprises genotyping, the production of a formalmorphological description of the SEM images associated with the genetic type and then the allocation of themost appropriate taxonomic name by comparison with the formal type description. Using this approach, wewere able to apply taxonomic names to fifteen genetic types. One of the remaining two may be potentially cryptic,and one is undescribed in the literature. In general, the phylogeographic distribution is in agreement with ourknowledge of the ecology and biogeographical distribution of the corresponding morphospecies, highlighting thegenerally robust taxonomic framework of the Elphidiidae in time and space