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norskBlar i forfatter "Schreck, Michael"
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Cyclostratigraphic age constraining for Quaternary sediments in the Makarov Basin of the western Arctic Ocean using manganese variability
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-26)The Quaternary paleoenvironmental history of the Arctic Ocean remains uncertain, mainly due to the limited chronological constraints, especially beyond the 14C dating limits of accelerator mass spectrometry (AMS). The difficulty in establishing reliable chronostratigraphies is mainly attributed to low sedimentation rates and diagenetic sediment changes, resulting in very poor preservation of ... -
The dinoflagellate cyst genera Achomosphaera Evitt 1963 and Spiniferites Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-14)We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus <i>Achomosphaera</i> Evitt 1963 and 33 of the genus <i>Spiniferites</i> Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by ... -
Evidence for ice-free summers in the late Miocene central Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-04)Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth’s climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger ... -
Late Quaternary depositional and glacial history of the Arliss Plateau off the East Siberian margin in the western Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-19)Sedimentary stratigraphy and facies analysis along with seismostratigraphic and multibeam bathymetrydata are used to reconstruct the last glacial impact on the Arliss Plateau (AP) and attendant sedimen-tation in the adjacent Chukchi Basin (CB) in the western Arctic Ocean off the East Siberian margin.Sediment core ARA02B/16B-GC from the AP lower slope captures glacier-related depositional historyduring ... -
Neogene dinoflagellate cysts and acritarchs from the high northern latitudes and their relation to sea surface temperature
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-13)<p>Organic-walled dinoflagellate cysts and acritarchs are a vital tool for reconstructing past environmental change, in particular in the Neogene of the high northern latitudes where marine deposits are virtually barren of traditionally used calcareous microfossils. Yet only little is known about the paleoenvironmental value of fossil assemblages that do not have modern analogues, so that reconstructions ... -
On the causes of Arctic sea ice in the warm Early Pliocene
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-30)Scattered and indirect evidence suggests that sea ice occurred as far south as the Iceland Sea during the Early Pliocene, when the global climate was warmer than present. However, conclusive evidence as well as potential mechanisms governing sea ice occurrence outside the Arctic Ocean during a time with elevated greenhouse gas concentrations are still elusive. Here we present a suite of organic ...
